Draft California 2026 Integrated Report (303(d) List/305(b) Report)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Unspecified

Objective/Criterion Reference:

Evaluation Guideline:

Unspecified

Guideline Reference:

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116894, Diazinon	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67230

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The sample was below both the reporting limit (5 ng/g dry weight) and the organic carbon-normalized evaluation guideline value (1.1 ug/g OC) and could not be quantified with the level of certainty required by the listing policy.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline value for diazinon, 1.1 ug/g OC, is one-tenth of the median lethal concentration for H. azteca (LC50; 11 ug/g OC). The LC50 (11 ug/g OC) is the geometric mean of OC-normalized LC50 values for diazinon (Ding et al. 2011).

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 116894, Diazinon	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

23044

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

107

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

140 Water samples were collected from Merced River from January 2000 through June 2005, representing 107 4-day average concentrations and 140 1-hour average concentrations.1 of 107 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.1 ug/L. 3 of 140 available 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.16 ug/L.

Data Reference:

Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005

Correspondence between the Department of Pesticide Regulation and Central Valley Regional Water Quality Control Board regarding water quality data for waterbodies in the Central Valley

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected at variable intervals (e.g. hourly, weekly, monthly) from January 2000 through June 2005.

Environmental Conditions:

QAPP Information:

Data quality: Good. Minimum requirements for the CDPR Surface Water Database are: Name of the sampling agency or organization, Date that each sample was collected, Date of each sample analysis, County where samples were taken, Detailed sampling location information (including latitude and longitude or township/range/section if available), detailed map or description of each sampling site (i.e., address, cross roads, etc.), Name or description of water body sampled, Name of the active ingredient analyzed for; concentration detected (with unit of measurement), and limit of quantitation, Description of analytical QA/QC plan, or statement that no formal plan exists. Additional optional requirements are included on DPR's webpage at http://www.cdpr.ca.gov/docs/emon/surfwtr/caps/req.htm

QAPP Information Reference(s):

Standard Operating Procedure for Conducting Surface Water Monitoring for Pesticides

Line of Evidence (LOE) for Decision ID 116894, Diazinon	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

23022

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

17 water samples were collected from Merced River from February to March 2003, representing 6 4-day average concentrations and 19 1-hour average concentrations.0 of 6 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.10 ug/L. 0 of 17 available 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.16 ug/L.

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (CVRWQCB, 2007). All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CVRWQCB, 2007).

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected at variable intervals (hourly or daily) from February to March 2003.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116894, Diazinon	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

23042

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

14 water samples were collected from Merced River from March through August 2005, representing 14 4-day average concentrations and 14 1-hour average concentrations.0 of 14 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.10 ug/L. 0 of 14 available 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.16 ug/L.

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected at weekly interval from January through March 2005.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116894, Diazinon	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

23041

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

14 water samples were collected from Merced River from January through March 2005, representing 6 4-day average concentrations and 14 1-hour average concentrations.0 of 6 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.10 ug/L. 0 of 14 available 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.16 ug/L.

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected at variable intervals (hourly, daily, and weekly) from January through March 2005.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116894, Diazinon	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

23024

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

10 water samples were collected from Merced River in February 2004, representing 2 4-day average concentrations and 10 1-hour average concentrations.0 of 2 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.10 ug/L. 1 of 10 available 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.16 ug/L.

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected at variable intervals (hourly and daily) during two storm events in February 2004.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116894, Diazinon	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

23025

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

13 water samples were collected from Merced River from March to August 2004, representing 13 4-day average concentrations and 13 1-hour average concentrations.0 of 13 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.10 ug/L. 0 of 13 available 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.16 ug/L.

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected at variable intervals (weekly or biweekly) from March to August 2004.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116894, Diazinon	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

23043

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

22 water samples were collected from Merced River from January through August 2006, representing 15 4-day average concentrations and 22 1-hour average concentrations.0 of 15 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.10 ug/L. 0 of 22 available 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.16 ug/L.

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected at daily and weekly intervals from January through August 2006.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	164564	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Group A Pesticides
Final Listing Decision:	Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Reason for Delisting:	Flaws in original listing
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. This LOE documented an impairment and was made prior to 2006 and not held in an assessment database. There is insufficient information to determine if fishing occurs at this waterbody; therefore, beneficial use support for COMM cannot be determined at this time. If new information is submitted during subsequent cycles, this assessment may be revised. However, the exceedances of the evaluation guideline indicate that beneficial uses may be threatened. This decision may be reevaluated in the next Integrated Report cycle as more data and information become available. Additional data and information may include information demonstrating that fishing is occurring in this waterbody. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. This LOE documented an impairment and was made prior to 2006 and not held in an assessment database. There is insufficient information to determine if fishing occurs at this waterbody; therefore, beneficial use support for COMM cannot be determined at this time. If new information is submitted during subsequent cycles, this assessment may be revised. However, the exceedances of the evaluation guideline indicate that beneficial uses may be threatened. This decision may be reevaluated in the next Integrated Report cycle as more data and information become available. Additional data and information may include information demonstrating that fishing is occurring in this waterbody. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) list because applicable water quality standards for the pollutant are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 164564, Group A Pesticides	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

4478

Pollutant:

Group A Pesticides

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Not Recorded

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Unspecified

Objective/Criterion Reference:

Evaluation Guideline:

Unspecified

Guideline Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):


DECISION ID	158875	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Chlorpyrifos
Final Listing Decision:	Delist from 303(d) list (being addressed by action other than TMDL)
Last Listing Cycle's Final Listing Decision:	Delist from 303(d) list (being addressed by action other than TMDL)(2020)
Revision Status	Revised
Reason for Delisting:	Applicable WQS attained; reason for recovery unspecified
Expected Attainment Date:	2026
Implementation Action Other than TMDL:	This water body segment-pollutant combination is being addressed through Basin Plan requirements established under CRWQCB-CVR resolution R5-20140041, and implemented through Board established Waste Discharge Requirements for agricultural discharges. The sources of chlorpyrifos to this segment have been identified as offsite movement of chlorpyrifos from chlorpyrifos applications by the agricultural dischargers regulated by the CRWQCB-CVR WDRs. The Basin Plan identifies numeric water quality objectives for diazinon and chlorpyrifos. The Basin Plan and WDRs require growers to implement management practices through the development and implementation of water quality management plans to meet water quality objectives for chlorpyrifos as soon as possible but no longer than ten years from the date of approval of the Basin Plan Amendment. These management plans are required to be developed and implemented within one year of the Basin Plan Amendment approval. Agricultural management practices to be implemented may include pest management practices, pesticide application practices, vegetation management practices and water management practices, all of which are effective in reducing offsite movement of chlorpyrifos into surface water. The Basin Plan and the Monitoring and Reporting programs in the WDRs require monitoring to determine if adequate reductions are being attained. The Basin Plan and WDRs require management practices to be iteratively improved through updates of the management plans until the water quality objectives are achieved.
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Eighteen lines of evidence are available in the administrative record to assess this pollutant. Ten of the 256 water samples exceeded the evaluation guideline and zero of 9 sediment samples exceed the evaluation guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Ten of the 256 water samples exceeded the evaluation guideline and this does not exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) list because applicable water quality standards for the pollutant are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187420

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (4 day average)(Siepmann and Finlayson 2000).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-18 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196052

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for chlorpyrifos, 0.177 ug/g, is one-tenth of the median lethal concentration (LC50; 1.77 ug/g) and is normalized by the percentage of organic carbon in the sediment sample (Amweg and Weston, 2007).

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535XMRAOR.

Temporal Representation:

Date for this waterbody were collected over the date range 2018-09-11 to 2018-09-11

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187497

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (4 day average)(Siepmann and Finlayson 2000).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR)

Temporal Representation:

The samples were collected between the dates of 2017-10-10 and 2017-11-07

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187522

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (4 day average)(Siepmann and Finlayson 2000).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2016-10-29

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331014

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Chlorpyrifos is 0.015 ug/L (4-day average).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-10-09 and 2020-11-10

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

4476

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Unspecified

Objective/Criterion Reference:

Evaluation Guideline:

Unspecified

Guideline Reference:

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67192

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The sample was not assessed because, after the laboratory method detection limit result was organic carbon-normalized, the result was above the evaluation guideline and, therefore the result could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline value for chlorpyrifos, 0.177 ug/g OC, is one-tenth of the median lethal concentration for H. azteca (LC50; 1.77 ug/g OC). The LC50 (1.77 ug/g OC) is the geometric mean of OC-normalized LC50 values for chlorpyrifos from Amweg and Weston (2007).

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

132406

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP Stream Pollution Trends

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 (Station Codes: 535MER546).

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2013-07-10

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plan for the Statewide Stream Pollution Trends Monitoring Program

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22244

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

8 water samples were collected from Merced River in January and February 2005, representing 2 4-day average concentrations and 8 1-hour average concentrations.1 of 2 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.015 ug/L. 3 of 8 available 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.025 ug/L.

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

California Department of Fish and Game Hazard Assessment Criteria - 0.015 ug/L 4-day average and 0.025 ug/L 1-hour average (Siepmann and Finlayson, 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005).

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected at daily in January and February 2005.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22255

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

13 water samples were collected from Merced River between March and August 2006, representing 13 4-day average concentrations and 13 1-hour average concentrations.1 of 13 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.015 ug/L. 0 of 13 available 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.025 ug/L.

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected weekly in March, July, and August 2006.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22241

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

17 water samples were collected from Merced River from January to March 2003, representing 5 4-day average concentrations and 17 1-hour average concentrations.0 of 5 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.015 ug/L. 0 of 17 available 1-hour average concentrations exceeded the maximum 1-hour chlorpyrifos concentration of 0.025 ug/L.

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected daily during two storms in February and March 2003.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22242

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

10 water samples were collected from Merced River in February 2004, representing 2 4-day average concentrations and 10 1-hour average concentrations.0 of 2 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.015 ug/L. 0 of 10 available 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.025 ug/L.

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected daily during two storms in February 2004.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22254

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

14 water samples were collected from Merced River between March and August 2005, representing 14 4-day average concentrations and 14 1-hour average concentrations.2 of 14 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.015 ug/L. 0 of 14 available 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.025 ug/L.

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected at weekly in March, July, and August 2005.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22256

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

17 water samples were collected from Merced River from July 2004 through September 2006, representing 13 4-day average concentrations and 13 1-hour average concentrations.0 of 13 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.015 ug/L.0 of 13 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.025 ug/L. 4 samples were not used in this analysis because of the quantitation limit (0.0254 ug/L) greater than the water quality criteria concentrations (0.015 ug/L).

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at Santa Fe.

Temporal Representation:

Samples were collected weekly from July 2004 through September 2006.

Environmental Conditions:

QAPP Information:

Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22243

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

13 water samples were collected from Merced River between March and August 2004, representing 9 4-day average concentrations and 13 1-hour average concentrations.0 of 9 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.015 ug/L. 0 of 13 available 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.025 ug/L.

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected at weekly interval in March, July, and August 2004.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

132657

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for East San Joaquin Water Quality Coalition

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The freshwater criterion continuous concentration [CCC] to protect aquatic organisms from chronic exposure is 0.015 ug/L (Siepmann and Finlayson 2000).

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site(s) (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22257

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

109

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

140 water samples were collected from Merced River from January 2000 through June 2005, representing 109 4-day average concentrations and 140 1-hour average concentrations. 4 of 109 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.015 ug/L.1 of 140 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.025 ug/L.

Data Reference:

Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005

Correspondence between the Department of Pesticide Regulation and Central Valley Regional Water Quality Control Board regarding water quality data for waterbodies in the Central Valley

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected at variable intervals from Merced River at River Road Bridge near Newman.

Temporal Representation:

Samples were collected weekly between January 2000 and June 2005.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Standard Operating Procedure for Conducting Surface Water Monitoring for Pesticides

Line of Evidence (LOE) for Decision ID 158875, Chlorpyrifos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

195952

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	165420	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Mercury
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.5 and 4.11 of the Listing Policy. Under section 4.5 a single line of evidence is necessary to assess listing status. Under section 4.11 when all other listing factors do not result in the listing of a water segment, but information indicates non-attainment of standards, a water segment shall be evaluated to determine whether the weight of evidence demonstrates that water quality standard is not attained. If the weight of evidence indicates non-attainment, the water segment shall be placed on the CWA section 303(d) List. The COMM beneficial use has not been designated to this waterbody. While there is not a specific health advisory for Merced River, Lower (McSwain Reservoir to San Joaquin River), in 2022 OEHHA released Statewide Health Advisory and Guidelines for Eating Fish from California’s Rivers, Streams, and Creeks without Site-Specific Advice for mercury. Fishing occurs in Merced River, Lower (McSwain Reservoir to San Joaquin River) and the black bass species and channel cat species sampled for the assessment are part of 2022 Advisory. Additionally, data were collected in this waterbody by CDFW to monitor pollutants in fish tissue for the purpose of evaluating risks to human health from consumption. The weight of evidence of the data and information indicate water quality standards are not attained. Two lines of evidence are available in the administrative record to assess pollutant. Two of the two tissue samples exceed the criteria for COMM. Also, zero of six samples exceed the sediment evaluation guideline for COLD. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two of the two samples exceed the criteria for COMM and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	This decision was made by SWRCB staff.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 165420, Mercury	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

333223

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for mercury is the probable effect concentration (PEC) of 1.06 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546 (Merced River @ River Road).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-08-22 to 2020-08-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 165420, Mercury	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196826

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Mercury from MacDonald et al., 2000a which states that the probable effect concentration for Mercury is 1.06 mg/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 165420, Mercury	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

2753

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Two out of 2 samples exceeded. Two filet composite samples were collected in 1998. One sample each of largemouth bass and one of channel catfish. Both samples exceeded the guideline (TSMP, 2002).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Central Valley RWQCB Basin Plan: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or produce detrimental physiological responses in human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Evaluation Guideline:

OEHHA Screening Value of 0.3 ug/g for mercury (Brodberg & Pollock, 1999).

Guideline Reference:

Spatial Representation:

One station located at George J. Hatfield State Recreation Area.

Temporal Representation:

Samples were collected on 11/5/98.

Environmental Conditions:

QAPP Information:

Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program, 1996-2000. Department of Fish and Game.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 165420, Mercury	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67120

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the evaluation guideline value for Mercury.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for mercury is 1.06 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	158882	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Oxygen, Dissolved
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Twenty-nine lines of evidence are available in the administrative record to assess this pollutant for Cold Freshwater Habitat and Fish Spawning. Thirty-six of 205 samples exceed the objective for Cold Freshwater Habitat. Thirty-five of 183 samples exceed the objective for Fish Spawning. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Thirty-six of 205 samples exceed the objective for Cold Freshwater Habitat. Thirty-five of 183 samples exceed the objective for Fish Spawning and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

233876

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality standard for Oxygen, Dissolved.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for dissolved oxygen in this water body is 8 mg/L expressed as a 7 day minimum averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER210)

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2017-06-27

Environmental Conditions:

QAPP Information:

SWAMP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

233878

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Stream Pollution Trends data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality standard for Oxygen, Dissolved.

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for dissolved oxygen in this water body is 8 mg/L expressed as a 7 day minimum averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2014-07-09 and 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

233874

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Oxygen, Dissolved.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for dissolved oxygen in this water body is 8 mg/L expressed as a 7 day minimum averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER209)

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67170

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the criterion for Oxygen, Dissolved.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as COLD is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 5/15/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67173

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data to determine beneficial use support: Three of 41 sample results exceed the criterion for Oxygen, Dissolved.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as COLD is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [Merced River @ Santa Fe-535XMRSFD].

Temporal Representation:

Data was collected monthly between 2/12/2007 and 7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67172

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the criterion for Oxygen, Dissolved.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as COLD is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ Merced Falls Gauging St. - 535MER209]

Temporal Representation:

Data was collected on 8/31/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAMP (2002) was used for data before Septemper 1, 2008 and SWAMP QAPP (2008) was thereafter.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67175

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

0 of 1 samples exceed the water quality objective.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region (CVRWQCB 2007): The dissolved oxygen concentrations shall not be reduced below the following minimum level at any time: Waters designated COLD 7.0 mg/l

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the 535MER209 (Merced River @ Merced Falls Gauging St.).

Temporal Representation:

Samples were collected on 8/31/2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

59515

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The sample collected did not exceed the objective.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Table III-2 of the Sacramento/San Joaquin Basin plans delineates temporal and spatial specific objectives. For the Merced River from Cressy to New Exequer Dam, the minimum dissolved oxygen concentration is 8.0 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The sample was collected from the Merced River @ River Road station (535MER546).

Temporal Representation:

The sample was collected on 5/15/2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67174

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data to determine beneficial use support: Three of 41 sample results exceed the criterion for Oxygen, Dissolved.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as SPWN is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [Merced River @ Santa Fe-535XMRSFD].

Temporal Representation:

Data was collected monthly between 2/12/2007 and 7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67169

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the criterion for Oxygen, Dissolved.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as SPWN is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 5/15/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67171

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the criterion for Oxygen, Dissolved.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as SPWN is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ Merced Falls Gauging St. - 535MER209]

Temporal Representation:

Data was collected on 8/31/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAMP (2002) was used for data before Septemper 1, 2008 and SWAMP QAPP (2008) was thereafter.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22229

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Twenty samples were taken from the Lower Merced River between 2004 and 2006. One of the twenty samples fell below the Water Quality Objective for minimum dissolved oxygen content in surface water.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

From the Sacramento/San Joaquin River Basin Plan the (COLD) Cold Freshwater Habitat criterion is a Minimum Dissolved Oxygen content of 7mg/L.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the Lower Merced River at Santa Fe Avenue in Merced County.

Temporal Representation:

Samples were collected between July 2004 and September 2006. Samples were collected at bi-monthly and monthly intervals.

Environmental Conditions:

QAPP Information:

Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

329995

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as COLD is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-NRS_CA-10948 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2018-07-16 and 2018-07-16

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332162

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as SPWN is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2017-10-10 and 2021-09-22

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

329996

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as SPWN is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-NRS_CA-10948 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2018-07-16 and 2018-07-16

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332257

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as COLD is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2017-10-10 and 2021-09-22

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330037

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as SPWN is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-CARO-1042 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332133

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Stream Pollution Trends data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 1 of 3 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as SPWN is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2019-08-27 and 2021-09-05

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332236

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Stream Pollution Trends data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 1 of 3 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as COLD is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2019-08-27 and 2021-09-05

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

233875

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Oxygen, Dissolved.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for dissolved oxygen in this water body is 8 mg/L expressed as a 7 day minimum averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER202)

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

233877

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 4 of 28 samples exceeded the water quality standard for Oxygen, Dissolved.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for dissolved oxygen in this water body is 8 mg/L expressed as a 7 day minimum averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2010-09-20 and 2017-10-26

Environmental Conditions:

QAPP Information:

SWAMP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

233873

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for dissolved oxygen in this water body is 8 mg/L expressed as a 7 day minimum averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2016-12-09

Environmental Conditions:

QAPP Information:

2015-1124_ESJWQC_QAPP_no_SOPs.pdf, 2017-0213_esjwqc_qapp_amend.pdf, 2017-0919_esjwqc_qapp_amend_req.pdf, 2017-1220_esjwqc_qapp_apprvl.pdf, 2018-0302_esjwqc_qapp_amend_apprvl.pdf, 2018-0427_ESJ_QAPPaprvl.pdf, ESJ_Delta_QAPP_Amend_Approval.pdf, ESJ_QAPP_Amdt_Signed_041017.pdf, ESJWQC_QAPP_Approval.pdf, ILRP_ESJ_QAPP_Amendment_SedimentLabChange.pdf

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

233871

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Oxygen, Dissolved.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for dissolved oxygen in this water body is 8 mg/L expressed as a 7 day minimum averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER209)

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

233872

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for dissolved oxygen in this water body is 8 mg/L expressed as a 7 day minimum averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2014-07-09 and 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

233869

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Oxygen, Dissolved.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for dissolved oxygen in this water body is 8 mg/L expressed as a 7 day minimum averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER202)

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

233868

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 4 of 28 samples exceeded the water quality standard for Oxygen, Dissolved.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for dissolved oxygen in this water body is 8 mg/L expressed as a 7 day minimum averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2010-09-20 and 2017-10-26

Environmental Conditions:

QAPP Information:

SWAMP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330050

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as COLD is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-CARO-1042 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

233870

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for dissolved oxygen in this water body is 8 mg/L expressed as a 7 day minimum averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER210)

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2017-06-27

Environmental Conditions:

QAPP Information:

SWAMP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158882, Oxygen, Dissolved	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

233867

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for dissolved oxygen in this water body is 8 mg/L expressed as a 7 day minimum averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2016-12-09

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	158886	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Temperature, water
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2024)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Grab sample temperature data from this waterbody were available for the 2024 Cycle. These data are insufficient to satisfy the Listing Policy requirements for spatial and temporal representation (sections 6.1.5.2 and 6.1.5.3). The surface water grab samples collected did not provide sufficient temporal and spatial representation to determine if temperature conditions experienced by aquatic life were within the optimal temperature range throughout the entire water column or the length of time temperature conditions may have exceeded the optimal temperature range. However, continuous monitoring data was considered in this assessment. This pollutant is being considered for removal from the CWA section 303(d) List under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Thirty-one lines of evidence are available in the administrative record to assess this pollutant. Four hundred twenty-eight of 516 continuous monitoring samples exceed the SPWN evaluation guideline, 163 of 216 continuous monitoring samples exceed the MIGR evaluation guideline, and 75 of 223 continuous monitoring samples exceed the COLD evaluation guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Four hundred twenty-eight of 516 continuous monitoring samples exceed the SPWN evaluation guideline, 163 of 216 continuous monitoring samples exceed the MIGR evaluation guideline, and 75 of 223 continuous monitoring samples exceed the COLD evaluation guideline. This exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

26540

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Stream temperatures were measured by CDFG using data loggers (Stowaways, Tidbits and Hobo Temp Pros). Monitoring occurred from 1992 to 2007 depending on the monitoring station, identified by a river mile. The 7DADM was recorded weekly for each river mile. The maximum 7DADM value was calculated for each year. Based on the data provided, 31 out of 47 maximum 7DADM values exceeded the <18 degrees C criteria from 1992 to 2007.

Data Reference:

Access and DSS database files of water temperature data, one each for the San Joaquin, Merced, Stanislaus, and Tuolumne rivers

Cover letter, data and information regarding elevated water temperatures in the San Joaquin, Merced, Stanislaus, and Tuolumne rivers

USEPA Partial Approval Disapproval Letter and enclosures for California's 2008-2010 303(d) List

USEPA Final Decision Letter with enclosures and responsiveness summary regarding waters added to California's 2008-2010 303(d) List

USEPA Region 9 data summary for addition of temperature to California 2010 303(d) list for Merced River, Lower (McSwain Reservoir to San Joaquin River)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses.

In determining compliance with the water quality objectives for temperature, appropriate averaging periods may be applied provided that beneficial uses will be fully protected. (Central Valley Regional Board Basin Plan, Pg. III-8.00, Water Quality Objectives)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The guideline used was the 2003 US EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards (USEPA, 2003). The document includes recommended temperature criteria for salmon and trout based on different life stages. The recommended temperature for steelhead summer rearing is <18 degrees C for a 7DADM. The steelhead summer rearing life stage occurs from river mile 42 (Hwy 59 Bridge) to river mile 52 (Merced River Hatchery). This life stage occurs during Julian weeks 24 through 37, which is approximately June 15th through September 15th.

Guideline Reference:

EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.

Spatial Representation:

The steelhead summer rearing life stage occurs from river mile 42 (Hwy 59 Bridge) to river mile 52 (Merced River Hatchery). Stream temperatures were monitored at the following stream locations during the steelhead summer rearing life stage: River Miles 42 (Hwy 59 Bridge), 43 (Robinson), 44 (upper Robinson), 46 (G Street Bridge), 47 (NRS), and 52 (Merced River Hatchery).

Temporal Representation:

The steelhead summer rearing life stage occurs during Julian weeks 24 through 37, which is approximately June 15th through September 15th. Data was collected during this life stage on a continuous basis (hourly intervals) from 1992 through 2007, depending on the station and year monitored. Refer to the CDFG 2007 report (Gordus, 2007) for specific years for each location.

Environmental Conditions:

QAPP Information:

Data is supported by a Quality Assurance Project Plan (QAPP) pursuant to the requirements of 40 CFR 31.45 and are acceptable for use in developing the section 303(d) list.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

26539

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

124

Number of Exceedances:

101

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Stream temperatures were measured by CDFG using data loggers (Stowaways, Tidbits and Hobo Temp Pros). Monitoring occurred from 1992 to 2007 depending on the monitoring station, identified by a river mile. The 7DADM was recorded weekly for each river mile. The maximum 7DADM value was calculated for each year. Based on the data provided, 101 out of 124 maximum 7DADM values exceeded the <16 degrees C criteria from 1992 to 2007.

Data Reference:

USEPA Region 9 data summary for addition of temperature to California 2010 303(d) list for Merced River, Lower (McSwain Reservoir to San Joaquin River)

Access and DSS database files of water temperature data, one each for the San Joaquin, Merced, Stanislaus, and Tuolumne rivers

Cover letter, data and information regarding elevated water temperatures in the San Joaquin, Merced, Stanislaus, and Tuolumne rivers

USEPA Partial Approval Disapproval Letter and enclosures for California's 2008-2010 303(d) List

USEPA Final Decision Letter with enclosures and responsiveness summary regarding waters added to California's 2008-2010 303(d) List

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The guideline used was the 2003 US EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards (USEPA, 2003). The document includes recommended temperature criteria for salmon and trout based on different life stages. The recommended temperature for salmon and trout juvenile rearing is <16 degrees C for a 7DADM. The juvenile rearing life stage occurs from river mile 52 (Merced River Hatchery) to river mile 0 (confluence with the San Joaquin River). This life stage occurs during Julian weeks 11 to 24, which is approximately March 15th through June 15th.

Guideline Reference:

EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.

Spatial Representation:

The juvenile rearing life stage occurs from river mile 52 (Merced River Hatchery) to river mile 0 (confluence with the San Joaquin River). Stream temperatures were monitored at the following stream locations during the juvenile rearing life stage: River Miles 0 (confluence with the San Joaquin River), 1 (Hatfield Park), 4 (below and above Stevinson Spill), 12 (NRS), 13 (Haggaman Park), 21 (above Livingston Spill), 22 (Hwy 99 Bridge), 28 (near Santa Fe Bridge), 30.5 (Dry Creek above Merced River), 31 (Shaffer Bridge), 39 (Gallo Ranch Bridge), 40 (on the Ratzlaff property), 41 (Hwy 59 Bridge), 42 (Hwy 59 Bridge), 43 (Robinson), 44 (upper Robinson), 46 (G Street Bridge), 47 (NRS), and 52 (Merced River Hatchery).

Temporal Representation:

The juvenile rearing life stage occurs during Julian weeks 11 to 24, which is approximately March 15th through June 15th. Data was collected during this life stage on a continuous basis (hourly intervals) from 1992 through 2007, depending on the station and year monitored. Refer to the CDFG 2007 report (Gordus, 2007) for specific years for each location.

Environmental Conditions:

QAPP Information:

Data is supported by a Quality Assurance Project Plan (QAPP) pursuant to the requirements of 40 CFR 31.45 and are acceptable for use in developing the section 303(d) list.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

26538

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

124

Number of Exceedances:

101

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Stream temperatures were measured by CDFG using data loggers (Stowaways, Tidbits and Hobo Temp Pros). Monitoring occurred from 1992 to 2007 depending on the monitoring station, identified by a river mile. The 7DADM was recorded weekly for each river mile. The maximum 7DADM value was calculated for each year. Based on the data provided, 101 out of 124 maximum 7DADM values exceeded the <16 degrees C criteria from 1992 to 2007.

Data Reference:

USEPA Region 9 data summary for addition of temperature to California 2010 303(d) list for Merced River, Lower (McSwain Reservoir to San Joaquin River)

Access and DSS database files of water temperature data, one each for the San Joaquin, Merced, Stanislaus, and Tuolumne rivers

Cover letter, data and information regarding elevated water temperatures in the San Joaquin, Merced, Stanislaus, and Tuolumne rivers

USEPA Partial Approval Disapproval Letter and enclosures for California's 2008-2010 303(d) List

USEPA Final Decision Letter with enclosures and responsiveness summary regarding waters added to California's 2008-2010 303(d) List

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The guideline used was the 2003 US EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards (USEPA, 2003). The document includes recommended temperature criteria for salmon and trout based on different life stages. The recommended temperature for salmon and trout smoltification is <16 degrees C for a 7DADM. The smoltification life stage occurs from river mile 52 (Merced River Hatchery) to river mile 0 (confluence with the San Joaquin River). This life stage occurs during Julian weeks 11 to 24, which is approximately March 15th through June 15th.

Guideline Reference:

EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.

Spatial Representation:

The smoltification life stage occurs from river mile 52 (Merced River Hatchery) to river mile 0 (confluence with the San Joaquin River). Stream temperatures were monitored at the following stream locations during the smoltification life stage: River Miles 0 (confluence with the San Joaquin River), 1 (Hatfield Park), 4 (below and above Stevinson Spill), 12 (NRS), 13 (Haggaman Park), 21 (above Livingston Spill), 22 (Hwy 99 Bridge), 28 (near Santa Fe Bridge), 30.5 (Dry Creek above Merced River), 31, (Shaffer Bridge), 39 (Gallo Ranch Bridge), 40 (on the Ratzlaff property), 41 (Hwy 59 Bridge), 42 (Hwy 59 Bridge), 43 (Robinson), 44 (upper Robinson), 46 (G Street Bridge), 47 (NRS), and 52 (Merced River Hatchery).

Temporal Representation:

The smoltification life stage occurs during Julian weeks 11 to 24, which is approximately March 15th through June 15th. Data was collected during this life stage on a continuous basis (hourly intervals) from 1992 through 2007, depending on the station and year monitored. Refer to the CDFG 2007 report (Gordus, 2007) for specific years for each location.

Environmental Conditions:

QAPP Information:

Data is supported by a Quality Assurance Project Plan (QAPP) pursuant to the requirements of 40 CFR 31.45 and are acceptable for use in developing the section 303(d) list.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67219

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the evaluation guideline value for Water Temperature.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Inland Fishes of California (1976)

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 5/15/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67220

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of 6 sample results exceed the evaluation guideline value for Water Temperature.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Inland Fishes of California (1976)

Spatial Representation:

Data for this line of evidence was collected at two monitoring sites [ Merced River @ Merced Falls Gauging St. - 535MER209, Merced River at Henderson Park - 535MER210]

Temporal Representation:

Data was collected over the time period 8/27/2008-9/3/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAMP (2002) was used for data before Septemper 1, 2008 and SWAMP QAPP (2008) was thereafter.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67221

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 18 of 41 samples exceed the criterion for Water Temperature.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Inland Fishes of California (1976)

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67243

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Fish Migration

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

One of the 2 samples exceeded the evaluation guideline.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. In determining compliance with the water quality objectives for temperature, appropriate averaging periods may be applied provided that beneficial uses will be fully protected. (Central Valley Regional Board Basin Plan, Pg. III-8.00, Water Quality Objectives)

Objective/Criterion Reference:

Evaluation Guideline:

The guideline used was the 2003 US EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards (USEPA, 2003). The document includes recommended temperature criteria for salmon and trout based on different life stages. The recommended temperature for salmon and trout adult migration is <18oC for a 7DADM. The adult migration life stage occurs from river mile 0 (confluence with the San Joaquin River) to river mile 52 (Merced River Hatchery). This life stage occurs during Julian weeks 36 through 43, which is approximately September 1st through October 31st.

Guideline Reference:

EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.

Spatial Representation:

Samples were collected from the Merced River @ Merced Falls Gauging St. (535MER209) and Merced River at Henderson Park (535MER210) stations. The exceedence occurred at the Merced River at Henderson Park (535MER210) station.

Temporal Representation:

Samples were collected on 9/3/2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP (2008).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67229

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Fish Migration

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Stream temperatures were measured by California Department of Fish and Game (CDFG) using data loggers (Stowaways, Tidbits and Hobo Temp Pros). The 7DADM was recorded weekly for each river mile. The Maximum 7DADM or the Weekly Maximum Temperature (MWMT) was calculated for each year. Based on the data provided, 44 out of 53 MWMT values exceeded the <18 degree C criteria in 2008 and 2009.

Data Reference:

Data for Hydromodification in Various Water Bodies in Region 5, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. In determining compliance with the water quality objectives for temperature, appropriate averaging periods may be applied provided that beneficial uses will be fully protected. (Central Valley Regional Board Basin Plan, Pg. III-8.00, Water Quality Objectives)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The guideline used was the 2003 US EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards (USEPA, 2003). The document includes recommended temperature criteria for salmon and trout based on different life stages. The recommended temperature for salmon and trout adult migration is <18oC for a 7DADM. The adult migration life stage occurs from river mile 0 (confluence with the San Joaquin River) to river mile 52 (Merced River Hatchery). This life stage occurs during Julian weeks 36 through 43, which is approximately September 1st through October 31st.

Guideline Reference:

EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.

Spatial Representation:

The adult migration life stage occurs from river mile 0 (confluence with the San Joaquin River) to river mile 52 (Merced River Hatchery). Samples were collected at the following monitoring locations: MRH-Merced River Hatchery MGST-Merced River (G Street Bridge) MUROB-Merced River (Upper Robinson) MROB-Merced River (Robinson) M59B-Merced River (Hwy 59 Bridge) MRAT-Merced River (Ratzlaff) MBRAT-Merced River (below Ratzlaff) MGAL-Merced River (Gallo Ranch Bridge) MRSHAF-Merced River at Shaffer Bridge MRSFB-Merced River near Santa Fe Bridge MRLIVING-Merced River above Livingston Spill M99-Merced River at Highway 99 Bridge MHAG2-Merced River at Haggaman Park RST access MASTVSP-Merced River above Stevinson Spill MBSTVSP-Merced River below Stevinson Spill MHFLD-Merced River (Hatfield Park) MRSJR-Merced River at San Joaquin River Confluence

Temporal Representation:

The adult migration life stage occurs during Julian weeks 36 through 43, which is approximately September 1st through October 31st. Data was collected during this life stage on a continuous basis (hourly intervals) in 2008 and 2009, although it should be noted that some stations did not have data collected during this time period. If there was no data collected during this time period, these stations were not counted in the assessment.

Environmental Conditions:

QAPP Information:

Data is supported by a Quality Assurance Project Plan (QAPP) pursuant to the requirements of 40 CFR 31.45 and are acceptable for use in developing the section 303(d) list.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67228

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Stream temperatures were measured by California Department of Fish and Game (CDFG) using data loggers (Stowaways, Tidbits and Hobo Temp Pros). The 7DADM was recorded weekly for each river mile. The Maximum 7DADM or the Maximum Weekly Maximum Temperature (MWMT) was calculated for each year. Based on the data provided, 8 out of 10 MWMT values exceeded the <18 degree C criteria in 2008 and 2009.

Data Reference:

Data for Hydromodification in Various Water Bodies in Region 5, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. In determining compliance with the water quality objectives for temperature, appropriate averaging periods may be applied provided that beneficial uses will be fully protected. (Central Valley Regional Board Basin Plan, Pg. III-8.00, Water Quality Objectives)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.

Spatial Representation:

The steelhead summer rearing life stage occurs from river mile 42 (Hwy 59 Bridge) to river mile 52 (Merced River Hatchery). Samples were collected at the following monitoring locations: MRH-Merced River Hatchery MGST-Merced River (G Street Bridge) MUROB-Merced River (Upper Robinson) MROB-Merced River (Robinson) M59B-Merced River (Hwy 59 Bridge)

Temporal Representation:

Environmental Conditions:

QAPP Information:

Data is supported by a Quality Assurance Project Plan (QAPP) pursuant to the requirements of 40 CFR 31.45 and are acceptable for use in developing the section 303(d) list.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67072

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The sample collected did not exceed the site specific objective.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. In determining compliance with the water quality objectives for temperature, appropriate averaging periods may be applied provided that beneficial uses will be fully protected. (Central Valley Regional Board Basin Plan, Pg. III-8.00, Water Quality Objectives). The table specifies that the temperature for this water body shall not exceed 21.1 deg. C on the specified date of 8/31/2008.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data were collected at the Upper Sacramento River at Dog Creek confluence (506SHA951) station.

Temporal Representation:

Data were collected at collected on 8/31/2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP (2008).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67236

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Stream temperatures were measured by California Department of Fish and Game (CDFG) using data loggers (Stowaways, Tidbits and Hobo Temp Pros). The 7DADM was recorded weekly for each river mile. The Maximum 7DADM or the Maximum Weekly Maximum Temperature (MWMT) was calculated for each year. Based on the data provided, all 12 MWMT values exceeded the <13 degree C criteria in 2008 and 2009.

Data Reference:

Data for Hydromodification in Various Water Bodies in Region 5, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. In determining compliance with the water quality objectives for temperature, appropriate averaging periods may be applied provided that beneficial uses will be fully protected. (Central Valley Regional Board Basin Plan, Pg. III-8.00, Water Quality Objectives)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The guideline used was the 2003 US EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards (USEPA, 2003). The document includes recommended temperature criteria for salmon and trout based on different life stages. The recommended temperature for salmon and trout spawning is <13 degrees C for a 7DADM. The spawning life stage occurs from river mile 28 (near Santa Fe Bridge) to river mile 52 (Merced River Hatchery). This life stage occurs during Julian weeks 40 through 50, which is approximately October 1st through December 15th.

Guideline Reference:

EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.

Spatial Representation:

The spawning life stage occurs from river mile 0 (confluence with the San Joaquin River) to river mile 52 (Merced River Hatchery). Samples were collected at the following monitoring locations: MRH-Merced River Hatchery MGST-Merced River (G Street Bridge) MUROB-Merced River (Upper Robinson) MROB-Merced River (Robinson) M59B-Merced River (Hwy 59 Bridge) MRAT-Merced River (Ratzlaff) MBRAT-Merced River (below Ratzlaff) MGAL-Merced River (Gallo Ranch Bridge) MRSHAF-Merced River at Shaffer Bridge MRSFB-Merced River near Santa Fe Bridge

Temporal Representation:

The spawning life stage occurs during Julian Weeks 40 through 50, which is approximately October 1st through December 15th. Data was collected during this life stage on a continuous basis (hourly intervals) in 2008 and 2009, although it should be noted that some stations did not have data collected during this time period. If there was no data collected during this time period, these stations were not counted in the assessment.

Environmental Conditions:

QAPP Information:

Data is supported by a Quality Assurance Project Plan (QAPP) pursuant to the requirements of 40 CFR 31.45 and are acceptable for use in developing the section 303(d) list.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67244

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Four of the 6 samples exceeded the evaluation guideline.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. In determining compliance with the water quality objectives for temperature, appropriate averaging periods may be applied provided that beneficial uses will be fully protected. (Central Valley Regional Board Basin Plan, Pg. III-8.00, Water Quality Objectives)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.

Spatial Representation:

Samples were collected from the Merced River @ Merced Falls Gauging St. (535MER209) and Merced River at Henderson Park (535MER210) stations.

Temporal Representation:

Samples were collected on the following dates: 9/3/2008 8/31/2008 8/27/2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP (2008).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67222

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that the sample result exceeds the evaluation guideline value for Water Temperature (SSO).

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

The guideline used was the 2003 US EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards (USEPA, 2003). The document includes recommended temperature criteria for salmon and trout based on different life stages. The recommended temperature for salmon and trout smoltification is <16 degrees C for a 7DADM. The smoltification life stage occurs from river mile 52 (Merced River Hatchery) to river mile 0 (confluence with the San Joaquin River). This life stage occurs during Julian weeks 11 to 24, which is approximately March 15th through June 15th.

Guideline Reference:

EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 5/15/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAMP (2002) was used for data before Septemper 1, 2008 and SWAMP QAPP (2008) was thereafter.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67235

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Stream temperatures were measured by California Department of Fish and Game (CDFG) using data loggers (Stowaways, Tidbits and Hobo Temp Pros). The 7DADM was recorded weekly for each river mile. The Maximum 7DADM or the Maximum Weekly Maximum Temperature (MWMT) was calculated for each year. Based on the data provided, all 31 MWMT values exceeded the <16 degree C criteria in 2008 and 2009.

Data Reference:

Data for Hydromodification in Various Water Bodies in Region 5, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. In determining compliance with the water quality objectives for temperature, appropriate averaging periods may be applied provided that beneficial uses will be fully protected. (Central Valley Regional Board Basin Plan, Pg. III-8.00, Water Quality Objectives)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The guideline used was the 2003 US EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards (USEPA, 2003). The document includes recommended temperature criteria for salmon and trout based on different life stages. The recommended temperature for salmon and trout smoltification is <16 degrees C for a 7DADM. The smoltification life stage occurs from river mile 52 (Merced River Hatchery) to river mile 0 (confluence with the San Joaquin River). This life stage occurs during Julian weeks 11 to 24, which is approximately March 15th through June 15th.

Guideline Reference:

EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.

Spatial Representation:

Temporal Representation:

The smoltification life stage occurs during Julian weeks 11 to 24, which is approximately March 15th through June 15th. Data was collected during this life stage on a continuous basis (hourly intervals) in 2008 and 2009, although it should be noted that some stations did not have data collected during this time period. If there was no data collected during this time period, these stations were not counted in the assessment.

Environmental Conditions:

QAPP Information:

Data is supported by a Quality Assurance Project Plan (QAPP) pursuant to the requirements of 40 CFR 31.45 and are acceptable for use in developing the section 303(d) list.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67242

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Stream temperatures were measured by California Department of Fish and Game (CDFG) using data loggers (Stowaways, Tidbits and Hobo Temp Pros). The 7DADM was recorded weekly for each river mile. The Maximum 7DADM or the Maximum Weekly Maximum Temperature (MWMT) was calculated for each year. Based on the data provided, all 31 MWMT values exceeded the <16 degree C criteria in 2008 and 2009.

Data Reference:

Data for Hydromodification in Various Water Bodies in Region 5, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. In determining compliance with the water quality objectives for temperature, appropriate averaging periods may be applied provided that beneficial uses will be fully protected. (Central Valley Regional Board Basin Plan, Pg. III-8.00, Water Quality Objectives)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The guideline used was the 2003 US EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards (USEPA, 2003). The document includes recommended temperature criteria for salmon and trout based on different life stages. The recommended temperature for salmon and trout juvenile rearing is <16 degrees C for a 7DADM. The juvenile rearing life stage occurs from river mile 52 (Merced River Hatchery) to river mile 0 (confluence with the San Joaquin River). This life stage occurs during Julian weeks 11 to 24, which is approximately March 15th through June 15th.

Guideline Reference:

EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.

Spatial Representation:

The juvenile rearing life stage occurs from river mile 0 (confluence with the San Joaquin River) to river mile 52 (Merced River Hatchery). Samples were collected at the following monitoring locations: MRH-Merced River Hatchery MGST-Merced River (G Street Bridge) MUROB-Merced River (Upper Robinson) MROB-Merced River (Robinson) M59B-Merced River (Hwy 59 Bridge) MRAT-Merced River (Ratzlaff) MBRAT-Merced River (below Ratzlaff) MGAL-Merced River (Gallo Ranch Bridge) MRSHAF-Merced River at Shaffer Bridge MRSFB-Merced River near Santa Fe Bridge MRLIVING-Merced River above Livingston Spill M99-Merced River at Highway 99 Bridge MHAG2-Merced River at Haggaman Park RST access MASTVSP-Merced River above Stevinson Spill MBSTVSP-Merced River below Stevinson Spill MHFLD-Merced River (Hatfield Park) MRSJR-Merced River at San Joaquin River Confluence

Temporal Representation:

The juvenile rearing life stage occurs during Julian weeks 11 to 24, which is approximately March 15th through June 15th. Data was collected during this life stage on a continuous basis (hourly intervals) in 2008 and 2009, although it should be noted that some stations did not have data collected during this time period. If there was no data collected during this time period, these stations were not counted in the assessment.

Environmental Conditions:

QAPP Information:

Data is supported by a Quality Assurance Project Plan (QAPP) pursuant to the requirements of 40 CFR 31.45 and are acceptable for use in developing the section 303(d) list.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

214021

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER210)

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2017-06-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

213089

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER209)

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

214025

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Stream Pollution Trends data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 3 of 3 samples exceeded the water quality threshold for Temperature.

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2013-07-10 and 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

213230

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER202)

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

231055

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2010-09-20 and 2017-10-26

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

231054

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2016-12-09

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

243419

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed STORET data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 13 of 33 samples exceeded the water quality threshold for Temperature.

Data Reference:

WQX data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Spatial Representation:

The samples were collected at 1 monitoring site (CALWR_WQX-B0512500)

Temporal Representation:

The samples were collected between the dates of 2010-09-01 and 2015-10-05

Environmental Conditions:

QAPP Information:

STORET

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

243396

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Fish Migration

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Spatial Representation:

The samples were collected at 1 monitoring site (CALWR_WQX-B0512500)

Temporal Representation:

The samples were collected between the dates of 2010-09-01 and 2015-10-05

Environmental Conditions:

QAPP Information:

STORET

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

243303

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Spatial Representation:

The samples were collected at 1 monitoring site (CALWR_WQX-B0512500)

Temporal Representation:

The samples were collected between the dates of 2010-09-01 and 2015-10-05

Environmental Conditions:

QAPP Information:

STORET

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332898

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Stream Pollution Trends data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 3 of 3 samples exceeded the water quality threshold for Temperature.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2019-08-27 and 2021-09-05

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332975

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

QAPP Reference for Irrigated Lands Regulatory Program

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2017-10-10 and 2021-09-22

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330456

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Temperature.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-CARO-1042 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

WQX from the NWQMP for the 2026 Integrated Report in Region 5

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330468

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Temperature.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-NRS_CA-10948 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2018-07-16 and 2018-07-16

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Cover letter, data and information regarding elevated water temperatures in the San Joaquin, Merced, Stanislaus, and Tuolumne rivers

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

26541

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Migration

Number of Samples:

Number of Exceedances:

Data and Information Type:

QUALITATIVE (EVALUATED) ASSESSMENT - UNSPECIFIED

Data Used to Assess Water Quality:

Historically, spring-run and fall-run salmon and steelhead occurred in the Merced River. The spawning beds extended from the mouth of the river to Exchequer Dam, about 12 miles (G.H. Clark, 1929). Today, only the fall-run has survived. In 1852, Native Americans were observed harvesting salmon at Merced Falls. In November 1877, John Muir noted that salmon were abundant in deep pools. Unconfirmed reports suggest that both salmon and steelhead migrated as far up the South Fork as Wawona and in the mainstem as far as into Yosemite Valley. Reports from early residents along the river speak of high populations of fish coming up the river to spawn in the summer and fall.

In 1920, the Fish and Game Commission received a letter from a resident stating that there were fifty salmon in the past for each one now (1920). In 1928, a statement from Fish and Game said there were several hundred salmon in the fall. In 1961, the fall-run was described as poor. Estimates averaged about 250 salmon per year.

By the end of the six year drought, 1986-1992, escapement populations drastically declined believed to be attributed to low flow and elevated water temperatures during adult immigation and juvenile (smolt) spring-out migration from the Merced River. Between 1993 and 1998, salmon escapement improved when flow and water temperature improved. However, with the higher spring flows and cooler spring water of 1998 and 1999, the population has steadily declined since 2000. In 2000, fall-run salmon escapement numbers (over 13,000 spawners) have dramatically declined to only 2,000 spawners in 2006, a drop of about 84% below the year 2000 peak abundance.

There is a strong correlation between annual spring flow magnitude and future year adult production (Mesick and Marston 2007). As spring flow increases, smolt survival increases (CDFG Annual Reports). However, as temperatures begin to rise while salmon smolts out migrate, juveniles are still trying to migrate from the upper reach of the Merced River to the lower reaches of the Merced River, harming both critical life stages (Merced Irrigation District 1999-2005).

In addition to warm spring temperatures, the Department of Fish and Game submitted data to the Regional Water Quality Control Board regarding warm water temperatures present in the lower Merced River during the fall adult upstream migration season for the years 1998 thru 2005 (Tables 9 and 10 in CDFG¿s Letter to the RWQCB, 2007). Also, the Department of Fish and Game submitted data regarding warm water temperatures present in the lower Merced River spawning habitat reaches during the first half of the spawning season for years 1998 thru 2005 (Table 13 in CDFG¿s Letter to the RWQCB, 2007).

Steelhead in the Merced River are listed winter run. Juvenile rainbow trout have been caught in rotary screw traps out-migrating the Merced River. Anecdotal reports by anglers suggest that steelhead populations are good following years where summer rearing conditions are good (e.g. presence of cold water temperatures). State and Federal agencies believe their abundance trends mirrors those of salmon causing them to be listed as threatened in the Central Valley. The Department of Fish and Game submitted data to the Regional Water Quality Control Board regarding warm water temperatures present in the lower Merced River juvenile steelhead rearing reaches during the summer for years 1999 thru 2005 (Table 20 in CDFG¿s Letter to the RWQCB, 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

In the absence of necessary data to interpret numeric water quality objectives, recent temperature monitoring data shall be compared to the temperature requirements of aquatic life in the water segment. In many cases, fisheries, particularly salmonids, represent the beneficial uses most sensitive to temperature. Information on current and historic conditions and distribution of sensitive beneficial uses (e.g., fishery resources) in the water segment is necessary, as well as recent temperature data reflective of conditions experienced by the most sensitive life stage of the aquatic life species. If temperature data from past (historic) periods corresponding to times when the beneficial use was fully supported are not available, information about presence/absence or abundance of sensitive aquatic life species shall be used to infer past (historic) temperature conditions if loss of habitat, diversions, toxic spills, and other factors are also listed. (SWRCB, 2004)

Guideline Reference:

Water Quality Control Policy For Developing California's Clean Water Act Section 303(d) List. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency.

Spatial Representation:

Merced River

Temporal Representation:

Information references from year 1929 to 2006.

Environmental Conditions:

QAPP Information:

San Joaquin River Fall-Run Chinook Salmon and Steelhead Rainbow Trout Historical Population Trend Summary. Dean Marston. September 2007.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

26233

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Fish Migration

Number of Samples:

128

Number of Exceedances:

105

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Stream temperatures were measured by California Department of Fish and Game (CDFG) using data loggers (Stowaways, Tidbits and Hobo Temp Pros). Monitoring occurred from 1991 to 2007 depending on the monitoring station, identified by a river mile. The 7DADM was recorded weekly for each river mile.
The maximum 7DADM value was calculated for each year. Based on the data provided, 105 out of 128 maximum 7DADM values exceeded the <18oC criteria from 1991 to 2007.

Data Reference:

USEPA Region 9 data summary for addition of temperature to California 2010 303(d) list for Merced River, Lower (McSwain Reservoir to San Joaquin River)

Access and DSS database files of water temperature data, one each for the San Joaquin, Merced, Stanislaus, and Tuolumne rivers

Cover letter, data and information regarding elevated water temperatures in the San Joaquin, Merced, Stanislaus, and Tuolumne rivers

USEPA Partial Approval Disapproval Letter and enclosures for California's 2008-2010 303(d) List

USEPA Final Decision Letter with enclosures and responsiveness summary regarding waters added to California's 2008-2010 303(d) List

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The guideline used was the 2003 US EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards (USEPA, 2003). The document includes recommended temperature criteria for salmon and trout based on different life stages. The recommended temperature for salmon and trout adult migration is <18oC for a 7DADM. The adult migration life stage occurs from river mile 0 (confluence with the San Joaquin River) to river mile 52 (Merced River Hatchery). This life stage occurs during Julian weeks 36 through 43, which is approximately September 1st through October 31st.

Guideline Reference:

EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.

Spatial Representation:

The adult migration life stage occurs from river mile 0 (confluence with the San Joaquin River) to river mile 52 (Merced River Hatchery). Stream temperatures were monitored at the following stream locations during the adult migration life stage: River Miles 0 (confluence with the San Joaquin River), 1 (Hatfield Park), 4 (above and below Stevinson Spill), 12 (NRS), 13 (Haggaman Park), 21 (above Livingston Spill), 22 (Hwy 99 Bridge), 28 (near Santa Fe Bridge), 30.5 (Dry Creek), 31 (Shaffer Bridge), 39 (Gallo Ranch Bridge), 40 (on the Ratzlaff property), 41 (Hwy 59 Bridge), 42 (NRS), 43 (Robinson), 44 (upper Robinson), 46 (G Street Bridge), 47 (NRS) and 52 (Merced River Hatchery).

Temporal Representation:

The adult migration life stage occurs during Julian weeks 36 through 43, which is approximately September 1st through October 31st. Data was collected during this life stage on a continuous basis (hourly intervals) from 1991 through 2007, depending on the station and year monitored. Refer to the CDFG 2007 report (Gordus, 2007) for specific years for each location.

Environmental Conditions:

QAPP Information:

Data is supported by a Quality Assurance Project Plan (QAPP) pursuant to the requirements of 40 CFR 31.45 and are acceptable for use in developing the section 303(d) list.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158886, Temperature, water	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

26537

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Stream temperatures were measured by CDFG using data loggers (Stowaways, Tidbits and Hobo Temp Pros). Monitoring occurred from 1991 to 2007 depending on the monitoring station, identified by a river mile. The 7DADM was recorded weekly for each river mile. The maximum 7DADM value was calculated for each year. Based on the data provided, 95 out of 96 maximum 7DADM values exceeded the <13 degrees C criteria from 1991 to 2007.

Data Reference:

USEPA Region 9 data summary for addition of temperature to California 2010 303(d) list for Merced River, Lower (McSwain Reservoir to San Joaquin River)

Access and DSS database files of water temperature data, one each for the San Joaquin, Merced, Stanislaus, and Tuolumne rivers

Cover letter, data and information regarding elevated water temperatures in the San Joaquin, Merced, Stanislaus, and Tuolumne rivers

USEPA Partial Approval Disapproval Letter and enclosures for California's 2008-2010 303(d) List

USEPA Final Decision Letter with enclosures and responsiveness summary regarding waters added to California's 2008-2010 303(d) List

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The guideline used was the 2003 US EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards (USEPA, 2003). The document includes recommended temperature criteria for salmon and trout based on different life stages. The recommended temperature for salmon and trout spawning is <13 degrees C for a 7DADM. The spawning life stage occurs from river mile 28 (near Santa Fe Bridge) to river mile 52 (Merced River Hatchery). This life stage occurs during Julian weeks 40 through 50, which is approximately October 1st through December 15th.

Guideline Reference:

EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. U.S. Environmental Protection Agency Region 10 Office of Water, Seattle, WA.

Spatial Representation:

The spawning life stage occurs from river mile 28 (near Santa Fe Bridge) to river mile 52 (Merced River Hatchery). Stream temperatures were monitored at the following stream locations during the spawning life stage: River Miles 28 (near Santa Fe Bridge), 30.5 (Dry Creek above Merced River), 31 (Shaffer Bridge), 39 (Gallo Ranch Bridge), 40 (on the Ratzlaff property), 41 (Hwy 59 Bridge), 42 (NRS), 43 (Robinson), 44 (upper Robinson), 46 (G Street Bridge), 47 (NRS), and 52 (Merced River Hatchery).

Temporal Representation:

The spawning life stage occurs during Julian Weeks 40 through 50, which is approximately October 1st through December 15th. Data was collected during this life stage on a continuous basis (hourly intervals) from 1991 through 2007, depending on the station and year monitored. Refer to the CDFG 2007 report (Gordus, 2007) for specific years for each location.

Environmental Conditions:

QAPP Information:

Data is supported by a Quality Assurance Project Plan (QAPP) pursuant to the requirements of 40 CFR 31.45 and are acceptable for use in developing the section 303(d) list.

QAPP Information Reference(s):


DECISION ID	158887	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Toxicity
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Thirteen lines of evidence are available in the administrative record to assess pollutant. Fifteen of the 110 water samples exceed the objective for the aquatic life beneficial use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Fifteen of the 110 water samples exceed the objective for the aquatic life beneficial use, and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158887, Toxicity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

347518

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

0 of the 3 samples collected by SWAMP Stream Pollution Trends for Merced River, Lower (McSwain Reservoir to San Joaquin River) exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Growth (wt/surv indiv), Hyalella azteca for Survival, Chironomus dilutus for Growth (ash-free dry wt/surv indiv), Chironomus dilutus for Survival.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Evaluation Guideline:

The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing. An exceedance is counted when the significant effect code is "Significant; Less Similarity," which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold. The default evaluation threshold is 20% unless otherwise stated.

Guideline Reference:

Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013

Spatial Representation:

The samples were collected at monitoring site: 535MER546 ( Merced River @ River Road ).

Temporal Representation:

The samples were collected between the dates of 2018-08-22 and 2020-08-27.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

Line of Evidence (LOE) for Decision ID 158887, Toxicity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

347474

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

0 of the 3 samples collected by East San Joaquin Water Quality Coalition for Merced River, Lower (McSwain Reservoir to San Joaquin River) exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Survival.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 535XMRAOR ( Merced River @ Oakdale Rd ).

Temporal Representation:

The samples were collected between the dates of 2019-04-16 and 2020-09-11.

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158887, Toxicity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

347473

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

1 of the 18 samples collected by East San Joaquin Water Quality Coalition for Merced River, Lower (McSwain Reservoir to San Joaquin River) exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Survival, Selenastrum capricornutum for Total Cell Count, Ceriodaphnia dubia for Survival. The following tests exhibited toxicity: Hyalella azteca for Survival on 2021-08-11.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 535XMRAOR ( Merced River @ Oakdale Rd ).

Temporal Representation:

The samples were collected between the dates of 2018-10-09 and 2021-09-22.

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158887, Toxicity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

195740

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

0 of the 6 samples collected by SWAMP Stream Pollution Trends for Merced River, Lower (McSwain Reservoir to San Joaquin River) exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day, at the same location with the same lab sample ID (if provided). The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca, for Growth (wt/surv indiv), Hyalella azteca, for Survival

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life. Region 5 Basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing. For SWAMP data exceedances are counted with the significant effect code SL. SL is defined as the result being significant compared to the negative control based on a statistical test, less than stated the alpha level, AND less than the evaluation threshold.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 station. Monitoring site: ( 535MER546 )

Temporal Representation:

The samples were collected between the dates of 2010-09-01 and 2018-08-22.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158887, Toxicity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

195777

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

3 of the 12 samples collected by SWAMP RWB5 Monitoring for Merced River, Lower (McSwain Reservoir to San Joaquin River) exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day, at the same location with the same lab sample ID (if provided). The following organisms and parameters were utilized for the toxicity tests: Selenastrum capricornutum, for Total Cell Count, Pimephales promelas, for Biomass (wt/orig indiv), Ceriodaphnia dubia, for Survival, Pimephales promelas, for Survival, Ceriodaphnia dubia, for Young/female, Hyalella azteca, for Survival

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. Region 5 Basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing (parametric Dunnett's Test or non-parametric Kruskal-Wallis or Wilcoxon Two-sample Test). The t-test is used to determine if there is a statistically significant decrease in organism response in the sample as compared to the control.

Guideline Reference:

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. EPA-821-R-02-012

Guideline Reference:

Spatial Representation:

The samples were collected at 1 station. Monitoring site: ( 535MER546 )

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2017-09-12.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158887, Toxicity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67084

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One sample was collected to evaluate sediment toxicity. The sample did not exhibit significant toxicity. The toxicity test included survival and growth of Hyalella azteca.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing.

Guideline Reference:

Spatial Representation:

The sample was collected at station 535MER546.

Temporal Representation:

The sample was collected in July 2008.

Environmental Conditions:

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158887, Toxicity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

23080

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Five of the 11 samples tested with Pimephales promelas were toxic and violated the narrative toxicity objective. Fiver samples collected at River Road exhibited a statistically significant decrease in survival compared to the control. The sample dates and percent of control (in parentheses) are as follows:29 March 2005 (63)26 May 2005 (67)25 August 2005 (87)27 October 2005 (74)29 November 2005 (44)

Data Reference:

Monitoring Data from the Surface Water Ambient Monitoring Program (SWAMP), San Joaquin River Basin - 2007 Data Review

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Statistically significant difference from control using a Fisher's Exact test with 7-day chronic-style toxicity tests.

Guideline Reference:

Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fourth Edition. U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-821-R-02-013

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected from November 2004 to November 2005.

Environmental Conditions:

QAPP Information:

Data quality: Excellent. Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 158887, Toxicity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67085

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Thirty-nine samples were collected to evaluate water toxicity. Six of the samples exhibited significant toxicity (Ceriodaphnia dubia, 5 samples and Selenastrum capricornutum, 1 sample). The toxicity tests included survival of Ceriodaphnia dubia, survival of Pimephales promelas, and total cell count of Selenastrum capricornutum. One sample can have multiple toxicity test results but will be counted only once.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at Merced River at Santa Fe.

Temporal Representation:

The samples were collected from July 2004 to September 2008 and one sample in January 2010.

Environmental Conditions:

QAPP Information:

Data was collected under the Quality Assurance Project Plan For Monitoring By The East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158887, Toxicity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

23063

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One sample tested with Hyalella azteca was not toxic nor did it violate the narrative toxicity objective.

Data Reference:

Monitoring Data from the Surface Water Ambient Monitoring Program (SWAMP), San Joaquin River Basin - 2007 Data Review

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Statistically significant difference from control using a t-test with 10-day Hyalella azteca sediment toxicity tests.

Guideline Reference:

Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates, Second Edition. U.S. Environmental Protection Agency Office of Research and Development, Duluth, MI , U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-600/R-99/064

Spatial Representation:

Samples were collected from Merced River at River Road

Temporal Representation:

The sample was collected in May 2002

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 158887, Toxicity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

23062

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

None of the 6 samples tested with Hyalella azteca were toxic and violated the narrative toxicity objective.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Statistically significant difference from control using a t-test with 10-day Hyalella azteca sediment toxicity tests.

Guideline Reference:

Spatial Representation:

Samples were collected from Merced River at Santa Fe

Temporal Representation:

Samples were collected in August 2004 and August 2006

Environmental Conditions:

QAPP Information:

Data quality: Excellent. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158887, Toxicity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

23061

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Zero of the 11 samples tested with Ceriodaphnia dubia were toxic and violated the narrative toxicity objective.

Data Reference:

Monitoring Data from the Surface Water Ambient Monitoring Program (SWAMP), San Joaquin River Basin - 2007 Data Review

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Statistically significant difference from control using a t-test with 48-hour acute-style toxicity tests.

Guideline Reference:

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-821-R-02-012

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected from October 2001 to November 2002.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 158887, Toxicity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

23065

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

None of the 12 samples tested with Pimephales promelas were toxic and violated the narrative toxicity objective.

Data Reference:

Monitoring Data from the Surface Water Ambient Monitoring Program (SWAMP), San Joaquin River Basin - 2007 Data Review

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Statistically significant difference from control using a Fisher's Exact test with 4-day acute-style toxicity tests.

Guideline Reference:

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected from October 2000 to November 2002.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 158887, Toxicity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

59176

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Seven samples were collected to evaluate sediment toxicity. None of the samples exhibited significant toxicity. The toxicity tests included survival of Hyalella azteca. One sample can have multiple toxicity test results but will be counted only once. One sample is defined as being collected on the same day at the same location with the same lab sample id (if provided).

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing. For SWAMP data exceedances are counted using the significant effect code: S equals significant, SG equals significantly greater and SL equals significantly lower. If a sample has any one of these codes, it will be considered an exceedance.

Guideline Reference:

Spatial Representation:

The samples were collected at Merced River at Santa Fe.

Temporal Representation:

The samples were collected from August 2004 to August 2008.

Environmental Conditions:

QAPP Information:

Data was collected under the Quality Assurance Project Plan For Monitoring By The East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.


DECISION ID	116919	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	2,4-D (2,4-Dichlorophenoxy acetic acid)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	This decision was made by SWRCB staff.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116919, 2,4-D (2,4-Dichlorophenoxy acetic acid)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188860

Pollutant:

2,4-D (2,4-Dichlorophenoxy acetic acid)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan for the Sacramento and San Joaquin River Basins).

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for 2,4-D (2,4-Dichlorophenoxy acetic acid) is the USEPA Aquatic Life Benchmark of 299.2 ug/L for a vascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR)

Temporal Representation:

The samples were collected between the dates of 2018-02-13 and 2018-04-09

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116919, 2,4-D (2,4-Dichlorophenoxy acetic acid)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188589

Pollutant:

2,4-D (2,4-Dichlorophenoxy acetic acid)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for 2, 4-D incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.07 mg/L

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR)

Temporal Representation:

The samples were collected between the dates of 2018-02-13 and 2018-04-09

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	158871	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Acetamiprid
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 158871, Acetamiprid	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330599

Pollutant:

Acetamiprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for acetamiprid is the USEPA Aquatic Life Benchmark of 2.1 ug/L for an invertebrate (chronic).

Guideline Reference:

QAPP Reference for Irrigated Lands Regulatory Program

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2018-11-30

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):


DECISION ID	116951	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Aldicarb
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Seven lines of evidence are available in the administrative record to assess this pollutant for the Municipal and Domestic Supply (MUN) and Cold Freshwater Habitat (COLD) beneficial uses. Zero of one sample, reported in dissolved concentration, exceeds the evaluation criteria for MUN; zero of one samples, reported as dissolved concentration, exceed the evaluation criteria for COLD; zero of the thirty-seven samples, reported as total concentration, exceed the evaluation criteria for MUN; and zero of the fifty-eight samples exceed the evaluation criteria for COLD. LOE 67126 has been replaced by LOE 221718 due to a reassessment of data using a U.S. EPA aquatic life benchmark. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of one sample, reported in dissolved concentration, exceeds the evaluation criteria for MUN; zero of one samples, reported as dissolved concentration, exceed the evaluation criteria for COLD; zero of the thirty-seven samples, reported as total concentration, exceed the evaluation criteria for MUN; and zero of the fifty-eight samples exceed the evaluation criteria for COLD and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116951, Aldicarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

185926

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-25 and 2015-03-25

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116951, Aldicarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

185918

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for aldicarb incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 3 ug/L

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116951, Aldicarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

185921

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for aldicarb incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 3 ug/L

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 116951, Aldicarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

185917

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116951, Aldicarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

185888

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for aldicarb incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 3 ug/L

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-25 and 2015-03-25

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116951, Aldicarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

221718

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 21 samples exceeded the water quality threshold for Aldicarb.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2006-05-16 and 2008-09-23

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116951, Aldicarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

185919

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	164572	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Aldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess pollutant. Zero of the 23 samples, reported as a "Total" fraction or as fraction reported as "None," exceed the objective COLD beneficial use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 23 samples, reported as a "Total" fraction or as fraction reported as "None," exceed the objective COLD beneficial use. This exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 164572, Aldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

185970

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldrin. Although a total of 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Aldrin criteria for the protection of human health from the consumption of water and organisms is 0.00013 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-14 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164572, Aldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

185976

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Aldrin criteria for the protection of human health from the consumption of water and organisms is 0.00013 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-04-01 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164572, Aldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67128

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for Aldrin.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The criterion maximum concentration to protect aquatic life in freshwater for aldrin is 1.5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164572, Aldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67127

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Aldrin. Nine samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The CTR objective for aldrin to protect human health from the consumption of water and organisms is 0.00013 ug/L.

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164572, Aldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186081

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The established numeric criteria for aldrin to protect aquatic life in freshwater as an instantaneous maximum concentration is 3 ug/L . This established criteria was divided by 2 in order to better represent a CMC value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule, 2000.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164572, Aldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

185982

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	116955	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Ametryn
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116955, Ametryn	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186151

Pollutant:

Ametryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for ametryn is the USEPA Aquatic Life Benchmark of 3.67 ug/L for acute toxicity in nonvascular plants (7 day average).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116955, Ametryn	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186150

Pollutant:

Ametryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for ametryn is the USEPA Aquatic Life Benchmark of 3.67 ug/L for acute toxicity in nonvascular plants (7 day average).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	167354	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Ammonia
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 167354, Ammonia	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

329677

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia Freshwater 2013 document.

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-NRS_CA-10948 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2018-07-16 and 2018-07-16

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

Line of Evidence (LOE) for Decision ID 167354, Ammonia	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

6336

Pollutant:

Ammonia

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Zero of the 2 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation guideline for Ammonia.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Ammonia levels should not to exceed the calculated limit. Freshwater Aquatic Life Protection (Salmonid present) Criteria Maximum Concentration (CMC) (1-hour Average (mg N/L)) calculated based on the following formula: CMC = (0.275/(1 + 107.204-pH)) + (39.0/(1 + 10pH-7.204)) which incorporates pH (US EPA, 2005: Appendix C)

Guideline Reference:

1999 Update of Ambient Water Quality Criteria for Ammonia

Spatial Representation:

Samples were collected at Merced River at River Road.

Temporal Representation:

The samples were collected from May 25 2000 to Jul 27 2000.

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 167354, Ammonia	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330732

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-07 and 2019-09-10

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 167354, Ammonia	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

20480

Pollutant:

Ammonia

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

0 of the 2 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Ammonia.

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Ammonia levels should not exceed 30 mg/L (USEPA Health Advisory).

Guideline Reference:

2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013

Spatial Representation:

Samples were collected at Merced River at River Road.

Temporal Representation:

The samples were collected from May 25 2000 to Jul 27 2000

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 167354, Ammonia	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

79001

Pollutant:

Ammonia as N, Total

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Thirty-eight water samples collected from Merced River, Lower (McSwain Reservoir to San Joaquin River) by the East San Joaquin Water Quality Coalition and they were analyzed for ammonia, pH and temperature. None of the 38 water samples exceeded the calculated ammonia CMC values.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Per the National Recommended Water Quality Criteria (USEPA 2006): The 1-hour average concentration (acute criterion or CMC) of total ammonia nitrogen (in mg N/L) for freshwater where salmonid fish are present, which is not to be exceeded more than once every three years on average, is calculated using the following equation: CMC=0.275/(1+10^(7.204 - pH)) + 39.0/(1+10^(pH - 7.204)).

Guideline Reference:

Spatial Representation:

The 38 water samples were collected from Merced River, Lower (McSwain Reservoir to San Joaquin River) at one monitoring site [Merced River @ Santa Fe - 535XMRSFD].

Temporal Representation:

The 38 water samples were collected intermittently to monthly between 2/12/2007 and 7/20/2010

Environmental Conditions:

QAPP Information:

Data was collected under Irrigated Lands Regulatory Program

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.


DECISION ID	158870	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Arsenic
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158870, Arsenic	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

6338

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

None of the 13 samples collected by the Surface Water Ambient Monitoring Program exceeded the CTR citerion of 340 ug/L for dissolved arsenic

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Dissolved arsenic levels should not exceed the CTR 1-hour average maximum concentration of 340 ug/L

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the Merced River at River Road

Temporal Representation:

The samples were collected from Aug 29 2001 to Nov 20 2002

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158870, Arsenic	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67141

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 23 samples exceed the criterion for Arsenic.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 0.150 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-4/21/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158870, Arsenic	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67140

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for arsenic is 0.010 mg/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-4/21/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158870, Arsenic	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67139

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the evaluation guideline value for Arsenic.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Discharges shall not result in pesticide concentrations in bottom sediments or aquatic life that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins).

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for arsenic is 33 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158870, Arsenic	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

333099

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546 (Merced River @ River Road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-08-27 to 2020-08-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 158870, Arsenic	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186409

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 150 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158870, Arsenic	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

195861

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Arsenic from MacDonald et al., 2000a which states that the probable effect concentration for Arsenic is 33 mg/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2018-08-22

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158870, Arsenic	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186451

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for arsenic incorporated by reference in the Basin Plan is 0.010 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158870, Arsenic	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

20441

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 5 samples collected by the Surface Water Ambient Monitoring Program exceeded the USEPA Primary MCL of 10 ug/L for total arsenic

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Total arsenic levels must not exceed the USEPA Primary MCL of 10 ug/L

Objective/Criterion Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the Merced River at River Road

Temporal Representation:

The samples were collected between March 20, 2003 and June 30, 2003

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):


DECISION ID	116884	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Atrazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). LOE 67150 has been replaced by LOE 221444 due to a reassessment of data using a U.S. EPA aquatic life benchmark. The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116884, Atrazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186250

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for atrazine incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.001 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116884, Atrazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

221444

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of <1 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2006-05-16 and 2008-09-23

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116884, Atrazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67151

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 16 samples exceed the criterion for Atrazine.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for atrazine is 1 ug/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 116884, Atrazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186467

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for atrazine incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.001 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116884, Atrazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186226

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of <1 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116884, Atrazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186207

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for atrazine incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.001 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 116884, Atrazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186487

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of <1 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116884, Atrazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186222

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of <1 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):


DECISION ID	116905	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Azinphos-methyl (Guthion)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of the zero samples exceed the evaluation guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the zero samples exceed the evaluation guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples are needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116905, Azinphos-methyl (Guthion)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186492

Pollutant:

Azinphos-methyl (Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 35 samples were collected, 35 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria for azinphos methyl for freshwater aquatic life protection is 0.01 ug/l (instantaneous maximum)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-01-18 to 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 116905, Azinphos-methyl (Guthion)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67152

Pollutant:

Azinphos-methyl (Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Azinphos methyl. Twenty-four samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The National Recommended Water Quality criterion for Azinphos Methyl (Guthion) for the protection of freshwater aquatic life is a maximum of 0.01 ug/l.

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-5/19/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.


DECISION ID	170888	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Benthic Community Effects
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Benthic Community Effects are being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, additional lines of evidence (LOEs) associating the Benthic Community Effects decision with a water or sediment concentration of pollutants other than benthic-macroinvertebrate bioassessment or habitat assessment LOEs are necessary to place a water body on the 303(d) List for Benthic Community Effects. One line of evidence evaluating benthic-macroinvertebrate bioassessment data is available in the administrative record to assess this indicator. One of one benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. However, a minimum of two benthic-macroinvertebrate samples are needed to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this waterbody segment on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used does not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. One of one benthic-macroinvertebrate bioassessment samples had CSCI scores below 0.79. The available information is insufficient to determine whether the waterbody/pollutant combination should be placed on the 303(d) List of impaired waters at this time. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 170888, Benthic Community Effects	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

352647

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for 535CR0030 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the water quality standard. CSCI scores were from 0.528948708 to 0.528948708 .

Data Reference:

Benthic, Habitat from the EPA National Rivers and Streams Assessment for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Evaluation Guideline:

The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rhen, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.)

Guideline Reference:

Bioassessment in complex environments: designing an index for consistent meaning in different settings

Spatial Representation:

The samples were collected at 1 monitoring site: 535CR0030 (Merced River ~3.5mi below Hwy 99).

Temporal Representation:

Samples were collected from 2018-07-16 to 2018-07-16.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows


DECISION ID	158872	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Ten lines of evidence are available in the administrative record to assess this pollutant. Six LOEs are available for the COLD beneficial use and four LOEs are available for the MUN beneficial use. Zero of the 48 samples exceed the water quality objective for MUN, zero of the 25 water samples exceed the water quality objective for COLD, and zero of the eight sediment samples exceed the evaluation guideline for COLD. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 48 samples exceed the water quality objective for MUN, zero of the 25 water samples exceed the water quality objective for COLD, and zero of the eight sediment samples exceed the evaluation guideline for COLD and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158872, Cadmium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

20443

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 5 samples collected by the Surface Water Ambient Monitoring Program exceeded the California Primary MCL of 5 ug/L for total cadmium

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Total cadmium levels should not exceed the California Department of Public Health Primary MCL of 5 ug/L

Objective/Criterion Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the Merced River at River Road

Temporal Representation:

The samples were collected between March 20, 2003 and June 30, 2003

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158872, Cadmium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67167

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the evaluation guideline value for Cadmium.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for cadmium is 4.98 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158872, Cadmium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67168

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for cadmium is 5 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-4/21/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158872, Cadmium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67179

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed AgWaiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Cadmium.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The cadmium criterion in freshwater is hardness-dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [ Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-4/21/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158872, Cadmium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186817

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for cadmium incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.005 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158872, Cadmium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186613

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for cadmium incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.005 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2011-08-09

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158872, Cadmium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

333126

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546 (Merced River @ River Road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-08-27 to 2020-08-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 158872, Cadmium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

195977

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Cadmium from MacDonald et al., 2000a which states that the probable effect concentration for Cadmium is 4.98 mg/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2018-08-22

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158872, Cadmium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186570

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158872, Cadmium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

6340

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

None of the 6 samples collected by the Surface Water Ambient Monitoring Program exceeded the calculated CTR criterion for dissolved cadmium

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Dissolved cadmium levels should not exceed the calculated limit based on the formula: Criteria Maximum Concentration (1-hour Average dissolved)=(EXP(1.128*LN(hardness)-3.6867))*(1.136672-(LN(hardness)*0.041838))

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the Merced River at River Road

Temporal Representation:

The samples were collected between September 26, 2001 and November 20, 2002

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):


DECISION ID	116886	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Carbaryl
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Zero of the 53 samples exceed the evaluation guideline for COLD. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 53 samples exceed the evaluation guideline for COLD and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116886, Carbaryl	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186970

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA recommended water quality criteria for freshwater aquatic life for carbaryl is 2.1 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 116886, Carbaryl	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187153

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA recommended water quality criteria for freshwater aquatic life for carbaryl is 2.1 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116886, Carbaryl	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187084

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA recommended water quality criteria for freshwater aquatic life for carbaryl is 2.1 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116886, Carbaryl	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67180

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The USEPA recommended water quality criterion for freshwater aquatic life for carbaryl is 2.1 µg/L.

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.


DECISION ID	116887	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Carbofuran
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Eight lines of evidence are available in the administrative record to assess this pollutant. Zero of the 53 whole water samples exceed the objective for MUN. Zero of 53 whole water samples exceed the evaluation guideline for COLD. Additionally, zero of 1 water sample, measured as a dissolved fraction, exceed these guidelines. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 53 whole water samples exceed the objective for MUN. Zero of 53 whole water samples exceed the evaluation guideline for COLD. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116887, Carbofuran	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187071

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.018 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 116887, Carbofuran	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186977

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The interim water quality criterion for the protection of sensitive aquatic organisms from Carbofuran is 0.5 ug/l (DFG 92-3, 1992).

Guideline Reference:

Hazard Assessment of the Insecticide Carbofuran to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116887, Carbofuran	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67182

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for Carbofuran is 18 ug/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 116887, Carbofuran	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67181

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The freshwater criterion maximum concentration for carbofuran is 0.5 µg/L (DFG 92-3, 1992).

Guideline Reference:

Hazard Assessment of the Insecticide Carbofuran to Aquatic Organisms in the Sacramento River System

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 116887, Carbofuran	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186951

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.018 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116887, Carbofuran	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187067

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The interim water quality criterion for the protection of sensitive aquatic organisms from Carbofuran is 0.5 ug/l (DFG 92-3, 1992).

Guideline Reference:

Hazard Assessment of the Insecticide Carbofuran to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116887, Carbofuran	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186998

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.018 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116887, Carbofuran	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187044

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The interim water quality criterion for the protection of sensitive aquatic organisms from Carbofuran is 0.5 ug/l (DFG 92-3, 1992).

Guideline Reference:

Hazard Assessment of the Insecticide Carbofuran to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	164558	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Chlordane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 164558, Chlordane	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186889

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlordane. Although a total of 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The Chlordane criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0043 ug/L (California Toxics Rule, 2000).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-14 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164558, Chlordane	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187207

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The Chlordane criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0043 ug/L (California Toxics Rule, 2000).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164558, Chlordane	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187209

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlordane. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chlordane criterion for the protection of human health from the consumption of water and organisms is 0.00057 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-04-01 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164558, Chlordane	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187162

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlordane. Although a total of 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Chlordane criterion for the protection of human health from the consumption of water and organisms is 0.00057 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-14 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164558, Chlordane	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

195936

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Chlordane from MacDonald et al., 2000a which states that the probable effect concentration for Chlordane is 17.6 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164558, Chlordane	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67183

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Zero of 1 sample collected exceeded the criteria for chlordane concentration (Sum of trans-Chlordane, cis-Chlordane, cis-Nonachlor, trans-Nonachlor, and Oxychlordane).

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. Waters shall not contain substances in concentrations that result in the deposition of material that causes nuisance or adversely affects beneficial uses. (Water Quality Control Plan for the Sacramento and San Joaquin River Basins).

Objective/Criterion Reference:

Evaluation Guideline:

The Probable Effect Concentration for Chlordane in freshwater sediments is 17.6 ug/kg(MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected at the following station 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected on 7/23/2008.

Environmental Conditions:

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 164558, Chlordane	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

78644

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: nine samples were analyzed for Chlordane. The nine samples were not used in the assessment because the laboratory data reporting limit was above the objective, the available sample was below the laboratory data reporting limit, and therefore the results could not be quantified with the level of certainty required by the Listing Policy. 0 of 0 samples exceed the criterion for chlordane.

Data Reference:

Data for Various Pollutants for California Rice Commission, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Chlordane objective to protect human health (water and organism consumption) is 0.00057 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at one monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected between 10/21/2008 and 7/20/2010

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

Data was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Monitoring and Reporting Program Plan for California Rice Commission.

Line of Evidence (LOE) for Decision ID 164558, Chlordane	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

78643

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants for California Rice Commission, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The Chlordane criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0043 ug/L (California Toxics Rule, 2000).

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at one monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected between 10/21/2008 and 7/20/2010

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

Data was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Monitoring and Reporting Program Plan for California Rice Commission.


DECISION ID	158873	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Chloride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Data from previous cycles has been reassessed according to a new assessment method. LOEs have been replaced to reflect this change. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 158873, Chloride	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

345814

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Ambient Water Program data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the upper limit of the range for Chloride. Additionally, 0 of the 5 samples fall within the range, and 5 of 5 samples fall below the threshold.

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Secondary MCL that is incorporated by reference into the Water Quality Control Plan for the Sacramento and San Joaquin River Basins specifies a range for chloride of 250-500 mg/L assessed as an annual average.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: MER546 (MER546).

Temporal Representation:

The samples were collected between the dates of 1998-10-29 and 2003-06-30

Environmental Conditions:

QAPP Information:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 158873, Chloride	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

345810

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP BDAT data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the upper limit of the range for Chloride. Additionally, 0 of the 4 samples fall within the range, and 4 of 4 samples fall below the threshold.

Data Reference:

SWAMP data entered by SWRCB into BDAT database

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 1998-10-29 and 2001-11-28

Environmental Conditions:

QAPP Information:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 158873, Chloride	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346207

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DFW_ABL_Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the upper limit of the range for Chloride. Additionally, 0 of the 1 samples fall within the range, and 1 of 1 samples fall below the threshold.

Data Reference:

Habitat, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535CR1042 (Merced River -1042).

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158873, Chloride	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

329760

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-NRS_CA-10948 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2018-07-16 and 2018-07-16

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

San Joaquin River SWAMP Monitoring Data - Eastside Basin

Line of Evidence (LOE) for Decision ID 158873, Chloride	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

345807

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin River SWAMP Monitoring Data - Eastside Basin data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the upper limit of the range for Chloride. Additionally, 0 of the 1 samples fall within the range, and 1 of 1 samples fall below the threshold.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: MER209 (Merced_River_at_Merced_Falls_MER209).

Temporal Representation:

The samples were collected between the dates of 2003-06-30 and 2003-06-30

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158873, Chloride	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

329759

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-CARO-1042 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.


DECISION ID	158904	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Chloropicrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158904, Chloropicrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187318

Pollutant:

Chloropicrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chloropicrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Chloropicrin is the USEPA Aquatic Life Benchmark of 5.5 ug/L for a fish (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR).

Temporal Representation:

Date for this waterbody was collected over the date range 2017-10-10 to 2018-09-11

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158904, Chloropicrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330959

Pollutant:

Chloropicrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chloropicrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for chloropicrin is the USEPA Aquatic Life Benchmark of 5.5 ug/L for a fish (acute).

Guideline Reference:

QAPP Reference for Irrigated Lands Regulatory Program

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-10-09 and 2019-09-10

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):


DECISION ID	158874	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Chlorothalonil
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 158874, Chlorothalonil	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330970

Pollutant:

Chlorothalonil

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for chlorothalonil is the USEPA Aquatic Life Benchmark of 0.6 ug/L for an invertebrate (chronic).

Guideline Reference:

QAPP Reference for Irrigated Lands Regulatory Program

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2019-03-08 and 2019-04-16

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):


DECISION ID	158898	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Chromium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 158898, Chromium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67193

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the evaluation guideline value for Chromium.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for chromium is 111 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158898, Chromium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196083

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Chromium from MacDonald et al., 2000a which states that the probable effect concentration for Chromium is 111 mg/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158898, Chromium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

333140

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546 (Merced River @ River Road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-08-27 to 2020-08-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5


DECISION ID	158876	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Copper
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. LOEs for this waterbody-pollutant combination from previous cycles were reassessed according to a new assessment method. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158876, Copper	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

333151

Pollutant:

Copper

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546 (Merced River @ River Road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-08-27 to 2020-08-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 158876, Copper	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346308

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Secondary Maximum Contaminant Level for copper incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 1.0 mg/L assessed as an annual average.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRSFD (Merced River @ Santa Fe).

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2016-12-09

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158876, Copper	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346307

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2017-12-05 and 2018-01-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158876, Copper	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331089

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2019-04-16

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158876, Copper	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331103

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2019-04-16

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158876, Copper	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196027

Pollutant:

Copper

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Copper from MacDonald et al., 2000a which states that the probable effect concentration for Copper is 149 mg/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2018-08-22

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158876, Copper	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

6342

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 13 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Copper.

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Toxics Rule 4-day average criteria for dissolved Copper.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at Merced River at River Road.

Temporal Representation:

The samples were collected from October 2000 to November 2002.

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158876, Copper	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67196

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed AgWaiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Copper.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The chromium criterion in freshwater is hardness-dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness-dependent formula for metals criteria.

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [ Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-6/15/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158876, Copper	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67194

Pollutant:

Copper

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the evaluation guideline value for Copper.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for copper is 149 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158876, Copper	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187833

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR)

Temporal Representation:

The samples were collected between the dates of 2017-12-05 and 2018-01-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158876, Copper	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187820

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2016-12-09

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	116947	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Cyanazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant for Cold Freshwater Habitat. Zero out of one sample, reported as a dissolved concentration, exceeds the guideline for Cold Freshwater Habitat. Zero out of 52 samples, reported as a total concentration or with the fraction not reported, exceed the guideline for Cold Freshwater Habitat. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero out of 52 samples, reported as a total concentration or with the fraction not reported, exceed the guideline for Cold Freshwater Habitat and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116947, Cyanazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67206

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The EC50 for Navicula pelliculosa (freshwater diatom) for cyanazine is 4.8 ug/L (USEPA Office of Pesticide Programs Ecotoxicity database).

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116947, Cyanazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187848

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for cyanazine is the EC50 of 4.8 ug/L for Navicula pelliculosa (freshwater diatom) (USEPA Office of Pesticide Programs Ecotoxicity database).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116947, Cyanazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187911

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for cyanazine is the EC50 of 4.8 ug/L for Navicula pelliculosa (freshwater diatom) (USEPA Office of Pesticide Programs Ecotoxicity database).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116947, Cyanazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187846

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for cyanazine is the EC50 of 4.8 ug/L for Navicula pelliculosa (freshwater diatom) (USEPA Office of Pesticide Programs Ecotoxicity database).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	158896	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Cyfluthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 67207 has been replaced by LOE 352988 due to a reassessment of data.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158896, Cyfluthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

352988

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 8 samples were collected, 8 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for cyfluthrin is 0.2 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of cyfluthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRSFD (Merced River @ Santa Fe).

Temporal Representation:

The samples were collected between the dates of 2007-02-12 and 2007-09-11

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158896, Cyfluthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67208

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline value for cyfluthrin, 0.11 ug/g OC, is one-tenth of the median lethal concentration for H. azteca (LC50; 1.1 ug/g OC). The LC50 (1.1 ug/g OC) is the geometric mean of OC-normalized LC50 values for cyfluthrin from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158896, Cyfluthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187811

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for Cyfluthrin is 0.2 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Cyfluthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-01-10 to 2018-07-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158896, Cyfluthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187851

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-18 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158896, Cyfluthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196121

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Stream Pollution Trends data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin, total. Although a total of 5 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for cyfluthrin, 0.11 ug/g, is one-tenth of the median lethal concentration (LC50; 1.1 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Date for this waterbody were collected over the date range 2011-09-08 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158896, Cyfluthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196262

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin, total. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535XMRAOR.

Temporal Representation:

Date for this waterbody were collected over the date range 2018-09-11 to 2018-09-11

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158896, Cyfluthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331141

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 15 samples were collected, 15 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2021-09-22

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program


DECISION ID	158892	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Cypermethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2024)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 67216 has been replaced by LOE 353007 due to a reassessment of data.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158892, Cypermethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353007

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 8 samples were collected, 8 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for cypermethrin is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Cypermethrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRSFD (Merced River @ Santa Fe).

Temporal Representation:

The samples were collected between the dates of 2007-02-12 and 2007-09-11

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158892, Cypermethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67217

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline value for cypermethrin, 0.03 ug/g OC, is one-tenth of the median lethal concentration for H. azteca (LC50; 0.3 ug/g OC). The LC50 is the geometric mean of OC-normalized LC50 values for cypermethrin from Maund et al. (2002).

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158892, Cypermethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188188

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for Cypermethrin is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Cypermethrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-18 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158892, Cypermethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331185

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 17 samples were collected, 17 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2021-09-22

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158892, Cypermethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

291376

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Stream Pollution Trends data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin, Total. Although a total of 5 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for cypermethrin, 0.03 ug/g, is one-tenth of the median lethal concentration (LC50; 0.3 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al. (2002).

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Date for this waterbody were collected over the date range 2011-09-08 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158892, Cypermethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

291391

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin, Total. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535XMRAOR.

Temporal Representation:

Date for this waterbody were collected over the date range 2018-09-11 to 2018-09-11

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158892, Cypermethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188243

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-03-05 to 2018-07-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	168540	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	DDD (Dichlorodiphenyldichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 168540, DDD (Dichlorodiphenyldichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188032

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 9 samples were collected, 9 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The DDD(p,p) criteria for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-01-18 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 168540, DDD (Dichlorodiphenyldichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67218

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The sample result did not exceed the evaluation guideline value (28.0 ug/Kg dry weight).

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for the sum of DDD (o,p' + p,p') is 28.0 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 168540, DDD (Dichlorodiphenyldichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

78837

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

The DDD method detection limit for all 23 analyzed sample results collected from Merced River, Lower (McSwain Reservoir to San Joaquin River) are greater than the criterion; therefore, the data could not be assessed with the accuracy required by the Listing Policy.

Data Reference:

Data for Metals and Nutrients for the City of Anderson, 2006-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Sacramento/San Joaquin River Basin Plan (CVRWQCB, 2007) Pesticides: Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the Executive Officer.- California Toxics Rule Criteria (USEPA, 2000), for Inland Surface Waters based on drinking water and aquatic organism consumption. The criteria are based on human health protection for carcinogenicity at 1-in-a-million risk level (30-day average) with a limit of 0.00083 ug/L for DDD

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Twenty-three water samples collected from Merced River, Lower (McSwain Reservoir to San Joaquin River) [Merced River @ Santa Fe - 535XMRSFD] were analyzed for DDD(p,p')

Temporal Representation:

The samples were collected monthly on 23 dates between 2/12/2007 and 4/21/2009

Environmental Conditions:

QAPP Information:

The data was collected under the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 168540, DDD (Dichlorodiphenyldichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188228

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The DDD(p,p) criteria for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-04-01 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 168540, DDD (Dichlorodiphenyldichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196127

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Sum DDD from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDD is 28 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	169096	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 169096, DDE (Dichlorodiphenyldichloroethylene)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188111

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The DDE(p,p) criteria for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-04-01 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169096, DDE (Dichlorodiphenyldichloroethylene)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

187999

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 9 samples were collected, 9 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The DDE(p,p) criteria for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-01-18 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 169096, DDE (Dichlorodiphenyldichloroethylene)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196275

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Sum DDE from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDE is 31.3 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169096, DDE (Dichlorodiphenyldichloroethylene)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

78889

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

The DDE method detection limit for all 23 analyzed sample results collected from Merced River, Lower (McSwain Reservoir to San Joaquin River) are greater than the criterion; therefore, the data could not be assessed with the accuracy required by the Listing Policy.

Data Reference:

Data for Metals and Nutrients for the City of Anderson, 2006-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Twenty-three water samples collected from Merced River, Lower (McSwain Reservoir to San Joaquin River) [Merced River @ Santa Fe - 535XMRSFD] were analyzed for DDE(p,p')

Temporal Representation:

The samples were collected monthly on 23 dates between 2/12/2007 and 4/21/2009

Environmental Conditions:

QAPP Information:

The data was collected under the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 169096, DDE (Dichlorodiphenyldichloroethylene)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67223

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The sample result did not exceed the evaluation guideline value (31.3 ug/Kg dry weight).

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for the sum of DDE is 31.3 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	169189	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 169189, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188313

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The DDT(p,p) criteria for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-04-01 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169189, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188520

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The DDT criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.005 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-04-01 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169189, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196377

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Sum DDT from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDT is 62.9 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169189, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

197081

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Total DDTs from MacDonald et al., 2000a which states that the probable effect concentration for Total DDTs is 572 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169189, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67224

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The sample result did not exceed the evaluation guideline value (62.9 ug/Kg dry weight).

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for the sum of DDT is 62.9 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 169189, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67225

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for DDT(p,p). Twenty-three samples were not used in the assessment because the laboratory data reporting limit was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The criterion for total DDT to protect human health from consumption of water and organisms is 0.00059 ug/L (California Toxics Rule).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-4/21/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 169189, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188454

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the water quality threshold for DDT(p,p'). Although a total of 9 samples were collected, 8 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The DDT(p,p) criteria for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Data for this waterbody was collected over the date range 2011-01-18 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 169189, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188564

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The DDT criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.005 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Data for this waterbody was collected over the date range 2011-01-18 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 169189, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67226

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for DDT(p,p). Twenty three samples were not used in the assessment because the laboratory data reporting limit was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The DDT criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-4/21/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.


DECISION ID	116892	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Dacthal
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant using the Cold Freshwater Habitat (COLD) and Municipal and Domestic Supply (MUN) beneficial uses. Zero of the one samples exceed the evaluation guideline for COLD and zero of the one hundred and forty-three samples exceed the evaluation guideline for MUN. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the one samples exceed the evaluation guideline for COLD and zero of the one hundred and forty-three samples exceed the evaluation guideline for MUN and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116892, Dacthal	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

26155

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

143

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Zero of 143 water samples collected from Merced River by the United States Geological Survey, under the National Water Information System program, between January 2000 and August 2005 exceeded the USEPA National Ambient Water Quality Criterion for dacthal (DCPA) of 70 ug/L.

Data Reference:

National Water Quality Assessment database, Sacramento Study Unit data

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CRWQCB, 2007).

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

USEPA National Ambient Water Quality Criterion for dacthal (DCPA) of 70 ug/L.

Guideline Reference:

2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013

Spatial Representation:

Water samples were collected from the Merced River at River Road.

Temporal Representation:

Samples were collected hourly, daily or weekly from the Merced River between January 2000 and August 2005.

Environmental Conditions:

QAPP Information:

Data Quality: Good: U.S. Geological Survey, variously dated, National field manual for the collection of water-quality data: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chaps. A1-A9, available online at http://pubs.water.usgs.gov/twri9A

QAPP Information Reference(s):

National field manual for the collection of water quality data. Reston, VA. U.S. Geological Survey. Office of Water Quality

QAPP Information Reference(s):

Field measurements: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chap. A6. In United States Geological Survey (USGS). Variously dated. National field manual for the collection of water-quality data: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chaps. A1-A9, available online at http://pubs.water.usgs.gov/twri9A.

Line of Evidence (LOE) for Decision ID 116892, Dacthal	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188062

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Dacthal is the USEPA Aquatic Life Benchmark of >1100 ug/L for a nonvascular plant (acute) and vascular plant (acute). The benchmark was derived from a \greater-than\" value (for example, > 265,000) and may overestimate toxicity."

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	171139	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Deltamethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2024)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. Previously considered water quality data was reevaluated according to new guidelines as part of this assessment. Lines of evidence have been replaced.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171139, Deltamethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67227

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline value for deltamethrin, 0.079 ug/g OC, is one-tenth of the median lethal concentration for H. azteca (LC50; 0.79 ug/g OC). The LC50 (0.79 ug/g OC) is the geometric mean of OC-normalized LC50 values for deltamethrin from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 171139, Deltamethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353019

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 171139, Deltamethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

291356

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Stream Pollution Trends data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for deltamethrin, 0.079 ug/g, is one-tenth of the median lethal concentration (LC50; 0.79 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Date for this waterbody were collected over the date range 2011-09-08 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 171139, Deltamethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

291365

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535XMRAOR.

Temporal Representation:

Date for this waterbody were collected over the date range 2018-09-11 to 2018-09-11

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	116965	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Demeton
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollution

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116965, Demeton	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188528

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria toxicity threshold for demeton for freshwater aquatic life protection is 0.1 ug/l (4 day average)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	116882	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Desethyl-Atrazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116882, Desethyl-Atrazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188330

Pollutant:

Desethyl-Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Desethyl-Atrazine.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Desethyl-Atrazine is the USEPA Aquatic Life Benchmark of 1000 ug/L for a nonvascular plant (acute) for Triazine DEA degradate.

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116882, Desethyl-Atrazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188346

Pollutant:

Desethyl-Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Desethyl-Atrazine.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Desethyl-Atrazine is the USEPA Aquatic Life Benchmark of 1000 ug/L for a nonvascular plant (acute) for Triazine DEA degradate.

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	116895	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Dichlorvos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116895, Dichlorvos	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188752

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichlorvos. Although a total of 35 samples were collected, 35 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-01-18 to 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):


DECISION ID	116896	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Dicofol
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the thirty-seven samples exceed the evaluation guideline. LOE 67232 has been replaced by LOE 221500 due to a reassessment of data using a U.S. EPA aquatic life benchmark. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the thirty-seven samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116896, Dicofol	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

221500

Pollutant:

Dicofol

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 28 samples exceeded the water quality threshold for Dicofol.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Dicofol is the USEPA Aquatic Life Benchmark of 4.4 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2006-05-16 and 2009-04-21

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116896, Dicofol	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188694

Pollutant:

Dicofol

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Dicofol is the USEPA Aquatic Life Benchmark of 4.4 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):


DECISION ID	164560	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Dieldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 164560, Dieldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67233

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The sample result did not exceed the evaluation guideline value (61.8 ug/Kg dry weight).

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for dieldrin is 61.8 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAMP (2002) was used for data before Septemper 1, 2008 and SWAMP QAPP (2008) was thereafter.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 164560, Dieldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196548

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Dieldrin from MacDonald et al., 2000a which states that the probable effect concentration for Dieldrin is 61.8 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164560, Dieldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188979

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Dieldrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164560, Dieldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188832

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Dieldrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164560, Dieldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188999

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dieldrin. Although a total of 9 samples were collected, 9 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Dieldrin criteria for the protection of human health from the consumption of water and organisms is 0.00014 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-01-18 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164560, Dieldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67234

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Dieldrin. Twenty-three samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The criterion for Dieldrin to protect human health from the consumption of water and organisms is 0.00014 ug/L (California Toxics Rule).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-4/21/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164560, Dieldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188799

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dieldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Dieldrin criteria for the protection of human health from the consumption of water and organisms is 0.00014 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-04-01 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164560, Dieldrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67237

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Dieldrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-4/21/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.


DECISION ID	158893	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Dimethoate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158893, Dimethoate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189127

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158893, Dimethoate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

221417

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 29 samples exceeded the water quality threshold for Dimethoate.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2006-05-16 and 2009-05-19

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158893, Dimethoate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331430

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

QAPP Reference for Irrigated Lands Regulatory Program

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2019-03-08 and 2019-03-08

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):


DECISION ID	116898	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Disulfoton
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence is available in the administrative record to assess this pollutant. Zero of the eight samples exceed the evaluation guideline for COLD. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the eight samples exceed the evaluation guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples are needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	This decision was made by SWRCB staff.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116898, Disulfoton	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

188922

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Disulfoton. Although a total of 35 samples were collected, 35 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for disulfoton is the USEPA Aquatic Life Benchmark of 0.01 ug/L for chronic toxicity in invertebrates (7 day average).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-01-18 to 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116898, Disulfoton	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67239

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 8 samples exceed the criterion for Disulfoton.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The USEPA National Recommended Water Quality criterion for disulfoton in freshwater (0.05 ug/L) is an aquatic life maximum (instantaneous) level.

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-5/19/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.


DECISION ID	171134	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Diuron
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant for Cold Freshwater Habitat. Zero out of one sample, reported as a dissolved concentration, exceeds the guideline for Cold Freshwater Habitat. Zero out of 53 samples, reported as a total concentration, exceed the guideline for Cold Freshwater Habitat. Previously considered water quality data was reevaluated according to new guidelines as part of this assessment. Lines of evidence have been replaced. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero out of 53 samples, reported as a total concentration or with the fraction not reported, exceed the guideline for Cold Freshwater Habitat and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171134, Diuron	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189157

Pollutant:

Diuron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the 4-day average concentration of diuron does not exceed 1.3 ug/L (UC Davis Aquatic Life Criteria).

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: III. Diuron. Reviews of Environmental Contamination and Toxicology 216:105-141.

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 171134, Diuron	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353029

Pollutant:

Diuron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 16 samples exceeded the water quality threshold for Diuron.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the 4-day average concentration of diuron does not exceed 1.3 ug/L (UC Davis Aquatic Life Criteria).

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: III. Diuron. Reviews of Environmental Contamination and Toxicology 216:105-141.

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRSFD (Merced River @ Santa Fe).

Temporal Representation:

The samples were collected between the dates of 2007-02-12 and 2008-09-23

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 171134, Diuron	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189073

Pollutant:

Diuron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the 4-day average concentration of diuron does not exceed 1.3 ug/L (UC Davis Aquatic Life Criteria).

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: III. Diuron. Reviews of Environmental Contamination and Toxicology 216:105-141.

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 171134, Diuron	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189115

Pollutant:

Diuron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the 4-day average concentration of diuron does not exceed 1.3 ug/L (UC Davis Aquatic Life Criteria).

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: III. Diuron. Reviews of Environmental Contamination and Toxicology 216:105-141.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	171141	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Dodine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. Previously considered water quality data was reevaluated according to new guidelines as part of this assessment. Lines of evidence have been replaced.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171141, Dodine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353046

Pollutant:

Dodine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for dodine is the USEPA Aquatic Life Benchmark of 0.08 ug/L for nonvascular plants.

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-04-09 and 2018-04-09

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):


DECISION ID	116900	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Dyfonate (Fonofos or Fonophos)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	This decision was made by SWRCB staff.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116900, Dyfonate (Fonofos or Fonophos)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190052

Pollutant:

Dyfonate (Fonofos or Fonophos)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Fonofos is the maximum acceptable toxicant concentration (MATC) of 0.45 ug/L. The MATC is calculated as the geometric mean of the lowest observed effect concentration (LOEC) of 0.64 ug/L and the no observed effect concentration (NOEC) of 0.31 ug/L, as determined in a 21 day toxicity study with the water flea, Daphnia magna. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	164561	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Endosulfan sulfate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 164561, Endosulfan sulfate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189598

Pollutant:

Endosulfan sulfate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Endosulfan Sulfate.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The endosulfan sulfate criteria for the protection of human health from the consumption of water and organisms is 110 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164561, Endosulfan sulfate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189601

Pollutant:

Endosulfan sulfate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Endosulfan Sulfate.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria toxicity threshold for endosulfan sulfate for freshwater aquatic life protection is 0.056 ug/l (24 hour average)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	164562	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Endrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 164562, Endrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189304

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Endrin criteria for the protection of human health from the consumption of water and organisms is 0.76 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164562, Endrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189459

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endrin criteria for the protection of human health from the consumption of water and organisms is 0.76 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164562, Endrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189606

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Endrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.036 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164562, Endrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189461

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.036 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164562, Endrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196439

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Endrin from MacDonald et al., 2000a which states that the probable effect concentration for Endrin is 207 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164562, Endrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67067

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The sample result did not exceed the evaluation guideline value (207 ug/Kg dry weight).

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for endrin is 207 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAMP (2002) was used for data before Septemper 1, 2008 and SWAMP QAPP (2008) was thereafter.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 164562, Endrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67069

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.036 ug/L. (California Toxics Rule, 2000)

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-4/21/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164562, Endrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67068

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endrin criterion for the protection of human health from the consumption of water and organisms is 0.76 ug/L. (California Toxics Rule, 2000)

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-4/21/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.


DECISION ID	164563	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Endrin aldehyde
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 164563, Endrin aldehyde	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189692

Pollutant:

Endrin aldehyde

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Endrin Aldehyde.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Endrin Aldehyde criteria for the protection of human health from the consumption of water and organisms is 0.76 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158900	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Esfenvalerate/Fenvalerate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 67078 has been replaced by LOE 214884 due to a reassessment of data.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158900, Esfenvalerate/Fenvalerate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189836

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-01-10 to 2018-06-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158900, Esfenvalerate/Fenvalerate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196571

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for esfenvalerate/fenvalerate, 0.15 ug/g, is one-tenth of the median lethal concentration (LC50; 1.5 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2011-09-08 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158900, Esfenvalerate/Fenvalerate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189858

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-18 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158900, Esfenvalerate/Fenvalerate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331514

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 17 samples were collected, 17 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for esfenvalerate is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Esfenvalerate were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2021-09-22

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158900, Esfenvalerate/Fenvalerate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67079

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline value for esfenvalerate/fenvalerate, 0.15 ug/g OC, is one-tenth of the median lethal concentration for H. azteca (LC50; 1.5 ug/g OC). The LC50 (1.5 ug/g OC) is the geometric mean of OC-normalized LC50 values for esfenvalerate/fenvalerate from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158900, Esfenvalerate/Fenvalerate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196520

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535XMRAOR.

Temporal Representation:

Date for this waterbody were collected over the date range 2018-09-11 to 2018-09-11

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158900, Esfenvalerate/Fenvalerate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

214884

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for Esfenvalerate is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Esfenvalerate were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used. The evaluation guideline for fenvalerate, 0.113 ug/L, is one-tenth of the median lethal concentration (LC50 = 1.13 ug/L) as determined in a 96 hour toxicity test using the fathead minnow, Pimephales promelas. (USEPA OPP Ecotoxicity database)

Guideline Reference:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/11/2007.

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.


DECISION ID	116936	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Ethion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116936, Ethion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189940

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria toxicity threshold for ethion for freshwater aquatic life protection is 0.02 ug/l

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-18 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	116948	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Ethoprop
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116948, Ethoprop	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189680

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	116953	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Fenitrothion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	This decision was made by SWRCB staff.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116953, Fenitrothion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189727

Pollutant:

Fenitrothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Fenitrothion is the USEPA Aquatic Life Benchmark of 0.087 ug/L for chronic toxicity in invertebrates (7 day average).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	158899	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Fenpropathrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 189828 has been replaced by LOE 353055 due to a reassessment of data.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158899, Fenpropathrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67080

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline value for fenpropathrin, 0.1 ug/g OC, is one-tenth of the median lethal concentration for H. azteca (LC50; one ug/g OC). The LC50 is the geometric mean of OC-normalized LC50 values for fenpropathrin (Ding et al. 2011).

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158899, Fenpropathrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196559

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for fenpropathrin, 0.1 ug/g, is one-tenth of the median lethal concentration (LC50; 1 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1 ug/g is the geometric mean of LC50 values for fenpropathrin from Ding et al. ( 2011).

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2011-09-08 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158899, Fenpropathrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331556

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

QAPP Reference for Irrigated Lands Regulatory Program

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2020-08-11

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158899, Fenpropathrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353055

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 158899, Fenpropathrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196557

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535XMRAOR.

Temporal Representation:

Date for this waterbody were collected over the date range 2018-09-11 to 2018-09-11

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	116973	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Flumioxazin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	This decision was made by SWRCB staff.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116973, Flumioxazin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189951

Pollutant:

Flumioxazin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Flumioxazin is the USEPA Aquatic Life Benchmark of 0.49 ug/L for a vascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR)

Temporal Representation:

The samples were collected between the dates of 2018-02-13 and 2018-03-05

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):


DECISION ID	158877	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Glyphosate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. LOE 67086 has been replaced by LOE 221810 due to a reassessment of data using a U.S. EPA aquatic life benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158877, Glyphosate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67087

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for Glyphosate is 700 ug/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158877, Glyphosate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190172

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Glyphosate is the USEPA Aquatic Life Benchmark of 11900 ug/L for a vascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR)

Temporal Representation:

The samples were collected between the dates of 2018-01-10 and 2018-07-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158877, Glyphosate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190097

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Glyphosate incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.7 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-07-14

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158877, Glyphosate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331588

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for glyphosate is the USEPA Aquatic Life Benchmark of 11900 ug/L for a vascular plant (acute).

Guideline Reference:

QAPP Reference for Irrigated Lands Regulatory Program

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2019-07-09

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158877, Glyphosate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190240

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Glyphosate is the USEPA Aquatic Life Benchmark of 11900 ug/L for a vascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-07-14

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158877, Glyphosate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

221810

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Glyphosate is the USEPA Aquatic Life Benchmark of 11900 ug/L for a vascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2006-05-16 and 2008-09-23

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158877, Glyphosate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331582

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Glyphosate incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.7 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2019-07-09

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158877, Glyphosate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190121

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Glyphosate incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.7 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR)

Temporal Representation:

The samples were collected between the dates of 2018-01-10 and 2018-07-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	164565	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Heptachlor
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 164565, Heptachlor	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67089

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Heptachlor. Nine samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Heptachlor criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164565, Heptachlor	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67088

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Heptachlor. Nine samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The CTR objective for Heptachlor to protect human health from the consumption of water and organisms is 0.00021 ug/L.

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164565, Heptachlor	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190368

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor. Although a total of 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Heptachlor criteria for the protection of human health from the consumption of water and organisms is 0.00021 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-14 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164565, Heptachlor	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190472

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor. Although a total of 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Heptachlor criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-14 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164565, Heptachlor	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190412

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Heptachlor criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164565, Heptachlor	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190370

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Heptachlor criteria for the protection of human health from the consumption of water and organisms is 0.00021 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-04-01 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	164566	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Heptachlor epoxide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 164566, Heptachlor epoxide	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67102

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Heptachlor epoxide. Nine samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Heptachlor Epoxide criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164566, Heptachlor epoxide	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67090

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Heptachlor epoxide. Nine samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The CTR objective for Heptachlor epoxide to protect human health from the consumption of water and organisms is 0.0001 ug/L.

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164566, Heptachlor epoxide	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190556

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor Epoxide. Although a total of 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Heptachlor Epoxide criteria for the protection of human health from the consumption of water and organisms is 0.0001 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-14 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164566, Heptachlor epoxide	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190335

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor Epoxide. Although a total of 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Heptachlor Epoxide criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-14 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164566, Heptachlor epoxide	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190377

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Heptachlor Epoxide.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Heptachlor Epoxide criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164566, Heptachlor epoxide	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190334

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor Epoxide. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Heptachlor Epoxide criteria for the protection of human health from the consumption of water and organisms is 0.0001 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-04-01 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	164567	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Hexachlorobenzene/ HCB
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 164567, Hexachlorobenzene/ HCB	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190422

Pollutant:

Hexachlorobenzene/ HCB

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Hexachlorobenzene. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Hexachlorobenzene criteria for the protection of human health from the consumption of water and organisms is 0.00075 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-04-01 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	164574	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Hexachlorocyclohexane (HCH), alpha
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 164574, Hexachlorocyclohexane (HCH), alpha	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190108

Pollutant:

Hexachlorocyclohexane (HCH), alpha

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The alpha-HCH (alpha-BHC) criteria for the protection of human health from consumption of water and organisms is 0.0039 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164574, Hexachlorocyclohexane (HCH), alpha	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190126

Pollutant:

Hexachlorocyclohexane (HCH), alpha

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for HCH, alpha-. Although a total of 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The alpha-HCH (alpha-BHC) criteria for the protection of human health from consumption of water and organisms is 0.0039 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-14 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	164573	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Hexachlorocyclohexane (HCH), beta
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 164573, Hexachlorocyclohexane (HCH), beta	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190186

Pollutant:

Hexachlorocyclohexane (HCH), beta

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The BHC, beta criteria for the protection of human health from the consumption of water and organisms is 0.014 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164573, Hexachlorocyclohexane (HCH), beta	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190162

Pollutant:

Hexachlorocyclohexane (HCH), beta

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The BHC, beta criteria for the protection of human health from the consumption of water and organisms is 0.014 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	116881	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Hydroxyatrazine, 2-
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116881, Hydroxyatrazine, 2-	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190609

Pollutant:

Hydroxyatrazine, 2-

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Hydroxyatrazine, 2-.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Hydroxyatrazine, 2- is the USEPA Aquatic Life Benchmark of 1,500 ug/L for a fish (acute) for Triazine HA degradate.

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116881, Hydroxyatrazine, 2-	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190607

Pollutant:

Hydroxyatrazine, 2-

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Hydroxyatrazine, 2-.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Hydroxyatrazine, 2- is the USEPA Aquatic Life Benchmark of 1,500 ug/L for a fish (acute) for Triazine HA degradate.

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	158890	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Imidacloprid
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158890, Imidacloprid	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331648

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Imidacloprid. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2019-04-16 and 2019-05-14

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158890, Imidacloprid	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190736

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Imidacloprid. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L. (UC Davis Water Quality Criteria)

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-04-09 to 2018-05-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	165304	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Indicator Bacteria
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Seven lines of evidence are available in the administrative record to assess this pollutant for Water Contact Recreation (REC-1). Historical bacteria LOEs (pre-2010 data) have been removed and data has been compared to the newer E. coli bacteria water quality objective. Seven of the 91 samples, expressed as a Statistical Threshold Value, exceed the objective for REC-1. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Seven of the 91 samples, expressed as a Statistical Threshold Value, exceed the objective for REC-1 and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 165304, Indicator Bacteria	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

194742

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly).

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 535MER210

Temporal Representation:

The samples were collected between the days of 2010-08-31 and 2014-01-02 .

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 165304, Indicator Bacteria	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

194695

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and the results are as follows: 1 of the 10 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 535MER546

Temporal Representation:

The samples were collected between the days of 2010-11-08 and 2014-05-06 .

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 165304, Indicator Bacteria	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

194460

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and the results are as follows: 3 of the 52 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 535XMRSFD

Temporal Representation:

The samples were collected between the days of 2010-09-14 and 2015-09-08 .

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 165304, Indicator Bacteria	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

194458

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and the results are as follows: 2 of the 12 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 535XMRAOR

Temporal Representation:

The samples were collected between the days of 2017-10-10 and 2018-09-11 .

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 165304, Indicator Bacteria	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

329433

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and the results are as follows: 1 of the 11 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The bacteria water quality objective to protect the REC-1 beneficial use where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018).

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the days of 2018-10-09 and 2019-09-10 .

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 165304, Indicator Bacteria	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

329482

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and the results are as follows: 0 of the 3 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Benthic, Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the days of 2017-05-31 and 2017-10-26 .

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Benthic, Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

Line of Evidence (LOE) for Decision ID 165304, Indicator Bacteria	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

329468

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 535MER210 (Merced River at Henderson Park).

Temporal Representation:

The samples were collected between the days of 2017-06-27 and 2017-06-27 .

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):


DECISION ID	158878	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Lead
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158878, Lead	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67103

Pollutant:

Lead

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the evaluation guideline value for Lead.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for lead is 128 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158878, Lead	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67104

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [ Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-4/21/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158878, Lead	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

6345

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Zero of the 14 samples collected by the Surface Water Ambient Monitoring Program exceeded the calculated CTR CMC for dissolved lead

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Dissolved lead levels should not exceed the calculated CTR value based on the formula: Criteria Maximum Concentration (1-hour Average, dissolved)=(EXP(1.273*LN(hardness)-1.46))*(1.46203-(LN(hardness)*0.145712))

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the Merced River at River Road

Temporal Representation:

The samples were collected between October 26, 2000 and November 20, 2002

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158878, Lead	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

333215

Pollutant:

Lead

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546 (Merced River @ River Road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-08-27 to 2020-08-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 158878, Lead	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190872

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: At a minimum, water designated for use as MUN shall not contain lead in excess of 0.015 mg/l.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2015-02-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158878, Lead	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190914

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2015-02-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158878, Lead	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196723

Pollutant:

Lead

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Lead from MacDonald et al., 2000a which states that the probable effect concentration for Lead is 128 mg/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2018-08-22

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158878, Lead	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190868

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: At a minimum, water designated for use as MUN shall not contain lead in excess of 0.015 mg/l.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2014-02-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158878, Lead	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

20791

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Zero of the 15 samples collected by the Surface Water Ambient Monitoring Program exceeded the Primary MCL of 15 ug/L for total lead

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Total lead levels should not exceed 15 ug/L (Department of Public Health Primary MCL)

Objective/Criterion Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the Merced River at River Road

Temporal Representation:

The samples were collected between June 24, 1998 and June 30, 2003

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):


DECISION ID	164568	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Eight lines of evidence are available in the administrative record to assess this pollutant. Zero of the 23 samples, reported as "Total" fraction or as fraction reported as "None," exceed the objective for the COLD beneficial use. Zero of the 23 samples, reported as "Total" fraction or as fraction reported as "None," exceed the objective for the MUN beneficial use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 23 samples, reported as "Total" fraction or as fraction reported as "None," exceed the objective for the COLD beneficial use. Zero of the 23 samples, reported as "Total" fraction or as fraction reported as "None," exceed the objective for the MUN beneficial use. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 164568, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190137

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The gamma-BHC (Lindane) criterion maximum concentration to protect aquatic life in freshwater is 0.95 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164568, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190166

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The BHC, gamma(Lindane) criteria for the protection of human health from the consumption of water and organisms is 0.019 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164568, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190090

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The gamma-BHC (Lindane) criterion maximum concentration to protect aquatic life in freshwater is 0.95 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164568, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196681

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Stream Pollution Trends data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the evaluation guideline for HCH, gamma-. Although a total of 5 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Lindane from MacDonald et al., 2000a which states that the probable effect concentration for Lindane is 4.99 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164568, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190165

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The BHC, gamma(Lindane) criteria for the protection of human health from the consumption of water and organisms is 0.019 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164568, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67105

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

One sediment sample was collected and analyzed for the SWAMP.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for Lindane (gamma-HCH) is 4.99 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 164568, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67107

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The gamma-HCH (Lindane) criterion maximum concentration to protect aquatic life in freshwater is 0.95 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164568, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67106

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for HCH, gamma (Lindane) is 0.2 ug/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.


DECISION ID	116911	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Linuron
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 67118 has been replaced by LOE 222004 due to a reassessment of data using a U.S. EPA aquatic life benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116911, Linuron	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191150

Pollutant:

Linuron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Linuron is the USEPA Aquatic Life Benchmark of 0.09 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116911, Linuron	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191273

Pollutant:

Linuron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Linuron is the USEPA Aquatic Life Benchmark of 0.09 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116911, Linuron	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190993

Pollutant:

Linuron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Linuron. Although a total of 36 samples were collected, 36 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Linuron is the USEPA Aquatic Life Benchmark of 0.09 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-01-18 to 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116911, Linuron	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

222004

Pollutant:

Linuron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Linuron. Although a total of 21 samples were collected, 21 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Linuron is the USEPA Aquatic Life Benchmark of 0.09 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2006-05-16 to 2008-09-23

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):


DECISION ID	158879	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Malathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 67119 has been replaced by LOE 353082 due to a reassessment of data.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158879, Malathion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191173

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the 4-day average concentration of malathion does not exceed 0.028 ug/L (UC Davis Aquatic Life Criteria).

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-18 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158879, Malathion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331767

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the 4-day average concentration of malathion does not exceed 0.028 ug/L (UC Davis Aquatic Life Criteria).

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-10-09 and 2019-09-10

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158879, Malathion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353082

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 24 samples were collected, 24 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the 4-day average concentration of malathion does not exceed 0.028 ug/L (UC Davis Aquatic Life Criteria).

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRSFD (Merced River @ Santa Fe).

Temporal Representation:

The samples were collected between the dates of 2007-02-12 and 2009-05-19

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158879, Malathion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190981

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 35 samples were collected, 35 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the 4-day average concentration of malathion does not exceed 0.028 ug/L (UC Davis Aquatic Life Criteria).

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-01-18 to 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	116943	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Methidathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. LOE 67121 has been replaced by LOE 222031 due to a reassessment of data using a U.S. EPA aquatic life benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116943, Methidathion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191350

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116943, Methidathion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

222031

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 29 samples exceeded the water quality threshold for Methidathion.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2006-05-16 and 2009-05-19

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):


DECISION ID	116938	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Methiocarb
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. LOE 67129 has been replaced by LOE 221926 due to a reassessment of data using a U.S. EPA aquatic life benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116938, Methiocarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191580

Pollutant:

Methiocarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Methiocarb is the USEPA Aquatic Life Benchmark of 2.75 ug/L for a invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116938, Methiocarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

221926

Pollutant:

Methiocarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Methiocarb is the USEPA Aquatic Life Benchmark of 2.75 ug/L for a invertebrate (chronic).

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2006-05-16 and 2008-09-23

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116938, Methiocarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191418

Pollutant:

Methiocarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Methiocarb is the USEPA Aquatic Life Benchmark of 2.75 ug/L for a invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116938, Methiocarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191298

Pollutant:

Methiocarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Methiocarb is the USEPA Aquatic Life Benchmark of 2.75 ug/L for a invertebrate (chronic).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):


DECISION ID	116939	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Methomyl
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Zero of the one samples exceed the evaluation guideline for Cold Freshwater Habitat in the dissolved fraction. Zero of the 53 samples exceed the evaluation guideline for Cold Freshwater Habitat in the total/unspecified fraction. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the one samples exceed the evaluation guideline for Cold Freshwater Habitat in the dissolved fraction. Zero of the 53 samples exceed the evaluation guideline for Cold Freshwater Habitat in the total/unspecified fraction. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116939, Methomyl	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67130

Pollutant:

Methomyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The criteria continuous concentration for Methomyl in the San Joaquin River system is 0.5 ug/L (4-day average). (CDFG, 1996)

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116939, Methomyl	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191319

Pollutant:

Methomyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The Basin Plan states: \Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide...\" The criteria continuous concentration for Methomyl in the San Joaquin River system is 0.5 ug/L (4-day average). "

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116939, Methomyl	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191585

Pollutant:

Methomyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116939, Methomyl	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191360

Pollutant:

Methomyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	116913	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Methoxychlor
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. Zero of 33 samples exceed the water quality criteria for MUN and zero of 33 samples exceed the criteria for COLD. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of 33 samples exceed the water quality criteria for MUN and zero of 33 samples exceed the criteria for COLD and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116913, Methoxychlor	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67132

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the Executive Officer (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-4/21/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 116913, Methoxychlor	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67131

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for Methoxychlor, 30 ug/L, is incorporated by reference into the (Water Quality Control Plan, Central Valley Region, Sacramento and San Joaquin Basins).

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-4/21/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 116913, Methoxychlor	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191410

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Methoxychlor incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.03 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 116913, Methoxychlor	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191389

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria toxicity threshold for methoxychlor for freshwater aquatic life protection is 0.03 ug/l.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116913, Methoxychlor	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191386

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria toxicity threshold for methoxychlor for freshwater aquatic life protection is 0.03 ug/l.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 116913, Methoxychlor	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191614

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Methoxychlor incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.03 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	116914	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Methyl Parathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116914, Methyl Parathion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192985

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Methyl. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for Methyl Parathion is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System. California Department of Fish and Game. Environmental Services Division. Administrative Report 92-1

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-18 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116914, Methyl Parathion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192925

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Methyl. Although a total of 35 samples were collected, 35 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for Methyl Parathion is 0.08 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-01-18 to 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 116914, Methyl Parathion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196872

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for methyl parathion, 0.6 ug/g, is one-tenth of the median lethal concentration (LC50; 6 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 6 ug/g is the geometric mean of LC50 values for methyl parathion from Ding et al. (2011).

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116914, Methyl Parathion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67143

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline value for methyl parathion, 0.6 ug/g OC, is one-tenth of the median lethal concentration for H. azteca (LC50; 6 ug/g OC). The LC50 is the geometric mean of OC-normalized LC50 values for methyl parathion (Ding et al. 2011).

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 116914, Methyl Parathion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67142

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Parathion, Methyl. Twenty-four samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for Methyl Parathion is 0.08 ug/L.

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-5/19/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.


DECISION ID	116915	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Mirex
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116915, Mirex	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191675

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Mirex. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria criterion continuous concentraion for mirex for freshwater aquatic life protection is 0.001 ug/l

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-04-01 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	116916	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Molinate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. LOE 67144 has been replaced by LOE 221830 due to a reassessment of data using a U.S. EPA aquatic life benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116916, Molinate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

221830

Pollutant:

Molinate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The California Department of Fish and Wildlife hazard assessment instantaneous criterion (1-hour average) for the protection of aquatic life for Molinate is 13 ug/L.

Guideline Reference:

Hazard Assessment of the Rice Herbicides Molinate and Thiobencarb to Aquatic Organisms in the Sacramento River System. Administrative Report 90-1. California Department of Fish and Game, Environmental Services Division

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2006-05-16 and 2008-09-23

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 116916, Molinate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191795

Pollutant:

Molinate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The California Department of Fish and Wildlife hazard assessment instantaneous criterion (1-hour average) for the protection of aquatic life for Molinate is 13 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116916, Molinate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191772

Pollutant:

Molinate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Molinate incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.02 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116916, Molinate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67145

Pollutant:

Molinate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for Molinate is 20 ug/L .

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 116916, Molinate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191749

Pollutant:

Molinate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Molinate incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.02 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116916, Molinate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191747

Pollutant:

Molinate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The California Department of Fish and Wildlife hazard assessment instantaneous criterion (1-hour average) for the protection of aquatic life for Molinate is 13 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158880	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Nickel
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158880, Nickel	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

333233

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546 (Merced River @ River Road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-08-27 to 2020-08-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 158880, Nickel	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191829

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158880, Nickel	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191685

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for nickel incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.1 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158880, Nickel	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

191928

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for nickel incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.1 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2011-12-06

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158880, Nickel	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

20847

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Zero of the 15 samples collected by the Surface Water Ambient Monitoring Program exceeded the Primary MCL of 100 ug/L for total nickel

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Total nickel levels should not exceed 100 ug/L (Department of Public Health Primary MCL)

Objective/Criterion Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the Merced River at River Road

Temporal Representation:

The samples were collected between June 24, 1998 to June 30, 2003

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158880, Nickel	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196688

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Nickel from MacDonald et al., 2000a which states that the probable effect concentration for Nickel is 48.6 mg/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2018-08-22

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158880, Nickel	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67155

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the evaluation guideline value for Nickel.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for nickel is 48.6 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158880, Nickel	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67156

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for nickel is 0.1 mg/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-5/19/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158880, Nickel	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67157

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed AgWaiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 8 samples exceed the criterion for Nickel.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [ Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-5/19/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158880, Nickel	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

6352

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Zero of the 14 samples collected by the Surface Water Ambient Monitoring Program exceeded the calculated CTR CMC for dissolved nickel

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Dissolved nickel levels should not exceed the calculated CTR limit based on the formula: Criteria Maximum Concentration (1-hour Average, dissolved)=(EXP(0.846*LN(hardness)+2.255))*(0.998)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the Merced River at River Road

Temporal Representation:

The samples were collected between October 26, 2000, and November 20, 2002

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158880, Nickel	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67146

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the evaluation guideline value for Nickel.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for nickel is 48.6 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	158881	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158881, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192225

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nitrate + nitrite (as N) incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 10 mg/L (California Code of Regulations, Title 22).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158881, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192117

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DFW_ABL_Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nitrate + Nitrite as N.

Data Reference:

Habitat, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535CR1042)

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158881, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67158

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 22 samples exceed the criterion for Nitrate/Nitrite as N.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for nitrate + nitrite (as N) is 10.0 mg/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158881, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192264

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR)

Temporal Representation:

The samples were collected between the dates of 2017-10-10 and 2018-09-11

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158881, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331928

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Primary California Maximum Contaminant Level for nitrate + nitrite (as N) incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 10 mg/L (California Code of Regulations, Title 22).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-10-09 and 2019-09-10

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program


DECISION ID	128292	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Nitrogen, Nitrate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the 17 samples exceed the objective for Municipal & Domestic Supply. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 17 samples exceed the objective for Municipal & Domestic Supply and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 128292, Nitrogen, Nitrate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67159

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for nitrate (NO3 as N) is 10.0 mg/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 128292, Nitrogen, Nitrate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192045

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Habitat, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Nitrate as N incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 10 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535CR1042)

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	169080	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Nitrogen, Nitrite
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 169080, Nitrogen, Nitrite	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192548

Pollutant:

Nitrogen, Nitrite

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Habitat, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Nitrite as N incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 1000 ug/L .

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535CR1042)

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169080, Nitrogen, Nitrite	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

329980

Pollutant:

Nitrogen, Nitrite

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Nitrite as N incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 1000 ug/L .

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-NRS_CA-10948 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2018-07-16 and 2018-07-16

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Data for Various Pollutants in East San Joaquin, 2004-2009.

Line of Evidence (LOE) for Decision ID 169080, Nitrogen, Nitrite	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67160

Pollutant:

Nitrogen, Nitrite

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for nitrite (as N) is 1 mg/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.


DECISION ID	116940	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Oryzalin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116940, Oryzalin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192462

Pollutant:

Oryzalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Oryzalin is the USEPA Aquatic Life Benchmark of 13 ug/L for a vascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR)

Temporal Representation:

The samples were collected between the dates of 2018-04-09 and 2018-07-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):


DECISION ID	171135	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Oxadiazon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. Previously considered water quality data was reevaluated according to new guidelines as part of this assessment. Lines of evidence have been replaced.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171135, Oxadiazon	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353133

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.


DECISION ID	116921	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Oxamyl (Vydate)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Seven lines of evidence are available in the administrative record to assess this pollutant. Four lines of evidence are available to assess for MUN. Three lines of evidence are available to assess for COLD. Zero out of one sample, reported as a dissolved concentration, exceeds the objective for MUN. Zero of the 53 samples, reported as a total concentration or with the fraction not reported, exceeds the objective for MUN. Zero out of one sample, reported as a dissolved concentration, exceeds the guideline for COLD. Zero of the 37 samples, reported as a total concentration, exceeds the guideline for COLD. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 53 samples, reported as a total concentration or with the fraction not reported, exceeds the objective for MUN. Zero of the 37 samples, reported as a total concentration, exceeds the guideline for COLD. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116921, Oxamyl (Vydate)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192717

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for oxamyl is the USEPA Aquatic Life Benchmark of 27 ug/L for chronic toxicity in invertebrates (7 day average).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116921, Oxamyl (Vydate)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192539

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for oxamyl is the USEPA Aquatic Life Benchmark of 27 ug/L for chronic toxicity in invertebrates (7 day average).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116921, Oxamyl (Vydate)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192538

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for oxamyl is the USEPA Aquatic Life Benchmark of 27 ug/L for chronic toxicity in invertebrates (7 day average).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116921, Oxamyl (Vydate)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192650

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Oxamyl incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.05 mg/L

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 116921, Oxamyl (Vydate)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192666

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Oxamyl incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.05 mg/L

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 116921, Oxamyl (Vydate)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

79626

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed ILRP data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 16 samples exceed the criterion for Oxamyl.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for Oxamyl incorporated by reference in the Water Quality Control Plan, Central Valley Region, Sacramento and San Joaquin Basins is 50 ug/L (Water Quality Control Plan, Central Valley Region, Sacramento and San Joaquin Basins).

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [ Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116921, Oxamyl (Vydate)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192446

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Oxamyl incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.05 mg/L

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158894	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Oxyfluorfen
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 192423 has been replaced by LOE 353146 due to a reassessment of data.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158894, Oxyfluorfen	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332008

Pollutant:

Oxyfluorfen

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of oxyfluorfen does not exceed 0.14 ug/L (Bower, et al. 2017).

Guideline Reference:

Water quality criteria report for Oxyfluorfen. Phase III: application of the pesticide water quality criteria methodology.

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-07 and 2019-02-06

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158894, Oxyfluorfen	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353146

Pollutant:

Oxyfluorfen

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of oxyfluorfen does not exceed 0.14 ug/L (Bower, et al. 2017).

Guideline Reference:

Water quality criteria report for Oxyfluorfen. Phase III: application of the pesticide water quality criteria methodology.

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2017-10-10 and 2018-01-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	164570	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	PCBs (Polychlorinated biphenyls)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 164570, PCBs (Polychlorinated biphenyls)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192778

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for PCBs (Polychlorinated biphenyls). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The PCBs criteria for the protection of human health from the consumption of water and organisms is 0.00017 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-18 to 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164570, PCBs (Polychlorinated biphenyls)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196631

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Total PCBs from MacDonald et al., 2000a which states that the probable effect concentration for Total PCBs is 676 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164570, PCBs (Polychlorinated biphenyls)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67185

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Zero of 1 sample collected for Total PCBs exceeded the evaluation guideline.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain substances in concentrations that result in the deposition of material that causes nuisance or adversely affects beneficial uses (Water Quality Control Plan for the Sacramento and San Joaquin River Basins).

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for total PCB is 676 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected at the following station 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected on 7/23/2008.

Environmental Conditions:

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	158901	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Paraquat
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158901, Paraquat	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332267

Pollutant:

Paraquat

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Paraquat. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for paraquat is the USEPA Aquatic Life Benchmark of 0.396 ug/L for a nonvascular plant (acute) for Paraquat dichloride.

Guideline Reference:

QAPP Reference for Irrigated Lands Regulatory Program

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2019-07-09 and 2019-07-09

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158901, Paraquat	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192652

Pollutant:

Paraquat

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Paraquat. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Paraquat is the USEPA Aquatic Life Benchmark of 0.396 ug/L for a nonvascular plant (acute) for Paraquat dichloride.

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-01-10 to 2018-07-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158901, Paraquat	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

222268

Pollutant:

Paraquat

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Paraquat. Although a total of 21 samples were collected, 21 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Paraquat is the USEPA Aquatic Life Benchmark of 0.396 ug/L for a nonvascular plant (acute) for Paraquat dichloride.

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2006-05-16 to 2008-09-23

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158901, Paraquat	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192651

Pollutant:

Paraquat

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Paraquat. Although a total of 9 samples were collected, 9 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Paraquat is the USEPA Aquatic Life Benchmark of 0.396 ug/L for a nonvascular plant (acute) for Paraquat dichloride.

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-01-18 to 2015-07-14

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):


DECISION ID	116923	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Parathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116923, Parathion	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192795

Pollutant:

Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Ethyl. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA recommended freshwater aquatic life ambient water quality chronic criteria for Parathion is 0.013 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-18 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158895	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Pendimethalin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 158895, Pendimethalin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332314

Pollutant:

Pendimethalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for pendimethalin is the USEPA Aquatic Life Benchmark of 5.2 ug/L for a nonvascular plant (acute).

Guideline Reference:

QAPP Reference for Irrigated Lands Regulatory Program

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2019-05-14

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158895, Pendimethalin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192885

Pollutant:

Pendimethalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Pendimethalin is the USEPA Aquatic Life Benchmark of 5.2 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR)

Temporal Representation:

The samples were collected between the dates of 2017-10-10 and 2018-05-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):


DECISION ID	158902	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Permethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 67186 has been replaced by LOE 214885 due to a reassessment of data.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158902, Permethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196919

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for permethrin, 0.89 ug/g, is one-tenth of the median lethal concentration (LC50; 8.9 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2011-09-08 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158902, Permethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196815

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535XMRAOR.

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-11 to 2018-09-11

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158902, Permethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192762

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for Permethrin is 1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Permethrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-18 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158902, Permethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

214885

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Permethrin, Total. Eight samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/11/2007.

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158902, Permethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192785

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-01-10 to 2018-01-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158902, Permethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332347

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 16 samples were collected, 16 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for permethrin is 1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Permethrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2021-09-22

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158902, Permethrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67187

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline value for permethrin, 0.89 ug/g OC, is one-tenth of the median lethal concentration for H. azteca (LC50; 8.9 ug/g OC). The LC50 is the geometric mean of OC-normalized LC50 values for permethrin (Amweg et al. 2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	116950	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Phorate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. LOE 67202 has been replaced by LOE 222217 due to a reassessment of data using a U.S. EPA aquatic life benchmark.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116950, Phorate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

222217

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 29 samples exceeded the water quality threshold for Phorate.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2006-05-16 and 2009-05-19

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116950, Phorate	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193058

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):


DECISION ID	171138	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Phosmet
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the sixty-four samples exceed the evaluation guideline for COLD. Previously considered water quality data was reevaluated according to new guidelines as part of this assessment. Lines of evidence have been replaced. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the sixty-four samples exceed the evaluation guideline for COLD and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171138, Phosmet	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353204

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 29 samples exceeded the water quality threshold for Phosmet.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRSFD (Merced River @ Santa Fe).

Temporal Representation:

The samples were collected between the dates of 2006-05-16 and 2009-05-19

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171138, Phosmet	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353178

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRSFD (Merced River @ Santa Fe).

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):


DECISION ID	116926	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Prometon (Prometone)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116926, Prometon (Prometone)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193157

Pollutant:

Prometon (Prometone)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Prometon (Prometone) is the USEPA Aquatic Life Benchmark of 98 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116926, Prometon (Prometone)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193159

Pollutant:

Prometon (Prometone)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Prometon (Prometone) is the USEPA Aquatic Life Benchmark of 98 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	171137	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Prometryn
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. Previously considered water quality data was reevaluated according to new guidelines as part of this assessment. Lines of evidence have been replaced.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171137, Prometryn	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353232

Pollutant:

Prometryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of Prometryn does not exceed 0.562 ug/L in the water column more than once every three years on average (Bower, et al. 2017).

Guideline Reference:

Water Quality Criteria Report for Prometryn Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis.

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 171137, Prometryn	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353224

Pollutant:

Prometryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Prometryn Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis.

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.


DECISION ID	116956	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Propazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116956, Propazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193323

Pollutant:

Propazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Propazine is the USEPA Aquatic Life Benchmark of 24.8 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116956, Propazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193343

Pollutant:

Propazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Propazine is the USEPA Aquatic Life Benchmark of 24.8 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	171140	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Propiconazole
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. Previously considered water quality data was reevaluated according to new guidelines as part of this assessment. Lines of evidence have been replaced.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171140, Propiconazole	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353246

Pollutant:

Propiconazole

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Propiconazole is the USEPA Aquatic Life Benchmark of 15 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-02-13 and 2018-02-13

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):


DECISION ID	158903	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Pyraclostrobin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 158903, Pyraclostrobin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332540

Pollutant:

Pyraclostrobin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for pyraclostrobin is the USEPA Aquatic Life Benchmark of 1.5 ug/L for a nonvascular plant (acute).

Guideline Reference:

QAPP Reference for Irrigated Lands Regulatory Program

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2019-02-06 and 2019-07-09

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):


DECISION ID	158889	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Pyrethroids
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.6 of the Listing Policy. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Six lines of evidence are available in the administrative record to assess this pollutant. Four of the seven samples exceed the evaluation guideline. Zero of nine samples exhibited sediment toxicity. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Four of the seven samples exceed the evaluation guideline. Zero of nine samples exhibited sediment toxicity. This sample size is insufficient to determine beneficial use support, with the power and confidence of the Listing Policy. There is an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that although this water body exceeds the guideline for sediment chemistry, this water body-pollutant combination should not be placed on the section 303(d) list because there is no associated evidence of sediment toxicity as required by the Listing Policy.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158889, Pyrethroids	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

197043

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective 1/10 LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535XMRAOR.

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-11 to 2018-09-11

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158889, Pyrethroids	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332621

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The summed ratios of the pyrethroid pesticides bifenthrin, cyfluthrin, cypermethrin, esfenvalerate, lambda-cyhalothrin, permethrin and their respective chronic concentration goals are not to exceed 1. If the freely dissolved concentrations of these pesticides were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2019-07-09 and 2021-09-22

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158889, Pyrethroids	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196998

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2011-09-08 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158889, Pyrethroids	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

347518

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 535MER546 ( Merced River @ River Road ).

Temporal Representation:

The samples were collected between the dates of 2018-08-22 and 2020-08-27.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

Line of Evidence (LOE) for Decision ID 158889, Pyrethroids	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332594

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 18 samples were collected, 18 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2021-09-22

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158889, Pyrethroids	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

333264

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546 (Merced River @ River Road).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-08-27 to 2019-08-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 158889, Pyrethroids	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

195740

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 station. Monitoring site: ( 535MER546 )

Temporal Representation:

The samples were collected between the dates of 2010-09-01 and 2018-08-22.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	116927	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Selenium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. Three lines of evidence are available to assess for MUN. Three lines of evidence are available to assess for COLD. Zero of the 105 samples, reported as a total concentration or with the fraction not reported, exceed the objective for MUN. One of the 105 samples, reported as a total concentration or with the fraction not reported, exceed the objective for COLD. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 105 samples, reported as a total concentration or with the fraction not reported, exceed the objective for MUN. One of the 105 samples, reported as a total concentration or with the fraction not reported, exceed the objective for COLD. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 116927, Selenium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193273

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for selenium incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.05 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 116927, Selenium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

21071

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

0 of the 69 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Selenium.

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

Evaluation Guideline:

Selenium levels should not exceed 50 ug/L (Department of Public Health Primary MCL)

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

Samples were collected at Merced River at River Road.

Temporal Representation:

The samples were collected from Jan 28 1998 to Nov 29 2005

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116927, Selenium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67211

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 20 samples exceed the criterion for Selenium.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for selenium is 0.05 mg/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-5/19/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 116927, Selenium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193452

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 116927, Selenium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67212

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.005 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-5/19/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 116927, Selenium	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

6936

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

0 of the 69 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Selenium.

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at Merced River at River Road.

Temporal Representation:

The samples were collected from Jan 28 1998 to Nov 29 2005

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):


DECISION ID	158884	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Simazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Nineteen lines of evidence are available in the administrative record to assess this pollutant. One of 289 samples reported as total fraction exceed the objective for MUN and zero of 59 samples reported as total fraction exceed the objective for COLD. Zero of one sample reported as dissolved concentration exceed the objective for MUN and zero of one sample reported as dissolved concentration exceed the objective for COLD. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of 289 samples reported as total fraction exceed the objective for MUN and zero of 59 samples reported as total fraction exceed the objective for COLD. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193413

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Simazine is the USEPA Aquatic Life Benchmark of 6 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193515

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Simazine incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.004 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193432

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Simazine is the USEPA Aquatic Life Benchmark of 6 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193634

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Simazine incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.004 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193434

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Simazine incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.004 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332682

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for simazine is the USEPA Aquatic Life Benchmark of 6 ug/L for a nonvascular plant (acute).

Guideline Reference:

QAPP Reference for Irrigated Lands Regulatory Program

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-07 and 2019-02-06

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22214

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

140

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

140 water samples were collected from Merced River from January 2000 through June 2005, representing 140 concentrations.1 of 140 concentrations exceeded the MCLs for drinking water standard (4 ug/L)

Data Reference:

Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005

Correspondence between the Department of Pesticide Regulation and Central Valley Regional Water Quality Control Board regarding water quality data for waterbodies in the Central Valley

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

At a minimum, water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels (MCLs) specified in the following provisions of Title 22 of the California Code of Regulations, which are incorporated by reference into this plan: Tables 64431-A (Inorganic Chemicals) and 64431-B (Fluoride) of Section 64431, Table 64444-A (Organic Chemicals) of Section 64444, and Tables 64449-A (Secondary Maximum Contaminant Levels-Consumer Acceptance Limits) and 64449-B (Secondary Maximum Contaminant Levels-Ranges) of Section 64449.

The Maximum Contaminant Level (MCL) for simazine is 4 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

Samples were collected from Merced River at River Road near Newman.

Temporal Representation:

Samples were collected at variable intervals (e.g. several samples per day, daily, and weekly) from January 2000 through June 2005.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Standard Operating Procedure for Conducting Surface Water Monitoring for Pesticides

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22213

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

5 water samples were collected from Merced River from July 2004 through September 2006, representing 5 concentrations.0 of 5 concentrations exceeded the MCL (4 ug/L).

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from Merced River at Santa Fe.

Temporal Representation:

Samples were collected weekly from July 2004 through September 2006.

Environmental Conditions:

QAPP Information:

Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332683

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Simazine incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.004 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2018-11-07 and 2019-02-06

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

222563

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Simazine is the USEPA Aquatic Life Benchmark of 6 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2006-05-16 and 2008-09-23

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67214

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for Simazine is 4 ug/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-9/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22197

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

19 water samples were collected from Merced River from March to August 2003, representing 19 concentrations.0 of 19 available concentrations exceeded the MCL (4 ug/L)

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected biweekly from March through August 2003.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22196

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

17 water samples were collected from Merced River from January to March 2003, representing 17 concentrations.0 of 17 available concentrations exceeded the MCL (4 ug/L)

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected daily during two storms from January through March 2003.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22212

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

13 water samples were collected from Merced River between March and August 2006, representing 13 concentrations. 0 of 13 available concentrations exceeded MCL (4 ug/L).

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected at weekly in March, July, and August 2006.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22199

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

13 water samples were collected from Merced River between March and August 2004, representing 13 concentrations.0 of 13 available concentrations exceeded the MCL (4 ug/L).

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected at weekly interval in March, July, and August 2004.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22198

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

10 water samples were collected from Merced River in February 2004, representing 10 concentrations.0 of 10 available concentrations exceeded the MCL (4 ug/L).

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected daily during two storms in February 2004.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22211

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

9 water samples were collected from Merced River between March and August 2005, representing 9 concentrations. 0 of 9 available concentrations exceeded the MCL (4 ug/L).

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

Temporal Representation:

Samples were collected at weekly in March, July, and August 2005.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22210

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

9 water samples were collected from Merced River in January and February 2005, representing 9 concentrations.0 of 9 available concentrations exceeded the MCL (4 ug/L).

Data Reference:

Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Samples were collected at daily in two storms in January and February 2005.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158884, Simazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193481

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Simazine is the USEPA Aquatic Life Benchmark of 6 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	158885	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Sulfates
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available LOE 193935 has been replaced by LOE 346672 due to a reassessment of data.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 158885, Sulfates	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330347

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Secondary MCL that is incorporated by reference into the Water Quality Control Plan for the Sacramento and San Joaquin River Basins specifies a range for sulfate of 250-500 mg/L assessed as an annual average.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-CARO-1042 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

WQX from the NWQMP for the 2026 Integrated Report in Region 5

Line of Evidence (LOE) for Decision ID 158885, Sulfates	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330313

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-NRS_CA-10948 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2018-07-16 and 2018-07-16

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Habitat, Water data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 158885, Sulfates	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346672

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DFW_ABL_Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the upper limit of the range for Sulfate. Additionally, 0 of the 1 samples fall within the range, and 1 of 1 samples fall below the threshold.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535CR1042 (Merced River -1042).

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	116957	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Terbuthylazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 116957, Terbuthylazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193946

Pollutant:

Terbuthylazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Terbuthylazine.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for terbuthylazine is the USEPA Aquatic Life Benchmark of 1800 ug/L for acute toxicity in fish (4 day average).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 116957, Terbuthylazine	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193969

Pollutant:

Terbuthylazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Terbuthylazine.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for terbuthylazine is the USEPA Aquatic Life Benchmark of 1800 ug/L for acute toxicity in fish (4 day average).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):


DECISION ID	166355	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Thiobencarb
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Zero samples exceeded the objectives, guidelines, or criteria for the Cold Freshwater Habitat beneficial uses applicable to this water segment-pollutant combination for the total pollutant. There is insufficient information for the dissolved pollutant and the Municipal and Domestic Supply beneficial use. The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 166355, Thiobencarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

194090

Pollutant:

Thiobencarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Thiobencarb is the USEPA Aquatic Life Benchmark of 1 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 166355, Thiobencarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346718

Pollutant:

Thiobencarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Secondary Maximum Contaminant Level for thiobencarb by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.001 mg/L assessed as an annual average.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 166355, Thiobencarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346720

Pollutant:

Thiobencarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 166355, Thiobencarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

194038

Pollutant:

Thiobencarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Thiobencarb is the USEPA Aquatic Life Benchmark of 1 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-03-18 and 2015-03-18

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 166355, Thiobencarb	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

222594

Pollutant:

Thiobencarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Thiobencarb is the USEPA Aquatic Life Benchmark of 1 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2006-05-16 and 2008-09-23

Environmental Conditions:

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):


DECISION ID	166354	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Total Dissolved Solids
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Data from previous cycles has been reassessed according to a new assessment method. LOEs have been replaced to reflect the new assessment. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 166354, Total Dissolved Solids	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346080

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the upper limit of the range for Total Dissolved Solids. Additionally, 0 of the 3 samples fall within the range, and 3 of 3 samples fall below the threshold.

Data Reference:

Monitoring Data from the Surface Water Ambient Monitoring Program (SWAMP), San Joaquin River Basin - 2007 Data Review

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Secondary MCL that is incorporated by reference into the Water Quality Control Plan for the Sacramento and San Joaquin River Basins specifies a range for total dissolved solids of 500-1000 mg/L assessed as an annual average.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: MER546 (MER546).

Temporal Representation:

The samples were collected between the dates of 1998-06-24 and 2001-11-28

Environmental Conditions:

QAPP Information:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 166354, Total Dissolved Solids	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346077

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP BDAT data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the upper limit of the range for Total Dissolved Solids. Additionally, 0 of the 3 samples fall within the range, and 3 of 3 samples fall below the threshold.

Data Reference:

SWAMP data entered by SWRCB into BDAT database

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 1998-06-24 and 2001-11-28

Environmental Conditions:

QAPP Information:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 166354, Total Dissolved Solids	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346110

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Ambient Water Program data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the upper limit of the range for Total Dissolved Solids. Additionally, 0 of the 3 samples fall within the range, and 3 of 3 samples fall below the threshold.

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: MER546 (MER546).

Temporal Representation:

The samples were collected between the dates of 1998-06-24 and 2001-11-28

Environmental Conditions:

QAPP Information:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 166354, Total Dissolved Solids	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346732

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the upper limit of the range for Total Dissolved Solids. Additionally, 0 of the 4 samples fall within the range, and 4 of 4 samples fall below the threshold.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRSFD (Merced River @ Santa Fe).

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2013-09-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	164571	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Toxaphene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 164571, Toxaphene	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67083

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Toxaphene. Nine samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Toxaphene criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0002 ug/L. (California Toxics Rule, 2000)

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164571, Toxaphene	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67082

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Toxaphene. Nine samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Toxaphene criterion for the protection of human health from the consumption of water and organisms is 0.00073 ug/L. (California Toxics Rule, 2000)

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164571, Toxaphene	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193930

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Toxaphene. Although a total of 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Toxaphene criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0002 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-14 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164571, Toxaphene	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193954

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Toxaphene. Although a total of 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Toxaphene criteria for the protection of human health from the consumption of water and organisms is 0.00073 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-14 to 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	171136	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Trifluralin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the Clean Water Act (CWA) section 303(d) List under section 3.1 of the Listing Policy. A total of one line of evidence is available in the administrative record to assess this pollutant. A total of zero of 35 samples exceed the evaluation guideline for the cold freshwater habitat beneficial use. Previously considered water quality data was reevaluated according to new guidelines as part of this assessment. Lines of evidence have been replaced. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. A total of zero of 35 samples exceed the evaluation guideline for the cold freshwater habitat beneficial use. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171136, Trifluralin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353255

Pollutant:

Trifluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of Trifluralin does not exceed 0.33 ug/L in the water column more than once every three years on average (Bower, et al. 2017).

Guideline Reference:

Water Quality Criteria Report for Trifluralin Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology University of California, Davis.

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRSFD (Merced River @ Santa Fe).

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2015-09-08

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	171142	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Ziram
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. Previously considered water quality data was reevaluated according to new guidelines as part of this assessment. Lines of evidence have been replaced.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171142, Ziram	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353302

Pollutant:

Ziram

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ziram. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for ziram is the USEPA Aquatic Life Benchmark of 1.4 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2017-10-10 and 2017-10-10

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):


DECISION ID	164559	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	alpha-Endosulfan (Endosulfan 1)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. Zero of the 23 samples, reported as a "Total" fraction or as fraction reported as "None," exceed the objective for the COLD beneficial use. Zero of the 23 samples, reported as a "Total" fraction or as fraction reported as "None," exceed the objective for the MUN beneficial use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 23 samples, reported as a "Total" fraction or as fraction reported as "None," exceed the objective for the COLD beneficial use. Zero of the 23 samples, reported as a "Total" fraction or as fraction reported as "None," exceed the objective for the MUN beneficial use. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	This decision was made by SWRCB staff.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 164559, alpha-Endosulfan (Endosulfan 1)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67138

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endosulfan I criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164559, alpha-Endosulfan (Endosulfan 1)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67137

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endosulfan I criterion for the protection of human health from consumption of water and organisms is 110 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164559, alpha-Endosulfan (Endosulfan 1)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189139

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The alpha-endosulfan criteria for the protection of human health from the consumption of water and organisms is 110 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164559, alpha-Endosulfan (Endosulfan 1)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189182

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The alpha-endosulfan criteria for the protection of human health from the consumption of water and organisms is 110 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164559, alpha-Endosulfan (Endosulfan 1)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189096

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The endosulfan I criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.028 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164559, alpha-Endosulfan (Endosulfan 1)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189228

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The endosulfan I criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.028 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	164569	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	beta-Endosulfan (Endosulfan 2)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Six lines of evidence are available in the administrative record to assess this pollutant. Zero of the 23 samples, reported as "Total" fraction or as fraction reported as "None," exceed the objective for the COLD beneficial use. Zero of the 23 samples, reported as "Total" fraction or as fraction reported as "None," exceed the objective for the MUN beneficial use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 23 samples, reported as "Total" fraction or as fraction reported as "None," exceed the objective for the COLD beneficial use. Zero of the 23 samples, reported as "Total" fraction or as fraction reported as "None," exceed the objective for the MUN beneficial use. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	This decision was made by SWRCB staff.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 164569, beta-Endosulfan (Endosulfan 2)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189617

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The beta-endosulfan criteria for the protection of human health from the consumption of water and organisms is 110 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164569, beta-Endosulfan (Endosulfan 2)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189339

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The endosulfan II criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.028 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2015-04-01 and 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164569, beta-Endosulfan (Endosulfan 2)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189286

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The endosulfan II criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.028 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 164569, beta-Endosulfan (Endosulfan 2)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67154

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The beta-endosulfan criterion for the protection of human health from consumption of water and organisms is 110 ug/L. (California Toxics Rule, 2000)

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164569, beta-Endosulfan (Endosulfan 2)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67164

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endosulfan II criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 164569, beta-Endosulfan (Endosulfan 2)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

189291

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The beta-endosulfan criteria for the protection of human health from the consumption of water and organisms is 110 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition


DECISION ID	158883	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Thirty-eight lines of evidence are available in the administrative record to assess this pollutant. Twelve of the 345 samples exceeded the OBJECTIVE for COLD. Zero of the 48 samples exceeded the OBJECTIVE for MUN. Six of the 131 samples exceeded the OBJECTIVE for REC-2. Six of the 138 samples exceeded the OBJECTIVE for REC-1. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Twelve of the 345 samples exceeded the OBJECTIVE for COLD. Zero of the 48 samples exceeded the OBJECTIVE for MUN. Six of the 131 samples exceeded the OBJECTIVE for REC-2. Six of the 138 samples exceeded the OBJECTIVE for REC-1. This does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332475

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2017-10-10 and 2021-09-22

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330115

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-CARO-1042 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

WQX from the NWQMP for the 2026 Integrated Report in Region 5

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330091

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-NRS_CA-10948 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2018-07-16 and 2018-07-16

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Monitoring Data from the Surface Water Ambient Monitoring Program (SWAMP), San Joaquin River Basin - 2007 Data Review

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22226

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

101

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The Central Valley Regional Water Quality Control Board Surface Water Ambient Monitoring Program collected 101 samples from January 1998 to November 2005. Three out of 101 samples were outside the acceptable range; all three samples were higher than the acceptable range.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The pH of water shall not be depressed below 6.5,raised above 8.5, or changed at any time more than 0.5 units from normal ambient pH.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from Merced River at River Road.

Temporal Representation:

Sampling occurred from January 1998 to November 2005.

Environmental Conditions:

QAPP Information:

Data quality: Good. Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

79628

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed ILRP data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 41 samples exceed the criterion for pH.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [ Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67201

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of 6 sample results exceed the criterion for pH.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

pH should not be lower than 6.5 or higher than 8.5. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at two monitoring sites [ Merced River @ Merced Falls Gauging St. - 535MER209, Merced River at Henderson Park - 535MER210]

Temporal Representation:

Data was collected over the time period 8/27/2008-9/3/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

209483

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER209)

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

22225

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The East San Joaquin Water Quality Coalition collected 20 samples from July 2004 to September 2006. One out of 20 samples was outside the acceptable range; the sample was lower than the acceptable range.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH of water shall not be depressed below 6.5,raised above 8.5, or changed at any time more than 0.5 units from normal ambient pH.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from Merced River at Santa Fe.

Temporal Representation:

Sampling occurred from July 2004 to September 2006.

Environmental Conditions:

QAPP Information:

Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67200

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of 6 sample results exceed the criterion for pH.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

pH should not be lower than 6.5 or higher than 8.5. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at two monitoring sites [ Merced River @ Merced Falls Gauging St. - 535MER209, Merced River at Henderson Park - 535MER210]

Temporal Representation:

Data was collected over the time period 8/27/2008-9/3/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

79629

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [ Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 2/12/2007-7/20/2010.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67197

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the criterion for pH.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

pH should not be lower than 6.5 or higher than 8.5. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 5/15/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67199

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of 6 sample results exceed the criterion for pH.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

pH should not be lower than 6.5 or higher than 8.5. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at two monitoring sites [ Merced River @ Merced Falls Gauging St. - 535MER209, Merced River at Henderson Park - 535MER210]

Temporal Representation:

Data was collected over the time period 8/27/2008-9/3/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67188

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the criterion for pH.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

pH should not be lower than 6.5 or higher than 8.5. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 5/15/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192811

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Habitat, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535CR1042)

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

193071

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Habitat, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535CR1042)

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

192878

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Habitat, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535CR1042)

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

234117

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed STORET data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 2 of 33 samples exceeded the water quality threshold for pH.

Data Reference:

WQX data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (CALWR_WQX-B0512500)

Temporal Representation:

The samples were collected between the dates of 2010-09-01 and 2015-10-05

Environmental Conditions:

QAPP Information:

STORET

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

234129

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (CALWR_WQX-B0512500)

Temporal Representation:

The samples were collected between the dates of 2010-09-01 and 2015-10-05

Environmental Conditions:

QAPP Information:

STORET

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

234130

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (CALWR_WQX-B0512500)

Temporal Representation:

The samples were collected between the dates of 2010-09-01 and 2015-10-05

Environmental Conditions:

QAPP Information:

STORET

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

209933

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2014-07-09 and 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

210486

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER209)

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

210028

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2014-07-09 and 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

210901

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER202)

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

209954

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER209)

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

210775

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER210)

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2017-06-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

211064

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER210)

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2017-06-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

209952

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER202)

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

209482

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER202)

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

209895

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER210)

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2017-06-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332426

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2019-08-27 and 2021-09-05

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

228881

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2016-12-09

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

229083

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2010-09-20 and 2017-10-26

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

228412

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2010-09-20 and 2017-10-26

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

229336

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2016-12-09

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

228607

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2010-09-20 and 2017-10-26

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

229520

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2010-09-14 and 2016-12-09

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

209922

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546)

Temporal Representation:

The samples were collected between the dates of 2014-07-09 and 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158883, pH	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67198

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the criterion for pH.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

pH should not be lower than 6.5 or higher than 8.5. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 5/15/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	158891	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Bifenthrin
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. LOE 67165 has been replaced by LOE 352973 due to a reassessment of data. Nine lines of evidence are available in the administrative record to assess this pollutant. Two of the two samples exceed the evaluation guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. The water quality objective for pesticides states, in relevant part, that "discharges shall not result in pesticide concentrations in bottom sediments or aquatic life that adversely affect beneficial uses." Pesticides are not naturally occurring in the environment, so any measured concentrations of pesticides are presumed to be the result of discharges. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two of the two samples exceed the evaluation guideline, and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158891, Bifenthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186841

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 5 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for Bifenthrin is 0.1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Bifenthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-04-09 to 2018-08-14

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158891, Bifenthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

186545

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-18 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158891, Bifenthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

195870

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for bifenthrin, 0.043 ug/g, is one-tenth of the median lethal concentration (LC50; 0.43 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin from Amweg et al. (2005) and Amweg and Weston (2007).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535XMRAOR.

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-11 to 2018-09-11

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158891, Bifenthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

195740

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 station. Monitoring site: ( 535MER546 )

Temporal Representation:

The samples were collected between the dates of 2010-09-01 and 2018-08-22.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158891, Bifenthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330813

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and the results are as follows: 2 of the 2 samples exceeded the water quality threshold for Bifenthrin. Although a total of 16 samples were collected, 14 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for bifenthrin is 0.1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of bifenthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2021-09-22

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 158891, Bifenthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

333105

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546 (Merced River @ River Road).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-08-27 to 2019-08-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Data for Various Pollutants in East San Joaquin, 2004-2009.

Line of Evidence (LOE) for Decision ID 158891, Bifenthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

352973

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 8 samples were collected, 8 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRSFD (Merced River @ Santa Fe).

Temporal Representation:

The samples were collected between the dates of 2007-02-12 and 2007-09-11

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158891, Bifenthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67166

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline value for bifenthrin, 0.043 ug/g OC, is one-tenth of the median lethal concentration for H. azteca (LC50; 0.43 ug/g OC). The LC50 (0.43 ug/g OC) is the geometric mean of OC-normalized LC50 values for bifenthrin from Amweg et al. (2005) and Amweg and Weston (2007).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158891, Bifenthrin	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

195871

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Stream Pollution Trends data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and the results are as follows: 2 of the 4 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 5 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2011-09-08 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158897	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Cyhalothrin, Lambda
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Seven lines of evidence are available in the administrative record to assess this pollutant. Two of the two water samples exceed the evaluation guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. The water quality objective for pesticides states, in relevant part, that "discharges shall not result in pesticide concentrations in bottom sediments or aquatic life that adversely affect beneficial uses." Pesticides are not naturally occurring in the environment, so any measured concentrations of pesticides are presumed to be the result of discharges. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two of the two water samples exceed the evaluation guideline, and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158897, Cyhalothrin, Lambda	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196316

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for lambda-cyhalothrin, 0.044 ug/g, is one-tenth of the median lethal concentration (LC50; 0.44 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535XMRAOR.

Temporal Representation:

Date for this waterbody were collected over the date range 2018-09-11 to 2018-09-11

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158897, Cyhalothrin, Lambda	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190774

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for Lambda-cyhalothrin is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Lambda-cyhalothrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site (535MER546).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-18 to 2015-04-01

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158897, Cyhalothrin, Lambda	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

190741

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-05-08 to 2018-06-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158897, Cyhalothrin, Lambda	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196089

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Stream Pollution Trends data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda-. Although a total of 5 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Date for this waterbody were collected over the date range 2011-09-08 to 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158897, Cyhalothrin, Lambda	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67215

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline value for lambda-cyhalothrin, 0.044 ug/g OC, is one-tenth of the median lethal concentration for H. azteca (LC50; 0.44 ug/g OC). The LC50 (0.44 ug/g OC) is the geometric mean of OC-normalized LC50 values for lambda-cyhalothrin from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 158897, Cyhalothrin, Lambda	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

353078

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_ESJWQC data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 8 samples were collected, 8 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for lambda-cyhalothrin is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Lambda-cyhalothrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRSFD (Merced River @ Santa Fe).

Temporal Representation:

The samples were collected between the dates of 2007-02-12 and 2007-09-11

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158897, Cyhalothrin, Lambda	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

331702

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and the results are as follows: 2 of the 2 samples exceeded the water quality threshold for Lambda-cyhalothrin. Although a total of 16 samples were collected, 14 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRAOR).

Temporal Representation:

The samples were collected between the dates of 2018-11-30 and 2021-09-22

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program


DECISION ID	165452	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Specific Conductivity
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Eighteen lines of evidence are available in the administrative record to assess this pollutant. Twenty-two of the 56 samples exceed the objective for MUN. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Twenty-two of the 56 samples exceed the objective for MUN and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346426

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 1 samples fall within the range, and 1 of 1 samples fall below the threshold.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Secondary MCL that is incorporated by reference into the Water Quality Control Plan for the Sacramento and San Joaquin River Basins specifies a range for specific conductance of 900-1600 uS/cm assessed as an annual average.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER202 (Merced River @ Hwy 99).

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346496

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DFW_ABL_Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 1 samples fall within the range, and 1 of 1 samples fall below the threshold.

Data Reference:

Habitat, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535CR1042 (Merced River -1042).

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346366

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 1 samples fall within the range, and 1 of 1 samples fall below the threshold.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER209 (Merced River @ Merced Falls Gauging St.).

Temporal Representation:

The samples were collected between the dates of 2012-01-12 and 2012-01-12

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

345901

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 1 samples fall within the range, and 0 of 1 samples fall below the threshold.

Data Reference:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER210 (Merced River at Henderson Park).

Temporal Representation:

The samples were collected between the dates of 2008-09-03 and 2008-09-03

Environmental Conditions:

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346495

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER210 (Merced River at Henderson Park).

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2017-06-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

345898

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 2 samples fall within the range, and 0 of 2 samples fall below the threshold.

Data Reference:

Monitoring Data from the Surface Water Ambient Monitoring Program (SWAMP), San Joaquin River Basin - 2007 Data Review

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: MER209 (Merced_River_at_Merced_Falls_MER209).

Temporal Representation:

The samples were collected between the dates of 2003-11-19 and 2004-01-07

Environmental Conditions:

QAPP Information:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346353

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 7 samples fall within the range, and 7 of 7 samples fall below the threshold.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2010-11-08 and 2017-10-26

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

345981

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER209 (Merced River @ Merced Falls Gauging St.).

Temporal Representation:

The samples were collected between the dates of 2008-09-03 and 2008-09-03

Environmental Conditions:

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

345934

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Ambient Water Program data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 8 of 8 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 8 samples fall within the range, and 0 of 8 samples fall below the threshold.

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: MER546 (MER546).

Temporal Representation:

The samples were collected between the dates of 1998-06-25 and 2005-11-29

Environmental Conditions:

QAPP Information:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332754

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Stream Pollution Trends data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 3 samples fall within the range, and 3 of 3 samples fall below the threshold.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2019-08-27 and 2021-09-05

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

WQX from the NWQMP for the 2026 Integrated Report in Region 5

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330279

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-CARO-1042 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2014-06-19 and 2014-06-19

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

332769

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 5 samples fall within the range, and 5 of 5 samples fall below the threshold.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRAOR (Merced River @ Oakdale Rd).

Temporal Representation:

The samples were collected between the dates of 2017-12-05 and 2021-09-22

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

330246

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-NRS_CA-10948 (Merced River).

Temporal Representation:

The samples were collected between the dates of 2018-07-16 and 2018-07-16

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

345867

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB5S SJR Trends FY0708 FY0809 data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 1 samples fall within the range, and 1 of 1 samples fall below the threshold.

Data Reference:

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2008-05-15 and 2008-05-15

Environmental Conditions:

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346604

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Stream Pollution Trends data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 1 of the 3 samples fall within the range, and 2 of 3 samples fall below the threshold.

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2013-07-10 and 2016-08-17

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346517

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed East San Joaquin Water Quality Coalition data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 7 samples fall within the range, and 7 of 7 samples fall below the threshold.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRSFD (Merced River @ Santa Fe).

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2016-12-09

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

345967

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin River SWAMP Monitoring Data - Eastside Basin data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 2 samples fall within the range, and 0 of 2 samples fall below the threshold.

Data Reference:

San Joaquin River SWAMP Monitoring Data - Eastside Basin

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: MER209 (Merced_River_at_Merced_Falls_MER209).

Temporal Representation:

The samples were collected between the dates of 2003-11-19 and 2004-01-07

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 165452, Specific Conductivity	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

345974

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 8 of 8 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 8 samples fall within the range, and 0 of 8 samples fall below the threshold.

Data Reference:

Monitoring Data from the Surface Water Ambient Monitoring Program (SWAMP), San Joaquin River Basin - 2007 Data Review

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: MER546 (MER546).

Temporal Representation:

The samples were collected between the dates of 1998-06-25 and 2005-11-29

Environmental Conditions:

QAPP Information:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	158888	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Zinc
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Nine lines of evidence are available in the administrative record to assess this pollutant. Two of seven samples, reported in the dissolved fraction, exceed the objective for MUN, zero of 37 samples, reported in the dissolved fraction, exceed the criteria for COLD, zero of eight samples reported with no fraction exceed the criteria for COLD and zero of eight sediment samples exceed the evaluation guideline for COLD. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two of seven samples, reported in the dissolved fraction, exceed the objective for MUN and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158888, Zinc	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

196927

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The evaluation guideline for Zinc from MacDonald et al., 2000a which states that the probable effect concentration for Zinc is 459 mg/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-01 to 2018-08-22

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158888, Zinc	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

333279

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 535MER546 (Merced River @ River Road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-08-27 to 2020-08-27

Environmental Conditions:

QAPP Information:

SWAMP QAPrP

QAPP Information Reference(s):

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

Line of Evidence (LOE) for Decision ID 158888, Zinc	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

6357

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Zero of the 21 samples collected by the Surface Water Ambient Monitoring Program exceeded the calculated CTR CMC for dissolved zinc

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Dissolved zinc levels should not exceed the calculated limit based on the formula: Criteria Maximum Concentration =EXP((0.8473*LN(hardness))+0.884)*(0.978)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the Merced River at River Road

Temporal Representation:

The samples were collected between April 27, 2000 and June 30, 2003

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158888, Zinc	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67093

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed AgWaiver data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 0 of 8 samples exceed the criterion for Zinc.

Data Reference:

Data for Various Pollutants in East San Joaquin, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Merced River, Lower (McSwain Reservoir to San Joaquin River) was collected at 1 monitoring site [ Merced River @ Santa Fe - 535XMRSFD]

Temporal Representation:

Data was collected over the time period 10/21/2008-5/19/2009.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan by the East San Joaquin Water Quality Coalition, Revision 1.0.

Line of Evidence (LOE) for Decision ID 158888, Zinc	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346165

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP BDAT data for Merced River, Lower (McSwain Reservoir to San Joaquin River) to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the water quality threshold for Zinc.

Data Reference:

SWAMP data entered by SWRCB into BDAT database

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Secondary Maximum Contaminant Level for zinc incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 5.0 mg/L assessed as an annual average.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535MER546 (Merced River @ River Road).

Temporal Representation:

The samples were collected between the dates of 2001-12-26 and 2002-03-27

Environmental Conditions:

QAPP Information:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 158888, Zinc	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

194298

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (535XMRSFD)

Temporal Representation:

The samples were collected between the dates of 2011-01-18 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158888, Zinc	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346811

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 535XMRSFD (Merced River @ Santa Fe).

Temporal Representation:

The samples were collected between the dates of 2011-12-06 and 2014-08-12

Environmental Conditions:

QAPP Information:

Michael L. Johnson LLC. 2015. Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring by the East San Joaquin Water Quality Coalition

Line of Evidence (LOE) for Decision ID 158888, Zinc	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

346162

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: MER546 (MER546).

Temporal Representation:

The samples were collected between the dates of 2000-12-28 and 2002-11-20

Environmental Conditions:

QAPP Information:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 158888, Zinc	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67091

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the evaluation guideline value for Zinc.

Data Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

In freshwater sediments, the probable effect concentration (predictive of sediment toxicity) for zinc is 459 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Merced River @ River Road - 535MER546]

Temporal Representation:

Data was collected on 7/23/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	73661	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Boron
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for listing under sections 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Data is available from 1 line of evidence for this pollutant. Based on the readily available data and information, the weight of evidence indicates that there is not sufficient justification for placing this water segment-pollution combination on the section 303(d) list. The recommendation is based on staff findings that 0 of 64 available concentrations exceeded the water quality objective and this does not exceed the allowable frequency using Table 3.1 of the Listing Policy. Table 3.1 of the listing policy recommends listing if a sample size of 64 has 6 or more samples that exceed the evaluation criteria. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 73661, Boron	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

21070

Pollutant:

Boron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 64 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective of 1,000 ug/L for boron

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Boron levels should not exceed 1,000 ug/L (Department of Health Services Health Advisory)

Guideline Reference:

Drinking Water Notification and Response Levels: An Overview

Spatial Representation:

Samples were collected from the Merced River at River Road

Temporal Representation:

The samples were collected between January 28, 1998 and November 29, 2005

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):


DECISION ID	70862	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Chromium (total)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	The decision has not changed. Region 5 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle. This pollutant is being considered for listing under sections 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Data is available from 1 line of evidence for this pollutant. Based on the readily available data and information, the weight of evidence indicates that there is not sufficient justification for placing this water segment-pollution combination on the section 303(d) list. The recommendation is based on staff findings that 0 of 15 available concentrations exceeded the water quality objective and this does not exceed the allowable frequency using Table 3.1 of the Listing Policy. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 70862, Chromium (total)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

20778

Pollutant:

Chromium (total)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Zero of the 15 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Chromium.

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Chromium levels should not exceed 50 ug/L (Department of Public Health Primary MCL).

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

Samples were collected at Merced River at River Road.

Temporal Representation:

The samples were collected from June 24 1998 to June 30 2003.

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):


DECISION ID	73161	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Invasive Species
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollution

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.10 of the Listing Policy. Under section 3.10 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Three studies, two in 1969-1971 and one in 1986 were used for this assessment, which showed an overall increase of native and non-native species over time. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. Three studies were conducted, two in 1969-1971 and one in 1986. 2. Baseline data was taken from the 1969-1971 studies. All three studies sampled the same geographic area, with similar sampling sizes. 3. Rank abundance, Pearson product moment correlations, and principal components analysis were the statistical analyses employed during these studies. 4. The comparison showed a net increase of native and non-native species observed at all sampling sites. The data was based on the percentage of sites the species were collected at for each study. 5. Some native species were collected at more sites in 1986 than in 1969-71. Some non-native species were collected at more sites than in 1969-71. Eight native species increased in the watersheds they were observed from 1969-71 to 1986, while 5 native species decreased. Nine non-native species increased over time from 1969-71 to 1986, while 7 non-native species decreased. 6. It cannot be determined if the trend in water quality is expected to meet water standards by the next listing cycle. 7. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 73161, Invasive Species	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

2754

Pollutant:

Invasive Species

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish surveys

Data Used to Assess Water Quality:

Two previous studies (conducted in 1969-71) (Moyle and Nichols, 1973; Moyle and Nichols, 1974) were used as baseline comparisons to a study conducted in 1986 (Brown and Moyle, 1993). Species percent collection data were the same for each baseline study at the sampling sites. The baseline studies and this study sampled the same geographic area, with similar sampling sizes. The baseline data was compared to the data collected in 1986. The comparison showed an overall net increase of native species observed at all sampling sites, as well as a net increase in non-native species. The data was based on the percentage of sites the species were collected at for each study. Overall, some native species were collected at more sites in 1986 (an increase in percent) than in the 1969-71 studies (Brown and Moyle, 1993). Some non-native species were collected at more sites (an increase in percent) than in the 1969-71 studies. Eight native species increased in the watersheds they were observed (collected at more sites over time) from 1969-71 to 1986, while 5 native species decreased (collected at less sites over time). Nine non-native species increased over time (collected at more sites over time) from 1969-71 to 1986, while 7 non-native species decreased (collected at less sites over time).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. Compliance with this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, and biotoxicity tests of appropriate duration or other methods as specified by the Regional Water Board. Taken from Region 5 Basin Plan, Page III-8.00, Water Quality Objectives.

Objective/Criterion Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Stanislaus, Tuolumne, Merced, Chowchilla, Fresno, San Joaquin, Kings, Kaweah, and Tule Rivers, between 90 and 1100 meters elevation.

Temporal Representation:

Baseline studies: 37 samples taken during the summer and autumn of 1969, 1970 and 1971 and 130 samples were taken from 7/27-9/4/1970. Another survey was conducted from Sept. 1985 to Sept. 1986 at 186 sites. Only 156 sites were used from this study for statistical analyses, (Brown and Moyle, 1993).

Environmental Conditions:

Changes in relative diversity and abundance of native species may also be driven by habitat alteration, flow changes, or hydromodification.

QAPP Information:

Peer Reviewed Journal Articles.

QAPP Information Reference(s):


DECISION ID	73109	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Nitrate as Nitrate (NO3)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	The decision has not changed. Region 5 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle. This pollutant is being considered for listing under sections 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Data is available from 2 lines of evidence for this pollutant. Based on the readily available data and information, the weight of evidence indicates that there is not sufficient justification for placing this water segment-pollution combination on the section 303(d) list. The recommendation is based on staff findings that 0 of 15 available concentrations exceeded the USEPA Primary MCL for MUN, and 0 of 15 samples exceeded the evaluation guideline for COLD and this does not exceed the allowable frequency using Table 3.1 of the Listing Policy. The recommendation is based on staff findings that 0 of 15 available concentrations exceeded the USEPA National Ambient Water Quality Objective and this does not exceed the allowable frequency using Table 3.1 of the Listing Policy. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 73109, Nitrate as Nitrate (NO3)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

6353

Pollutant:

Nitrate as Nitrate (NO3)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

0 of the 15 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation guideline for Nitrate-N.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Nitrate-N levels should not to exceed 100 mg/L (USEPA National Ambient Water Quality Objective)

Guideline Reference:

Spatial Representation:

Samples were collected at Merced River at River Road.

Temporal Representation:

The samples were collected from Jun 29 2000 to Oct 24 2001

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 73109, Nitrate as Nitrate (NO3)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

20485

Pollutant:

Nitrate as Nitrate (NO3)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

0 of the 15 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Nitrate-N.

Data Reference:

San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Nitrate-N levels should not exceed 45 mg/L (Department of Public Health Primary MCL)

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

Samples were collected at Merced River at River Road.

Temporal Representation:

The samples were collected from Jun 29 2000 to Oct 24 2001

Environmental Conditions:

QAPP Information:

Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):


DECISION ID	91700	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

Pollutant:	Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of the one samples exceed the evaluation guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the one samples exceed the evaluation guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples are needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 91700, Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)	Region 5
Merced River, Lower (McSwain Reservoir to San Joaquin River)

LOE ID:

67081

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The sample result did not exceed the evaluation guideline value (572 ug/Kg dry weight).

Data Reference: