Draft California 2024 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name:	Calaveras River, Lower (from Stockton Diverting Canal to the Delta Waterways)
Water Body ID:	CAR5313000020221114032492
Water Body Type:	River & Stream


DECISION ID	152350	Region 5
Calaveras River, Lower (from Stockton Diverting Canal to the Delta Waterways)

Pollutant:	Chlorpyrifos
Final Listing Decision:	Delist from 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Delist from 303(d) list (being addressed by USEPA approved TMDL)(2020)
Revision Status	Revised
Reason for Delisting:	Applicable WQS attained; reason for recovery unspecified
TMDL Name:	Delta Diazinon and Chlorpyrifos Project
TMDL Project Code:	185
Date TMDL Approved by USEPA:	10/10/2007
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This waterbody was split as part of the 2024 cycle Delta Remapping Project. Decisions were reassessed based on the new spatial representation, which resulted in a delisting. 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. Four lines of evidence are available in the administrative record to assess this pollutant. Two of the 32 samples exceeded the evaluation guideline for WARM. 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. Two of the 32 samples exceeded the evaluation guideline for WARM 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:	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 152350, Chlorpyrifos	Region 5
Calaveras River, Lower (from Stockton Diverting Canal to the Delta Waterways)

LOE ID:

309691

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:

One of sixteen water samples collected from the lower Calaveras River by the Central Valley Water Board, Pesticide TMDL program between June 2002 and September 2003, exceeded the 4-day average criterion of 0.015 ug/L. Zero of sixteen water samples exceeded the 1-hour average criterion of 0.025 ug/L. The water sample that exceeded the 4-day average criterion was collected on 18 March 2003.

Data Reference:

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

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:

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 chlorpyrifos criteria for the protection of freshwater aquatic life: 0.015 ug/L (4-day average concentration), and 0.025 ug/L (1-hour average concentration), not to be exceeded more than once every three years.

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 the lower Calaveras River at Ijams Road.

Temporal Representation:

Seven water samples were collected approximately monthly from 18 June 2002 to18 February 2003, and 9 water samples were collected approximately weekly from 3 March 2003 to 19 May 2003.

Environmental Conditions:

QAPP Information:

Data quality: Good. Calanchini, H. 2006. Quality Assurance Project Plan, Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. John Muir Institute of the Environment, U.C. Davis. Davis, CA.

QAPP Information Reference(s):

Quality Assurance Project Plan. Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. Final. SWAMP Project ID 02TM5001 (Revision 0.0). John Muir Institute of the Environment, U.C. Davis. Davis, CA. January 26, 2006

Line of Evidence (LOE) for Decision ID 152350, Chlorpyrifos	Region 5
Calaveras River, Lower (from Stockton Diverting Canal to the Delta Waterways)

LOE ID:

309698

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:

Five water samples were collected from the lower Calaveras River, under the Central Valley Water Board's pesticide TMDL program, in March and April 2005, representing five calculated 4-day average concentrations and five 1-hour average concentrations. Zero of the five calculated 4-day average concentrations exceeded the 4-day average criterion of 0.100 ug/L. Zero of the five 1-hour average concentrations exceeded the 1-hour average criterion of 0.160 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:

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:

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 Fish and Game Hazard Assessment chlorpyrifos criteria for freshwater aquatic life protection: 0.025 ug/L (1-hour average) and 0.015 ug/L (4-day average) concentrations, not to be exceeded more than once every three years.

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:

Water samples were collected from the lower Calaveras River at Ijams Road.

Temporal Representation:

Samples were collected weekly between 2 March and 6 April 2005.

Environmental Conditions:

QAPP Information:

Data quality: Excellent. Calanchini, H. 2006. Quality Assurance Project Plan, Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. John Muir Institute of the Environment, U.C. Davis. Davis, CA.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 152350, Chlorpyrifos	Region 5
Calaveras River, Lower (from Stockton Diverting Canal to the Delta Waterways)

LOE ID:

309693

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:

Fifteen water samples were collected from the lower Calaveras River, under the Central Valley Water Board, Pesticide TMDL program, between February and April 2004. The fifteen water samples represent nine calculated 4-day average concentrations and fifteen 1-hour average concentrations. One of the nine calculated 4-day average concentrations exceeded the 4-day average criterion of 0.015 ug/L. Zero of the fifteen 1-hour average concentrations exceeded the 1-hour average criterion of 0.025 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:

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:

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 chlorpyrifos criteria for freshwater aquatic life protection: 0.015 ug/L (4-day average concentration), and 0.025 ug/L (1-hour average concentration), not to be exceeded more than once every three years.

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:

Water samples were collected from the lower Calaveras River at Ijams Road.

Temporal Representation:

Samples were collected from the lower Calaveras River daily during two storm events (2 February to 6 February 2004 and 16 February to 20 February 2004), weekly in March, and once in early April 2004.

Environmental Conditions:

Water samples were collected during, and after, two storm events in February 2004.

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.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 152350, Chlorpyrifos	Region 5
Calaveras River, Lower (from Stockton Diverting Canal to the Delta Waterways)

LOE ID:

309692

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:

Five water samples were collected from the lower Calaveras River, under the Central Valley Regional Board's Pesticide TMDL program, daily between 15 February and 19 February 2005, representing two calculated 4-day average chlorpyrifos concentrations and five 1-hour average chlorpyrifos concentrations. Zero of the two calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion of 0.015 ug/L. Zero of the five 1-hour average chlorpyrifos concentrations exceeded the 1-hour average chlorpyrifos criterion 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:

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:

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:

Water samples were collected from the lower Calaveras River at Ijams Road.

Temporal Representation:

Samples were collected daily during a storm event, between 15 February and 19 February 2005.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	152351	Region 5
Calaveras River, Lower (from Stockton Diverting Canal to the Delta Waterways)

Pollutant:	Diazinon
Final Listing Decision:	Delist from 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Delist from 303(d) list (being addressed by USEPA approved TMDL)(2020)
Revision Status	Revised
Reason for Delisting:	Applicable WQS attained; reason for recovery unspecified
TMDL Name:	Delta Diazinon and Chlorpyrifos Project
TMDL Project Code:	185
Date TMDL Approved by USEPA:	10/10/2007
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This waterbody was split as part of the 2024 cycle Delta Remapping Project. Decisions were reassessed based on the new spatial representation. This pollutant is being considered for removal from the CWA section 303(d) List under section 4.11 of the Listing Policy. Under this section when all other delisting factors do not result in the delisting of a water segment but information indicates attainment of standards, a water segment shall be evaluated to determine whether the weight of evidence demonstrates that water quality standard is attained. If the weight of evidence indicates attainment, the water segment shall be removed from the CWA section 303(d) List. After the watebody was split, all four LOEs were not considered in this assessment as those data were collected prior to the approval of a TMDL and thus are no longer considered representative of conditions in the water body. 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: The data used satisfies the data quality requirements of section 6.1.4 of the Policy. Data collected prior to the USEPA approval of a TMDL in October of 2007 was not considered as part of this assessment in accordance with Section 6.1.5.3 of the Listing Policy.

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:	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 152351, Diazinon	Region 5
Calaveras River, Lower (from Stockton Diverting Canal to the Delta Waterways)

LOE ID:

309697

Pollutant:

Diazinon

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:

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

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:

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 Fish and Game Hazard Assessment diazinon criteria for freshwater aquatic life protection: 0.160 ug/L (1-hour average) and 0.100 ug/L (4-day average) concentrations, not to be exceeded more than once every three years.

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

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

Water samples were collected from the lower Calaveras River at Ijams Road.

Temporal Representation:

Samples were collected weekly between 2 March and 6 April 2005.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 152351, Diazinon	Region 5
Calaveras River, Lower (from Stockton Diverting Canal to the Delta Waterways)

LOE ID:

309696

Pollutant:

Diazinon

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:

Sixteen water samples were collected from the lower Calaveras River between 18 June 2002 and 19 May 2003, representing sixteen calculated 4-day average concentrations and sixteen 1-hour average concentrations. Six of the sixteen 4-day average concentrations exceeded the 4-day average criterion of 0.100 ug/L. Three of the sixteen 1-hour average concentrations exceeded the 1-hour average criterion of 0.160 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:

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:

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

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

Water samples were collected from the lower Calaveras River at Ijams Road.

Temporal Representation:

Samples were collected monthly between 18 June and 17 September 2002; on 19 December 2002; on 22 January 2003 and 18 February 2003; and nine times, either weekly or every two weeks, between 3 March and 19 May 2003.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 152351, Diazinon	Region 5
Calaveras River, Lower (from Stockton Diverting Canal to the Delta Waterways)

LOE ID:

309695

Pollutant:

Diazinon

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:

Five water samples were collected daily from the lower Calaveras River between 15 February and 19 February 2005, representing two calculated 4-day average concentrations and five 1-hour average concentrations. Zero of the two calculated 4-day average concentrations exceeded the 4-day average criterion of 0.100 ug/L. Zero of the five 1-hour average concentrations exceeded the 1-hour average criterion of 0.160 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:

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:

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

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

Water samples were collected from the lower Calaveras River at Ijams Road.

Temporal Representation:

Samples were collected daily during a storm event, between 15 February and 19 February 2005.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 152351, Diazinon	Region 5
Calaveras River, Lower (from Stockton Diverting Canal to the Delta Waterways)

LOE ID:

309694

Pollutant:

Diazinon

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:

Fifteen water samples were collected from the lower Calaveras River, under the Central Valley Water Board's Pesticide TMDL program, between February and April 2004, representing nine calculated 4-day average concentrations and fifteen 1-hour average concentrations. Two of nine calculated 4-day average concentrations (2 February to 5 February 2005, and 16 February to 19 February 2005) exceeded the 4-day average criterion of 0.100 ug/L. Four of fifteen 1-hour average concentrations (2 February, 3 February, 26 February, and 17 February 2005) exceeded the 1-hour average criterion of 0.160 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:

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:

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

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

Water samples were collected from the lower Calaveras River at Ijams Road.

Temporal Representation:

Samples were collected from the lower Calaveras River daily during two storm events (2 February to 6 February 2004 and 16 February to 20 February 2004), weekly in March, and once in early April 2004.

Environmental Conditions:

Water samples were collected during, and after, two storm events in February 2004.

QAPP Information:

QAPP Information Reference(s):


DECISION ID	152349	Region 5
Calaveras River, Lower (from Stockton Diverting Canal to the Delta Waterways)

Pollutant:	Indicator Bacteria
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2018)
Revision Status	Revised
Sources:	Urban Runoff/Storm Sewers
TMDL Name:	Stockton Area Sloughs and Rivers - Pathogens
TMDL Project Code:	721
Date TMDL Approved by USEPA:	05/13/2008
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This waterbody was split as part of the 2024 cycle Delta Remapping Project. Decisions were reassessed based on the new spatial representation. There is sufficient justification to place this pollutant on the Being Addressed portion of the 303(d) list, because a TMDL has been completed and approved by RWQCB and USEPA, and it is expected to result in attainment of the standard.. The Stockton Urban Waterbodies Pathogen TMDL has been approved by the Central Valley Water Board in 2008 and approved by USEPA on 13 may 2008. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are being 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 Being Addressed portion of the section 303(d) list because a TMDL has been completed and approved by USEPA and is expected to result in attainment of the standard. No new data or information was available during the 2024 Integrated Report cycle to reassess this water body segment and pollutant. 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 152349, Indicator Bacteria	Region 5
Calaveras River, Lower (from Stockton Diverting Canal to the Delta Waterways)

LOE ID:

309690

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:

Total Maximum Daily Load Report for Pathogens in: Five-Mile Slough, Lower Calaveras River, Mormon Slough, Mosher Slough, Smith Canal and Walker Slough, Final Staff Report, Appendix A, Unpublished Water Quality Data. Though included in the datasets for this LOE, the data described in this section does not include Deltakeeper water samples and results assessed in LOE 7003 (ref2932). Twelve of the 57 daily average results for water samples collected by the Deltakeeper exceeded the E. coli Evaluation Guideline value of 235 MPN/100 ml; the dates (and daily average E. coli MPN values) for the exceedances at "Diverting Canal" was: 21 October 2004 (754 MPN); at "UOP" was: 4 February 2004 (6,867 MPN); at "UOP footbridge" were: 21 April 2001 (1,302 MPN); 20 July 2001 (294 MPN); 8 March 2003 (>24,192 MPN); 11 April 2002 (472 MPN); 20 May 2002 (1,872 MPN); 14 April 2003 (3,609 MPN); and 6 February 2004 (419 MPN); at "DR Dock" were: 27 October 2004 (3,464 MPN); and 7 December 2004 (759 MPN); and at an unspecified location on 11 December 2003 (3,783 MPN) . Eight of the 17 daily average results for water samples collected by the CVRWQCB exceeded the E. coli Evaluation Guideline value of 235 MPN/100 ml; the dates (and daily average E. coli MPN values) for the exceedances at "Deltakeeper" were: 17 November 2005 (240 MPN); 19 December 2005 (850 MPN); and 20 December 2005 (700 MPN); at "McAllen Rd" were: 12 October 2005 (260 MPN); 25 October 2005 (600 MPN); and 17 November 2005 (300 MPN); at "UOP" were: 12 October 2005 (550 MPN); and 19 December 2005 (850 MPN).

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. (CRWQCB, 2006)

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:

E. coli bacteria levels should not exceed 235 MPN/100 mL in any single sample (USEPA E. coli objective).

Guideline Reference:

Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Spatial Representation:

Though included in the datasets for this LOE, the data described in this section does not include water samples and results assessed in LOE 7003 (ref2932). Water samples were collected by Deltakeeper from the Calaveras River at "Deltakeeper's Dock", "Diverting Canal", "DR Dock", "UOP", "UOP footbridge", and 1 or more unspecified locations (the latter data was not assessed). Water samples were collected by the CVRWQCB from the Calaveras River at "Deltakeeper", McAllen Rd", and "UOP".

Temporal Representation:

Though included in the datasets for this LOE, the data described in this section does not include water samples and results collected by Deltakeeper and assessed as described in LOE 7003 (ref2932). Water samples were collected from the Calaveras River by Deltakeeper at "Diverting Canal" on: 21 October 2004; at "DR Dock" on: 27 March 2003; 8 April 2003; 12, 17,21 and 25 May 2004; 1, 5, 12, 19 and 27 July 2004; 1, 15, 22, and 30 September 2004; 27 October 2004; 7, 13, 20 and 27 December 2004; 5 January 2005; and 26 May 2005; at "UOP" on: 4 February 2004; at "UOP footbridge" on: 12 and 21 April 2001; 30 May 2001; 28 June 2001; 7 and 20 July 2001; 24 and 28 January 2002; 8, 11, 14 and 24 February 2002; 4, 8, 14, 20 and 29 March 2002; 11, 18 and 25 April 2002; 2, 9, 14, 20 and 31 May 2002; 27 March 2003; 14 April 2003; 2, 6 and 9 February 2004; and 26 March 2004; and at unspecified location(s) on: 11 December 2003; 25 April 2000; 2 May 2000; 13 June 2000; and 9 August 2000. Water samples were collected from the Calaveras River by the CVRWQCB at "Deltakeeper" on: 12 and 25 October 2005; 11, 17 and 28 November 2005; and 6, 19 and 20 December 2005; at "McAllen Rd" on: 12 and 25 October 2005; and 17 November 2005; at "UOP" on: 12 and 25 October 2005; 11, 17 and 28 November 2005; and 6, 19 and 20 December 2005.

Environmental Conditions:

QAPP Information:

Good. Monitoring was conducted by Deltakeeper and by the Central Valley Water Board for the San Joaquin River TMDL for pathogens

QAPP Information Reference(s):