Draft California 2020 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name:	San Marcos Creek, Lower (below San Marcos Lake)
Water Body ID:	CAR9045100020200514035451
Water Body Type:	River & Stream


DECISION ID	105577	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Benthic Community Effects
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:	Delisting due to spatial change or other CalWQA administrative reason
Expected TMDL Completion Date:	2025
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Benthic Community Effects is being considered for delisting from the CWA Section 303(d) list under sections 4.9 and 4.1 of the Listing Policy. Based on the readily available data and information, the weight of evidence provides sufficient justification for removing Benthic Community Effects in this water segment 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. Pursuant to section 4.9 of the Listing Policy, the water does not exhibit significant degradation in biological populations and/or communities as compared to reference site(s) using the California Stream Condition Index. This segment was remapped during this cycle and CSCI scores within the segment do not warrant listing for impairment. 4. Pursuant to section 4.11 of the Listing Policy, 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 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 105577, Benthic Community Effects	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134503

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

BIOLOGICAL MONITORING

Data Used to Assess Water Quality:

Data used to generate the SWAMP Bioassessment Scores Map. The one sample collected produced a CSCI score of 0.85. Therefore, it is not exceeding the water quality objective for the aquatic life beneficial use.

Data Reference:

CSCI scores downloaded from: https://www.waterboards.ca.gov/water_issues/programs/swamp/bioassessment/csci_scores_map.html

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 or animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board. Region 9 Basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

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:

Samples were collected at 904S02585.

Temporal Representation:

Samples were collected on 5/19/2010.

Environmental Conditions:

QAPP Information:

Data collected following SWAMP QA protocols.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 105577, Benthic Community Effects	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134501

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Eight samples were taken at two stations on San Marcos Creek below San Marcos reservoir. The CSCI scores for are above the 0.79 threshold, and therefore the site is not exceeding the water quality objective for the aquatic life beneficial use.

Data Reference:

Data for Various Pollutants from the County of San Diego Copermittees Receiving Waters Monitoring and Reporting Program, 2001-2008.

Region 9 CSCI Scores & Water Body Information

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

A Quantitative Tool for Assessing the Integrity of Southern Coastal California Streams. Environmental Management. Volume 35, number 1 (2005): pp. 1-13

Spatial Representation:

The samples were collected at stations 904SMC-LCCC and 904SMC-RSFR

Temporal Representation:

The samples were collected twice a year in May and October from 2001 to 2004.

Environmental Conditions:

QAPP Information:

The data was collected under the County of San Diego NPDES MS4 Copermittees Receiving Waters Monitoring and Reporting Program.

QAPP Information Reference(s):

Quality Assurance Project Plan for SWAMP Bioassessment and Freshwater Bioassessment.

QAPP Information Reference(s):

Data for Various Pollutants from the County of San Diego Copermittees Receiving Waters Monitoring and Reporting Program, 2001-2008.


DECISION ID	105580	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Phosphorus
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)(2018)
Revision Status	Revised
Sources:	A Source Unknown \| Unknown Nonpoint Source \| Unknown Point Source \| Urban Runoff/Storm Sewers
Expected TMDL Completion Date:	2019
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. Three lines of evidence are available in the administrative record to assess pollutant. Thirty-three of the 55 samples exceed the threshold. 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-three of the 55 samples exceed the threshold, 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:	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 105580, Phosphorus	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

216580

Pollutant:

Phosphorus

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:

Four water samples, four samples exceeding (SWAMP, 2004).

Data Reference:

Monitoring data for Region 9

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growth causes nuisances or adversely affects beneficial uses. Water Quality Control Plan for the San Diego Basin Goal of 0.1 mg/L in stream and flowing waters.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at 1 monitoring station (904CBSAM6).

Temporal Representation:

Samples were collected March to September of 2002.

Environmental Conditions:

QAPP Information:

SWAMP Quality Assurance Plan.

QAPP Information Reference(s):

This is a placeholder for previously assessed data that does not have quality assurance information but would require it under newly developed policies. These LOEs were previously assessed and approved at the Regional, State and Federal level in past cycles. The LOEs needed to be moved and/or reassessed but required this reference code for movement within the decision making database.

Line of Evidence (LOE) for Decision ID 105580, Phosphorus	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

145823

Pollutant:

Phosphorus

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:

Water Board staff assessed San Diego Coastkeeper Ambient Monitoring Program data for San Marcos Creek, Lower (below San Marcos Lake) to determine beneficial use support and results are as follows: 21 of 43 samples exceeded the water quality threshold for Phosphorus as P.

Data Reference:

Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Concentrations of nitrogen and phosphorus, by themselves or in combination with other nutrients, shall be maintained at levels below those which stimulate algae and emergent plant growth. A desired goal in order to prevent plant nuisance in streams and other flowing waters appears to be 0.1 mg/L total P. Analogous threshold values have not been set for nitrogen compounds; however, natural ratios of nitrogen to phosphorus are to be determined by surveillance and monitoring and upheld. If data are lacking, a ratio of N:P = 10:1, on a weight to weight basis shall be used (Water Quality Control Plan, San Diego Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (BTQ-020)

Temporal Representation:

The samples were collected between the dates of 2010-09-11 and 2018-10-06

Environmental Conditions:

QAPP Information:

San Diego Coastkeeper. 2010. San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan.

QAPP Information Reference(s):

San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan

Line of Evidence (LOE) for Decision ID 105580, Phosphorus	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134421

Pollutant:

Phosphorus

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:

Eight water samples, eight samples exceeding (SWAMP, 2004).

Data Reference:

Placeholder reference 2006 303(d)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Placeholder reference 2006 303(d)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Two stations at San Marcos Creek: 33.13027 - 117.192
and at 33.08791 - 117.26933.

Temporal Representation:

Eight samples collected from March through September of 2002.

Environmental Conditions:

San Marcos Creek Watershed 904.5.

QAPP Information:

SWAMP Quality Assurance Plan.

QAPP Information Reference(s):


DECISION ID	105583	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Selenium
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)(2018)
Revision Status	Revised
Sources:	A Source Unknown
Expected TMDL Completion Date:	2021
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. One line of evidence is available in the administrative record to assess pollutant. Three of the four samples exceed the water quality threshold. 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. Three of the four samples exceed the water quality threshold, 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:	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 105583, Selenium	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

216582

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Four water samples were collected at San Marcos Creek station 904CBSAM6 on March, April, June and September 2002. Three of four samples showed excessive selenium concentrations according to results in California's Surface Water Ambient Monitoring Program Report, 2007.

Data Reference:

Monitoring data for Region 9

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

CTR Freshwater Chronic (CCC) 5 ug/L; (U.S. EPA, 2000).

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Objective/Criterion Reference:

Water Quality Standards; Establishment of Numeric Criteria for Priority Toxic Pollutants for the State of California; Rule. 40 CFR Part 131. U.S. Environmental Protection Agency, Region IX, Water Division, San Francisco, CA

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at San Marcos Creek station 904CBSAM6.

Temporal Representation:

Samples were collected on March, April, June and September 2002.

Environmental Conditions:

QAPP Information:

Quality control for the chemical analysis portion of this study was conducted in accordance with the California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA


DECISION ID	105579	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Revised
Sources:	A Source Unknown
Expected TMDL Completion Date:	2019
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under sections 4.1 and 4.6 of the Listing Policy. Under sections 4.1 and 4.6, at least one line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. Four of four water samples exhibited toxicity, and three of five sediment samples exhibited toxicity. 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 of four water samples exhibited toxicity, and three of five sediment samples exhibited toxicity, and this sample size is sufficient to determine beneficial use support, with the power and confidence 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 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:	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 105579, Toxicity	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134420

Pollutant:

Sediment Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Chemical monitoring of sediments

Data Used to Assess Water Quality:

Two out of four samples displayed statistically significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%. One of the four samples (collected April 23, 2002) also displayed statistically significant toxicity in the survival endpoint compared to the negative control, but this data point is not included in the total 'toxic' samples as it had a data qualifier. All samples were tested using the 10-day Hyallela azteca test (SWAMP, 2004).

Data Reference:

Placeholder reference 2006 303(d)

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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, bioassays of appropriate duration or other appropriate methods as specified by the Regional Board (Region 9 Basin Plan, pages 3-15 to 3-16; September 8, 1994).

Objective/Criterion Reference:

Placeholder reference 2006 303(d)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

All samples were collected from one station, San Marcos Creek 6.

Temporal Representation:

Samples were collected from March 2002 through September 2002. Toxicity in the survival endpoint was detected in samples collected on March 13, 2002 and September 17, 2002.

Environmental Conditions:

QAPP Information:

SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 105579, Toxicity	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

216584

Pollutant:

Toxicity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Ambient toxicity testing (chronic)

Data Used to Assess Water Quality:

Four samples were collected at San Marcos Creek station 904CBSAM6. Four of four samples showed significant toxicity levels (SL) in the Selenastrum algae growth test. Toxicity test results can be found in California's Surface Water Ambient Monitoring Program Report, 2007.

Data Reference:

Monitoring data for Region 9

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

From the Basin Plan, all waters shall be free of toxic substances that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

According to SWAMP, waters are considered toxic when samples show significant toxicity levels (SWAMP code "SL") when compared to a negative control. Significant toxicity is determined when statistical tests result in an alpha of less than 5% and percent control values less than the evaluation threshold.

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:

Samples were collected from station: San Marcos Creek 6 (904CBSAM6).

Temporal Representation:

Samples were collected on March, April, June and September 2002.

Environmental Conditions:

QAPP Information:

Quality control for the chemical analysis portion of this study was conducted in accordance with the California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 105579, Toxicity	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134493

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm 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 exhibited significant toxicity. The toxicity test included survival and growth 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:

Statewide Project Urban Pyrethroid Status Monitoring

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 9 Basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

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:

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:

The sample was collected at station 904CBSAM6.

Temporal Representation:

The sample was collected in January 2007.

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):


DECISION ID	127835	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Ammonia
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:	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 are available in the administrative record to assess this pollutant. One of the 37 samples exceed the water quality threshold. 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 the 37 samples exceed the water quality threshold, 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 127835, Ammonia	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

184991

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 San Diego Coastkeeper Ambient Monitoring Program data for San Marcos Creek, Lower (below San Marcos Lake) to determine beneficial use support and results are as follows: 1 of 37 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-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 (BTQ-020)

Temporal Representation:

The samples were collected between the dates of 2010-11-20 and 2018-10-06

Environmental Conditions:

QAPP Information:

San Diego Coastkeeper. 2010. San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan.

QAPP Information Reference(s):

San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan


DECISION ID	115598	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Ammonia (Unionized)
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:	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 lines of evidence are available in the administrative record to assess this pollutant. One of the 37 samples exceed the water quality threshold. 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 37 samples exceeded the threshold 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 115598, Ammonia (Unionized)	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

185323

Pollutant:

Ammonia (Unionized)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 San Diego Coastkeeper Ambient Monitoring Program data for San Marcos Creek, Lower (below San Marcos Lake) to determine beneficial use support and results are as follows: 1 of 37 samples exceeded the water quality threshold for Ammonia as N, Unionized.

Data Reference:

Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The discharge of wastes shall not cause concentrations of un-ionized ammonia (NH3) to exceed 0.025 mg/l (as N) in inland surface waters, enclosed bays and estuaries and coastal lagoons (Water Quality Control Plan, San Diego Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (BTQ-020)

Temporal Representation:

The samples were collected between the dates of 2010-11-20 and 2018-10-06

Environmental Conditions:

QAPP Information:

San Diego Coastkeeper. 2010. San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan.

QAPP Information Reference(s):

San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan


DECISION ID	105593	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(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 105593, Copper	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

216586

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Non-fixed station physical/chemical (conventional + toxicants)

Data Used to Assess Water Quality:

One sample was taken, and the one sample exceeded the hardness adjusted criteria.

Data Reference:

Data for Various Pollutants in Region 9, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Inland surface waters, enclosed bays, and estuaries shall not contain toxic pollutants in excess of the numerical objectives applicable to California specified in 40 CFR 131.36 (section 131.36 revised at 57 FR 60848, December 22, 1992).

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) 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. If no hardness data were available, a value of 100 mg/L was used.

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:

The sample was collected from San Marcos Creek at Site 3, a location downstream from Lake San Marcos just outside the dam.

Temporal Representation:

The sample was collected on May 18, 2009.

Environmental Conditions:

QAPP Information:

The samples were collected and analyzed by the San Diego Regional Water Quality Control Board.

QAPP Information Reference(s):


DECISION ID	105610	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Fipronil Sulfide
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 105610, Fipronil Sulfide	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134470

Pollutant:

Fipronil Sulfide

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:

One of one sample result was not used in the assessment because the laboratory data was non-detect and the method detection limit was above the guideline and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the San Diego Basin (SDRWQCB 2007): 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:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

The evaluation guideline for fipronil sulfide is the median lethal concentration (LC50) of 0.16 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al. 2008).

Guideline Reference:

Effect of sediment-associated pyrethroids, fipronil, and metabolites on Chironomus tentans growth rate, body mass, condition index, immobilization, and survival. Environ. Toxicol. Chem. 27(12):2582-2590.

Spatial Representation:

Data for this line of evidence for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105613	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(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 105613, Lead	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

216594

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Non-fixed station physical/chemical (conventional + toxicants)

Data Used to Assess Water Quality:

One sample was taken, and the result was reported as "ND"; no reporting limit was provided with the data, so it could not be used in this assessment.

Data Reference:

Data for Various Pollutants in Region 9, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

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:

The sample was collected from San Marcos Creek at Site 3, a location downstream from Lake San Marcos just outside the dam.

Temporal Representation:

The sample was collected on May 18, 2009.

Environmental Conditions:

QAPP Information:

The sample was collected and analyzed by the San Diego Regional Water Quality Control Board.

QAPP Information Reference(s):


DECISION ID	105617	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(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 105617, Nickel	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

216596

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Non-fixed station physical/chemical (conventional + toxicants)

Data Used to Assess Water Quality:

The one sample did not exceed the hardness adjusted criteria.

Data Reference:

Data for Various Pollutants in Region 9, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

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:

The sample was collected from San Marcos Creek at Site 3, a location downstream from Lake San Marcos just outside the dam.

Temporal Representation:

The sample was collected on May 18, 2009.

Environmental Conditions:

QAPP Information:

The samples were collected and analyzed by the San Diego Regional Water Quality Control Board.

QAPP Information Reference(s):


DECISION ID	105618	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Oxygen, Dissolved
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 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 105618, Oxygen, Dissolved	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

216601

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

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 sample was collected, and the one sample exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Data for Various Pollutants in Region 9, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Dissolved oxygen levels shall not be less than 5.0 mg/l in inland surface waters with designated MAR or WARM beneficial uses. The annual mean dissolved oxygen concentration shall not be less than 7 mg/l more than 10% of the time.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The sample was collected from San Marcos Creek at Site 3, a location downstream from Lake San Marcos just outside the dam.

Temporal Representation:

The sample was collected on May 18, 2009.

Environmental Conditions:

QAPP Information:

NPDES quality assurance.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 105618, Oxygen, Dissolved	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

144396

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm 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 San Diego Coastkeeper Ambient Monitoring Program data for San Marcos Creek, Lower (below San Marcos Lake) to determine beneficial use support and results are as follows: 0 of 11 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Dissolved oxygen levels shall not be less than 5.0 mg/l in inland surface waters with the WARM beneficial use designated (Water Quality Control Plan, San Diego Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (BTQ-020)

Temporal Representation:

The samples were collected between the dates of 2016-07-16 and 2018-10-06

Environmental Conditions:

QAPP Information:

San Diego Coastkeeper. 2010. San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan.

QAPP Information Reference(s):

San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan


DECISION ID	105574	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Turbidity
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 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One lines of evidence are available in the administrative record to assess this pollutant. One of the 28 samples exceed the water quality threshold. 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. One of 28 samples exceeded the threshold 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:	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 105574, Turbidity	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

147823

Pollutant:

Turbidity

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:

Water Board staff assessed San Diego Coastkeeper Ambient Monitoring Program data for San Marcos Creek, Lower (below San Marcos Lake) to determine beneficial use support and results are as follows: 1 of 28 samples exceeded the water quality threshold for Turbidity.

Data Reference:

Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Turbidity water quality threshold in this HSA is 20 NTU, and this level is not to be exceeded more than 10% of the time during any one year period (Basin Plan, Table 3-2).

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (BTQ-020)

Temporal Representation:

The samples were collected between the dates of 2011-05-21 and 2018-10-06

Environmental Conditions:

QAPP Information:

San Diego Coastkeeper. 2010. San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan.

QAPP Information Reference(s):

San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan

Line of Evidence (LOE) for Decision ID 105574, Turbidity	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134413

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data were collected by RWQCB9 in 1998. One sample was collected and was not in exceedance (SWRCB, 2003).

Data Reference:

Placeholder reference 2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

From the Basin Plan: For inland surface waters and all beneficial uses, the WQO for turbidity is 20 ntu. This concentration is not to be exceeded more than 10% of the time during any one year period.

Objective/Criterion Reference:

Placeholder reference 2006 303(d)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Sample was collected at San Marcos Creek at Rancho Santa Fe Rd.

Temporal Representation:

Sample was collected on 06/03/1998.

Environmental Conditions:

QAPP Information:

Data used in 2002 assessment.

QAPP Information Reference(s):


DECISION ID	105626	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Zinc
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 105626, Zinc	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

216603

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Non-fixed station physical/chemical (conventional + toxicants)

Data Used to Assess Water Quality:

The one sample did not exceed the hardness adjusted criteria.

Data Reference:

Data for Various Pollutants in Region 9, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

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:

The sample was collected from San Marcos Creek at Site 3, a location downstream from Lake San Marcos just outside the dam.

Temporal Representation:

The sample was collected on May 18, 2009.

Environmental Conditions:

QAPP Information:

The samples were collected and analyzed by the San Diego Regional Water Quality Control Board.

QAPP Information Reference(s):


DECISION ID	105621	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(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 3.2 of the Listing Policy. Under section 3.2 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 41 samples exceed the Water Quality Objective for pH. 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. Zero of 41 samples exceeded the Water Quality Objective for pH, and this sample size is sufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. 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 105621, pH	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

216598

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The one sample did not exceed the objective.

Data Reference:

Data for Various Pollutants in Region 9, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH of all inland surface waters shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The sample was collected from San Marcos Creek at Site 3, a location downstream from Lake San Marcos just outside the dam.

Temporal Representation:

The sample was collected on May 18, 2009.

Environmental Conditions:

QAPP Information:

NPDES quality assurance.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 105621, pH	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

145236

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm 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 San Diego Coastkeeper Ambient Monitoring Program data for San Marcos Creek, Lower (below San Marcos Lake) to determine beneficial use support and results are as follows: 0 of 40 samples exceeded the water quality threshold for pH.

Data Reference:

Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

In inland surface waters the pH shall not be depressed below 6.5 nor raised above 8.5.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (BTQ-020)

Temporal Representation:

The samples were collected between the dates of 2010-11-20 and 2018-10-06

Environmental Conditions:

QAPP Information:

San Diego Coastkeeper. 2010. San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan.

QAPP Information Reference(s):

San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan


DECISION ID	127624	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Nitrogen
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	A Source Unknown
Expected TMDL Completion Date:	2033
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. Four of the 44 samples exceed the water quality threshold. 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. Four of the 44 samples exceed the water quality threshold, 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 127624, Nitrogen	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

144254

Pollutant:

Total Nitrogen as N

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 San Diego Coastkeeper Ambient Monitoring Program data for San Marcos Creek, Lower (below San Marcos Lake) to determine beneficial use support and results are as follows: 4 of 44 samples exceeded the water quality threshold for Nitrogen, Total.

Data Reference:

Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (BTQ-020)

Temporal Representation:

The samples were collected between the dates of 2010-09-11 and 2018-10-06

Environmental Conditions:

QAPP Information:

San Diego Coastkeeper. 2010. San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan.

QAPP Information Reference(s):

San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan


DECISION ID	105598	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
Final Listing Decision:	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)(2018)
Revision Status	Original
Reason for Delisting:	Delisting due to spatial change or other CalWQA administrative reason
Expected TMDL Completion Date:	2019
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. The waterbody was split for assessment purposes. In this waterbody section, one line of evidence is available in the administrative record to assess this pollutant. Zero of the one sample exceeded the water quality threshold. This sample size is insufficient to determine beneficial use support with the statistical power and confidence of the Listing Policy. 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. Zero of one sample exceeded the water quality threshold, and this sample size is insufficient to determine beneficial use support with the statistical power and confidence 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 105598, DDE (Dichlorodiphenyldichloroethylene)	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134452

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for DDE.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDE (o,p' + p,p') 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 for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105606	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Indicator Bacteria
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	Original
Reason for Delisting:	Applicable WQS attained; due to change in WQS
Expected TMDL Completion Date:	2025
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) list under section 4.3 of the Listing Policy. Under this section 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. Six of 42 samples exceeded the STV threshold for E. coli. 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 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. Six of 42 samples exceeded the E. coli water quality threshold for the protection of REC-1, and this does not exceed 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 not met. The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the “ISWEBE Plan”) contains two bacteria water quality objectives applicable to the REC-1 beneficial use, which were adopted on August 7, 2018. Because the salinity level of this waterbody is equal to or less than 1 part per thousand 95 percent or more of the time, the E. coli bacteria objective applies Therefore, this waterbody is being considered for placement on or removal from the CWA section 303(d) List under section 3.3 or 4.3 of the Listing Policy, as applicable, using the E. coli objective. In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Indicator bacteria (total coliform, fecal coliform, E. coli, enterococci) populations may fluctuate substantially on a daily, seasonal, or yearly basis. Lacking constant inputs, they do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of indicator bacteria in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Additionally, water quality conditions in waterbodies may change as a result of management actions that have been implemented to address bacteria. Unrepresentative data may result in incorrectly placing or not placing a water body segment on the list, which could result in the unnecessary expenditure of public resources or missing a human health problem. Historic lines of evidence for data collected prior to 2010 were evaluated pursuant to these considerations and were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy. For E. coli data, Listing Policy sections 3.3 and 4.3 instructs to use the binomial distribution table in sections 3.2 and 4.2, as applicable. To use the binomial table that uses a four percent exceedance frequency, the data must be collected from coastal beaches or inland surface waters from April 1 through October 31 only, and where collected from inland waters from April 1 through October 31 only, bacterial measurements must be indicative of human fecal matter, and there is substantial human contact in the waterbody. No fecal coliform data are used in this assessment because the fecal coliform water quality objective was superseded and is no longer used as the basis of any 303(d) List decision for water contact recreation.

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:	The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the “ISWEBE Plan”) contains two bacteria water quality objectives applicable to the REC-1 beneficial use, which were adopted on August 7, 2018. Because the salinity level of this waterbody is equal to or less than 1 part per thousand 95 percent or more of the time, the E. coli bacteria objective applies Therefore, this waterbody is being considered for placement on or removal from the CWA section 303(d) List under section 3.3 or 4.3 of the Listing Policy, as applicable, using the E. coli objective. In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Indicator bacteria (total coliform, fecal coliform, E. coli, enterococci) populations may fluctuate substantially on a daily, seasonal, or yearly basis. Lacking constant inputs, they do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of indicator bacteria in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Additionally, water quality conditions in waterbodies may change as a result of management actions that have been implemented to address bacteria. Unrepresentative data may result in incorrectly placing or not placing a water body segment on the list, which could result in the unnecessary expenditure of public resources or missing a human health problem. Historic lines of evidence for data collected prior to 2010 were evaluated pursuant to these considerations and were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy. For E. coli data, Listing Policy sections 3.3 and 4.3 instructs to use the binomial distribution table in sections 3.2 and 4.2, as applicable. To use the binomial table that uses a four percent exceedance frequency, the data must be collected from coastal beaches or inland surface waters from April 1 through October 31 only, and where collected from inland waters from April 1 through October 31 only, bacterial measurements must be indicative of human fecal matter, and there is substantial human contact in the waterbody. No fecal coliform data are used in this assessment because the fecal coliform water quality objective was superseded and is no longer used as the basis of any 303(d) List decision for water contact recreation.

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 105606, Indicator Bacteria	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

216590

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:

Not Specified

Data Used to Assess Water Quality:

The one sample exceeded the E. Coli objective.

Data Reference:

Data for Various Pollutants in Region 9, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The E. Coli concentration shall not exceed more than 235/100 ml.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The sample was collected from San Marcos Creek at Site 3, a location downstream from Lake San Marcos just outside the dam.

Temporal Representation:

The sample was collected on May 18, 2009.

Environmental Conditions:

QAPP Information:

No QAPP documents were included with the Regional Board Lab data.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 105606, Indicator Bacteria	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

216592

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The one sample exceeded the fecal coliform objective.

Data Reference:

Data for Various Pollutants in Region 9, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The fecal coliform concentration shall not exceed 400/100ml. 9 Basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The sample was collected from San Marcos Creek at Site 3, a location downstream from Lake San Marcos just outside the dam.

Temporal Representation:

The sample was collected on May 18, 2009.

Environmental Conditions:

QAPP Information:

Data was Regional Board Lab data.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 105606, Indicator Bacteria	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

216588

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The one sample exceeded the enterococcus objective.

Data Reference:

Data for Various Pollutants in Region 9, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The enterococcus concentration shall not exceed 61/100ml.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The sample was collected from San Marcos Creek at Site 3, a location downstream from Lake San Marcos just outside the dam.

Temporal Representation:

The sample was collected on May 18, 2009.

Environmental Conditions:

QAPP Information:

Data was Regional Board Lab data.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 105606, Indicator Bacteria	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

220617

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 San Marcos Creek, Lower (below San Marcos Lake) to determine beneficial use support and the results are as follows: 6 of the 42 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:

Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The bacteria water quality objective applicable to all non-saline waters, is a Statistical Threshold Value (STV) of 320 cfu/100 mL. The applicable STV shall not be exceeded by more than 10 percent of the samples collected in a calendar month, calculated in a static manner (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): BTQ-020

Temporal Representation:

The samples were collected between the days of 2010-09-11 and 2018-10-06 .

Environmental Conditions:

QAPP Information:

San Diego Coastkeeper. 2010. San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan.

QAPP Information Reference(s):

San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan

Line of Evidence (LOE) for Decision ID 105606, Indicator Bacteria	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

216600

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The one sample did not exceed the total coliform objective.

Data Reference:

Data for Various Pollutants in Region 9, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The total coliform concentration shall not exceed 10000/100ml. 9 Basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The sample was collected from San Marcos Creek at Site 3, a location downstream from Lake San Marcos just outside the dam.

Temporal Representation:

The sample was collected on May 18, 2009.

Environmental Conditions:

QAPP Information:

Data was Regional Board Lab data. No QAPP documents were included.

QAPP Information Reference(s):


DECISION ID	105587	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Bifenthrin
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	Original
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 105587, Bifenthrin	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134437

Pollutant:

Bifenthrin

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Bifenthrin.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 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 for this line of evidence for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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 105587, Bifenthrin	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134493

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The sample was collected at station 904CBSAM6.

Temporal Representation:

The sample was collected in January 2007.

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):


DECISION ID	105585	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Original
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 105585, Chlordane	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134434

Pollutant:

Chlordane

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:

0 of 1 samples collected exceeded the criteria for chlordane concentration (Sum of trans-Chlordane, cis-Chlordane, cis-Nonachlor, trans-Nonachlor, and Oxychlordane).

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

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. 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 San Diego Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

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 904CBSAM6 (San Marcos Creek 6).

Temporal Representation:

The samples were collected on 1/7/2007.

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	105590	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Chlorpyrifos
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	Original
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 105590, Chlorpyrifos	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134441

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:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

There is no chlorpyrifos evaluation guideline specific to "sediment, interstitial water" (pore water). The following evaluation guideline was used to evaluate an exceedance in water quality standards: the freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (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 (with minor corrections to significant figures as described in Beaulaurier et al., 2005).

Spatial Representation:

Data for this line of evidence for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105594	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Original
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 105594, Cyfluthrin	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134448

Pollutant:

Cyfluthrin

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Cyfluthrin, total.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 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

Spatial Representation:

Data for this line of evidence for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105595	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Cyhalothrin, Lambda
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	Original
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 105595, Cyhalothrin, Lambda	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134449

Pollutant:

Cyhalothrin, Lambda

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Cyhalothrin, lambda, total.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 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

Spatial Representation:

Data for this line of evidence for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105596	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Original
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 105596, Cypermethrin	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134450

Pollutant:

Cypermethrin

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Cypermethrin, total.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 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 for this line of evidence for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105597	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Original
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 105597, DDD (Dichlorodiphenyldichloroethane)	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134451

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for DDD.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for 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 for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105599	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Original
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 105599, DDT (Dichlorodiphenyltrichloroethane)	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134453

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for DDT.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDT (o,p' + p,p') 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 for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105600	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Original
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 105600, Deltamethrin	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134454

Pollutant:

Deltamethrin

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Deltamethrin.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 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

Spatial Representation:

Data for this line of evidence for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105602	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Diazinon
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	Original
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 105602, Diazinon	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134456

Pollutant:

Diazinon

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Diazinon.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

There is no diazinon evaluation guideline specific to "sediment, interstitial water" (pore water). The following evaluation guideline was used to evaluate an exceedance in water quality standards: the freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

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:

Data for this line of evidence for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105603	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Original
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 105603, Dieldrin	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134457

Pollutant:

Dieldrin

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Dieldrin.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

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 for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105604	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Original
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 105604, Endrin	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134458

Pollutant:

Endrin

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Endrin.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

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 for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105607	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Original
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 105607, Esfenvalerate/Fenvalerate	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134464

Pollutant:

Esfenvalerate/Fenvalerate

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Esfenvalerate/Fenvalerate, total.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 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

Spatial Representation:

Data for this line of evidence for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105608	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Original
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 105608, Fenpropathrin	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134468

Pollutant:

Fenpropathrin

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Fenpropathrin.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

The evaluation guideline for fenpropathrin is the median lethal concentration (LC50) of 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 for this line of evidence for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105609	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Fipronil
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	Original
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 105609, Fipronil	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134469

Pollutant:

Fipronil

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:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

The evaluation guideline for fipronil is the median lethal concentration (LC50) of 0.13 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al. 2008).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105611	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Fipronil Sulfone
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	Original
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 105611, Fipronil Sulfone	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134471

Pollutant:

Fipronil Sulfone

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:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

The evaluation guideline for fipronil sulfone is the median lethal concentration (LC50) of 0.12 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al. 2008).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105614	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Original
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 105614, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134477

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

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:

Water Board staff assessed SWAMP data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for HCH, gamma.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

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 for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105623	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

Pollutant:	Temperature, water
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	Original
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 105623, Temperature, water	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134487

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Four of the 9 samples exceeded the evaluation guideline for temperature in this water body.

Data Reference:

Data for Trash, Nutrients, and Pathogens in Region 9, 2007-2010.

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 Board that such alteration in temperature does not adversely affect beneficial uses. At no time or place shall the temperature of any COLD water be increased more than 5°F above the natural receiving water temperature.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

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). Since there is no evaluation guideline for assessing temperature for the warm freshwater aquatic life beneficial use, this line of evidence will not be used for Listing Decisions in the 2012 Integrated Report and will be retired for said Listing cycle.

Guideline Reference:

Fish introductions in CA: History and impact on native fishes. Davis, CA: University of CA, Davis

Spatial Representation:

Samples were collected at station BTQ-02-Box Canyon Dam (downstream at bank).

Temporal Representation:

Samples were collected between January, 2009 and July, 2010.

Environmental Conditions:

QAPP Information:

San Diego Regional Water Quality Assessment and Outreach Project Quality Assurance Project Plan Prepared by: Clay Clifton (San Diego Coastkeeper, Local Project Sponsor Manager), Bob Stafford (San Diego Stream Team), Dr. Rick Gersberg (San Diego State University), Bryan Bjorndal (Assure Controls, Inc.), and Morgan Justice-Black (I Love A Clean San Diego).

QAPP Information Reference(s):


DECISION ID	105624	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Original
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 105624, Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134491

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:

Warm 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 data for San Marcos Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for DDT, Total.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for total DDTs (Sum DDT + Sum DDD + Sum DDE) is 572 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 for San Marcos Creek was collected at 1 monitoring site [ San Marcos Creek 6 - 904CBSAM6]

Temporal Representation:

Data was collected on a single day 1/7/2007.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 2002.

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	105573	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

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)(2018)
Revision Status	Original
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 105573, Total Dissolved Solids	Region 9
San Marcos Creek, Lower (below San Marcos Lake)

LOE ID:

134412

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total Dissolved

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data were collected by RWQCB9 in 1998. One sample was collected, it was in exceedance. (SWRCB, 2003).

Data Reference:

Placeholder reference 2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

From the Basin Plan: For inland surface waters and all beneficial uses, the WQO for TDS is 500 mg/L. This concentration is not to be exceeded more than 10% of the time during any one year period.

Objective/Criterion Reference:

Placeholder reference 2006 303(d)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Sample was collected at San Marcos Creek at Rancho Santa Fe Rd.

Temporal Representation:

Sample was collected on 06/03/1998.

Environmental Conditions:

QAPP Information:

Data used in 2002 assessment.

QAPP Information Reference(s):