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

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name:	Los Coches Creek
Water Body ID:	CAR9071400020081210155144
Water Body Type:	River & Stream


DECISION ID	127887	Region 9
Los Coches Creek

Pollutant:	Indicator Bacteria
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:	2027
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 section 4.3 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 five samples exceed the STV threshold for E. coli. 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 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. Four of five sample exceeded the E. coli water quality threshold for the protection of REC-1, and this is insufficient information 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 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:	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 127887, Indicator Bacteria	Region 9
Los Coches Creek

LOE ID:

220668

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 Los Coches Creek to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, Habitat, Sediment, Toxicity, 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): CT_SDR-1024

Temporal Representation:

The samples were collected between the days of 2017-08-09 and 2017-08-09 .

Environmental Conditions:

QAPP Information:

County of San Diego - Dept of Public Works. 2008. Quality Assurance Project Plan from Southern California Bight. ., Weston Solutions, Inc.. 2014. Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program., Wood. 2019. Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load., Weston Solutions, Inc.. 2019. Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 127887, Indicator Bacteria	Region 9
Los Coches Creek

LOE ID:

220696

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:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): CT_SDR-041

Temporal Representation:

The samples were collected between the days of 2017-08-09 and 2017-08-09 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 127887, Indicator Bacteria	Region 9
Los Coches Creek

LOE ID:

220675

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:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): CT_SDR-740

Temporal Representation:

The samples were collected between the days of 2017-08-09 and 2017-08-09 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 127887, Indicator Bacteria	Region 9
Los Coches Creek

LOE ID:

220646

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 Los Coches Creek to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): CT_SDR-754

Temporal Representation:

The samples were collected between the days of 2017-08-09 and 2017-08-09 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 127887, Indicator Bacteria	Region 9
Los Coches Creek

LOE ID:

220706

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:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): CT_SDR-751

Temporal Representation:

The samples were collected between the days of 2017-08-09 and 2017-08-09 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 127887, Indicator Bacteria	Region 9
Los Coches Creek

LOE ID:

74205

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:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed County of San Diego data for Los Coches Creek to determine beneficial use support and results are as follows: 12 of 13 samples exceed the criterion for Enterococci.

Data Reference:

Data for Metals, Nutrients, Inorganics, Organics, Pathogens, and Pesticides from the County of San Diego, 2003-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Samples shall not exceed 61 organisms per 100 ml for enterococcus in waters designated for REC I beneficial use (Water Quality Control Plan for the San Diego Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Los Coches Creek was collected at 2 monitoring sites [ Los Coches Creek @ I-8 Business Route, Los Coches Creek @ Los Coches Road and Ha Hana Road]

Temporal Representation:

Data was collected over the time period 5/21/2003-6/24/2009.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8.

Line of Evidence (LOE) for Decision ID 127887, Indicator Bacteria	Region 9
Los Coches Creek

LOE ID:

74206

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:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed County of San Diego data for Los Coches Creek to determine beneficial use support and results are as follows: 8 of 13 samples exceed the criterion for Coliform, Fecal.

Data Reference:

Data for Metals, Nutrients, Inorganics, Organics, Pathogens, and Pesticides from the County of San Diego, 2003-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

In waters designated for water contact recreation (REC I), the fecal coliform concentration shall not exceed 400 MPN/100 ml.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Los Coches Creek was collected at 2 monitoring sites [ Los Coches Creek @ I-8 Business Route, Los Coches Creek @ Los Coches Road and Ha Hana Road]

Temporal Representation:

Data was collected over the time period 5/21/2003-6/24/2009.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8.

Line of Evidence (LOE) for Decision ID 127887, Indicator Bacteria	Region 9
Los Coches Creek

LOE ID:

74217

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:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed County of San Diego data for Los Coches Creek to determine beneficial use support and results are as follows: 3 of 13 samples exceed the criterion for Coliform, Total.

Data Reference:

Data for Metals, Nutrients, Inorganics, Organics, Pathogens, and Pesticides from the County of San Diego, 2003-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxicsubstances in concentrations which are toxic to,or which produce detrimental physiologicalresponses in human, plant, animal, or indigenousaquatic life (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

In waters designated for water contact recreation (REC I), the total coliform concentration shall not exceed 10000 MPN/100 ml (CDPH 2006).

Guideline Reference:

Draft Guidance for Fresh Water Beaches. Last Update: May 8, 2006. Initial Draft: November 1997. California Department of Public Health.

Spatial Representation:

Data for this line of evidence for Los Coches Creek was collected at 2 monitoring sites [ Los Coches Creek @ I-8 Business Route, Los Coches Creek @ Los Coches Road and Ha Hana Road]

Temporal Representation:

Data was collected over the time period 5/21/2003-6/24/2009.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8.


DECISION ID	127615	Region 9
Los Coches Creek

Pollutant:	Nitrogen
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:	2027
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. Six of the six 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. Six of the six 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 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:	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 127615, Nitrogen	Region 9
Los Coches Creek

LOE ID:

144195

Pollutant:

Total Nitrogen as N

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 Region NPDES data for Los Coches Creek to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Nitrogen, Total.

Data Reference:

Field, Habitat, Sediment, Toxicity, 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 (907M23331)

Temporal Representation:

The samples were collected between the dates of 2016-06-08 and 2016-06-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 127615, Nitrogen	Region 9
Los Coches Creek

LOE ID:

143905

Pollutant:

Total Nitrogen as N

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 SMC Regional Watershed Monitoring data for Los Coches Creek to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Nitrogen, Total.

Data Reference:

Field, Sediment, Toxicity, 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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 127615, Nitrogen	Region 9
Los Coches Creek

LOE ID:

26189

Pollutant:

Nitrogen

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

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 of four samples collected at Los Coches Creek station (907SDLCO2) from May 2004 to April 2005 showed excessive nitrogen concentrations (SWAMP, 2007).

Data Reference:

Monitoring data for Region 9

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water bodies shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growths cause nuisance or adversely affect beneficial uses (RWQCB, 2007).

A desired goal in order to prevent plant nuisance in streams and other flowing waters appears to be 0.1 mg/L total phosphorus, P. These values are not to be exceeded more than 10% of the time unless studies of the specific water body in question clearly show that water quality objective changes are permissible and changes are approved by the Regional Board. 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 (RWQCB, 2007).

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Water samples were collected at Los Coches Creek station 2 (907SDLCO2).

Temporal Representation:

Samples were collected in May 2004, September 2004, February 2005, and April 2005.

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	113484	Region 9
Los Coches Creek

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
Expected TMDL Completion Date:	2023
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. Three of the six 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. Three of the six samples exceeded 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 113484, Phosphorus	Region 9
Los Coches Creek

LOE ID:

146075

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 SMC Regional Watershed Monitoring data for Los Coches Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Phosphorus as P.

Data Reference:

Field, Sediment, Toxicity, 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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113484, Phosphorus	Region 9
Los Coches Creek

LOE ID:

26190

Pollutant:

Phosphorus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

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:

Two of four samples collected at Los Coches Creek station 2(907SDLCO2) from May 2004 to April 2005 showed excessive phosphorus concentrations (SWAMP, 2007).

Data Reference:

Monitoring data for Region 9

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

As described in San Diego Basin Plan; inland surface waters, bays and estuaries and coastal lagoon waters shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growths cause nuisance or adversely affect beneficial uses (RWQCB, 2007).

From the Basin Plan: For inland surface waters-streams and other flowing waters, with all beneficial uses, the water quality objective for total phosphorus is 0.1 mg/L (RWQCB, 2007).

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Water samples were collected at Los Coches Creek station 2 (907SDLCO2).

Temporal Representation:

Samples were collected in May 2004, September 2004; February 2005; and April 2005.

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

Line of Evidence (LOE) for Decision ID 113484, Phosphorus	Region 9
Los Coches Creek

LOE ID:

145958

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:

Data Reference:

Field, Habitat, Sediment, Toxicity, 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 (907M23331)

Temporal Representation:

The samples were collected between the dates of 2016-06-08 and 2016-06-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	113485	Region 9
Los Coches Creek

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:	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. Two lines of evidence are available in the administrative record to assess pollutant. Three of the five 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 five samples exceeded 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 113485, Selenium	Region 9
Los Coches Creek

LOE ID:

146652

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.005 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113485, Selenium	Region 9
Los Coches Creek

LOE ID:

146569

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California MCL for Selenium is .05 mg/L (Title 22 California Code of Regulations).

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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113485, Selenium	Region 9
Los Coches Creek

LOE ID:

146545

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.005 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113485, Selenium	Region 9
Los Coches Creek

LOE ID:

146563

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, 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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113485, Selenium	Region 9
Los Coches Creek

LOE ID:

26191

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:

Three of four samples collected at Los Coches Creek station 2 (907SDLCO2) from May 2004 to April 2005 showed excessive phosphorus concentrations (SWAMP, 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 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:

Water samples were collected at Los Coches Creek station 2(907SDLCO2).

Temporal Representation:

Samples were collected in May 2004, September 2004; February 2005; and April 2005.

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	113489	Region 9
Los Coches Creek

Pollutant:	Alkalinity as CaCO3
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 113489, Alkalinity as CaCO3	Region 9
Los Coches Creek

LOE ID:

139543

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, San Diego Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

The CCC of 20mg/L is a minimum value except where alkalinity is naturally lower, in which case the criterion cannot be lower than 25% of the natural level (USEPA National Recommended Water Quality Criteria Aquatic Life)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (907M23331)

Temporal Representation:

The samples were collected between the dates of 2016-06-08 and 2016-06-08

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113489, Alkalinity as CaCO3	Region 9
Los Coches Creek

LOE ID:

139560

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, 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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113489, Alkalinity as CaCO3	Region 9
Los Coches Creek

LOE ID:

139559

Pollutant:

Alkalinity as CaCO3

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 Region NPDES data for Los Coches Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3.

Data Reference:

Field, Habitat, Sediment, Toxicity, 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 (907M23331)

Temporal Representation:

The samples were collected between the dates of 2016-06-08 and 2016-06-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	127830	Region 9
Los Coches Creek

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 127830, Ammonia	Region 9
Los Coches Creek

LOE ID:

185170

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, 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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	115531	Region 9
Los Coches Creek

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:	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 115531, Ammonia (Unionized)	Region 9
Los Coches Creek

LOE ID:

185378

Pollutant:

Ammonia (Unionized)

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 SMC Regional Watershed Monitoring data for Los Coches Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ammonia as N, Unionized. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Sediment, Toxicity, 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 (SMC11430).

Temporal Representation:

Date for this waterbody was collected over the date range 2012-07-12 to 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	113476	Region 9
Los Coches Creek

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 113476, Arsenic	Region 9
Los Coches Creek

LOE ID:

140158

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 0.150 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113476, Arsenic	Region 9
Los Coches Creek

LOE ID:

140310

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Maximum Contaminant Level for arsenic is 0.01 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113476, Arsenic	Region 9
Los Coches Creek

LOE ID:

140338

Pollutant:

Arsenic

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:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 0.150 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113476, Arsenic	Region 9
Los Coches Creek

LOE ID:

140247

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Maximum Contaminant Level for arsenic is 0.01 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	126076	Region 9
Los Coches Creek

Pollutant:	Benthic Community Effects
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:	Benthic Community Effects are being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, additional lines of evidence (LOEs) associating the Benthic Community Effects decision with a water or sediment concentration of pollutants other than benthic-macroinvertebrate bioassessment or habitat assessment LOEs are necessary to place a water body on the 303(d) List for Benthic Community Effects. Two line(s) of evidence evaluating benthic-macroinvertebrate bioassessment data is/are available in the administrative record to assess this indicator. One of three benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. These data indicate that the waterbody is likely unimpaired for Benthic Community Effects and therefore no other pollutant LOEs need be associated with this decision at this time. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this waterbody segment on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of three benthic-macroinvertebrate bioassessment samples had CSCI scores below 0.79. Therefore, this water body is not exceeding the water quality threshold for the protection of the COLD beneficial use. The available information indicates that the waterbody/pollutant combination should not be placed on the 303(d) List of impaired waters at this time. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list 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 126076, Benthic Community Effects	Region 9
Los Coches Creek

LOE ID:

133504

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 at 907S11430 produced a CSCI score of 0.85, and the one sample collected at 907LCCHW8 produced a CSCI score of 0.94, and the one sample collected at . 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 907S11430 and 907LCCHW8.

Temporal Representation:

Samples were collected on 7/12/2012 at 907S11430 and on 4/29/2014 at 907LCCHW8.

Environmental Conditions:

QAPP Information:

Data collected following SWAMP QA protocols.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 126076, Benthic Community Effects	Region 9
Los Coches Creek

LOE ID:

215722

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:

Water Board staff assessed data for 907M23331 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.7754 to 0.7754 .

Data Reference:

California Stream Condition Index Scores for the 2020 Integrated Report

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Bioassessment in complex environments: designing an index for consistent meaning in different settings

Spatial Representation:

Samples were collected from station 907M23331

Temporal Representation:

Samples were collected from 6/8/2016 to 6/8/2016.

Environmental Conditions:

QAPP Information:

The data was collected under a permit required receiving waters monitoring and reporting program

QAPP Information Reference(s):

Quality Assurance Project Plan for Southern California Regional Watershed Monitoring Program Bioassessment, Version 1.0, and Freshwater Bioassessment from Weston Solutions.


DECISION ID	113477	Region 9
Los Coches Creek

Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(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 113477, Cadmium	Region 9
Los Coches Creek

LOE ID:

140511

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Maximum Contaminant Level for cadmium is 0.005 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113477, Cadmium	Region 9
Los Coches Creek

LOE ID:

140556

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Maximum Contaminant Level for cadmium is 0.005 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113477, Cadmium	Region 9
Los Coches Creek

LOE ID:

141085

Pollutant:

Cadmium

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:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113477, Cadmium	Region 9
Los Coches Creek

LOE ID:

74202

Pollutant:

Cadmium

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 County of San Diego DWM data for Los Coches Creek to determine beneficial use support and results are as follows: 0 of 13 samples exceed the criterion for Cadmium.

Data Reference:

Data for Metals, Nutrients, Inorganics, Organics, Pathogens, and Pesticides from the County of San Diego, 2003-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Los Coches Creek was collected at 2 monitoring sites [ Los Coches Creek @ I-8 Business Route, Los Coches Creek @ Los Coches Road and Ha Hana Road]

Temporal Representation:

Data was collected from May 2003 to June 2009.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8.


DECISION ID	125570	Region 9
Los Coches Creek

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 125570, Chloride	Region 9
Los Coches Creek

LOE ID:

215133

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Chloride objective in this HSA is 400 mg/L, and this concentration 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 (907M23331)

Temporal Representation:

The samples were collected on 6/8/2016

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 125570, Chloride	Region 9
Los Coches Creek

LOE ID:

215134

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Chloride objective in this HSA is 400 mg/L, and this concentration 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 (SMC11430)

Temporal Representation:

The samples were collected on 7/12/2012

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	113490	Region 9
Los Coches Creek

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 113490, Chromium	Region 9
Los Coches Creek

LOE ID:

141121

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for total chromium is 0.05 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113490, Chromium	Region 9
Los Coches Creek

LOE ID:

141249

Pollutant:

Chromium

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:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113490, Chromium	Region 9
Los Coches Creek

LOE ID:

141125

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for total chromium is 0.05 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	113478	Region 9
Los Coches Creek

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 113478, Copper	Region 9
Los Coches Creek

LOE ID:

141715

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Secondary MCL for copper is 1.0 mg/L (Title 22 California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113478, Copper	Region 9
Los Coches Creek

LOE ID:

74204

Pollutant:

Copper

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 County of San Diego DWM data for Los Coches Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Copper.

Data Reference:

Data for Metals, Nutrients, Inorganics, Organics, Pathogens, and Pesticides from the County of San Diego, 2003-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Los Coches Creek was collected at 2 monitoring sites [ Los Coches Creek @ I-8 Business Route, Los Coches Creek @ Los Coches Road and Ha Hana Road]

Temporal Representation:

Data was collected from May 2003 to June 2009.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8.

Line of Evidence (LOE) for Decision ID 113478, Copper	Region 9
Los Coches Creek

LOE ID:

141672

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113478, Copper	Region 9
Los Coches Creek

LOE ID:

141932

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Secondary MCL for copper is 1.0 mg/L (Title 22 California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	113479	Region 9
Los Coches Creek

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 113479, Lead	Region 9
Los Coches Creek

LOE ID:

143118

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Maximum Contaminant Level for lead is .015 mg/L (Title 22 of the California Code of Regulations).

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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113479, Lead	Region 9
Los Coches Creek

LOE ID:

142868

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Maximum Contaminant Level for lead is .015 mg/L (Title 22 of the California Code of Regulations).

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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113479, Lead	Region 9
Los Coches Creek

LOE ID:

74215

Pollutant:

Lead

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 County of San Diego DWM data for Los Coches Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Lead.

Data Reference:

Data for Metals, Nutrients, Inorganics, Organics, Pathogens, and Pesticides from the County of San Diego, 2003-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Los Coches Creek was collected at 2 monitoring sites [ Los Coches Creek @ I-8 Business Route, Los Coches Creek @ Los Coches Road and Ha Hana Road]

Temporal Representation:

Data was collected from May 2003 to June 2009.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8.

Line of Evidence (LOE) for Decision ID 113479, Lead	Region 9
Los Coches Creek

LOE ID:

142904

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	113480	Region 9
Los Coches Creek

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 113480, Nickel	Region 9
Los Coches Creek

LOE ID:

143643

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nickel is 0.1 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113480, Nickel	Region 9
Los Coches Creek

LOE ID:

143661

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nickel is 0.1 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113480, Nickel	Region 9
Los Coches Creek

LOE ID:

143666

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	113481	Region 9
Los Coches Creek

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 113481, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 9
Los Coches Creek

LOE ID:

143833

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nitrate + nitrite (as N) is 10.0 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (907M23331)

Temporal Representation:

The samples were collected between the dates of 2016-06-08 and 2016-06-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 113481, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 9
Los Coches Creek

LOE ID:

143896

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nitrate + nitrite (as N) is 10.0 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	127773	Region 9
Los Coches Creek

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 127773, Nitrogen, Nitrite	Region 9
Los Coches Creek

LOE ID:

144054

Pollutant:

Nitrogen, Nitrite

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nitrite (as N) is 1.0 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	113482	Region 9
Los Coches Creek

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 113482, Oxygen, Dissolved	Region 9
Los Coches Creek

LOE ID:

144532

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, 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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113482, Oxygen, Dissolved	Region 9
Los Coches Creek

LOE ID:

144605

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, 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 (907M23331)

Temporal Representation:

The samples were collected between the dates of 2016-06-08 and 2016-06-08

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	127659	Region 9
Los Coches Creek

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 127659, Specific Conductivity	Region 9
Los Coches Creek

LOE ID:

146900

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Table 64449-A of section 64449 of Title 22 of the California Code of Regulations (Secondary Maximum Contaminant Levels, Consumer Acceptance Limits) which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Secondary MCL for specific conductance is 900 uS/cm (Title 22 California Code of Regulations).

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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 127659, Specific Conductivity	Region 9
Los Coches Creek

LOE ID:

146810

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Table 64449-A of section 64449 of Title 22 of the California Code of Regulations (Secondary Maximum Contaminant Levels, Consumer Acceptance Limits) which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Secondary MCL for specific conductance is 900 uS/cm (Title 22 California Code of Regulations).

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 (907M23331)

Temporal Representation:

The samples were collected between the dates of 2016-06-08 and 2016-06-08

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	125571	Region 9
Los Coches Creek

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 125571, Sulfates	Region 9
Los Coches Creek

LOE ID:

215171

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Sulfate objective in this HSA is 500 mg/L, and this concentration 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 (SMC11430).

Temporal Representation:

The samples were collected on 7/12/2012.

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 125571, Sulfates	Region 9
Los Coches Creek

LOE ID:

215172

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Sulfate objective in this HSA is 500 mg/L, and this concentration 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 (907M23331).

Temporal Representation:

The samples were collected on 6/8/2016.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	113486	Region 9
Los Coches Creek

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 113486, Toxicity	Region 9
Los Coches Creek

LOE ID:

134739

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

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:

0 of the 1 samples collected by SMC Regional Watershed Monitoring for Los Coches Creek exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day, at the same location with the same lab sample ID (if provided). The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia, for Survival, Ceriodaphnia dubia, for Young/female

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-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.

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 station. Monitoring site: ( SMC11430 )

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12.

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	113487	Region 9
Los Coches Creek

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 113487, Turbidity	Region 9
Los Coches Creek

LOE ID:

147648

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:

Data Reference:

Field, Sediment, Toxicity, 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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113487, Turbidity	Region 9
Los Coches Creek

LOE ID:

147393

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Secondary California Maximum Contaminant Level for Turbidity is 5 NTU (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (907M23331)

Temporal Representation:

The samples were collected between the dates of 2016-06-08 and 2016-06-08

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113487, Turbidity	Region 9
Los Coches Creek

LOE ID:

147489

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:

Data Reference:

Field, Sediment, Toxicity, 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 (907M23331)

Temporal Representation:

The samples were collected between the dates of 2016-06-08 and 2016-06-08

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113487, Turbidity	Region 9
Los Coches Creek

LOE ID:

148080

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Secondary California Maximum Contaminant Level for Turbidity is 5 NTU (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	113488	Region 9
Los Coches Creek

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 113488, Zinc	Region 9
Los Coches Creek

LOE ID:

148197

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Secondary MCL for zinc is 5.0 mg/L (Title 22 California Code of Regulations).

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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113488, Zinc	Region 9
Los Coches Creek

LOE ID:

148143

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113488, Zinc	Region 9
Los Coches Creek

LOE ID:

148171

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Secondary MCL for zinc is 5.0 mg/L (Title 22 California Code of Regulations).

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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113488, Zinc	Region 9
Los Coches Creek

LOE ID:

74218

Pollutant:

Zinc

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 County of San Diego DWM data for Los Coches Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Zinc.

Data Reference:

Data for Metals, Nutrients, Inorganics, Organics, Pathogens, and Pesticides from the County of San Diego, 2003-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Los Coches Creek was collected at 2 monitoring sites [ Los Coches Creek @ I-8 Business Route, Los Coches Creek @ Los Coches Road and Ha Hana Road]

Temporal Representation:

Data was collected from May 2003 to June 2009.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8.


DECISION ID	113483	Region 9
Los Coches Creek

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 113483, pH	Region 9
Los Coches Creek

LOE ID:

145670

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:

Data Reference:

Field, Sediment, Toxicity, 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 (907M23331)

Temporal Representation:

The samples were collected between the dates of 2016-06-08 and 2016-06-08

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition

Line of Evidence (LOE) for Decision ID 113483, pH	Region 9
Los Coches Creek

LOE ID:

145563

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:

Data Reference:

Field, Sediment, Toxicity, 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 (SMC11430)

Temporal Representation:

The samples were collected between the dates of 2012-07-12 and 2012-07-12

Environmental Conditions:

QAPP Information:

Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.

QAPP Information Reference(s):

Regional Monitoring of Southern California's Coastal Watersheds

QAPP Information Reference(s):

Bioassessment Survey of the Stormwater Monitoring Coalition


DECISION ID	81472	Region 9
Los Coches Creek

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)(2016)
Revision Status	Original
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 one line of evidence are necessary to assess listing status. One lines of evidence are available in the administrative record to assess this pollutant. Zero of the Zero samples exceed the guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the 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 Zero samples exceeded the GUIDELINE and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 81472, Chlorpyrifos	Region 9
Los Coches Creek

LOE ID:

74203

Pollutant:

Chlorpyrifos

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 County of San Diego data for Los Coches Creek to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Chlorpyrifos.

Data Reference:

Data for Metals, Nutrients, Inorganics, Organics, Pathogens, and Pesticides from the County of San Diego, 2003-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in the water column, sediments or biota at concentration(s) that adversely affect beneficial uses (Water Quality Control Plan, San Diego Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

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

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game (with minor corrections to significant figures as described in Beaulaurier et al., 2005).

Spatial Representation:

Data for this line of evidence for Los Coches Creek was collected at 2 monitoring sites [ Los Coches Creek @ Los Coches Road and Ha Hana Road, Los Coches Creek @ I-8 Business Route]

Temporal Representation:

Data was collected over the time period 8/5/2004-6/24/2009.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8.


DECISION ID	81784	Region 9
Los Coches Creek

Pollutant:	Malathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
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 one line of evidence are necessary to assess listing status. One lines of evidence is available in the administrative record to assess this pollutant. 0 of the 9 samples exceed the criterion. 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 nine samples exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy,

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should 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 81784, Malathion	Region 9
Los Coches Creek

LOE ID:

74216

Pollutant:

Malathion

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 County of San Diego data for Los Coches Creek to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for Malathion.

Data Reference:

Data for Metals, Nutrients, Inorganics, Organics, Pathogens, and Pesticides from the County of San Diego, 2003-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

The USEPA national ambient water quality criteria for freshwater aquatic life instantaneous maximum for malathion is 0.1 µg/L.

Guideline Reference:

2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013

Spatial Representation:

Data for this line of evidence for Los Coches Creek was collected at 2 monitoring sites [ Los Coches Creek @ I-8 Business Route, Los Coches Creek @ Los Coches Road and Ha Hana Road]

Temporal Representation:

Data was collected over the time period 9/23/2005-6/24/2009.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8 was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from the Truesdail Laboratories, Rev. 12, Enviromatrix Analytical and Dry Weather Monitoring Program Rev. 8.