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

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name:	Cottonwood Creek below Barrett Reservoir
Water Body ID:	CAR9112300020200819032043
Water Body Type:	River & Stream


DECISION ID	105629	Region 9
Cottonwood Creek below Barrett Reservoir

Pollutant:	Selenium
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
Expected TMDL Completion Date:	2019
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under 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. Two of the 10 samples exceeded the aquatic life objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two of 10 samples exceeded the objective, 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 105629, Selenium	Region 9
Cottonwood Creek below Barrett Reservoir

LOE ID:

146415

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:

Water Board staff assessed San Diego Region NPDES data for Cottonwood Creek below Barrett Reservoir to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Selenium.

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 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 (CT_TIJ07)

Temporal Representation:

The samples were collected between the dates of 2011-03-28 and 2012-04-10

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 105629, Selenium	Region 9
Cottonwood Creek below Barrett Reservoir

LOE ID:

146554

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, Habitat, 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 (CT_TIJ07)

Temporal Representation:

The samples were collected between the dates of 2011-03-28 and 2012-04-10

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 105629, Selenium	Region 9
Cottonwood Creek below Barrett Reservoir

LOE ID:

134505

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:

Two water samples were collected at Cottonwood Creek 10, station 911TCWD10 on June 2005, and April 2006.

Data Reference:

Monitoring data for Region 9

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Water samples were collected at Cottonwood Creek station 2, 911TCWD10.

Temporal Representation:

Samples were collected on June 2005, and April 2006.

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 105629, Selenium	Region 9
Cottonwood Creek below Barrett Reservoir

LOE ID:

146416

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:

Water Board staff assessed San Diego Region NPDES data for Cottonwood Creek below Barrett Reservoir to determine beneficial use support and results are as follows: 0 of 9 samples exceeded the water quality threshold for Selenium.

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 (CT_TIJ07)

Temporal Representation:

The samples were collected between the dates of 2011-02-07 and 2012-04-10

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 105629, Selenium	Region 9
Cottonwood Creek below Barrett Reservoir

LOE ID:

146480

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, Habitat, 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 (CT_TIJ07)

Temporal Representation:

The samples were collected between the dates of 2011-02-07 and 2012-04-10

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 105629, Selenium	Region 9
Cottonwood Creek below Barrett Reservoir

LOE ID:

146692

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 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 (CT_TIJ07)

Temporal Representation:

The samples were collected between the dates of 2011-02-07 and 2012-04-10

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 105629, Selenium	Region 9
Cottonwood Creek below Barrett Reservoir

LOE ID:

146551

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 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 (CT_TIJ07)

Temporal Representation:

The samples were collected between the dates of 2011-03-28 and 2012-04-10

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	105676	Region 9
Cottonwood Creek below Barrett Reservoir

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. One line(s) of evidence evaluating benthic-macroinvertebrate bioassessment data is/are available in the administrative record to assess this indicator. Zero of one 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. Zero of one 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:	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 105676, Benthic Community Effects	Region 9
Cottonwood Creek below Barrett Reservoir

LOE ID:

215211

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Data used to generate the SWAMP Bioassessment Scores Map. The one sample collected from 911S12262 produced a CSCI score of 0.94.

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 911S12262.

Temporal Representation:

Samples were collected from 911S12262 on 5/24/2010.

Environmental Conditions:

QAPP Information:

Data collected following SWAMP QA Protocols

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 105676, Benthic Community Effects	Region 9
Cottonwood Creek below Barrett Reservoir

LOE ID:

134586

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

BIOLOGICAL MONITORING

Data Used to Assess Water Quality:

Data used to generate the SWAMP Bioassessment Scores Map. The one sample collected from 911S12262 produced a CSCI score of 0.94. The three samples collected from 911NP9UCW produced the following CSCI scores: 1.01, 0.91 and 0.98. Therefore, it is not exceeding the water quality objective for the aquatic life beneficial use. Additionally, this water body at Station 911NP9UCW passed several screening criteria and was identified as a reference water body for the purposes of developing the CSCI. Reference sites where human disturbance is absent or minimal are used to set benchmark expectations for healthy streams. A large set of nearly 600 reference sites representing the broad diversity of natural stream types found across California was used to develop the CSCI.

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:

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 at 911S12262 and 911NP9UCW.

Temporal Representation:

Samples were collected from 911S12262 on 5/24/2010. Samples were collected from 911NP9UCW on 3/24/2014, 4/29/2014 and 3/18/2015.

Environmental Conditions:

QAPP Information:

Data collected following SWAMP QA protocols.

QAPP Information Reference(s):