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

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name:	Cottonwood Creek above Morena Reservoir
Water Body ID:	CAR9116000020200819035396
Water Body Type:	River & Stream


DECISION ID	115463	Region 9
Cottonwood Creek above Morena Reservoir

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 115463, Alkalinity as CaCO3	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

139748

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 SWAMP RWB9 Monitoring data for Cottonwood Creek above Morena Reservoir to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Alkalinity as CaCO3.

Data Reference:

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

SWAMP Data:

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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 115463, Alkalinity as CaCO3	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

139746

Pollutant:

Alkalinity as CaCO3

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

QAPP Information Reference(s):

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


DECISION ID	127866	Region 9
Cottonwood Creek above Morena Reservoir

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 127866, Ammonia	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

184964

Pollutant:

Nitrogen, ammonia (Total Ammonia)

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 127866, Ammonia	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

185196

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

QAPP Information Reference(s):

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


DECISION ID	115599	Region 9
Cottonwood Creek above Morena Reservoir

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:

Line of Evidence (LOE) for Decision ID 115599, Ammonia (Unionized)	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

185600

Pollutant:

Ammonia (Unionized)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB9 Monitoring data for Cottonwood Creek above Morena Reservoir to determine beneficial use support and the results are as follows: 0 of the 4 samples exceeded the water quality threshold for Ammonia as N, Unionized. Although a total of 5 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

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 (911NP9UCW).

Temporal Representation:

Data for this waterbody was collected over the date range 2014-03-24 to 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 115599, Ammonia (Unionized)	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

185553

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:

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (911NP9UCW).

Temporal Representation:

Data for this waterbody was collected over the date range 2014-03-24 to 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

QAPP Information Reference(s):

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


DECISION ID	105630	Region 9
Cottonwood Creek above Morena 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. Four line(s) of evidence evaluating benthic-macroinvertebrate bioassessment data is/are available in the administrative record to assess this indicator. Zero of Eight 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 eight 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 105630, Benthic Community Effects	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134587

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:

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 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):

Line of Evidence (LOE) for Decision ID 105630, Benthic Community Effects	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

215210

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 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:

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 State or Regional Board. Region 9 Basin Plan.

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 911NP9UCW.

Temporal Representation:

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):

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

Line of Evidence (LOE) for Decision ID 105630, Benthic Community Effects	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

215672

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for 911CCH80x to determine beneficial use support and the results are as follows: 0 of 1 samples exceeded the threshold. CSCI scores were from 0.9271 to 0.9271 .

Data Reference:

California Stream Condition Index Scores for the 2020 Integrated Report

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 from station 911CCH80x

Temporal Representation:

Samples were collected from 5/9/2018 to 5/9/2018.

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 105630, Benthic Community Effects	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

215671

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for 911NP9UCW to determine beneficial use support and the results are as follows: 0 of 2 samples exceeded the threshold. CSCI scores were from 0.928 to 0.9288 .

Data Reference:

California Stream Condition Index Scores for the 2020 Integrated Report

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 from station 911NP9UCW

Temporal Representation:

Samples were collected from 4/20/2016 to 5/2/2017.

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 105630, Benthic Community Effects	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

215661

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for 911REFCWC to determine beneficial use support and the results are as follows: 0 of 2 samples exceeded the threshold. CSCI scores were from 0.971 to 1.1431 .

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 911REFCWC

Temporal Representation:

Samples were collected from 2012 to 2014.

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	115458	Region 9
Cottonwood Creek above Morena Reservoir

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 115458, Chloride	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

140734

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chloride water quality threshold in this HSA is 250 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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 115458, Chloride	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

140773

Pollutant:

Chloride

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chloride water quality threshold in this HSA is 250 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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 115458, Chloride	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

141430

Pollutant:

Chloride

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chloride water quality threshold in this HSA is 250 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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 115458, Chloride	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

141335

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chloride water quality threshold in this HSA is 250 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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

QAPP Information Reference(s):

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


DECISION ID	105660	Region 9
Cottonwood Creek above Morena Reservoir

Pollutant:	Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(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 105660, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

143774

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB9 Monitoring data for Cottonwood Creek above Morena Reservoir to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nitrate + Nitrite as N.

Data Reference:

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

SWAMP Data:

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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2017-05-02 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 105660, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

143730

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:

Water Board staff assessed SWAMP RWB9 Monitoring data for Cottonwood Creek above Morena Reservoir to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Nitrate + Nitrite as N.

Data Reference:

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

SWAMP Data:

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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2016-04-20

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 105660, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134557

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed County of San Diego data for Cottonwood Creek (Tijuana River watershed) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Nitrate/Nitrite as N.

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:

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:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected on a single day 7/1/2004.

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	127487	Region 9
Cottonwood Creek above Morena Reservoir

Pollutant:	Nitrogen
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 127487, Nitrogen	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

143822

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:

Data Reference:

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

SWAMP Data:

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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 127487, Nitrogen	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

144348

Pollutant:

Total Nitrogen as N

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

QAPP Information Reference(s):

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


DECISION ID	115459	Region 9
Cottonwood Creek above Morena Reservoir

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 115459, Oxygen, Dissolved	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

144665

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

SWAMP Data:

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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 115459, Oxygen, Dissolved	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

144543

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Dissolved oxygen levels shall not be less than 6.0 mg/l in inland surface waters with the COLD 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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

QAPP Information Reference(s):

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


DECISION ID	115461	Region 9
Cottonwood Creek above Morena Reservoir

Pollutant:	Phosphorus
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 115461, Phosphorus	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

145863

Pollutant:

Phosphorus

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 115461, Phosphorus	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

145917

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the San Diego Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

QAPP Information Reference(s):

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


DECISION ID	127504	Region 9
Cottonwood Creek above Morena Reservoir

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 127504, Specific Conductivity	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

146963

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

SWAMP Data:

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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

QAPP Information Reference(s):

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


DECISION ID	115462	Region 9
Cottonwood Creek above Morena Reservoir

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 115462, Turbidity	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

147889

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

SWAMP Data:

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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-04-29 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 115462, Turbidity	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

147912

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

SWAMP Data:

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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-04-29 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 115462, Turbidity	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

147844

Pollutant:

Turbidity

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

SWAMP Data:

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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-04-29 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

QAPP Information Reference(s):

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


DECISION ID	115460	Region 9
Cottonwood Creek above Morena Reservoir

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 115460, pH	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

145460

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB9 Monitoring data for Cottonwood Creek above Morena Reservoir to determine beneficial use support and results are as follows: 2 of 5 samples exceeded the water quality threshold for pH.

Data Reference:

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

SWAMP Data:

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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

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 115460, pH	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

145311

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

SWAMP Data:

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 (911NP9UCW)

Temporal Representation:

The samples were collected between the dates of 2014-03-24 and 2017-05-02

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008, Nagoda and Busse, 2013. Quality Assurance Project Plan for Screening of Cyanotoxins in Lakes/Reservoirs and Coastal Wetlands in the San Diego Region, SWAMP QAPrP 2017

QAPP Information Reference(s):

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


DECISION ID	105635	Region 9
Cottonwood Creek above Morena Reservoir

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	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2029
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 4.3 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. This water body was split for assessment purposes. In this water body section, no new E. coli data is available in the administrative record to assess this pollutant. Under section 4.3 of the Listing Policy, a minimum of 26 samples is required to delist. 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. No new data were assessed for the current cycle. Under section 4.3 of the Listing Policy, a minimum of 26 samples is required to delist. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are 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:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:	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 105635, Indicator Bacteria	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134513

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 Cottonwood Creek (Tijuana River watershed) to determine beneficial use support and results are as follows: 3 of 8 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 Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected over the time period 5/28/2003-6/2/2009.

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 105635, Indicator Bacteria	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134511

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 Cottonwood Creek (Tijuana River watershed) to determine beneficial use support and results are as follows: 5 of 8 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 Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected over the time period 5/28/2003-6/2/2009.

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 105635, Indicator Bacteria	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134572

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 Cottonwood Creek (Tijuana River watershed) to determine beneficial use support and results are as follows: 1 of 8 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 Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected over the time period 5/28/2003-6/2/2009.

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	105651	Region 9
Cottonwood Creek above Morena Reservoir

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	Original
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 105651, Cadmium	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134539

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed County of San Diego DWM data for Cottonwood Creek (Tijuana River watershed) to determine beneficial use support and results are as follows: 0 of 1 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:

The California Maximum Contaminant Level for cadmium is 0.005 mg/L (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:

Data for this line of evidence for Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected 5/28/2003 - 6/2/2009.

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 105651, Cadmium	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134540

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed County of San Diego DWM data for Cottonwood Creek (Tijuana River watershed) to determine beneficial use support and results are as follows: 0 of 6 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:

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:

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 Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected 5/28/2003 - 6/2/2009.

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	105653	Region 9
Cottonwood Creek above Morena Reservoir

Pollutant:	Chlorpyrifos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 105653, Chlorpyrifos	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134584

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed County of San Diego data for Cottonwood Creek (Tijuana River watershed) to determine beneficial use support and results are as follows: 0 of 4 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 USEPA drinking water health advisory for chlorpyrifos is 2.1 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 Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected over the time period 5/2/2006-6/2/2009.

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 105653, Chlorpyrifos	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134543

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed County of San Diego data for Cottonwood Creek (Tijuana River watershed) 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:

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 Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected over the time period 5/2/2006-6/2/2009.

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	105656	Region 9
Cottonwood Creek above Morena Reservoir

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	Original
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 105656, Copper	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134550

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

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:

Secondary Maximum Contaminant Levels and Compliance. CCR Title 22 section 64449.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected 5/28/2003 - 6/2/2009.

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 105656, Copper	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134551

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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 Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected 5/28/2003 - 6/2/2009.

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	105634	Region 9
Cottonwood Creek above Morena Reservoir

Pollutant:	Diazinon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 105634, Diazinon	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134582

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for 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 drinking water health advisory for diazinon is 1.4 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 Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected over the time period 5/2/2006-6/2/2009.

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 105634, Diazinon	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134510

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for 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 freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

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

Spatial Representation:

Data for this line of evidence for Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected over the time period 5/2/2006-6/2/2009.

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	105640	Region 9
Cottonwood Creek above Morena Reservoir

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	Original
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 105640, Lead	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134519

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for 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 Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected 5/28/2003 - 6/2/2009.

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 105640, Lead	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134520

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for Lead is 0.015 mg/L (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:

Data for this line of evidence for Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected 5/28/2003 - 6/2/2009.

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	105641	Region 9
Cottonwood Creek above Morena Reservoir

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)(2018)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 105641, Malathion	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134521

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for 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 Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected over the time period 5/2/2006-6/2/2009.

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 105641, Malathion	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134583

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for 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 drinking water health advisory for malathion is 100 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 Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected over the time period 5/2/2006-6/2/2009.

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	105662	Region 9
Cottonwood Creek above Morena Reservoir

Pollutant:	Nitrogen, Nitrite
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 105662, Nitrogen, Nitrite	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134559

Pollutant:

Nitrogen, Nitrite

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed County of San Diego data for Cottonwood Creek (Tijuana River watershed) to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Nitrite as N.

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:

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:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected over the time period 5/28/2003-7/1/2004.

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	105647	Region 9
Cottonwood Creek above Morena Reservoir

Pollutant:	Nitrogen, ammonia (Total Ammonia)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 105647, Nitrogen, ammonia (Total Ammonia)	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134531

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed County of San Diego data for Cottonwood Creek (Tijuana River watershed) to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Ammonia As N, 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:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations 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:

EPA's Lifetime Health advisory level for total ammonia is 30.0 mg/L as stated on page 8 of the 2006 edition of the drinking water standards and health advisories. This Advisory Level is defined as "the concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for up to ten days of exposure."

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 Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected over the time period 5/28/2003-7/9/2004.

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	105675	Region 9
Cottonwood Creek above Morena Reservoir

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	Original
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 105675, Zinc	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134579

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for 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 chemical or combination of chemicals shall be present in concentrations 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 California Secondary MCL for zinc is 5.0 mg/L (Title 22 California Code of Regulations).

Guideline Reference:

Secondary Maximum Contaminant Levels and Compliance. CCR Title 22 section 64449.

Spatial Representation:

Data for this line of evidence for Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected 5/28/2003 - 6/2/2009.

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 105675, Zinc	Region 9
Cottonwood Creek above Morena Reservoir

LOE ID:

134581

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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 Cottonwood Creek (Tijuana River watershed) was collected at 1 monitoring site [ Cottonwood Creek @ Old Highway 80 (Bridge Crossing)]

Temporal Representation:

Data was collected 5/28/2003 - 6/2/2009.

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.