Final California 2018 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name:	Oso Flaco Lake
Water Body ID:	CAL3121003020011121102545
Water Body Type:	Lake & Reservoir


DECISION ID	83432	Region 3
Oso Flaco Lake

Pollutant:	Dieldrin
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Agriculture
TMDL Name:	Santa Maria River Watershed Toxicity and Pesticides TMDL
TMDL Project Code:	1081
Date TMDL Approved by USEPA:	08/31/2015
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Six of the six fish tissue samples exceeded the evaluation guideline for consumption of fish. One of three fish tissue samples and zero of the two sediment samples exceed the evaluation guideline used to interpret the narrative water quality objective for aquatic life protection. These sample sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. 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. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Six of the six fish tissue samples exceeded the evaluation guideline for consumption of fish and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. The Santa Maria River Watershed Toxicity and Pesticide TMDL has been approved by USEPA on October 31, 2015. 5. 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 removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard.

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 83432, Dieldrin	Region 3
Oso Flaco Lake

LOE ID:

77328

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 3 of 3 samples exceed the criterion for Dieldrin. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

Cruise report for the Surface Water Ambient Monitoring Program (SWAMP) bioaccumulation screening study in California lakes and reservoirs year two (FY 07-08). Sampling dates: April 2008 - November 2008.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (2011): There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for dieldrin in fish tissue is 0.32 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312POF158]. Samples were collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: April 2008-November 2008" (SWAMP, 2009).

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments

Line of Evidence (LOE) for Decision ID 83432, Dieldrin	Region 3
Oso Flaco Lake

LOE ID:

77327

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for Dieldrin. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan, Central Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Dieldrin concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments

Line of Evidence (LOE) for Decision ID 83432, Dieldrin	Region 3
Oso Flaco Lake

LOE ID:

55965

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Dieldrin.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (CCRWQCB 2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life (Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for dieldrin is 61.8 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 83432, Dieldrin	Region 3
Oso Flaco Lake

LOE ID:

700

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Three out of 3 samples exceeded (TSMP, 2002). A total of 2 filet composite samples of bluegill and one filet composite of hitch were collected. Bluegill were collected from 1993. Hitch were collected 2001. The guideline was exceeded in all samples.

Data Reference:

Placeholder reference 2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Central Coast RWQCB Basin Plan: No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Placeholder reference 2006 303(d)

Evaluation Guideline:

2 ng/g (OEHHA Screening Value) (Brodberg & Pollock, 1999).

Guideline Reference:

Placeholder reference 2006 303(d)

Spatial Representation:

One station located in lake at foot of Oso Flaco Road.

Temporal Representation:

Samples were collected 1993 and 2001.

Environmental Conditions:

QAPP Information:

Toxic Substances Monitoring Program 1992-93 Data Report.
Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program, 2001-2002. Department of Fish and Game.

QAPP Information Reference(s):


DECISION ID	86148	Region 3
Oso Flaco Lake

Pollutant:	Nitrate
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Agriculture \| Domestic Animals/Livestock \| Natural Sources
TMDL Name:	Santa Maria River Watershed Nitrogen Compounds and Orthophosphate TMDL
TMDL Project Code:	1082
Date TMDL Approved by USEPA:	03/08/2016
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess pollutant. Twenty-eight of the 28 samples exceed the evaluation guideline for Warm Freshwater Habitats (Central Coast Region NNE Technical Report, 2010). LOE summarizes evidence of eutrophic condition and staff provide the following supporting evidence of eutrophication in this water segment: 1. Oso Flaco Lake has been added to the 303(d) List for low dissolved oxygen. Dissolved oxygen for water body ranged from 5.84 mg/L to 18.86 mg/L, frequently exceeding (falling below) the Spawning Habitat water quality objective of 7.0 mg/L. In addition, this waterbody at times exceeds the upper dissolved oxygen screening level of 13.0 mg/L (R3 NNE Technical Report, 2010). 2. Based on predicted algae biomass, the California Benthic Biomass Tool, v. 13 (Tetratech, 2007) estimated an oxygen deficit for this water body of 2.98 mg/L. The level established by Central Coast staff as providing an acceptable level of protection for Central Coast waters is a maximum of 1.25 mg/L (RWQCB NNE Technical Approach, 2009). 3. Water column chlorophyll a concentrations averaged 36.57 and peaked at 96.00 ug/L often exceeding the screening level for chlorophyll a, which is 15 ug/L. Oso Flaco Lake is also on the CWA section 303(d) List due to elevated chlorophyll a concentrations.. 4. Staff have documented nuisance condition from emergent vegetation and algal cover in this water body See photos in LOE 29747. There is evidence of a eutrophic condition related to over growth of aquatic vegetation, algae and wide swings in dissolved oxygen levels in the lake caused (at least in part) by the high levels of nutrients, specifically nitrate, in the lake. This vegetation not only contributes to wide swings in dissolved oxygen levels but also prevents recreational use of the lake (i.e. fishing). 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. Twenty-eight of the 28 samples exceed the evaluation guidelines for Cold and Warm Freshwater Habitats and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. There is supporting evidence of eutrophic conditions including wide swings in dissolved oxygen and Oso Flaco Lake is on the CWA section 303(d) List for both low dissolved oxygen and chlorophyll a. 5.Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 86148, Nitrate	Region 3
Oso Flaco Lake

LOE ID:

29747

Pollutant:

Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Preservation of Rare & Endangered Species | Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

CCAMP data collected monthly in Oso Flaco Lake between January 2000 and January 2001 show elevated Nitrate levels which likely contributed to the elevated chlorophyll a concentrations in the water column, wide swings in Dissolved Oxygen concentrations and pH levels. Photo documentation also shows nuisance aquatic vegetation and algae filling the lake in summer months. Nitrate ranged from 28.0 - 31.7 mg/L in monthly grab samples taken from the lake. Dissolved Oxygen measurements (including both monthly grab samples and a single summer time pre-dawn sampling event) ranged from 5.05 mg/L to 21.0 mg/L. This indicates not only depressed but also super saturated oxygen conditions. Chlorophyll a measurements ranged between <1.0 ug/L and 160 ug/L. Three of these measurements were above 40 ug/L, the evaluation guideline used in this assessment.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

Oso Flaco Lake vegetation photo

Oso Flaco Lake aquatic vegetation nuisance condition

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Monthly grab samples collected at the culvert between Oso Flaco Lake and Little Oso Flaco Lake (312OFL).

Temporal Representation:

Samples were collected by CCAMP staff between January 2000 and Febuary 2001.

Environmental Conditions:

Measurements were taken and samples were collected from the down stream side of the culvert between the two lakes. Instream vegetation and algae are very dense in summer months.

QAPP Information:

CCAMP data is collected following the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 86148, Nitrate	Region 3
Oso Flaco Lake

LOE ID:

50904

Pollutant:

Nitrate

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:

Central Coast Water Board Staff assessed public submissions data for Oso Flaco Lake to determine beneficial use support and results are as follows: 12 of 12 samples exceed the criterion for Nitrate as N.

Data Reference:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (Basin Plan).

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Technical approach to develop nutrient numeric endpoints for California, Tetra Tech, June 2006. The Central Coast Region numeric target for maximum nitrate concentration is based on the Tetra Tech NNE (Nutrient Numeric Endpoint) Model and CCAMP data for 193 sites, monitored monthly for at least 1 year between January 1998 and December 2006. The model numeric target for aquatic life habitats in the Central Coast Region is 1.0 mg/L Nitrate as N.

Guideline Reference:

Technical Approach to Develop Nutrient Numeric Endpoints for California. U.S. EPA Region IX. State Water Resources Control Board. 68-C-02-108-To-111

Guideline Reference:

Central Coast RegionTechnical Paper: Interpreting Narrative Objectives for Biostimulatory Substances for California Central Coast Waters. This method uses the Technical Approach for Developing California Nutrient Numeric Endpoints.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 86148, Nitrate	Region 3
Oso Flaco Lake

LOE ID:

81184

Pollutant:

Nitrate

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:

All sixteen samples exceed the evaluation guideline. For these samples, nitrate concentrations ranged from 28.0 - 37.1 mg/L as N.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

Final Data File used for assessment: CCAMP Water Quality Data_file1

SWAMP Data:

Water Quality Objective/Criterion:

Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (Central Coast Region Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data are collected from one station, 312OFL - Oso Flaco Lake at culverts.

Temporal Representation:

Samples were collected between January 2000 and March 2001.

Environmental Conditions:

none

QAPP Information:

SWAMP QAPP

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 86148, Nitrate	Region 3
Oso Flaco Lake

LOE ID:

50905

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

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:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (Basin Plan).

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Guideline Reference:

Technical Approach to Develop Nutrient Numeric Endpoints for California. U.S. EPA Region IX. State Water Resources Control Board. 68-C-02-108-To-111

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	83421	Region 3
Oso Flaco Lake

Pollutant:	Aldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under section 3.5 of the Listing Policy. Under section 3.5, one line of evidence is necessary to assess listing status in tissue samples. One line of evidence is available in the administrative record to assess this pollutant. Zero of the three fish tissue samples exceeded the evaluation guideline for consumption of fish. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the three fish tissue samples exceed the evaluation guideline for consumption of fish and this does not exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should 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 83421, Aldrin	Region 3
Oso Flaco Lake

LOE ID:

77316

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Aldrin. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Aldrin concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	75458	Region 3
Oso Flaco Lake

Pollutant:	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)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	The pollutant name was changed from ¿Unionized Ammonia¿ to ¿Ammonia¿ in the 2014 assessment cycle. This decision replaces the two previously approved decisions, one for each of the pollutants unionized ammonia and total ammonia. This decision contains all of the LOEs from those decisions in addition to new LOEs. This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the 24 samples exceed the water quality objective for unionized ammonia set to protect aquatic life. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 24 samples exceed the water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	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 75458, Ammonia	Region 3
Oso Flaco Lake

LOE ID:

9673

Pollutant:

Ammonia (Unionized)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Santa Maria (SantaMaria) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Ammonia as N, Unionized.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin General Objective, Chapter III, Section II.A.2 (General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries) states that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 2/3/2000-3/1/2001. Santa Maria watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.

Environmental Conditions:

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

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 75458, Ammonia	Region 3
Oso Flaco Lake

LOE ID:

50902

Pollutant:

Ammonia (Unionized)

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:

Central Coast Water Board Staff assessed public submissions data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Ammonia as N, Unionized.

Data Reference:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	83579	Region 3
Oso Flaco Lake

Pollutant:	Azinphos-methyl (Guthion)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the evaluation guideline for aquatic life. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information' unless the beneficial use is not supported. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83579, Azinphos-methyl (Guthion)	Region 3
Oso Flaco Lake

LOE ID:

55895

Pollutant:

Azinphos-methyl (Guthion)

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Azinphos Methyl. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The Azinphos methyl (Guthion) criteria for the protection of freshwater aquatic life is 0.01 ug/L (National Recommended Water Quality Criteria, 2009).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	82945	Region 3
Oso Flaco Lake

Pollutant:	Bifenthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 at one line of evidence are necessary to assess listing status but under section 3.6 at least two lines of evidence are necessary to assess listing status and the pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single water sample did not exceed the evaluation guideline for aquatic life protection. Zero of the two sediment samples exceed the evaluation guideline used to protect aquatic life beneficial uses. However, this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Based on the readily available data and information, the weight of evidence indicates that even though this water body is impaired for sediment toxicity these water body-pollutant combinations should not be placed on the section 303(d) list because applicable water quality standards for these pollutants are not being exceeded. 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 the samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82945, Bifenthrin	Region 3
Oso Flaco Lake

LOE ID:

55897

Pollutant:

Bifenthrin

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Bifenthrin. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Bifenthrin does not exceed 0.0006 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 82945, Bifenthrin	Region 3
Oso Flaco Lake

LOE ID:

55896

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Bifenthrin.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Evaluation Guideline:

The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of three toxicity LC50 values from Amweg et al. (2005) and one toxicity LC50 value from Amweg and Weston (2007).

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	83377	Region 3
Oso Flaco Lake

Pollutant:	Chlordane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under section 3.6 of the Listing Policy. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Three lines of evidence are available in the administrative record to assess this pollutant. One of the three fish tissue samples exceeded the evaluation guideline for consumption of fish but zero of the three fish tissue samples exceeded the aquatic life protection evaluation guideline. In addition, Zero of the two sediment samples exceed the evaluation guideline used to interpret the narrative water quality objective for aquatic life protection. These sample sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of the three fish tissue samples exceeded the evaluation guideline for consumption of fish but zero of the three fish tissue samples and zero of the two sediment samples exceeded the aquatic life protection evaluation guideline. None of these exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83377, Chlordane	Region 3
Oso Flaco Lake

LOE ID:

77321

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for Chlordane, Total. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). Total chlordane was calculated as the sum of the following chlordane isomers: cis- and trans-chlordane, cis- and trans-nonachlor, and oxychlordane.

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (2011): There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for total chlordane in fish tissue is 3.9 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments

Line of Evidence (LOE) for Decision ID 83377, Chlordane	Region 3
Oso Flaco Lake

LOE ID:

55904

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Chlordane, Total.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for Chlordane is 17.6 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 83377, Chlordane	Region 3
Oso Flaco Lake

LOE ID:

77320

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Chlordane, Total. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). Total chlordane was calculated as the sum of the following chlordane isomers: cis- and trans-chlordane, cis- and trans-nonachlor, and oxychlordane.

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum total Chlordane concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	84045	Region 3
Oso Flaco Lake

Pollutant:	Chlorpyrifos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1, 3.5, and 3.6 of the Listing Policy. Under sections 3.1 and 3.5, a single line of evidence is necessary to assess listing status. Under section 3.6, two lines of evidence are necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. The single fish tissue sample did not exceed the evaluation guideline. Zero out of two sediment samples exceeded the evaluation guideline. Three sediment samples (pore water) were collected but are not counted in the assessment because the laboratory method detection limit was above the guideline and the results were non-detect. Therefore the results could not be quantified with the level of certainty required by the Listing Policy. Additionally, there is no chlorpyrifos evaluation guideline specific to "sediment, interstitial water" (pore water). LOEs summarizing pore water results will not be the sole basis for any decision. One water sample exceeded the evaluation guideline (Siepmann and Finlayson 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005). Six samples (quantified as either non-detect or detected but not quantified) were not used in this assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported using table 3.1. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single water sample exceeded the evaluation guideline while no tissue or sediment samples exceeded the evaluation guideline. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 84045, Chlorpyrifos	Region 3
Oso Flaco Lake

LOE ID:

55912

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Chlorpyrifos.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for chlorpyrifos is the median lethal concentration (LC50) of 1.77 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Amweg and Weston, 2007).

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 84045, Chlorpyrifos	Region 3
Oso Flaco Lake

LOE ID:

55921

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project data for Oso Flaco Creek. Three sample were collected but are not counted in the assessment because the laboratory method detection limit was above the guideline and the results were non-detect. Therefore the results could not be quantified with the level of certainty required by the Listing Policy. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

There is no chlorpyrifos evaluation guideline specific to "sediment, interstitial water" (pore water). The following evaluation guideline was used to evaluate an exceedance in water quality standards: the freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (Siepmann and Finlayson 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005). LOEs summarizing pore water results will not be the sole basis for any decision.

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 Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 1/16/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 84045, Chlorpyrifos	Region 3
Oso Flaco Lake

LOE ID:

55913

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project data for Oso Flaco Creek to determine beneficial use support and results are as follows: None of the samples exceed the criterion for Chlorpyrifos. Six samples (quantified as either non-detect or detected but not quantified) were not used in this assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

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

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 10/21/2008-8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 84045, Chlorpyrifos	Region 3
Oso Flaco Lake

LOE ID:

16297

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life 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:

Final Data File used for assessment: SWAMP Toxicity Data 2001-06

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Objective/Criterion 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

Evaluation Guideline:

One hour average maximum concentration 0.025 ug/L as stated in Sipmann 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

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected on a single day 2/28/2007. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 84045, Chlorpyrifos	Region 3
Oso Flaco Lake

LOE ID:

55914

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chlorpyrifos. One composite (3 fish per composite) was generated from one species: largemouth bass. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (2011): There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for chlorpyrifos in fish tissue is 660 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008; USEPA, 2000)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	67551	Region 3
Oso Flaco Lake

Pollutant:	Cyfluthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 at one line of evidence are necessary to assess listing status but under section 3.6 at least two lines of evidence are necessary to assess listing status and the pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single water sample did exceed the evaluation guideline for aquatic life protection. Zero of the two sediment samples exceed the evaluation guideline used to protect aquatic life beneficial uses. However, this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Based on the readily available data and information, the weight of evidence indicates that even though this water body is impaired for sediment toxicity these water body-pollutant combinations should not be placed on the section 303(d) list because applicable water quality standards for these pollutants are not being exceeded. 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. The single water sample exceeded the evaluation guideline but this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 67551, Cyfluthrin	Region 3
Oso Flaco Lake

LOE ID:

55923

Pollutant:

Cyfluthrin

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Cyfluthrin. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of cyfluthrin does not exceed 0.00005 ug/L and if the 1-h average concentration does not exceed 0.0003 ug/L. For this assessment the 4-day average guideline was used. Mixtures of cyfluthrin and other pyrethroids should be considered in an additive manner. (Fojut et al. 2012)

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 67551, Cyfluthrin	Region 3
Oso Flaco Lake

LOE ID:

55922

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Cyfluthrin.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	82993	Region 3
Oso Flaco Lake

Pollutant:	Cyhalothrin, Lambda
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 at one line of evidence are necessary to assess listing status but under section 3.6 at least two lines of evidence are necessary to assess listing status and the pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single water sample did not exceed the evaluation guideline for aquatic life protection. Zero of the two sediment samples exceed the evaluation guideline used to protect aquatic life beneficial uses. However, this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Based on the readily available data and information, the weight of evidence indicates that even though this water body is impaired for sediment toxicity these water body-pollutant combinations should not be placed on the section 303(d) list because applicable water quality standards for these pollutants are not being exceeded. 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 the samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82993, Cyhalothrin, Lambda	Region 3
Oso Flaco Lake

LOE ID:

55924

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Cyhalothrin, Lambda, Total.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 82993, Cyhalothrin, Lambda	Region 3
Oso Flaco Lake

LOE ID:

55932

Pollutant:

Cyhalothrin, Lambda

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Cyhalothrin, lambda, total. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Cyhalothrin, lambda, total does not exceed 0.0005 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	82895	Region 3
Oso Flaco Lake

Pollutant:	Cypermethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 at one line of evidence are necessary to assess listing status but under section 3.6 at least two lines of evidence are necessary to assess listing status and the pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single water sample did not exceed the evaluation guideline for aquatic life protection (Note,the single water sample result was not used in the assessment because the result was reported a ¿non detect¿ but the laboratory data reporting limit was above the objective and therefore the results could not be quantified.). Zero of the two sediment samples exceed the evaluation guideline used to protect aquatic life beneficial uses. However, this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Based on the readily available data and information, the weight of evidence indicates that even though this water body is impaired for sediment toxicity these water body-pollutant combinations should not be placed on the section 303(d) list because applicable water quality standards for these pollutants are not being exceeded. 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 the samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82895, Cypermethrin	Region 3
Oso Flaco Lake

LOE ID:

55934

Pollutant:

Cypermethrin

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Cypermethrin. The single sample result was not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Cypermethrin; Cypermethrin, total does not exceed 0.0002 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 82895, Cypermethrin	Region 3
Oso Flaco Lake

LOE ID:

55933

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Cypermethrin.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al. (2002).

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	83372	Region 3
Oso Flaco Lake

Pollutant:	DDD (Dichlorodiphenyldichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under section 3.6 of the Listing Policy. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. One line of evidence is available in the administrative record to assess this pollutant. Zero of the two samples exceed the evaluation guideline (MacDonald et al. 2000) used to interpret the narrative water quality objective for aquatic life protection. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the two samples exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83372, DDD (Dichlorodiphenyldichloroethane)	Region 3
Oso Flaco Lake

LOE ID:

55935

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for DDD.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDD is 28.0 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	83425	Region 3
Oso Flaco Lake

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under section 3.6 of the Listing Policy. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. Two of the two samples exceed the evaluation guideline (MacDonald et al. 2000) used to interpret the narrative water quality objective for aquatic life protection. Sediment toxicity data is available for the Lake but only one of the two samples resulted in a significant toxic effect to the test organisms. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. Additional chemistry samples for DDE paired with toxicity analyses for those sediment samples is needed. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two of the two samples exceed the evaluation guideline (MacDonald et al. 2000) used to interpret the narrative water quality objective for aquatic life protection. Sediment toxicity data is available for the Lake but only one of the two samples resulted in a significant toxic effect to the test organisms. Although the chemistry sample count does exceed the allowable frequency listed in Table 3.1 of the Listing Policy, the sediment toxicity data does not support listing this water segment for DDE. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 83425, DDE (Dichlorodiphenyldichloroethylene)	Region 3
Oso Flaco Lake

LOE ID:

55942

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 2 of 2 samples exceed the criterion for DDE.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDE is 31.3 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 83425, DDE (Dichlorodiphenyldichloroethylene)	Region 3
Oso Flaco Lake

LOE ID:

55947

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Three samples were collected to evaluate sediment toxicity. One of the three samples exhibited significant toxicity. The toxicity tests included survival and growth of Hyalella azteca. Statistically significant effects to survival of Hyalella azteca were reported for one sample, collected on 12/3/2008, at Oso Flaco Lake (312OFL).

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Toxicity was defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing. The t-test is used to determine if there is a statistically significant decrease in organism response in the sample as compared to the control.

Guideline Reference:

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. EPA-821-R-02-012

Guideline Reference:

Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013

Spatial Representation:

The samples were collected at site 312OFL - Oso Flaco Lake at culverts.

Temporal Representation:

The samples were collected in December of 2008 and March and June of 2009.

Environmental Conditions:

QAPP Information:

The data was collected for Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study and analyzed at the Marine Pollution Studies Laboratory. Sampling and analysis was conducted following the SWAMP QAPrP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	83379	Region 3
Oso Flaco Lake

Pollutant:	Deltamethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 at one line of evidence are necessary to assess listing status but under section 3.6 at least two lines of evidence are necessary to assess listing status and the pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single water sample did not exceed the evaluation guideline for aquatic life protection. Zero of the two sediment samples exceed the evaluation guideline used to protect aquatic life beneficial uses. However, this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Based on the readily available data and information, the weight of evidence indicates that even though this water body is impaired for sediment toxicity these water body-pollutant combinations should not be placed on the section 303(d) list because applicable water quality standards for these pollutants are not being exceeded. 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 the samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83379, Deltamethrin	Region 3
Oso Flaco Lake

LOE ID:

55944

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Deltamethrin.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 83379, Deltamethrin	Region 3
Oso Flaco Lake

LOE ID:

55945

Pollutant:

Deltamethrin

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Deltamethrin. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for deltamethrin is the maximum acceptable toxicant concentration (MATC) of 0.02 ug/L. The MATC (or Chronic Value as defined in USEPA 1985, P20 section F) is the geometric mean of the lowest observed effect concentration (LOEC) of 0.03 ug/L and the no observed effect concentration (NOEC) of 0.017 ug/L as determined in a 280 day toxicity study with the fathead minnow, Pimephales promelas. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Guideline Reference:

Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	83261	Region 3
Oso Flaco Lake

Pollutant:	Demeton
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the evaluation guideline for aquatic life. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information' unless the beneficial use is not supported. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83261, Demeton	Region 3
Oso Flaco Lake

LOE ID:

55952

Pollutant:

Demeton

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Demeton. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The USEPA National Recomm. WQ criteria, 4-day avg. is 0.1 ug/L.

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	84047	Region 3
Oso Flaco Lake

Pollutant:	Diazinon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under sections 3.1, 3.5, and 3.6 of the Listing Policy. Under sections 3.1 and 3.5, a single line of evidence is necessary to assess listing status. Under section 3.6, two lines of evidence are necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. The single fish tissue sample did not exceed the evaluation guideline. Zero out of seven water samples did not exceed the evaluation guideline (Siepmann and Finlayson, 2000). Zero out of two sediment samples exceeded the evaluation guideline. Zero of three sediment samples (pore water) exceeded the evaluation guideline. There is no chlorpyrifos evaluation guideline specific to "sediment, interstitial water" (pore water). LOEs summarizing pore water results will not be the sole basis for any decision. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported using table 3.1. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. No samples exceeded the evaluation guidelines. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the sample size is insufficient to determine with the power and confidence of the Listing Policy if water quality standards are being met.

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 84047, Diazinon	Region 3
Oso Flaco Lake

LOE ID:

16720

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life 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:

Final Data File used for assessment: SWAMP Toxicity Data 2001-06

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Objective/Criterion 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

Evaluation Guideline:

One hour average maximum concentration 0.16 ug/L as stated in Sipmann 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

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected on a single day 2/28/2007. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 84047, Diazinon	Region 3
Oso Flaco Lake

LOE ID:

55963

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Diazinon. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

There is no diazinon evaluation guideline specific to "sediment, interstitial water" (pore water). The following evaluation guideline was used to evaluate an exceedance in water quality standards: the freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004). LOEs summarizing pore water results will not be the sole basis for any decision.

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 Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 1/16/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 84047, Diazinon	Region 3
Oso Flaco Lake

LOE ID:

55953

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Diazinon.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for diazinon is the median lethal concentration (LC50) of 11 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 11 ug/g is the geometric mean of LC50 values for diazinon from Ding et al. (2011).

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 84047, Diazinon	Region 3
Oso Flaco Lake

LOE ID:

55954

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 6 samples exceed the criterion for Diazinon. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal 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 Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 10/21/2008-8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 84047, Diazinon	Region 3
Oso Flaco Lake

LOE ID:

55955

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Diazinon. One composite (3 fish per composite) was generated from one species: largemouth bass. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (2011): There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for diazinon in fish tissue is 1,500 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008; USEPA, 2000)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	83580	Region 3
Oso Flaco Lake

Pollutant:	Dichlorvos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the evaluation guideline for aquatic life. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information' unless the beneficial use is not supported. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83580, Dichlorvos	Region 3
Oso Flaco Lake

LOE ID:

55964

Pollutant:

Dichlorvos

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Dichlorvos. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for ddvp (dichlorvos) is the maximum acceptable toxicant concentration (MATC) of 7.2 ug/L. The MATC (or Chronic Value as defined in USEPA 1985, P20 section F) is calculated as the geometric mean of the lowest observed effect concentration (LOEC) of 10.1 ug/L and the no observed effect concentration (NOEC) of 5.2 ug/L as determined in a 61 day toxicity study with rainbow trout, Oncorhynchus mykiss. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Guideline Reference:

Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	83581	Region 3
Oso Flaco Lake

Pollutant:	Dimethoate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the evaluation guideline for aquatic life. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information' unless the beneficial use is not supported. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83581, Dimethoate	Region 3
Oso Flaco Lake

LOE ID:

55975

Pollutant:

Dimethoate

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Dimethoate. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Dimethoate is the median lethal concentration (LC50) of 43 ug/L, as determined in a 96 hour toxicity test with the stonefly, Pteronarcys californica (USEPA Office of Pesticide Programs Ecotoxicity database).

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	83100	Region 3
Oso Flaco Lake

Pollutant:	Esfenvalerate/Fenvalerate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 at one line of evidence are necessary to assess listing status but under section 3.6 at least two lines of evidence are necessary to assess listing status and the pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single water sample did not exceed the evaluation guideline for aquatic life protection. Zero of the two sediment samples exceed the evaluation guideline used to protect aquatic life beneficial uses. However, this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Based on the readily available data and information, the weight of evidence indicates that even though this water body is impaired for sediment toxicity these water body-pollutant combinations should not be placed on the section 303(d) list because applicable water quality standards for these pollutants are not being exceeded. 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 the samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83100, Esfenvalerate/Fenvalerate	Region 3
Oso Flaco Lake

LOE ID:

55994

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Esfenvalerate/Fenvalerate.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 83100, Esfenvalerate/Fenvalerate	Region 3
Oso Flaco Lake

LOE ID:

55995

Pollutant:

Esfenvalerate/Fenvalerate

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Fenvalerate. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.13 ug/L, as determined in a 96 hour toxicity test using the fathead minnow, Pimephales promelas (USEPA Office of Pesticide Programs Ecotoxicity database).

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	82837	Region 3
Oso Flaco Lake

Pollutant:	Ethion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the evaluation guideline for consumption of fish. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information' unless the beneficial use is not supported. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82837, Ethion	Region 3
Oso Flaco Lake

LOE ID:

55997

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Ethion. One composite (3 fish per composite) was generated from one species: largemouth bass. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (2011): There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for ethion in fish tissue is 1,100 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008; USEPA, 2000)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	82836	Region 3
Oso Flaco Lake

Pollutant:	Ethoprop
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the evaluation guideline for aquatic life. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information' unless the beneficial use is not supported. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82836, Ethoprop	Region 3
Oso Flaco Lake

LOE ID:

55863

Pollutant:

Ethoprop

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Ethoprop. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Ethoprop is the maximum acceptable toxicant concentration (MATC) of 1.4 ug/L. The MATC (or Chronic Value as defined in USEPA 1985, P20 section F) is calculated as the geometric mean of the lowest observed effect concentration (LOEC) of 2.4 ug/L and the no observed effect concentration (NOEC) of 0.80 ug/L, as determined in a 21 day toxicity study with the water flea, Daphnia magna. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Guideline Reference:

Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	83585	Region 3
Oso Flaco Lake

Pollutant:	Heptachlor
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.5 of the Listing Policy. Under sections 3.1 and 3.5, one line of evidence is necessary to assess listing status in water and tissue samples. One line of evidence is available in the administrative record to assess this pollutant. Zero of the three fish tissue samples exceeded the evaluation guideline for consumption of fish. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the three fish tissue samples exceed the evaluation guideline for consumption of fish and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83585, Heptachlor	Region 3
Oso Flaco Lake

LOE ID:

77310

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Heptachlor. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Heptachlor concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	82839	Region 3
Oso Flaco Lake

Pollutant:	Heptachlor epoxide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.5 of the Listing Policy. Under sections 3.1 and 3.5, one line of evidence is necessary to assess listing status in water and tissue samples. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the three fish tissue samples exceed the evaluation guideline for warm freshwater habitats but one of three samples exceed the evaluation guideline for consumption of fish. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the three fish tissue samples exceed the evaluation guideline for warm freshwater habitats but one of three samples exceed the evaluation guideline for consumption of fish. These do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82839, Heptachlor epoxide	Region 3
Oso Flaco Lake

LOE ID:

77312

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for Heptachlor epoxide. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (2011): There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for heptachlor epoxide in fish tissue is 0.93 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008; OEHHA, 1999)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Public Health Goal for Heptachlor and Heptachlor Epoxide in Drinking Water

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments

Line of Evidence (LOE) for Decision ID 82839, Heptachlor epoxide	Region 3
Oso Flaco Lake

LOE ID:

77311

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Heptachlor epoxide. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Heptachlor Epoxide concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	82840	Region 3
Oso Flaco Lake

Pollutant:	Hexachlorobenzene/ HCB
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.5 of the Listing Policy. Under sections 3.1 and 3.5, one line of evidence is necessary to assess listing status in water and tissue samples. One line of evidence is available in the administrative record to assess this pollutant. One of the three fish tissue samples exceeded the evaluation guideline for consumption of fish. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of the three fish tissue samples exceed the evaluation guideline for consumption of fish and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82840, Hexachlorobenzene/ HCB	Region 3
Oso Flaco Lake

LOE ID:

77313

Pollutant:

Hexachlorobenzene/ HCB

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for Hexachlorobenzene. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (2011): There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for hexachlorobenzene in fish tissue is 2.8 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008; OEHHA, 2005)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	75284	Region 3
Oso Flaco Lake

Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1, 3.5 and 3.6 of the Listing Policy. Under sections 3.1 and 3.5, one line of evidence is necessary to assess listing status in water and tissue samples. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the three fish tissue samples exceeded the evaluation guideline for consumption of fish. Zero of the three fish tissue samples and zero of the two sediment samples exceeds the evaluation guideline used to interpret the narrative water quality objective for aquatic life protection. These sample sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the samples exceeded the aquatic life protection evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 75284, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 3
Oso Flaco Lake

LOE ID:

77314

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for HCH, gamma. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Lindane concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments

Line of Evidence (LOE) for Decision ID 75284, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 3
Oso Flaco Lake

LOE ID:

55873

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for HCH, gamma.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for Lindane (gamma-HCH) is 4.99 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 75284, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 3
Oso Flaco Lake

LOE ID:

77315

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (2011): There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for lindane in fish tissue is 4.6 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	83635	Region 3
Oso Flaco Lake

Pollutant:	Malathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did exceed the evaluation guideline for aquatic life. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information' unless the beneficial use is not supported. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did exceed the evaluation guidelines but this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83635, Malathion	Region 3
Oso Flaco Lake

LOE ID:

55884

Pollutant:

Malathion

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Malathion. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Malathion does not exceed 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	82891	Region 3
Oso Flaco Lake

Pollutant:	Methidathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the evaluation guideline for aquatic life. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information' unless the beneficial use is not supported. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82891, Methidathion	Region 3
Oso Flaco Lake

LOE ID:

55889

Pollutant:

Methidathion

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Methidathion. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Methidathion is the maximum acceptable toxicant concentration (MATC) of 0.86 ug/L. The MATC (or Chronic Value as defined in USEPA 1985, P20 section F) is calculated as the geometric mean of the lowest observed effect concentration (LOEC) of 1.13 ug/L and the no observed effect concentration (NOEC) of 0.66 ug/L, as determined in a 21 day toxicity study with the water flea, Daphnia magna. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Guideline Reference:

Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	82896	Region 3
Oso Flaco Lake

Pollutant:	Methyl Parathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 at one line of evidence are necessary to assess listing status but under section 3.6 at least two lines of evidence are necessary to assess listing status and the pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single water sample did not exceed the evaluation guideline for aquatic life protection. Zero of the two sediment samples exceed the evaluation guideline used to protect aquatic life beneficial uses. However, this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Based on the readily available data and information, the weight of evidence indicates that even though this water body is impaired for sediment toxicity these water body-pollutant combinations should not be placed on the section 303(d) list because applicable water quality standards for these pollutants are not being exceeded. 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 the samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82896, Methyl Parathion	Region 3
Oso Flaco Lake

LOE ID:

55890

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Methyl Parathion.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for methyl parathion is the median lethal concentration (LC50) of 6 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 6 ug/g is the geometric mean of LC50 values for methyl parathion from Ding et al. (2011).

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 82896, Methyl Parathion	Region 3
Oso Flaco Lake

LOE ID:

55898

Pollutant:

Methyl Parathion

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Parathion, methyl. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The California Department of Fish and Game instantaneous criteria for Methyl Parathion is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	83313	Region 3
Oso Flaco Lake

Pollutant:	Mirex
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.5 of the Listing Policy. Under sections 3.1 and 3.5, one line of evidence is necessary to assess listing status in water and tissue samples. One line of evidence is available in the administrative record to assess this pollutant. Zero of the zero fish tissue samples exceeded the evaluation guideline for consumption of fish. Note, sample results were not used in the assessment because the result was reported a ¿non detect¿ but the laboratory data reporting limit was above the objective and therefore the results could not be quantified.This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the zero fish tissue samples exceed the evaluation guideline for consumption of fish and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83313, Mirex	Region 3
Oso Flaco Lake

LOE ID:

77319

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Mirex. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). Four composites were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (2011): There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for mirex in fish tissue is 0.28 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008; OEHHA, 1992)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Expedited Cancer Potency Values and Proposed Regulatory Levels for Certain Proposition 65 Carcinogens.

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	83371	Region 3
Oso Flaco Lake

Pollutant:	PAHs (Polycyclic Aromatic Hydrocarbons)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.5 of the Listing Policy. Under sections 3.1 and 3.5, one line of evidence is necessary to assess listing status in water and tissue samples. One line of evidence is available in the administrative record to assess this pollutant. The single fish tissue sample did not exceed the evaluation guideline for consumption of fish. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single fish tissue sample did not exceed the evaluation guideline for consumption of fish and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83371, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 3
Oso Flaco Lake

LOE ID:

55899

Pollutant:

PAHs (Polycyclic Aromatic Hydrocarbons)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for PAH, Total. One composite (3 fish per composite) was generated from one species: largemouth bass. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). PAH, Total is calculated as a potency weighted concentration with respect to benzo(a)pyrene and was calculated based on the following analytes: Dibenz(a,h)anthracene, Benzo(a)pyrene, Benz(a)anthracene, Benzo(b)fluoranthene, Benzo(k)fluoranthene, Indeno(1,2,3-c,d)pyrene, Anthracene, Benzo(g,h,i)perylene, Chrysene, Acenaphthene, Acenaphthylene, Fluoranthene, Fluorene, Phenanthrene, and Pyrene.

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (2011): All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for polycyclic aromatic hydrocarbons in fish tissue is 0.7 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Klasing, S., and R. Brodberg, 2008; USEPA, 2000)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	82995	Region 3
Oso Flaco Lake

Pollutant:	PCBs (Polychlorinated biphenyls)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1, 3.5 and 3.6 of the Listing Policy. Under sections 3.1 and 3.5, one line of evidence is necessary to assess listing status in water and tissue samples. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Three lines of evidence are available in the administrative record to assess this pollutant. One of the three fish tissue samples exceeded the evaluation guideline for consumption of fish. Zero of the three fish tissue samples and zero of the two sediment samples exceeds the evaluation guideline used to interpret the narrative water quality objective for aquatic life protection. These sample sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against of placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of the three fish tissue samples exceeds the evaluation guideline for consumption of fish and zero of the samples exceeded the aquatic life protection evaluation guideline and these do not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82995, PCBs (Polychlorinated biphenyls)	Region 3
Oso Flaco Lake

LOE ID:

55906

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for PCB, Total.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of PCBs is 676 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 82995, PCBs (Polychlorinated biphenyls)	Region 3
Oso Flaco Lake

LOE ID:

77322

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for PCB, Total. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). Total PCB was assessed for as follows: PCB aroclors and congeners were summed separately and the sum that yielded the highest value was used for the assessment.

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum total PCB concentration of 500 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments

Line of Evidence (LOE) for Decision ID 82995, PCBs (Polychlorinated biphenyls)	Region 3
Oso Flaco Lake

LOE ID:

77323

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for PCB, Total. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). Total PCB was assessed for as follows: PCB aroclors and congeners were summed separately and the sum that yielded the highest value was used for the assessment.

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for polychlorinated biphenyls in fish tissue is 2.6 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	82892	Region 3
Oso Flaco Lake

Pollutant:	Parathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the evaluation guideline for aquatic life. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information' unless the beneficial use is not supported. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82892, Parathion	Region 3
Oso Flaco Lake

LOE ID:

55905

Pollutant:

Parathion

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Parathion, Ethyl. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The criterion continuous concentration for Parathion, Ethyl is 0.013 ug/l from the National Recommended Water Quality Criteria. Parathion is synonymous with diethyl parathion and parathion-ethyl

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	82946	Region 3
Oso Flaco Lake

Pollutant:	Permethrin, total
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 at one line of evidence are necessary to assess listing status but under section 3.6 at least two lines of evidence are necessary to assess listing status and the pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Two lines of evidence are available in the administrative record to assess this pollutant. The single water sample did not exceed the evaluation guideline for aquatic life protection. Note, the single water sample result was not used in the assessment because the result was reported a ¿non detect¿ but the laboratory data reporting limit was above the objective and therefore the results could not be quantified. Zero of the two sediment samples exceed the evaluation guideline used to protect aquatic life beneficial uses. However, this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Based on the readily available data and information, the weight of evidence indicates that even though this water body is impaired for sediment toxicity these water body-pollutant combinations should not be placed on the section 303(d) list because applicable water quality standards for these pollutants are not being exceeded. 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 the samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82946, Permethrin, total	Region 3
Oso Flaco Lake

LOE ID:

55915

Pollutant:

Permethrin, total

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Permethrin.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 82946, Permethrin, total	Region 3
Oso Flaco Lake

LOE ID:

55916

Pollutant:

Permethrin, total

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: The single sample result was not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of permethrin does not exceed 0.002 ug/L and if the 1-h average concentration does not exceed 0.01 ug/L. In this assessment, the 4-day value was used. Mixtures of permethrin and other pyrethroids should be considered in an additive manner. (Fojut et al. 2012)

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	82893	Region 3
Oso Flaco Lake

Pollutant:	Phorate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the evaluation guideline for aquatic life. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information' unless the beneficial use is not supported. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 82893, Phorate	Region 3
Oso Flaco Lake

LOE ID:

55925

Pollutant:

Phorate

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Phorate. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Phorate is the median lethal concentration (LC50; 2 ug/L). This is based on a 96 hour toxicity study of bluegill sunfish (Lepomis macrochirus)

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	73140	Region 3
Oso Flaco Lake

Pollutant:	Phosmet
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample did not exceed the evaluation guideline for aquatic life. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information' unless the beneficial use is not supported. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 73140, Phosmet	Region 3
Oso Flaco Lake

LOE ID:

55926

Pollutant:

Phosmet

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 TMDL Project data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Phosmet. An arithmetic mean is calculated when replicates, such as field duplicates, are reported. If a non-detect is one of the results, then one half the reporting limit is used in this calculation.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland and Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

According to the USEPA Office of Pesticide Programs Ecotoxicity database, the aquatic life EC50 for Phosmet is 5.6 ug/L.

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected on a single day 8/26/2009.

Environmental Conditions:

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

QAPP Information:

Sampling and analysis was conducted following the SWAMP QAPP 2008.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	83370	Region 3
Oso Flaco Lake

Pollutant:	Selenium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.5 of the Listing Policy. Under sections 3.1 and 3.5, one line of evidence is necessary to assess listing status in water and tissue samples. One line of evidence is available in the administrative record to assess this pollutant. Zero of the two fish tissue samples exceeded the evaluation guideline for consumption of fish. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the two fish tissue samples exceed the evaluation guideline for consumption of fish and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83370, Selenium	Region 3
Oso Flaco Lake

LOE ID:

77324

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Selenium. Two composites (5 fish per composite) were generated from two species: 1 from goldfish and one from hitch. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The OEHHA Fish Contaminant Goal for selenium in fish tissue is 7.4 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A background dietary consumption rate of 0.114 mg/day is applied for this micronutrient. (Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	75423	Region 3
Oso Flaco Lake

Pollutant:	Turbidity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Two of the 25 samples exceed the Warm Freshwater Habitat evaluation guideline (Shoup, D.E. and Wahl D.H., 2009), Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two of the 25 samples exceed the Warm Freshwater Habitat evaluation guideline and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 75423, Turbidity	Region 3
Oso Flaco Lake

LOE ID:

13445

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Santa Maria (SantaMaria) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 2 of 8 samples exceed the criterion for Turbidity(NTU).

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.

Guideline Reference:

Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 4/10/2000-3/1/2001. Santa Maria watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 75423, Turbidity	Region 3
Oso Flaco Lake

LOE ID:

13466

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed RWQCB3 - Central Coast Ambient Monitoring Program (Lakes) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Turbidity(NTU).

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.

Guideline Reference:

Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 2 monitoring sites: 312OFL1b-Oso Flaco Lake Boardwalk at first alcove, and 312OFL2b-Oso Flaco Lake Boardwalk at second alcove. At each of the two locations, three different depth samples were collected consistent with section 6.1.5.6 of the Listing policy, the average turbidity measurement at each location was used for this assessment.

Temporal Representation:

Data was collected on two consecutive dates 9/7/2000-9/8/2000.

Environmental Conditions:

Oso Flaco Lake is no more than 4 feet deep at the two monitoring locations however temperature, salinity, dissolved oxygen and pH gradients were observed on the two sample dates.

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 75423, Turbidity	Region 3
Oso Flaco Lake

LOE ID:

50909

Pollutant:

Turbidity

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:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses (Basin Plan).

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Turbidities of 40 NTU or greater can cause a reduction in piscivorous fish (largemouth bass) growth due to interference with their ability to find food (Shoup, D.E. and Wahl D.H., 2009).

Guideline Reference:

The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 75423, Turbidity	Region 3
Oso Flaco Lake

LOE ID:

13463

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Turbidity(NTU).

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.

Guideline Reference:

Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 6/27/2000-9/6/2000. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):


DECISION ID	83637	Region 3
Oso Flaco Lake

Pollutant:	alpha-Endosulfan (Endosulfan 1)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.5 of the Listing Policy. Under sections 3.1 and 3.5, one line of evidence is necessary to assess listing status in water and tissue samples. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the three fish tissue samples exceeded the evaluation guidelines for consumption of fish or for Warm Freshwater Habitats. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the three fish tissue samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. 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 83637, alpha-Endosulfan (Endosulfan 1)	Region 3
Oso Flaco Lake

LOE ID:

77318

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Endosulfan I. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (2011): There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for endosulfan (l and ll) in fish tissue is 13,000 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008; USEPA, 2000)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments

Line of Evidence (LOE) for Decision ID 83637, alpha-Endosulfan (Endosulfan 1)	Region 3
Oso Flaco Lake

LOE ID:

77317

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Endosulfan, Total concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	77754	Region 3
Oso Flaco Lake

Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Twelve lines of evidence are available in the administrative record to assess this pollutant. Three beneficial uses are assessed. Two of the 30 samples exceed the water quality objective for Warm Freshwater Habitats and for three of the 30 samples exceed the water quality objectives for Drinking Water and Recreation. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two of the 30 samples exceed the water quality objective for Warm Freshwater Habitats and for three of the 30 samples exceed the water quality objectives for Drinking Water and Recreation. These do not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 77754, pH	Region 3
Oso Flaco Lake

LOE ID:

11624

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 2 monitoring sites: 312OFL1b-Oso Flaco Lake Boardwalk at first alcove, and 312OFL2b-Oso Flaco Lake Boardwalk at second alcove. At each of the two locations, three different depth samples were collected consistent with section 6.1.5.6 of the Listing policy, the highest pH measurement at each location was used for this assessment.

Temporal Representation:

Data was collected on two consecutive dates 9/7/2000-9/8/2000.

Environmental Conditions:

Oso Flaco Lake is no more than 4 feet deep at the two monitoring locations however temperature, salinity, dissolved oxygen and pH gradients were observed on the two sample dates.

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77754, pH	Region 3
Oso Flaco Lake

LOE ID:

11621

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 6/27/2000-9/6/2000. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77754, pH	Region 3
Oso Flaco Lake

LOE ID:

11640

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life 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:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 2 monitoring sites: 312OFL1b-Oso Flaco Lake Boardwalk at first alcove, and 312OFL2b-Oso Flaco Lake Boardwalk at second alcove. At each of the two locations, three different depth samples were collected consistent with section 6.1.5.6 of the Listing policy, the highest pH measurement at each location was used for this assessment.

Temporal Representation:

Data was collected on two consecutive dates 9/7/2000-9/8/2000.

Environmental Conditions:

Oso Flaco Lake is no more than 4 feet deep at the two monitoring locations however temperature, salinity, dissolved oxygen and pH gradients were observed on the two sample dates.

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77754, pH	Region 3
Oso Flaco Lake

LOE ID:

50908

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:

Central Coast Water Board Staff assessed public submissions data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for pH.

Data Reference:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH value shall not be depressed below 7.0 or raised above 8.5 (Basin Plan).

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 77754, pH	Region 3
Oso Flaco Lake

LOE ID:

50900

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Water Board Staff assessed public submissions data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for pH.

Data Reference:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH value shall neither be depressed below 6.5 nor raised above 8.3 (Basin Plan).

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 77754, pH	Region 3
Oso Flaco Lake

LOE ID:

50898

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Water Board Staff assessed public submissions data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for pH.

Data Reference:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH value shall neither be depressed below 6.5 nor raised above 8.3 (Basin Plan).

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 77754, pH	Region 3
Oso Flaco Lake

LOE ID:

11605

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Santa Maria (SantaMaria) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 1 of 13 samples exceed the criterion for pH.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77754, pH	Region 3
Oso Flaco Lake

LOE ID:

11622

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 6/27/2000-9/6/2000. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77754, pH	Region 3
Oso Flaco Lake

LOE ID:

11623

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life 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:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 6/27/2000-9/6/2000. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77754, pH	Region 3
Oso Flaco Lake

LOE ID:

11606

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Santa Maria (SantaMaria) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 13 samples exceed the criterion for pH.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77754, pH	Region 3
Oso Flaco Lake

LOE ID:

11604

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77754, pH	Region 3
Oso Flaco Lake

LOE ID:

11625

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 2 monitoring sites: 312OFL1b-Oso Flaco Lake Boardwalk at first alcove, and 312OFL2b-Oso Flaco Lake Boardwalk at second alcove. At each of the two locations, three different depth samples were collected consistent with section 6.1.5.6 of the Listing policy, the highest pH measurement at each location was used for this assessment.

Temporal Representation:

Data was collected on two consecutive dates 9/7/2000-9/8/2000.

Environmental Conditions:

Oso Flaco Lake is no more than 4 feet deep at the two monitoring locations however temperature, salinity, dissolved oxygen and pH gradients were observed on the two sample dates.

QAPP Information:

QAPP Information Reference(s):


DECISION ID	83256	Region 3
Oso Flaco Lake

Pollutant:	Chlorophyll-a
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2023
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Six of the 27 samples exceed the evaluation guideline (North Carolina Administrative code, Title 15A) used to interpret the narrative water quality objective for bio-stimulation risk and aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Six of the 27 samples exceed the evaluation guideline and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 83256, Chlorophyll-a	Region 3
Oso Flaco Lake

LOE ID:

9672

Pollutant:

Chlorophyll-a

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Santa Maria (SantaMaria) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 3 of 16 samples exceed the criterion for Chlorophyll a.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Objective/Criterion Reference:

North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards

Objective/Criterion Reference:

Water quality standards table

Evaluation Guideline:

North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.

Guideline Reference:

North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards

Guideline Reference:

North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/12/2000-3/1/2001. Santa Maria watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 83256, Chlorophyll-a	Region 3
Oso Flaco Lake

LOE ID:

50903

Pollutant:

Chlorophyll-a

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:

Central Coast Water Board Staff assessed public submissions data for Oso Flaco Lake to determine beneficial use support and results are as follows: 3 of 11 samples exceed the criterion for Chlorophyll a.

Data Reference:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Guideline Reference:

North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards

Guideline Reference:

North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards

Guideline Reference:

Water quality standards table

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	83312	Region 3
Oso Flaco Lake

Pollutant:	Mercury
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2027
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1 and 3.5 of the Listing Policy. Under sections 3.1 and 3.5, one line of evidence is necessary to assess listing status in water and tissue samples. Two lines of evidence are available in the administrative record to assess this pollutant. The California Office of Environmental Health Hazard Assessment has issued a fish consumption advisory due to mercury contamination in large mouth bass and one of the three fish tissue samples exceeded the evaluation guideline for consumption of fish. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3.The California Office of Environmental Health Hazard Assessment has issued a fish consumption advisory due to mercury contamination in large mouth bass and therefore, in accordance with section 3.4 of the Listing Policy this water segment shall be placed on the section 303(d) List. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	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 83312, Mercury	Region 3
Oso Flaco Lake

LOE ID:

55888

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for Mercury. Composites were generated from largemouth bass (3 composites - 1 fish per composite), goldfish (2 composites - 5 fish per composite), and hitch (2 composites - 5 fish per composite). The composites were averaged for each species. The 1 sample for largemouth bass exceeded the criterion. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The USEPA 304(a) recommended water quality criterion for concentrations of methylmercury in fish tissue of trophic level 4 fish (150 - 500 mm; fillet wet weight) is 0.20 mg/kg. This is assuming a 32 g/day consumption rate (USEPA, 2001).

Guideline Reference:

Water Quality Criterion for the Protection of Human Health: Methylmercury. Final. United States Environmental Protection Agency Office of Science and Technology Office of Water. EPA-823-R-01-001. January 2001

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments

Line of Evidence (LOE) for Decision ID 83312, Mercury	Region 3
Oso Flaco Lake

LOE ID:

79348

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The Office of Environmental Health Hazards Assessment has issued a fish consumption advisory has for Mercury in Oso Flaco Lake.

Data Reference:

OEHHA Fish Consumption Advisory Poster for Oso Flaco Lake, San Luis Obispo County.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from Oso Flaco Lake

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP

QAPP Information Reference(s):


DECISION ID	77940	Region 3
Oso Flaco Lake

Pollutant:	Oxygen, Dissolved
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2027
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Ten lines of evidence are available in the administrative record to assess this pollutant. Two water quality objectives are assessed. Five of the 29 samples exceeded the water quality objectives for dissolved oxygen in Spawning Habitats. But, zero samples exceeded the water quality objective for dissolved oxygen in Warm Freshwater Habitats. The Basin Plan general water quality objective for oxygen saturation states that the median value shall not fall below 85% saturation. However, the oxygen saturation objective is only applied ¿for waters not mentioned by a specific beneficial use¿¿ and this water body is designated for both Cold and Warm Freshwater Habitats. Therefore, the use support rating for oxygen saturation is set at Insufficient Information. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Five of the 29 samples exceeded the water quality objectives for dissolved oxygen in Spawning Habitats and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 77940, Oxygen, Dissolved	Region 3
Oso Flaco Lake

LOE ID:

50907

Pollutant:

Dissolved oxygen saturation

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:

Central Coast Water Board Staff assessed public submissions data for Oso Flaco Lake to determine beneficial use support and results are as follows: 7 of 12 samples exceed the criterion for Oxygen, Saturation.

Data Reference:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Median values should not fall below 85% saturation as a result of controllable water quality conditions (Basin Plan).

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 77940, Oxygen, Dissolved	Region 3
Oso Flaco Lake

LOE ID:

13444

Pollutant:

Dissolved oxygen saturation

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Santa Maria (SantaMaria) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 4 of 15 samples exceed the criterion for Oxygen, Saturation.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77940, Oxygen, Dissolved	Region 3
Oso Flaco Lake

LOE ID:

50901

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Water Board Staff assessed public submissions data for Oso Flaco Lake to determine beneficial use support and results are as follows: 1 of 12 samples exceed the criterion for Oxygen, Dissolved.

Data Reference:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time (Basin Plan).

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 77940, Oxygen, Dissolved	Region 3
Oso Flaco Lake

LOE ID:

13464

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life 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:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 2 monitoring sites: 312OFL1b-Oso Flaco Lake Boardwalk at first alcove, and 312OFL2b-Oso Flaco Lake Boardwalk at second alcove. At each of the two locations, three different depth samples were collected consistent with section 6.1.5.6 of the Listing policy, the lowest Dissolved Oxygen measurement at each location was used for this assessment.

Temporal Representation:

Data was collected on two consecutive dates 9/7/2000-9/8/2000.

Environmental Conditions:

Oso Flaco Lake is no more than 4 feet deep at the two monitoring locations however temperature, salinity, dissolved oxygen and pH gradients were observed on the two sample dates.

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77940, Oxygen, Dissolved	Region 3
Oso Flaco Lake

LOE ID:

13446

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life 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:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 6/27/2000-9/6/2000. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77940, Oxygen, Dissolved	Region 3
Oso Flaco Lake

LOE ID:

13443

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Santa Maria (SantaMaria) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Oxygen, Dissolved.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77940, Oxygen, Dissolved	Region 3
Oso Flaco Lake

LOE ID:

50906

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time (Basin Plan).

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 77940, Oxygen, Dissolved	Region 3
Oso Flaco Lake

LOE ID:

13462

Pollutant:

Dissolved oxygen saturation

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 1 of 2 samples exceed the criterion for Oxygen, Saturation.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 6/27/2000-9/6/2000. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77940, Oxygen, Dissolved	Region 3
Oso Flaco Lake

LOE ID:

13465

Pollutant:

Dissolved oxygen saturation

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data for this line of evidence for Oso Flaco Lake was collected at 2 monitoring sites: 312OFL1b-Oso Flaco Lake Boardwalk at first alcove, and 312OFL2b-Oso Flaco Lake Boardwalk at second alcove. At each of the two locations, three different depth samples were collected consistent with section 6.1.5.6 of the Listing policy, the lowest Oxygen Saturation measurement at each location was used for this assessment.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 6 monitoring sites [ 312OFL1b-Oso Flaco Lake Boardwalk at first alcove, 312OFL1b-Oso Flaco Lake Boardwalk at first alcove, 312OFL1b-Oso Flaco Lake Boardwalk at first alcove, 312OFL2b-Oso Flaco Lake Boardwalk at second alcove, 312OFL2b-Oso Flaco Lake Boardwalk at second alcove, 312OFL2b-Oso Flaco Lake Boardwalk at second alcove]

Temporal Representation:

Data was collected on two consecutive dates 9/7/2000-9/8/2000.

Environmental Conditions:

Oso Flaco Lake is no more than 4 feet deep at the two monitoring locations however temperature, salinity, dissolved oxygen and pH gradients were observed on the two sample dates.

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77940, Oxygen, Dissolved	Region 3
Oso Flaco Lake

LOE ID:

79337

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Water Board Staff assessed public submissions data for Oso Flaco Lake to determine beneficial use support and results are as follows: 4 of 17 samples exceed the criterion for Oxygen, Dissolved.

Data Reference:

CCAMP water quality data -file #1

CCAMP water quality data -file #2

CCAMP water quality data -file #3

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time (Basin Plan).

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 2/3/2000 - 3/1/2001.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	83048	Region 3
Oso Flaco Lake

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Agriculture
TMDL Name:	Santa Maria River Watershed Toxicity and Pesticides TMDL
TMDL Project Code:	1081
Date TMDL Approved by USEPA:	08/31/2015
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1, 3.5 and 3.6 of the Listing Policy. Under sections 3.1 and 3.5, one line of evidence is necessary to assess listing status in water and tissue samples. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Four lines of evidence are available in the administrative record to assess this pollutant. Three of the three fish tissue samples exceeded the evaluation guideline for consumption of fish. One of the three fish tissue samples and zero of the two sediment samples exceeds the evaluation guidelines used to interpret the narrative water quality objective for aquatic life protection. These sample sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Three of the three fish tissue samples exceeds the evaluation guideline for consumption of fish and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. The Santa Maria River pesticide and toxicity TMDL has been approved by the USEPA on August 31, 2015. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard.

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 83048, DDT (Dichlorodiphenyltrichloroethane)	Region 3
Oso Flaco Lake

LOE ID:

55927

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for DDT, Total.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for total DDTs is 572 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 83048, DDT (Dichlorodiphenyltrichloroethane)	Region 3
Oso Flaco Lake

LOE ID:

77325

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for DDT, Total. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). Total DDT was calculated as the sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD.

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum total DDT concentration of 1000 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments

Line of Evidence (LOE) for Decision ID 83048, DDT (Dichlorodiphenyltrichloroethane)	Region 3
Oso Flaco Lake

LOE ID:

55943

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for DDT.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDT is 62.9 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 83048, DDT (Dichlorodiphenyltrichloroethane)	Region 3
Oso Flaco Lake

LOE ID:

77326

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 3 of 3 samples exceed the criterion for DDT, Total. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). Total DDT was calculated as the sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD.

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (2011): There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for total DDT in fish tissue is 15 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments


DECISION ID	82947	Region 3
Oso Flaco Lake

Pollutant:	Endrin
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Agriculture
TMDL Name:	Santa Maria River Watershed Toxicity and Pesticides TMDL
TMDL Project Code:	1081
Date TMDL Approved by USEPA:	08/31/2015
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) List under sections 3.1, 3.5 and 3.6 of the Listing Policy. Under sections 3.1 and 3.5, one line of evidence is necessary to assess listing status in water and tissue samples. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) list. Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the three fish tissue samples exceeded the evaluation guideline for consumption of fish. Two of the three fish tissue samples exceeded the aquatic life protection evaluation guideline. In addition, zero of the two sediment samples exceeds the evaluation guideline used to interpret the narrative water quality objective for aquatic life protection. These sample sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information'. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) List in the Water Quality Limited Segments category. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two of the three fish tissue samples exceeded the aquatic life protection evaluation guideline and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard.

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 82947, Endrin	Region 3
Oso Flaco Lake

LOE ID:

77330

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Endrin. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Central Coastal Basin (2011): There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for endrin in fish tissue is 660 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008; USEPA, 2000)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments

Line of Evidence (LOE) for Decision ID 82947, Endrin	Region 3
Oso Flaco Lake

LOE ID:

77329

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Oso Flaco Lake to determine beneficial use support and results are as follows: 2 of 3 samples exceed the criterion for Endrin. Four composites (3-5 fish per composite) were generated from three species: 2 from goldfish, 1 from hitch, and 1 from largemouth bass. The goldfish composites were not spatially independent (as defined in the Listing Policy) and so were averaged. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).

Data Reference:

Statewide Lakes Sportfish Contamination Study 2007 2008

Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Endrin concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Data was collected on a single day 5/29/2008.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments

Line of Evidence (LOE) for Decision ID 82947, Endrin	Region 3
Oso Flaco Lake

LOE ID:

55985

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TMDL Project Data data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Endrin.

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of endrin is 207 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ Oso Flaco Lake - 312OFL]

Temporal Representation:

Data was collected over the time period 12/3/2008-6/10/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	83331	Region 3
Oso Flaco Lake

Pollutant:	Escherichia coli (E. coli)
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Domestic Animals/Livestock \| Urban Runoff/Storm Sewers
TMDL Name:	Santa Maria River Watershed Fecal Indicator Bacteria TMDL
TMDL Project Code:	917
Date TMDL Approved by USEPA:	04/24/2013
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for addition to the CWA section 303(d) List under sections 2.2, 3.2 and 3.3 of the Listing Policy. Under 3.3 of the Policy, a minimum of one line of evidence is needed to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Five of 12 samples exceed the evaluation standard (Ambient Water Quality Criteria for Bacteria, USEPA, 1986) set to protect for water contact recreation (i.e. swimming, wading etc.). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for adding this water segment-pollutant combination from the CWA section 303(d) List. In accordance with section 2.2 of the Policy, there is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. 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. Five of 12 samples exceed the evaluation guideline set to protect for water contact recreation (i.e. swimming, wading etc.) and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. The Santa Maria River Watershed Fecal Indicator Bacteria TMDL has been approved by USEPA on 04/24/2013. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	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 83331, Escherichia coli (E. coli)	Region 3
Oso Flaco Lake

LOE ID:

51164

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Central Coast Water Board Staff assessed public submissions data for Oso Flaco Lake to determine beneficial use support and results are as follows: 5 of 12 samples exceed the criterion for Escherichia coli.

Data Reference:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

USEPA Ambient Water Quality Criteria for Bacteria -1986.

Objective/Criterion Reference:

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

Evaluation Guideline:

Single sample maximum allowable density for E. coli in freshwater is 235 MPN/100mL (as stated in Table 4, page 15 of the USEPA Ambient Water Quality Criteria for Bacteria -1986).

Guideline Reference:

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

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	75510	Region 3
Oso Flaco Lake

Pollutant:	Fecal Coliform
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Domestic Animals/Livestock \| Urban Runoff/Storm Sewers
TMDL Name:	Santa Maria River Watershed Fecal Indicator Bacteria TMDL
TMDL Project Code:	917
Date TMDL Approved by USEPA:	04/24/2013
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for addition to the CWA section 303(d) List under sections 2.2, 3.2 and 3.3 of the Listing Policy. Under 3.3 of the Policy, a minimum of one line of evidence is needed to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Eight of 27 samples exceed the evaluation guideline set to protect for water contact recreation (i.e. swimming, wading etc.) and 0 of 27 samples exceed the water quality objective for non-contact recreation. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for adding this water segment-pollutant combination from the CWA section 303(d) List. In accordance with section 2.2 of the Policy, there is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. 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. Eight of 27 samples exceed the evaluation guideline set to protect for water contact recreation (i.e. swimming, wading etc.) ] and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. The Santa Maria River Watershed Fecal Indicator Bacteria TMDL has been approved by USEPA on 04/24/2013. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	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 75510, Fecal Coliform	Region 3
Oso Flaco Lake

LOE ID:

51163

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:

Central Coast Water Board Staff assessed public submissions data for Oso Flaco Lake to determine beneficial use support and results are as follows: 6 of 12 samples exceed the criterion for Coliform, Fecal.

Data Reference:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 200 MPN/100 ml, nor shall more than ten percent of total samples during any 30-day period exceed 400 MPN/100 ml.

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 75510, Fecal Coliform	Region 3
Oso Flaco Lake

LOE ID:

11603

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 75510, Fecal Coliform	Region 3
Oso Flaco Lake

LOE ID:

50899

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Data Reference:

Santa Maria Rotation field data 2007-2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected over the time period 1/31/2007-1/16/2008.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 75510, Fecal Coliform	Region 3
Oso Flaco Lake

LOE ID:

11602

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:

Central Coast Regional Board Staff assessed CCAMP Santa Maria (SantaMaria) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 2 of 15 samples exceed the criterion for Coliform, Fecal.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):


DECISION ID	83419	Region 3
Oso Flaco Lake

Pollutant:	Toxicity
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Agriculture
TMDL Name:	Santa Maria River Watershed Toxicity and Pesticides TMDL
TMDL Project Code:	1081
Date TMDL Approved by USEPA:	08/31/2015
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. One sample can have multiple toxicity test results but will be counted only once. One sample is defined as being collected on the same day and time at the same location. One LOE summarizes sediment samples. One of the three sediment samples resulted in a significant toxic effect to one or more test organisms and therefore exceeds the water quality objective for aquatic life protection. Five LOEs summarize water samples. One water samples are summarized in LOEs using each of the test organisms as the pollutant name (i.e. plant toxicity, invertebrate toxicity or vertebrate toxicity) and seven water samples are summarized in LOEs using the pollutant name ¿toxicity¿. Therefore, eight total samples are available to assess toxic effects in water samples. Five of the eight water samples resulted in a significant toxic effect to one or more test organisms and therefore exceeds the water quality objective for aquatic life protection. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. In accordance with section 2.2 of the Policy, there is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. 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. Five of the eight water samples resulted in a significant toxic effect to one or more test organisms for the water quality objective set for aquatic life protection. This exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. The Santa Maria River Watershed Toxicity and Pesticide TMDL has been approved by USEPA on October 31, 2015. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem. In accordance with section 2.2 of the Policy, there is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard.

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 83419, Toxicity	Region 3
Oso Flaco Lake

LOE ID:

55946

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Six samples were collected from Oso Flaco Lake to evaluate water toxicity. Three of the six samples exhibited significant toxicity. The toxicity tests included survival of Ceriodaphnia dubia. Statistically significant effects on Ceriodaphnia dubia were observed in three samples (10/21/2008, 12/3/2008, 03/31/2009).

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. EPA-821-R-02-012

Guideline Reference:

Spatial Representation:

The samples were collected atOso Flaco Lake.

Temporal Representation:

The samples were collected in October and December of 2008 and February, March, June and August of 2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 83419, Toxicity	Region 3
Oso Flaco Lake

LOE ID:

55936

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One sample was collected to evaluate water toxicity. The sample exhibited significant toxicity to Ceriodaphnia dubia survival and reproduction. The toxicity test included survival and reproduction of Ceriodaphnia dubia, survival and biomass of Pimephales promelas, and total cell count of Selenastrum capricornutum. One sample can have multiple toxicity test results but will be counted only once. One sample is defined as being collected on the same day at the same location with the same lab sample id (if provided).

Data Reference:

Santa Maria Rotation 2007 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life. Region 3 Basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing. For SWAMP data exceedances are counted with the significant effect code SL. SL is defined as the result being significant compared to the negative control based on a statistical test, less than stated the alpha level, AND less than the evaluation threshold.

Guideline Reference:

Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates, Second Edition. U.S. Environmental Protection Agency Office of Research and Development, Duluth, MI , U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-600/R-99/064

Guideline Reference:

SWAMP_Memo_Toxicity_Data_Intrepretation

Spatial Representation:

The sample was collected at station 312OFLxxx.

Temporal Representation:

The sample was collected in June 2007.

Environmental Conditions:

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 83419, Toxicity	Region 3
Oso Flaco Lake

LOE ID:

23947

Pollutant:

Invertebrate Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Ceriodaphnia dubia Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).

Data Reference:

Final Data File used for assessment: SWAMP Toxicity Data 2001-06

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.

Guideline Reference:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected on a single day 2/28/2007. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 83419, Toxicity	Region 3
Oso Flaco Lake

LOE ID:

24627

Pollutant:

Plant Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 1 of 1 samples exceed the criterion for Toxicity, Selenastrum capricornutum Growth (Cell Density) 4 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).

Data Reference:

Final Data File used for assessment: SWAMP Toxicity Data 2001-06

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Significant reduction in cell count of test organism relative to the control (alpha < 0.05) and cell count <80% of control.

Guideline Reference:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected on a single day 2/28/2007. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 83419, Toxicity	Region 3
Oso Flaco Lake

LOE ID:

23955

Pollutant:

Vertebrate Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP_SWAMP Monitoring (04SW3001) data for Oso Flaco Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Pimephales promelas Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).

Data Reference:

Final Data File used for assessment: SWAMP Toxicity Data 2001-06

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.

Guideline Reference:

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Spatial Representation:

Data for this line of evidence for Oso Flaco Lake was collected at 1 monitoring site [ 312OFL-Oso Flaco Lake at culvert]

Temporal Representation:

Data was collected on a single day 2/28/2007. SWAMP toxicity monitoring includes both water samples (collected in both winter and summer) and sediment samples (collected in spring).

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 83419, Toxicity	Region 3
Oso Flaco Lake

LOE ID:

55947

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Data from Santa Maria River Watershed and Oso Flaco Creek Watershed TMDL Monitoring Study

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. EPA-821-R-02-012

Guideline Reference:

Spatial Representation:

The samples were collected at site 312OFL - Oso Flaco Lake at culverts.

Temporal Representation:

The samples were collected in December of 2008 and March and June of 2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan