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

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name:	Las Vegas Creek
Water Body ID:	CAR3153100020190612032747
Water Body Type:	River & Stream


DECISION ID	126805	Region 3
Las Vegas Creek

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the six samples exceed the water quality objective for municipal and domestic supply. Six or the six samples exceed the evaluation guideline for aquatic life beneficial uses but there are not sufficient supporting evidence, such as dissolved oxygen or algae data, to support the conclusion that the waterbody is impaired by biostimulatory substances. Therefore, the use rating for these lines of evidence are 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 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 six samples exceed the water quality objective for municipal and domestic supply 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, there is insufficient information to support a conclusion that nitrate cases or contributes to a biostimulatory problem in this waterbody.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 126805, Nitrate	Region 3
Las Vegas Creek

LOE ID:

172565

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Barbara Channelkeeper Stream Team data for Las Vegas Creek to determine beneficial use support and results are as follows: 6 of 6 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.

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 (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

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:

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:

The samples were collected at 1 monitoring site (GVWLV1)

Temporal Representation:

The samples were collected between the dates of 2017-04-02 and 2019-05-05

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)

Line of Evidence (LOE) for Decision ID 126805, Nitrate	Region 3
Las Vegas Creek

LOE ID:

173522

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (GVWLV1)

Temporal Representation:

The samples were collected between the dates of 2017-04-02 and 2019-05-05

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)

Line of Evidence (LOE) for Decision ID 126805, Nitrate	Region 3
Las Vegas Creek

LOE ID:

172951

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Barbara Channelkeeper Stream Team data for Las Vegas Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All inland surface waters, enclosed bays, and estuaries shall not contain concentrations of inorganic chemicals in excess of the maximum contaminant levels for primary drinking water standards specified in California Code of Regulations, Title 22, Division 4, Chapter 15, Sections 64431 and 64433.2.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

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

Guideline Reference:

California MCLs - Title 17 and Title 22 documents for 2019 - California Regulations Related to Drinking Water

Spatial Representation:

The samples were collected at 1 monitoring site (GVWLV1)

Temporal Representation:

The samples were collected between the dates of 2017-04-02 and 2019-05-05

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)


DECISION ID	114945	Region 3
Las Vegas Creek

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

Regional Board Conclusion:	This pollutant is being considered for placement on the 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. Seven of 46 samples exceed the water quality objective for cold freshwater habitat (Basin Plan). Three of 46 samples exceed the water quality objective for warm freshwater habitat (Basin Plan). 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. The data support the conclusion that the aquatic life beneficial use is fully supported. 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. Seven of 46 samples exceed the objective for cold freshwater habitat and three of 46 samples exceed the objective for warm freshwater habitat. 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:

Line of Evidence (LOE) for Decision ID 114945, Oxygen, Dissolved	Region 3
Las Vegas Creek

LOE ID:

175051

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Barbara Channelkeeper Stream Team data for Las Vegas Creek to determine beneficial use support and results are as follows: 3 of 46 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (GVWLV1)

Temporal Representation:

The samples were collected between the dates of 2010-10-06 and 2019-05-05

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)

Line of Evidence (LOE) for Decision ID 114945, Oxygen, Dissolved	Region 3
Las Vegas Creek

LOE ID:

175070

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Barbara Channelkeeper Stream Team data for Las Vegas Creek to determine beneficial use support and results are as follows: 7 of 46 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 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 (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (GVWLV1)

Temporal Representation:

The samples were collected between the dates of 2010-10-06 and 2019-05-05

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)


DECISION ID	126255	Region 3
Las Vegas Creek

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

Regional Board Conclusion:	This pollutant is being considered for placement on the Clean Water Act (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. A total of one line of evidence is available in the administrative record to assess this pollutant. A total of one of 46 samples exceed the evaluation guideline (Moyle 1976) applied to protect the cold freshwater habitat beneficial use. 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. 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. A total of one of 46 samples exceed the evaluation guideline applied to protect the cold freshwater habitat beneficial use 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:

Line of Evidence (LOE) for Decision ID 126255, Temperature, water	Region 3
Las Vegas Creek

LOE ID:

217013

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Barbara Channelkeeper Stream Team data for Las Vegas Creek to determine beneficial use support and results are as follows: 1 of 46 samples exceeded the water quality threshold for Temperature.

Data Reference:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The optimum range for growth and completion of most life stages of rainbow trout is 13-21 degrees Celsius (Moyle 1976).

Guideline Reference:

Inland Fishes of California

Spatial Representation:

The samples were collected at 1 monitoring site (GVWLV1)

Temporal Representation:

The samples were collected between the dates of 2010-10-06 and 2019-05-05

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)


DECISION ID	114947	Region 3
Las Vegas Creek

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

Regional Board Conclusion:	This pollutant is being considered for placement on the Clean Water Act (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. A total of two lines of evidence are available in the administrative record to assess this pollutant. A total of five of 45 samples exceed the evaluation guideline for cold freshwater habitat (Sigler et al. 1984) and four of 45 samples exceed the evaluation guideline for warm freshwater habitat (Shoup, D.E. and Wahl D.H., 2009) used to interpret the water quality objectives for the aquatic life beneficial uses. 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. 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. A total of five of 45 samples exceed the evaluation guideline for cold freshwater habitat and four of 45 samples exceed the evaluation guideline for warm freshwater habitat 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:

Line of Evidence (LOE) for Decision ID 114947, Turbidity	Region 3
Las Vegas Creek

LOE ID:

182295

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Barbara Channelkeeper Stream Team data for Las Vegas Creek to determine beneficial use support and results are as follows: 4 of 45 samples exceeded the water quality threshold for Turbidity.

Data Reference:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-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).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009).

Guideline Reference:

The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass

Spatial Representation:

The samples were collected at 1 monitoring site (GVWLV1)

Temporal Representation:

The samples were collected between the dates of 2010-10-06 and 2019-05-05

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)

Line of Evidence (LOE) for Decision ID 114947, Turbidity	Region 3
Las Vegas Creek

LOE ID:

182029

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Barbara Channelkeeper Stream Team data for Las Vegas Creek to determine beneficial use support and results are as follows: 5 of 45 samples exceeded the water quality threshold for Turbidity.

Data Reference:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.

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:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Turbidities of 25 NTU or greater can cause a reduction in juvenile salmonid growth due to interference with their ability to find food (Sigler et al. 1984).

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:

The samples were collected at 1 monitoring site (GVWLV1)

Temporal Representation:

The samples were collected between the dates of 2010-10-06 and 2019-05-05

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)


DECISION ID	114946	Region 3
Las Vegas Creek

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

Regional Board Conclusion:	This pollutant is being considered for placement on the 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. Five lines of evidence is available in the administrative record to assess this pollutant. One of the 47 samples exceed the maximum pH water quality objective for Municipal and Domestic Supply, Contact and Non-contact Recreation beneficial uses. Zero of the 47 samples exceed the maximum pH water quality objectives for Cold and Warm Freshwater Habitat. 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 47 samples exceed the maximum pH water quality objective for Municipal and Domestic Supply, Contact and Non-contact Recreation beneficial uses, 0 of the 47 samples exceed the maximum pH water quality objectives for Cold and Warm Freshwater Habitat 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:

Line of Evidence (LOE) for Decision ID 114946, pH	Region 3
Las Vegas Creek

LOE ID:

179431

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Barbara Channelkeeper Stream Team data for Las Vegas Creek to determine beneficial use support and results are as follows: 1 of 47 samples exceeded the water quality threshold for pH.

Data Reference:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan, Central Coast Basin objective for municipal and domestic supply (Section 3.3.2 Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) states that the pH value shall neither be depressed below 6.5 nor raised above 8.3.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (GVWLV1)

Temporal Representation:

The samples were collected between the dates of 2010-10-06 and 2019-05-05

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)

Line of Evidence (LOE) for Decision ID 114946, pH	Region 3
Las Vegas Creek

LOE ID:

178956

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Barbara Channelkeeper Stream Team data for Las Vegas Creek to determine beneficial use support and results are as follows: 0 of 47 samples exceeded the water quality threshold for pH.

Data Reference:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan, Central Coast Basin objective for cold fresh water habitat (Section 3.3.2 Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) states that the pH value shall neither be depressed below 7.0 nor raised above 8.5.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (GVWLV1)

Temporal Representation:

The samples were collected between the dates of 2010-10-06 and 2019-05-05

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)

Line of Evidence (LOE) for Decision ID 114946, pH	Region 3
Las Vegas Creek

LOE ID:

179328

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:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan, Central Coast Basin objective for water contact recreation (Section 3.3.2 Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) states that the pH value shall neither be depressed below 6.5 nor raised above 8.3.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (GVWLV1)

Temporal Representation:

The samples were collected between the dates of 2010-10-06 and 2019-05-05

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)

Line of Evidence (LOE) for Decision ID 114946, pH	Region 3
Las Vegas Creek

LOE ID:

179018

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan, Central Coast Basin objective for warm fresh water habitat (Section 3.3.2 Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) states that the pH value shall neither be depressed below 7.0 nor raised above 8.5.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (GVWLV1)

Temporal Representation:

The samples were collected between the dates of 2010-10-06 and 2019-05-05

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)

Line of Evidence (LOE) for Decision ID 114946, pH	Region 3
Las Vegas Creek

LOE ID:

179529

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:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation (Section 3.3.2 Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) states that the pH value shall neither be depressed below 6.5 nor raised above 8.3.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (GVWLV1)

Temporal Representation:

The samples were collected between the dates of 2010-10-06 and 2019-05-05

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)


DECISION ID	125783	Region 3
Las Vegas Creek

Pollutant:	Escherichia coli (E. coli)
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	No Source Analysis Available
Expected TMDL Completion Date:	2035
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the ISWEBE Plan) contains two bacteria water quality objectives applicable to the REC-1 beneficial use, which were adopted on August 7, 2018. Because the salinity level of this waterbody is equal to or less than 1 part per thousand 95 percent or more of the time, the E. coli bacteria objective applies. Therefore, this waterbody is being considered for placement on the CWA section 303(d) List under section 3.3 of the Listing Policy, as applicable, using the E. coli objective. In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. E. coli populations may fluctuate substantially on a daily, seasonal, or yearly basis. Lacking constant inputs, indicator bacteria do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of E. coli in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Additionally, water quality conditions in waterbodies may change as a result of management actions that have been implemented to address E. coli. Unrepresentative data may result in incorrectly placing or not placing a water body segment on the CWA section 303(d) List, which could result in the unnecessary expenditure of public resources or missing a human health problem. Historic lines of evidence for data collected prior to 2010 were evaluated pursuant to these considerations and were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy. All samples are evaluated using the statistical threshold value (STV) water quality objective for water contact recreation (ISWEBE, SWRCB 2019). The water quality objective states that the STV shall not be exceeded by more than 10 percent of the samples collected in a calendar month. Where there are more than one samples collected within any six-week period, a geomean of those samples is calculated and evaluated using the geomean water quality objective for water contact recreation (ISWEBE, SWRCB 2019). One line of evidence is available in the administrative record to assess this pollutant and this decision is based upon evaluation of the E. coli data collected since 2010 which are most representative of existing conditions in the waterbody. A total of 29 of the 45 samples collected since 2010 exceed the STV water quality objective (see LOE 149915) and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. No geomeans could be calculated for these data. The data were collected between 2010 and 2018 and represent a range of hydrologic conditions (both wet and dry years). This sample count of data collected since 2010 is adequate to determine that the beneficial use is not supported in accordance with the Listing Policy. After review of the available data and information, the weight of evidence indicates that there is sufficient justification for 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. A total of 29 of the 45 samples collected since 2010 exceed the STV water quality objective 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 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:	One line of evidence is available in the administrative record to assess this pollutant and this decision is based upon evaluation of the E. coli data collected since 2010 which are most representative of existing conditions in the waterbody. A total of 29 of the 45 samples collected since 2010 exceed the STV water quality objective (see LOE 149915) and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. No geomeans could be calculated for these data. The data were collected between 2010 and 2018 and represent a range of hydrologic conditions (both wet and dry years). This sample count of data collected since 2010 is adequate to determine that the beneficial use is not supported in accordance with the Listing Policy. After review of the available data and information, the weight of evidence indicates that there is sufficient justification for 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. A total of 29 of the 45 samples collected since 2010 exceed the STV water quality objective 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 met.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 125783, Escherichia coli (E. coli)	Region 3
Las Vegas Creek

LOE ID:

149915

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for Las Vegas Creek to determine beneficial use support and the results are as follows: 29 of the 45 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, Habitat, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The bacteria water quality objective applicable to all non-saline waters, is a Statistical Threshold Value (STV) of 320 cfu/100 mL. The applicable STV shall not be exceeded by more than 10 percent of the samples collected in a calendar month, calculated in a static manner (ISWEBE 2018).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): GVWLV1

Temporal Representation:

The samples were collected between the days of 2010-10-06 and 2019-05-05 .

Environmental Conditions:

QAPP Information:

Santa Barbara Channelkeeper. 2019. Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP) with addendum for Goleta and Carpinteria watersheds.

QAPP Information Reference(s):

Ventura River Watershed Monitoring Program Quality Assurance Project Plan (QAPP)