Final California 2010 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name:	Los Gatos Creek (Fresno County)
Water Body ID:	CAR5511101120020628113523
Water Body Type:	River & Stream


DECISION ID	12061	Region 5
Los Gatos Creek (Fresno County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the 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. 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 1 sediment samples exhibited a siginificant decrease in Hyalella azteca (an alga) survival compared to control (the sample did not exhibit toxicity or exceed the narrative toxicity 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.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 12061, Sediment Toxicity	Region 5
Los Gatos Creek (Fresno County)

LOE ID:

21607

Pollutant:

Sediment Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One sediment sample tested for toxicity using Hyalella azteca was not found to have statistically significant different survival compared to the laboratory control sample.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances (CVRWQCB, 2007).

Objective/Criterion Reference:

Water Quality Control Plan for the Tulare Lake Basin Second Edition. rev. Jan 2004

Evaluation Guideline:

Statistically significant difference from control using a t-test with 10-day Hyalella azteca sediment toxicity test results.

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

Spatial Representation:

Sediment sample was collected from Arroyo Pasajero (Los Gatos Creek at Interstate 5).

Temporal Representation:

Sediment sample was collected on April 19, 2006.

Environmental Conditions:

QAPP Information:

Data quality: Fair. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements.

QAPP Information Reference(s):


DECISION ID	11325	Region 5
Los Gatos Creek (Fresno County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the 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. 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 1 water samples exhibited a significant decrease in Ceriodaphnia dubia (an invertebrate species) survival (the sample did not exceed the narrative toxicity objective), and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Zero of 1 water samples exhibited a significant decrease in Pimephales promelas (Fathead Minnow, a vertebrate species) survival (the sample did not exceed the narrative toxicity objective), and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 5. Zero of 1 water samples exhibited a significant difference in total cell counts in Selenastrum capricornutum (a plant species) survival (the sample did not exceed the narrative toxicity objective), and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 6. 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 it cannot be determined whether 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.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 11325, Unknown Toxicity	Region 5
Los Gatos Creek (Fresno County)

LOE ID:

21608

Pollutant:

Vertebrate Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One water sample tested for toxicity using Pimephales promelas was not found to have statistically significant different survival compared to the laboratory control sample.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Tulare Lake Basin Second Edition. rev. Jan 2004

Evaluation Guideline:

Statistically significant difference from control using a t-test with 4-day acute-style toxicity tests.

Guideline Reference:

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-821-R-02-012

Spatial Representation:

Water sample was collected from Arroyo Pasajero (Los Gatos Creek at Interstate 5).

Temporal Representation:

Water sample was collected on March 28, 2006.

Environmental Conditions:

QAPP Information:

Data quality: Fair. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 11325, Unknown Toxicity	Region 5
Los Gatos Creek (Fresno County)

LOE ID:

21609

Pollutant:

Plant Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One water sample tested for toxicity using Selenastrum capricornutum was not found to have statistically significant different total ceel counts compared to the laboratory control sample.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Tulare Lake Basin Second Edition. rev. Jan 2004

Evaluation Guideline:

Statistically significant difference from control using a t-test with 4-day chronic-style toxicity tests.

Guideline Reference:

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

Spatial Representation:

Water sample was collected from Arroyo Pasajero (Los Gatos Creek at Interstate 5).

Temporal Representation:

Water sample was collected on March 28, 2006.

Environmental Conditions:

QAPP Information:

Data quality: Fair. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 11325, Unknown Toxicity	Region 5
Los Gatos Creek (Fresno County)

LOE ID:

21606

Pollutant:

Invertebrate Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One water sample tested for toxicity using Ceriodaphnia dubia was not found to have statistically significant different survival compared to the laboratory control sample.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Tulare Lake Basin Second Edition. rev. Jan 2004

Evaluation Guideline:

Statistically significant difference from control using a t-test with 4-day acute-style toxicity tests.

Guideline Reference:

Spatial Representation:

The water sample was collected at Arroyo Pasajero (Los Gatos Creek, at Interstate 5).

Temporal Representation:

Sample was collected on March 28, 2006.

Environmental Conditions:

QAPP Information:

Data quality: Fair. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements.

QAPP Information Reference(s):