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

Supporting Information

Regional Board 8 - Santa Ana Region

Water Body Name:	San Timoteo River Reach 2 (Gage at San Timoteo to confluence with Yucaipa Creek)
Water Body ID:	CAR8015200020080917171942
Water Body Type:	River & Stream


DECISION ID	97999	Region 8
San Timoteo River Reach 2 (Gage at San Timoteo to confluence with Yucaipa Creek)

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

Regional Board Conclusion:	Benthic Community Effects is being considered for placement on the CWA section 303(d) List under sections 3.9 and 3.1 of the Listing Policy. Under section 3.9, an additional line of evidence associating Benthic Community Effects with a water or sediment concentration of pollutant(s) is necessary to assess listing status. One line of evidence is available in the administrative record to assess this indicator. Two of the 2 benthic macroinvertebrate samples exceed (fall below) the California Streams Condition Index (CSCI) threshold for likely altered biological condition. The water segment does not have associated pollutant(s) samples that exceed water quality objectives. Based on the readily available data and information, the weight of evidence provides sufficient justification for not placing Benthic Community Effects in this water segment on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Pursuant to section 3.9 of the Listing Policy, the water segment exhibits significant degradation in biological populations and/or communities as compared to reference site(s) using the California Stream Condition Index. 4. Pursuant to section 3.9 of the Listing Policy, the water segment does not have associated pollutant(s) samples that exceed water quality objectives. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not being met. The California Stream Condition Index is a new scoring tool for bioassessment data that is applicable statewide, accounts for a much wider range of natural variability, and provides equivalent scoring thresholds in all regions of the state. The CSCI has been used in some assessments this reporting cycle and will be used in the future for water quality assessment purposes statewide over the regional indices of biologic integrity (IBIs). If CSCI scores have not been calculated for data and only IBI scores are available, IBI scores will still be used to interpret the data.

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:	The California Stream Condition Index is a new scoring tool for bioassessment data that is applicable statewide, accounts for a much wider range of natural variability, and provides equivalent scoring thresholds in all regions of the state. The CSCI has been used in some assessments this reporting cycle and will be used in the future for water quality assessment purposes statewide over the regional indices of biologic integrity (IBIs). If CSCI scores have not been calculated for data and only IBI scores are available, IBI scores will still be used to interpret the data.

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 97999, Benthic Community Effects	Region 8
San Timoteo River Reach 2 (Gage at San Timoteo to confluence with Yucaipa Creek)

LOE ID:

82323

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Two samples were collected at two different stations to assess benthic macroinvertebrates. Two of the two samples collected had a CSCI score below the 0.79 threshold and therefore exceed the water quality objective for the aquatic life beneficial use. The CSCI scores for the sites are 0.73 (2006), and 0.76 (2007).

Data Reference:

Data for Various Pollutants in the Streams of Region 8, 2009.

Region 8 CSCI scores and data.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Inland surface water communities and populations, including vertebrate, invertebrate, and plant species, shall not be degraded as a result of the discharge of waste. Degradation is damage to an aquatic community or population with the result that balanced community no longer exists. The concentrations of toxic pollutants in the water column, sediments or biota shall not adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.

Guideline Reference:

Bioassessment in complex environments: designing an index for consistent meaning in different settings

Spatial Representation:

The samples were collected at station 801STW208 (SMCR8_208) and 801STW258 (SMCR8_258).

Temporal Representation:

The samples were collected in June 2007 at 801STW208 and June 2006 at 801STW258.

Environmental Conditions:

QAPP Information:

Samples were collected for the RWB8's Probabilistic Stream Survey CY2006 and CY2007 following SWAMP protocols and data were stored in the SWAMP database.

QAPP Information Reference(s):


DECISION ID	97273	Region 8
San Timoteo River Reach 2 (Gage at San Timoteo to confluence with Yucaipa Creek)

Pollutant:	Indicator Bacteria
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:	2029
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 (4) lines of evidence are available in the administrative record to assess this pollutant. Twenty-three (23) of the 23 samples exceed the E. coli Geomean Objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for 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. Twenty-three (23) of the 23 samples exceed the E. coli Geomean, and this does exceed the frequency listed in table 3.2 4. The line of evidence based on the single sample maximum was not included in the Final Use Rating as the Region 8 Basin Plan states that where a representative geometric mean can be calculated, single sample maximum values shall not be used for assessment (page 4-17, footnote 3). 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 97273, Indicator Bacteria	Region 8
San Timoteo River Reach 2 (Gage at San Timoteo to confluence with Yucaipa Creek)

LOE ID:

82326

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Forty-nine of the 52 samples exceeded the total coliform evaluation guideline.

Data Reference:

Data for Various Pollutants in Region 8, 2008-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentrations of toxic pollutants in the water column, sediments or biota shall not adversely affect beneficial uses. Santa Ana Region basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

The single sample total coliform concentration shall not exceed more than 10,000/100ml. Guidance for Fresh Water Beaches (CDPH 2011).

Guideline Reference:

Draft Guidance for Fresh Water Beaches. Last Update: May 8, 2006. Initial Draft: November 1997. California Department of Public Health.

Spatial Representation:

The samples were collected from San Timoteo Creek Reach 2 site ST3.

Temporal Representation:

The samples were collected once a week from July 2008 to November 2009.

Environmental Conditions:

QAPP Information:

Data was collected under the Qality Assurance Project Plan for the Upper Santa Ana River Watershed Water Quality Assessment Project.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 97273, Indicator Bacteria	Region 8
San Timoteo River Reach 2 (Gage at San Timoteo to confluence with Yucaipa Creek)

LOE ID:

82325

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:

Not Specified

Data Used to Assess Water Quality:

Thirty-five of the 35 samples exceeded the E. coli evaluation guideline for geometric mean.

Data Reference:

Data for Various Pollutants in Region 8, 2008-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentrations of toxic pollutants in the water column, sediments or biota shall not adversely affect beneficial uses. Santa Ana Region basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

Geomean: The E. coli concentration for geometric mean shall not exceed more than 126/100ml. USEPA Ambient Water Quality Criteria for Bacteria -1986.

Guideline Reference:

Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Spatial Representation:

The samples were collected from San Timoteo Creek Reach 2 station ST3.

Temporal Representation:

The samples were collected once a week from July 2008 to November 2009.

Environmental Conditions:

QAPP Information:

Data was collected under the Qality Assurance Project Plan for the Upper Santa Ana River Watershed Water Quality Assessment Project.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 97273, Indicator Bacteria	Region 8
San Timoteo River Reach 2 (Gage at San Timoteo to confluence with Yucaipa Creek)

LOE ID:

82327

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Thirty-five of the 35 samples exceeded the total coliform evaluation guideline for geometric mean.

Data Reference:

Data for Various Pollutants in Region 8, 2008-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentrations of toxic pollutants in the water column, sediments or biota shall not adversely affect beneficial uses. Santa Ana Region basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

Geomean: The total coliform concentration for geometric mean shall not exceed more than 1000/100ml. Guidance for Fresh Water Beaches (CDPH 2011).

Guideline Reference:

Draft Guidance for Fresh Water Beaches. Last Update: May 8, 2006. Initial Draft: November 1997. California Department of Public Health.

Spatial Representation:

The samples were collected from San Timoteo Creek ST3.

Temporal Representation:

The samples were collected once a week from July 2008 to November 2009.

Environmental Conditions:

QAPP Information:

Data was collected under the Qality Assurance Project Plan for the Upper Santa Ana River Watershed Water Quality Assessment Project.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 97273, Indicator Bacteria	Region 8
San Timoteo River Reach 2 (Gage at San Timoteo to confluence with Yucaipa Creek)

LOE ID:

82324

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:

Not Specified

Data Used to Assess Water Quality:

Forty-five of the 52 samples exceeded the E. coli evaluation guideline.

Data Reference:

Data for Various Pollutants in Region 8, 2008-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentrations of toxic pollutants in the water column, sediments or biota shall not adversely affect beneficial uses. Santa Ana Region basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

The single sample E. coli concentration shall not exceed more than 235/100ml. USEPA Ambient Water Quality Criteria for Bacteria -1986.

Guideline Reference:

Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Spatial Representation:

The samples were collected from San Timoteo Creek Reach 3 ST3.

Temporal Representation:

The samples were collected once a week from July 2008 to November 2009.

Environmental Conditions:

QAPP Information:

Data was collected under the Qality Assurance Project Plan for the Upper Santa Ana River Watershed Water Quality Assessment Project.

QAPP Information Reference(s):