Draft 2008 California 303(d)/305(b) Integrated Report

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name: Sweetwater River, Lower (below Sweetwater Reservoir)
Water Body ID: CAR9091200020091030145725
Water Body Type: River & Stream
 
DECISION ID
17866
 
Pollutant: Sulfates
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
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section3.2 one line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. All three of the samples exceed the water quality objective.

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. All three of the samples exceeded the sulfate water quality objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of five samples is needed for application of table 3.2.
4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
RWQCB Board Decision / Staff 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 if applicable water quality standards are not being exceeded.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17866
 
LOE ID: 30886
 
Pollutant: Sulfates
LOE Subgroup: Pollution
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 3
Number of Exceedances: 3
 
Data and Information Type: Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: Three of three samples collected at Sweetwater River show excessive sulfate concentrations according to results in California Surface Water Ambient Monitoring Program Report, 2007. Samples were collected in January 2003, April 2003, and May 2003.
Data Reference: Monitoring data for Region 9
 
Water Quality Objective/Criterion: The recommended secondary drinking water standard for sulfate is 250 mg/l (RWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Water samples were collected at Sweetwater River Stations 909SSWR08.
Temporal Representation: Samples were collected in January 2003, April 2003, and May 2003
Environmental Conditions:
QAPP Information: Quality control for the chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s): 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA.
 
DECISION ID
17875
 
Pollutant: Enterococcus
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Other Urban Runoff | Unknown Nonpoint Source | Unknown Point Source
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status.

One line of evidence are available in the administrative record to assess this pollutant. All 15 of the samples exceed the water quality objective for enterococcus.

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. All 15 samples exceed the enterococcus 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 not met.
 
RWQCB Board Decision / Staff 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17875
 
LOE ID: 30900
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 15
Number of Exceedances: 15
 
Data and Information Type: Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: All fifteen samples collected exceed the water quality objective for Enterococcus and thirteen of fifteen samples collected exceed the water quality objective for Fecal Coliform according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected two to four times a year from 2002-2006.
Data Reference: Urban Runoff Monitoring, Volume 1- Final Report.
 
Water Quality Objective/Criterion: From the Basin Plan, the most stringent of the US EPA bacteriological criteria for enterococcus sets a maximum limit at 61 colonies per 100mL (RWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline:
Guideline Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Spatial Representation: Samples were collected at the mass loading station located near the lower boundary of the watershed in Bonita, just north of Bonita Road and adjacent to the Plaza Bonita Road Bridge
Temporal Representation: Samples were collected two to four times a year from 2002-2006.
Environmental Conditions: Samples were collected during wet weather.
QAPP Information: QA/QC conducted according to Federal Regulations under requirements of a NPDES permit
QAPP Information Reference(s):
 
DECISION ID
17876
 
Pollutant: Fecal Coliform
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Other Urban Runoff | Unknown Nonpoint Source | Unknown Point Source
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status.

One lines of evidence is available in the administrative record to assess this pollutant. Thirteen of the 15 samples exceed the water quality objective for fecal coliform.

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. Thirteen of 15 samples exceed the fecal coliform 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 not met.
 
RWQCB Board Decision / Staff 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17876
 
LOE ID: 30901
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 15
Number of Exceedances: 13
 
Data and Information Type: Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: Thirteen of fifteen samples collected exceed the water quality objective according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected two to four times a year from 2002-2006.
Data Reference: Urban Runoff Monitoring, Volume 1- Final Report.
 
Water Quality Objective/Criterion: From the Basin Plan, no more than 10% of the samples during any 30-day period for waters designated for contact recreation shall exceed 400 per 100 ml.
From the Basin Plan, no more than 10% of the samples for waters designated for contact recreation shall exceed 400 per 100 ml (RWQCB, 2007)
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline:
Guideline Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Spatial Representation: Samples were collected at the mass loading station located near the lower boundary of the watershed in Bonita, just north of Bonita Road and adjacent to the Plaza Bonita Road Bridge
Temporal Representation: Samples were collected two to four times a year from 2002-2006.
Environmental Conditions: Samples were collected during wet weather.
QAPP Information: QA/QC conducted according to Federal Regulations under requirements of a NPDES permit
QAPP Information Reference(s):
 
DECISION ID
17868
 
Pollutant: Phosphorus
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Other Urban Runoff | Point Source | Unknown Nonpoint Source | Unknown Point Source
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: 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.

One line of evidence is available in the administrative record to assess this pollutant. All 15 of the samples exceed the water quality objective for phosphorus.

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. All 15 samples exceed the phosphorus 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 not met.
 
RWQCB Board Decision / Staff 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17868
 
LOE ID: 30889
 
Pollutant: Phosphorus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 15
Number of Exceedances: 15
 
Data and Information Type: Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: All fifteen samples collected exceed the water quality objective according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007.
Samples were collected two to four times a year from 2002-2006.
Data Reference: Urban Runoff Monitoring, Volume 1- Final Report.
 
Water Quality Objective/Criterion: Water bodies shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growths cause nuisance or adversely affect beneficial uses. (RWQCB, 2007)

Water Quality Control Plan for the San Diego Basin Goal of 0.1 mg/L for total phosphorus in streams and other flowing waters. (RWQCB, 2007)
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline:
Guideline Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Spatial Representation: Samples were collected at the mass loading station located near the lower boundary of the watershed in Bonita, just north of Bonita Road and adjacent to the Plaza Bonita Road Bridge
Temporal Representation: Samples were collected two to four times a year from 2002-2006.
Environmental Conditions: Samples were collected during wet weather.
QAPP Information: QA/QC conducted according to Federal Regulations under requirements of a NPDES permit
QAPP Information Reference(s):
 
DECISION ID
17871
 
Pollutant: Selenium
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Other Urban Runoff | Unknown Nonpoint Source | Unknown Point Source
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: 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.

Two lines of evidence are available in the administrative record to assess this pollutant. Four of the 15 samples exceed the water quality objective for selenium.

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. Fourof 15 samples exceed the selenium water quality objective 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.
 
RWQCB Board Decision / Staff 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17871
 
LOE ID: 30915
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 15
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: None of 15 samples collected at Sweetwater River exceed the water quality objective of 5 µg/L for dissolved selenium. Samples for Sweetwater River were collected in from February 2002 to February 2006.
Data Reference: Urban Runoff Monitoring, Volume 1- Final Report.
 
Water Quality Objective/Criterion: CTR Freshwater Chronic (CCC) 5 ug/L. (U.S. EPA, 2000).
Objective/Criterion Reference: Water Quality Standards; Establishment of Numeric Criteria for Priority Toxic Pollutants for the State of California; Rule. 40 CFR Part 131. U.S. Environmental Protection Agency, Region IX, Water Division, San Francisco, CA.
 
Evaluation Guideline:
Guideline Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Spatial Representation: Water samples were collected at Sweetwater River just North of Bonita Rd
Temporal Representation: Samples for Sweetwater River were collected February 2002 to February 2006.
Environmental Conditions:
QAPP Information: Quality assurance procedures in compliance with Weston Solutions Quality Assurance Manual.
QAPP Information Reference(s): Weston Solutions, 2004. Quality Management Manual. March 2004.
 
LOE ID: 30892
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 4
 
Data and Information Type: Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: Four of the four samples collected at Sweetwater River exceed the water quality objective of 5 µg/L for dissolved selenium according to results in California Surface Water Ambient Monitoring Program Report, 2007. Samples for Sweetwater River were collected in May 2005, September 2005, January 2006, and April 2006.
Data Reference: Monitoring data for Region 9
 
Water Quality Objective/Criterion: CTR Freshwater Chronic (CCC) 5 ug/L. (U.S. EPA, 2000).
Objective/Criterion Reference: Water Quality Standards; Establishment of Numeric Criteria for Priority Toxic Pollutants for the State of California; Rule. 40 CFR Part 131. U.S. Environmental Protection Agency, Region IX, Water Division, San Francisco, CA.
 
Evaluation Guideline:
Guideline Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Spatial Representation: Water samples were collected at Sweetwater River stations 909SSWR08.
Temporal Representation: Samples for Sweetwater River were collected in May 2005, September 2005, January 2006, and April 2006.
Environmental Conditions:
QAPP Information: Quality control for the chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):
 
DECISION ID
17867
 
Pollutant: Total Dissolved Solids
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Other Urban Runoff | Unknown Nonpoint Source | Unknown Point Source
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: 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.

One line of evidence is available in the administrative record to assess this pollutant. Eleven of 15 samples exceed the water quality objective for total dissolved solids.

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. Eleven of 15 samples exceed the total dissolved solids 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.
 
RWQCB Board Decision / Staff 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17867
 
LOE ID: 30888
 
Pollutant: Total Dissolved Solids
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 15
Number of Exceedances: 11
 
Data and Information Type: Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: Eleven of 15 samples collected exceed the water quality objective. Since a maximum of four samples were collected at most in a one year period, any exceedance results in an annual exceedance frequency greater than 10% according to the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected two to four times a year from 2002-2006.
Data Reference: Urban Runoff Monitoring, Volume 1- Final Report.
 
Water Quality Objective/Criterion: From the Basin Plan, concentrations of total dissolved solids cannot exceed 1500 mg/L. This concentration is not to be exceeded more than 10% of the time during any one year period (RWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at the mass loading station located near the lower boundary of the watershed in Bonita, just north of Bonita Road and adjacent to the Plaza Bonita Road Bridge
Temporal Representation: Samples were collected two to four times a year from 2002-2006.
Environmental Conditions: Samples were collected during wet weather.
QAPP Information: QA/QC conducted according to Federal Regulations under requirements of a NPDES permit
QAPP Information Reference(s):
 
DECISION ID
17872
 
Pollutant: Total Nitrogen as N
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Other Urban Runoff | Point Source | Unknown Nonpoint Source | Unknown Point Source
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: 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.

One line of evidence are available in the administrative record to assess this pollutant. Thirteen of the 15 samples exceed the water quality objective for total nitrogen.

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. Thirteen of 15 samples exceed the total nitrogen 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 not met.
 
RWQCB Board Decision / Staff 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17872
 
LOE ID: 30894
 
Pollutant: Total Nitrogen as N
LOE Subgroup: Health Advisories
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 15
Number of Exceedances: 13
 
Data and Information Type: Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: Thirteen of fifteen samples collected exceed the water quality objective according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected two to four times a year from 2002-2006.
Data Reference: Urban Runoff Monitoring, Volume 1- Final Report.
 
Water Quality Objective/Criterion: Water bodies shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growths cause nuisance or adversely affect beneficial uses. (RWQCB, 2007)

A desired goal in order to prevent plant nuisance in streams and other flowing waters appears to be 0.1 mg/L total phosphorus, P. These values are not to be exceeded more than 10% of the time unless studies of the specific water body in question clearly show that water quality objective changes are permissible and changes are approved by the Regional Board. Analogous threshold values have not been set for nitrogen compounds; however, natural ratios of nitrogen to phosphorus are to be determined by surveillance and monitoring and upheld. If data are lacking, a ratio of N:P = 10:1, on a weight to weight basis shall be used. (RWQCB, 2007)
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline:
Guideline Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Spatial Representation: Samples were collected at the mass loading station located near the lower boundary of the watershed in Bonita, just north of Bonita Road and adjacent to the Plaza Bonita Road Bridge.
Temporal Representation: Samples were collected two to four times a year from 2002-2006.
Environmental Conditions: Samples were collected during wet weather.
QAPP Information: QA/QC conducted according to Federal Regulations under requirements of a NPDES permit
QAPP Information Reference(s):
 
DECISION ID
17874
 
Pollutant: Toxicity
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Other Urban Runoff | Unknown Nonpoint Source | Unknown Point Source
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: 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 a single line of evidence is necessary to assess listing status.

Two lines of evidence is available in the administrative record to assess this pollutant. Twelve of 19 samples exceed the water quality objective.

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. Twelve of 19 samples exceed the toxicity water quality objective 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.
 
RWQCB Board Decision / Staff 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17874
 
LOE ID: 30899
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 4
 
Data and Information Type: Ambient toxicity testing (chronic)
Data Used to Assess Water Quality: Toxicity was observed in the following data from the Storm Water Ambient Monitoring Program

Selenastrum capricornutum-
All three samples showed significant toxicity levels.

Hyalella azteca - One of one samples were toxic for Hyalella growth in sediment.
Data Reference: Monitoring data for Region 9
 
Water Quality Objective/Criterion: From the Basin Plan, all waters shall be free of toxic substances that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (RWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline: According to SWAMP, waters are considered toxic when samples show significant toxicity levels (SWAMP code ‘SL’) when compared to a negative control. Significant toxicity is determined when statistical tests result in an alpha of less than 5% and percent control values less than the evaluation threshold.
Guideline Reference: Monitoring data for Region 9
 
Spatial Representation: Samples were collected from the monitoring station Sweetwater River 8 located on the main stem of the Sweetwater River.
Temporal Representation: Samples were taken between May 2005, September 2005, and January 2006.
Environmental Conditions:
QAPP Information: Quality control for the chemical analysis portion of this study was conducted in accordance with the California Surface Water Ambient Monitoring Program.
QAPP Information Reference(s): 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA.
 
LOE ID: 30897
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 15
Number of Exceedances: 8
 
Data and Information Type: Ambient toxicity testing (chronic)
Data Used to Assess Water Quality: Toxicity was observed in the following tests.
Selenastrum capricornutum-
Seven of fifteen samples collected were found to be toxic.

Ceriodaphnia dubia survival and reproduction: Five of 15 tests were found to be toxic.

Hyalella azteca; No samples were toxic.

Data was collected by San Diego County for their urban runoff monitoring program.
Data Reference: Urban Runoff Monitoring, Volume 1- Final Report.
 
Water Quality Objective/Criterion: From the Basin Plan, all waters shall be free of toxic substances that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (RWQCB, 2007).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline: Samples were found to exhibit toxicity when the No Observed Effect Concentration (NOEC) or median lethal concentration (LC50) for any given species was estimated to be less than 100% of the test sample concentration.
Guideline Reference: Waste Discharge Requirements for Discharges of Urban Runoff From the Municipal Separate Storm Sewer Systems Draining the Watersheds of the County of San Diego, the Incorporated Cities of San Diego, the San Diego Unified Port District, and the San Diego County Regional Airport. Order No. R9-2007-0001.
 
Spatial Representation: Samples were collected from the Sweetwater River at Bonita Rd near Plaza Bonita.
Temporal Representation: Samples were taken between February 2002 and February 2006.
Environmental Conditions:
QAPP Information: Quality control for the chemical analysis portion of this study was conducted in accordance Weston's quality assurance plan.
QAPP Information Reference(s): Weston Solutions, 2004. Quality Management Manual. March 2004.