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

Supporting Information

Regional Board 2 - San Francisco Bay Region

Water Body Name: Peralta Creek
Water Body ID: CAR2042004020080817191851
Water Body Type: River & Stream
 
DECISION ID
17558
 
Pollutant: Arsenic | Chromium (total) | Copper | Lead | Nickel | Silver | Zinc
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: These pollutants are 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. None 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.Zero of three samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, Water Board 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17558
 
LOE ID: 28830
 
Pollutant: Arsenic | Chromium (total) | Copper | Lead | Nickel | Silver | Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The Peralta Creek watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc.
Concentrations of total dissolved chromium were well below the objective for chromium VI.
Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L.
Objective/Criterion Reference: San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data were collected at one sampling location (PRL020) on Peralta Creek.
Temporal Representation: Samples were collected during wet (January), spring (April),and dry(June) seasons of 2005.
Environmental Conditions:
QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
DECISION ID
9456
 
Pollutant: Diazinon | Pyrethroids | 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
 
Weight of Evidence: This pollutant is being considered for listing under sections 3.6 and 3.1 of the Listing Policy. Under section 3.6 a single line of evidence is necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess toxicity in Peralta Creek. Based on the readily available data for this water body, the weight of evidence indicates that there is sufficient justification available 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 concerning current conditions and supporting the listing decision satisfy the data quality requirements of section 6.1.4 of the Policy.

2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy.

3. The allowable frequency listed in Table 3.1 of the Listing Policy are not exceeded for toxicity, pyrethroids and diazinon. Only one sample was tested for toxicity and amphipod toxicity was not detected. One sample was tested for pyrethroid concentration and showed 28 toxicity units indicating potential toxic effect but growth and survival of Hyalella azteca was unaffected. In one of three samples concentration of diazinon exceeded the acute water quality threshold.

4. The sample size for toxicity and pyrethroid is insufficient to determine with the power and confidence of the Listing Policy if standards are not met.

5. 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, Water Board staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there is insufficient information to confirm toxicity and to determine that the standards are not met.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 9456
 
LOE ID: 8974
 
Pollutant: Sediment Toxicity
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Data used to evaluate sediment toxicity comprise one sediment sample collected by the SWAMP in 2005. The sample did not exhibit amphipod toxicity.
Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.
Objective/Criterion Reference: San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan)
 
Evaluation Guideline: Sediment toxicity data were evaluated according to the SWAMP methodology. Sample toxicity was determined by comparing mean organism response in samples and in negative controls. Statistical evaluation and a default threshold of 80% of the control value were used to establish whether the sediment exhibited significant toxicity adversely impacting aquatic organisms.
Guideline Reference: Revised approach to toxicity test acceptability criteria using a statistical performance assessment. Environmental Toxicology and Chemistry, vol. 16, No. 6, pp 1322–1329
 
Spatial Representation: Data were collected at a sampling location at the lower part of Peralta Creek North of Hwy 185.
Temporal Representation: Sample was collected in spring 2005.
Environmental Conditions:
QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):
 
LOE ID: 8975
 
Pollutant: Pyrethroids
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Toxicity testing of sediments
Data Used to Assess Water Quality: Data used to evaluate pyrethroid toxicity comprise one sediment sample collected by the SWAMP in 2005.The pyrethroid concentration in the Peralta Creek sample exceeded 28TU but the growth and survival of Hyalella azteca was unaffected.
Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.

There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.
Objective/Criterion Reference: San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan)
 
Evaluation Guideline: Amweg et al. (2006) interpreted results of toxicity testing and sediment pyrethroid concentrations in urban creeks in California. Pyrethroid concentration data and analysis of toxicity units (TU) were used to determine whether pyrethroids could be linked to the observed toxicity to Hyalella azteca. The results indicated that samples with less than 1 TU were nontoxic and those with TU greater than 2 were consistently toxic.
Guideline Reference: Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706
 
Spatial Representation: Data were collected at a sampling location at the lower part of Peralta Creek North of Hwy 185.
Temporal Representation: Sample was collected in spring 2005.
Environmental Conditions:
QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):
 
LOE ID: 8977
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Diazinon concentration in one (January 2005) of three samples exceeded 0.1 ug/L.
Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.
Objective/Criterion Reference: San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan)
 
Evaluation Guideline: The TMDL for diazinon in urban creeks established diazinon concentration target of less than 0.1 ug/L expressed as a one-hour average.
Guideline Reference: San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan)
 
Spatial Representation: Data were collected at a sampling location at the lower part of Peralta Creek North of Hwy 185.
Temporal Representation: Samples were collected in January (we season) and June (dry season) of 2005.
Environmental Conditions:
QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):
 
DECISION ID
17560
 
Pollutant: Mercury
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 3.1 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. None 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. None of three samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, Water Board 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17560
 
LOE ID: 28847
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The Peralta Creek watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for mercury.
Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: mercury- 2.4 ug/L
Objective/Criterion Reference: San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data were collected at one sampling location (PRL020) on Peralta Creek.
Temporal Representation: Samples were collected during wet (January), spring (April),and dry(June) seasons of 2005.
Environmental Conditions:
QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
DECISION ID
17562
 
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
 
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. One 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. One of six[ samples exceeded the water quality objective 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.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, Water Board 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17562
 
LOE ID: 28895
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water quality assessment was conducted at Peralta Creek watershed as part of SWAMP assessment in 2004 and 2005. Continuous field monitoring of temperature, dissolved oxygen, pH, and specific conductance to determine temporal variability in basic water quality at two locations. The 7 day average minimum concentration of dissolved oxygen ranged from 5.4 to 9.9 mg/L and varied with season. Minimum dissolved oxygen levels fell below the objective of 7 mg/L once in August 2004. During that period average minimum values of DO were 5.4 mg/L.
Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
 
Water Quality Objective/Criterion: The numeric water quality objective for dissolved oxygen is 7.0 mg/L minimum for waters designated as cold water habitat. The median dissolved oxygen concentration for any three consecutive months shall not be less than 80 percent of the dissolved oxygen content at saturation.
Objective/Criterion Reference: San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Dissolved oxygen was measured at two sites located on the mainstem of Peralta Creek (PRL020, Casar Chavez Park), and PRL080 (Peralta at Rettig).
Temporal Representation: At both locations the SWAMP performed continuous monitoring of dissolved oxygen at 15 minute intervals lasting 7-8 days during spring (April 2004), summer dry seasons (August 2004), and winter wet season (February 2005).
Environmental Conditions:
QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002).
QAPP Information Reference(s):
 
DECISION ID
17563
 
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
 
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. Two 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. Two of six samples exceeded the water quality objective 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.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, Water Board 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17563
 
LOE ID: 28862
 
Pollutant: Temperature, water
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water quality assessment was conducted at the Peralta Creek watershed as part of SWAMP study in 2004-2005. Continuous field monitoring at 15 minute increments of temperature, dissolved oxygen, pH and specific conductance was conducted to determine temporal variability in basic water quality at two locations. Continuous monitoring sondes were deployed 6 times at 2 monitoring locations during wet, spring and dry seasons. The measured temperatures ranged from 11.3oC to 22.5oC and varied with season and location. During the dry season (Summer) the 7-day mean temperature threshold for steelhead was exceeded at both monitoring locations. PRL020 exceeded the 7 day mean with temperatures of 19.2oC in August 2004 and PRL080 exceeded with temperatures of 18.6oC in August 2004. In total, the 17oC criterion was exceeded in 2 out of 6 deployments.
Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
 
Water Quality Objective/Criterion: Temperature objectives for enclosed bays and estuaries are specified in the "Water Quality Control Plan for Control of Temperature in the Coastal and Interstate Waters and Enclosed Bays of California" including any revisions to the plan. In addition, the following temperature objectives apply to surface waters: The 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 an alteration does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.
Objective/Criterion Reference: San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan)
 
Evaluation Guideline: Sullivan et al. (2000) reviewed a wide range of studies incorporating information from laboratory-based research, field observations, and risk assessment approaches and developed criteria for assessing temperature risk to aquatic life. The 7-day mean temperature (maximum value of a 7-day moving average of the daily mean temperature) of 14.8°C was established as the upper threshold criterion for coho salmon and 17.0°C for steelhead trout. The risk assessment approach used by Sullivan et al. (2000) suggests that temperatures exceeding the above thresholds will cause a 10% reduction in average growth compared to optimal conditions.
Guideline Reference: An Analysis of the Effects of Temperature on Salmonids of the Pacific Northwest with Implications for Selecting Temperature Criteria
 
Spatial Representation: Temperature was measured at two sites (PRL020 Cesar Chavez Park and PRL080 Peralta at Rettig) located on the mainstem of Peralta Creek.
Temporal Representation: In 2004 and 2005 the SWAMP Program performed continuous monitoring of temperature at 15 minute intervals for periods of 1 week in each of three different seasons: summer (2 sites in August), spring (2 sites), and winter (2 sites).
Environmental Conditions:
QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002).
QAPP Information Reference(s):
 
DECISION ID
17565
 
Pollutant: 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
 
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.

One line of evidence is available in the administrative record to assess this pollutant. None 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. None of three samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, Water Board 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17565
 
LOE ID: 28827
 
Pollutant: Toxicity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Three samples were collected in 2005 to evaluate water toxicity at one monitoring location in Peralta Creek. The toxicity tests included survival and reproduction of Ceriodaphnia, survival and growth of fathead minnow, and growth of Selenastrum. No significant toxicity was observed in these sample.
Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.
Objective/Criterion Reference: San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan)
 
Evaluation Guideline: Water toxicity was evaluated according to the SWAMP methodology. The U.S.EPA whole effluent toxicity protocol (U.S.EPA 1994) was used to test the effect of water samples on three freshwater test organisms. Statistical evaluation (alpha = 0.05) and a default threshold of 80% of the control value were used to establish whether water exhibited significant toxicity adversely impacting aquatic organisms.
Guideline Reference: Revised approach to toxicity test acceptability criteria using a statistical performance assessment. Environmental Toxicology and Chemistry, vol. 16, No. 6, pp 1322–1329
  Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. EPA/600/4-91/002. Third Edition. July 1994
 
Spatial Representation: Data were collected at one sampling location at the lower reach of the creek.
Temporal Representation: SWAMP samples were collected during winter wet season (January), spring season (April), and dry season (June) of 2005.
Environmental Conditions:
QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
 
DECISION ID
17564
 
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
 
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. One 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. One of six samples exceeded the water quality objective 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.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, Water Board 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17564
 
LOE ID: 28791
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Comprehensive water quality assessment was conducted at Peralta Creek watershed as part of SWAMP assessment in 2004 and 2005. Continuous field monitoring of temperature, dissolved oxygen, pH, and specific conductance to determine temporal variability in basic water quality at one or two locations. The pH ranged from 7.3 to 8.8 and varied with season. The pH exceeded the maximum, (at 8.8) on one occasion, at the PRL020 sampling location in Spring 2004.
Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
 
Water Quality Objective/Criterion: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference: San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Continuous measurements were conducted at two sampling sites at PRL020 Cesar Chavez Park and PRL080 Peralta at Rettig (three each) located on the mainstem of Peralta Creek.
Temporal Representation: SWAMP Program performed continuous monitoring of pH at 15 minute intervals for periods of 7 to 8 days. PRL020 and PRL080 were sampled during spring (April 2004), summer dry season (August 2004), and winter wet season (February 2005).
Environmental Conditions:
QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002).
QAPP Information Reference(s):