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

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name: La Posta Creek
Water Body ID: CAR9117000020011025112350
Water Body Type: River & Stream
 
DECISION ID
16501
 
Pollutant: Ammonia as Nitrogen | Nickel | Phosphorus | Total Nitrogen as N
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 and 3.2 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 four samples exceed the water quality objectives.

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 the four samples exceeded the water quality objectives and this does not exceed the allowable frequency listed in Table 3.1 and is not enough samples for use of 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 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 16501
 
LOE ID: 26412
 
Pollutant: Ammonia as Nitrogen | Nickel | Phosphorus | Total Nitrogen as N
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: None of the four samples collected at La Posta Creek station 4 911TLAP04 exceeded the water quality objective. Samples were collected from June 2005, September 2005, January 2006, and April 2006, for conventional inorganics analyses.
Data Reference: Monitoring data for Region 9
 
Water Quality Objective/Criterion: Ammonia as N 0.025 mg/l, total nitrogen and phosphorus (If data are lacking, a ratio of N:P = 10:1, on a weight to weight basis shall be used), and sulfate 250 mg/l.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Water samples were collected at La Posta Creek station 4( 911TLAP04); (Latitude 32.6999, Longitude -116.4795).
Temporal Representation: Water samples were collected on June 2005, September 2005, January 2006, and April 2006.
Environmental Conditions:
QAPP Information: Quality control for 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
17897
 
Pollutant: Benthic Community Effects
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: Pollution
 
Weight of Evidence: Benthic Community Effects is being considered for placement on the section 303(d) list under sections 3.9 and 3.2 of the Listing Policy. Under section 3.9, an additional line of evidence associating the Benthic Community Effects with a water or sediment concentration of pollutants is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this indicator. 3 of 6 samples exceeded the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this water segment 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. 3 of 6 samples exceeded the Index of Biological Integrity (IBI) value of "poor" water quality for this area 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, 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 17897
 
LOE ID: 26409
 
Pollutant: Benthic Community Effects
LOE Subgroup: Adverse Biological Responses
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 3
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Six samples of IBI data were taken from November 2000 to 2007 at one sampling site. Three of the six samples exceeded the IBI impairment threshold.
Data Reference: Fish and Game IBI Data
  Southern California Postfire Study. IBI. 2007.
 
Water Quality Objective/Criterion: From the San Diego Basin Plan the objective is: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline: The Index of Biological Integrity (IBI) is an analytical tool that can be used to assess the biological and physical condition of streams and rivers within a zero to one hundred scoring range: Very Poor 0-19, Poor 20-39, Fair 40-59, Good 60- 79, Very Good 80-100. The IBI score of 39 was set as an impairment threshold because it is a statistical criterion of two standard deviations below the mean reference site score which defines the boundary between 'fair' and 'poor' IBI creek conditions. (Ode, p. 9)
Guideline Reference: "A Quantitative Tool for Assessing the Integrity of Southern Coastal California Streams". Environmental Management. Volume 35, number 1 (2005): 1-13.
 
Spatial Representation: Samples were collected at one site: 911LPCCTT on La Posta Creek.
Temporal Representation: Sampling occurred during six events from November 2000 to 2007.
Environmental Conditions:
QAPP Information: Quality Control for collection and identification was conducted in accordance with the Quality Assurance Project Plan for the California Stream Bioassessment Procedure and the State of California, California Monitoring an Assessment Program: "CMAP", Quality Assurance Project Plan.
QAPP Information Reference(s): State of California, California Monitoring and Assessment Program: "CMAP".
  Quality Assurance Project Plan for the California Stream Bioassessment Procedure
  The San Diego Stream Team Quality Assurance Project Plan
 
DECISION ID
16502
 
Pollutant: Metals
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 lines of evidence is available in the administrative record to assess this pollutant. None of the 4 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 4 samples exceeded the CTR or MCL values for selected metals 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, 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 16502
 
LOE ID: 26410
 
Pollutant: Metals
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: Four samples were collected at La Posta Creek station 4 (911TLAP04) during the months of June 2005, September 2005, January 2006, and April 2006, for the following constituents: aluminum, arsenic, cadmium, copper, selenium, silver, zinc. None of the four samples showed excessive concentrations.
Data Reference: Monitoring data for Region 9
 
Water Quality Objective/Criterion: The Maximum Contaminant Level (MCL) for aluminum is 1.0 mg /l. The dissolved chronic criterion for the following metals applies: arsenic 150 µg/l ,cadmium 2.2 µg/l, copper 9.0 µg/l , selenium 5.0 µg/l, zinc 120 µg/l, chromium 11 µg/l, manganese 0.05 mg/l, nickel 52 µg/l, lead 2.5 µg/l, and silver 3.4 µg/l. California Toxics Rule. 2007.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
  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:
 
Spatial Representation: Water samples were collected at La Posta Creek station 4 (911TLAP04); (Latitude 32.6999, Longitude -116.4795).
Temporal Representation: Water samples were collected on June 2005, September 2005, January 2006, and April 2006.
Environmental Conditions:
QAPP Information: Quality control for 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
16503
 
Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons)
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 4 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 4 samples exceeded the CTR value for PAHs 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, 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 16503
 
LOE ID: 26411
 
Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons)
LOE Subgroup: Health Advisories
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: Four samples were collected at La Posta Creek station 4 (911TLAP04) during the months of June 2005, September 2005, January 2006, and April 2006. None of the four samples showed excessive concentrations.
Data Reference: Monitoring data for Region 9
 
Water Quality Objective/Criterion: Water designated for use as domestic or
municipal supply (MUN) shall not contain
concentrations of chemical constituents in
excess of the maximum contaminant levels specified in California Code of Regulations, Title 22, Table 64444-A of section 64444 (Organic Chemicals) which is incorporated by reference into this plan.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline: Evaluation guidelines used came California Toxics Rule for Human Health Risk. Acenaphthene;1200 ug/l, Anthracene;9,600 ug/l, Benz(a)anthracene; 4.4 ug/l, Benzo(b)fluoranthene; 4.4 ug/l, Benzo(k)fluoranthene; 4.4 ug/l, Chrysene; 4.4 ug/l, Fluoranthene; 300 ug/l, and Fluorene; 1300 ug/l.
Guideline 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.
 
Spatial Representation: Water samples were collected at La Posta Creek station 4 (911TLAP04); (Latitude 32.6999, Longitude -116.4795).
Temporal Representation: Water samples were collected on June 2005, September 2005, January 2006, and April 2006.
Environmental Conditions:
QAPP Information: Quality control for 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
16504
 
Pollutant: PCBs (Polychlorinated biphenyls)
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 4 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 4 samples exceeded the CTR value for PCBs 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, 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 16504
 
LOE ID: 26543
 
Pollutant: PCBs (Polychlorinated biphenyls)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: Two samples were collected at La Posta Creek station 4 911TLAP04 during the months of June 2005, September 2005, January 2006, and April 2006, for PCBs analyses. None of the four samples showed excessive concentrations.
Data Reference: Monitoring data for Region 9
 
Water Quality Objective/Criterion: From the Basin Plan; waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in
excess of the maximum contaminant levels (MCL 0.5 ug/l) specified in California Code of Regulations, Title 22, Table 64444-A of section 64444 (Organic Chemicals) which is incorporated by reference into this plan.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin (9).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Water samples were collected at La Posta Creek station 4 911TLAP04; (Latitude 32.6999, Longitude -116.4795).
Temporal Representation: Water samples were collected on June 2005, September 2005, January 2006, and April 2006.
Environmental Conditions:
QAPP Information: Quality control for 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.