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

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name: Lawson Creek
Water Body ID: CAR9092100020081222142247
Water Body Type: River & Stream
 
DECISION ID
77452
Region 9     
Lawson Creek
 
Pollutant: Ammonia as Nitrogen | Phosphorus | Sulfates | Total Nitrogen as N
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: The decision has not changed from the previous listing cycle. No new data were assessed for the current listing cycle. Therefore, the previous conclusion remains unchanged, and is as follows:

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 sections 3.1 and 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 these pollutants. None of the 2 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 2 samples exceeded the Basin Plan objectives for ammonia, total nitrogen, and phosphorus and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
3. None of the 2 samples exceeded the Basin Plan objective for sulfates 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.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
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 77452, Multiple Pollutants
Region 9     
Lawson Creek
 
LOE ID: 26406
 
Pollutant: Ammonia as Nitrogen | Phosphorus | Sulfates | Total Nitrogen as N
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: Two samples were collected at Lawson Valley Creek station 909SLAW02 during the months of June 2005 and April 2006, for conventional inorganics analyses. None of the samples showed excessive concentrations.
Data Reference: Monitoring data for Region 9
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Ammonia as N 0.025 mg/l, nitrogen total a ratio of N:P = 10:1, on a weight to weight basis shall be used, Phosphorus, total 0.05 mg/l, and sulfate 250 mg/l.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Water samples were collected at Lawson Valley Creek station 909SLAW02; (Latitude 37.7540, Longitude -116.7788).
Temporal Representation: Water samples were collected on June 2005, 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
76317
Region 9     
Lawson 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.

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 does not exhibit 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.
 
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. Furthermore, what data is available does not indicate that the benthic community exhibits degradation when compared to reference.
 
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 76317, Benthic Community Effects
Region 9     
Lawson Creek
 
LOE ID: 79684
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: One sample was taken at one station on Lawson Valley Creek. The CSCI score for this site is above the 0.79 threshold, and is therefore not exceeding the water quality objective for the aquatic life beneficial use.
Data Reference: RWB9 Status Sampling 2007 and 2008
  Region 9 CSCI Scores & Water Body Information
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant or animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board. Region 9 Basin Plan.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego 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 (Rhen, 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: Samples were collected at the following station: 909SLAW02 (Lawson Valley Creek 2).
Temporal Representation: Surveys done May 6, 2008.
Environmental Conditions:
QAPP Information: Data collected following SWAMP QA protocols for the RWB9 Status Sampling 2007 and 2008 water quality monitoring project.
QAPP Information Reference(s): RWB9 Status Sampling 2007 and 2008
 
Line of Evidence (LOE) for Decision ID 76317, Benthic Community Effects
Region 9     
Lawson Creek
 
LOE ID: 26414
 
Pollutant: Benthic Community Effects
LOE Subgroup: Adverse Biological Responses
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: One sample of IBI data was taken on November 2005 at one sampling site. Of the total number of samples, one of the samples exceeded the IBI impairment threshold.
Data Reference: Fish and Game IBI Data
 
SWAMP Data: Non-SWAMP
 
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
 
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): pp. 1-13
 
Spatial Representation: Samples were collected at one site: 909LSCLVR on Lawson Creek.
Temporal Representation: Sampling occurred in November 2005.
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): Quality Assurance Project Plan for the California Stream Bioassessment Procedure
QAPP Information Reference(s): State of California, California Monitoring and Assessment Program: "CMAP".
QAPP Information Reference(s): The San Diego Stream Team Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 76317, Benthic Community Effects
Region 9     
Lawson Creek
 
LOE ID: 74131
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: The IBI score for this water body is 16 which indicates that this water body may be considered to have impaired conditions.
Data Reference: RWB9 Status Sampling 2007 and 2008
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: 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.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline: The IBI is a multi-metric assessment that employs biological metrics that respond to a habitat or water quality impairment. Each of the biological metrics measured at a site are converted to an IBI score then summed. These cumulative scores are then ranked. For the Southern California IBI, sites with scores below 40 are considered to have impaired conditions.
Guideline Reference: A Quantitative Tool for Assessing the Integrity of Southern Coastal California Streams. Environmental Management. Volume 35, number 1 (2005): pp. 1-13
 
Spatial Representation: Samples were collected at the following station: 909SLAW02 (Lawson Valley Creek 2).
Temporal Representation: Surveys done May 6, 2008.
Environmental Conditions:
QAPP Information: Data collected following SWAMP QA protocols for the RWB9 Status Sampling 2007 and 2008 water quality monitoring project.
QAPP Information Reference(s):
 
 
DECISION ID
76315
Region 9     
Lawson Creek
 
Pollutant: Metals
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: The decision has not changed from the previous listing cycle. No new data were assessed for the current listing cycle. Therefore, the previous conclusion remains unchanged, and is as follows:

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 2 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 the 2 samples exceeded the CTR 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.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
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 76315, Metals
Region 9     
Lawson Creek
 
LOE ID: 26404
 
Pollutant: Metals
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 2
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 Lawson Valley Creek station 2, 909SLAW02 during the months of June 2005, and April 2006, for the following constituents: aluminum, arsenic, cadmium, copper, silver, and zinc. None of the 2 samples showed excessive concentrations.
Data Reference: Monitoring data for Region 9
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Maximum Contaminant Level (MCL) for aluminum is 1.0 mg /l. Water Quality Control for the San Diego Basin. 2007. The dissolved chronic criterion for the following metals applies: arsenic 150 µg/l (ppb), cadmium 2.2 µg/l (ppb), copper 9.0 µg/l (ppb), zinc 120 µg/l (ppb), chromium 11 µg/l (ppb), manganese 0.05 mg/l, nickel 52 µg/l (ppb), lead 2.5 µg/l (ppb), and silver 3.4µg/l (ppb). California Toxics Rule. 2007.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
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:
 
Spatial Representation: Water samples were collected at Lawson Valley Creek station 2, 909SLAW02; (Latitude 37.7540, Longitude -116.7788).
Temporal Representation: Water samples were collected on June 2005 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
76179
Region 9     
Lawson Creek
 
Pollutant: PCBs (Polychlorinated biphenyls)
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: Region 9 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle.

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 2 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 the 2 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.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
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 76179, PCBs (Polychlorinated biphenyls)
Region 9     
Lawson Creek
 
LOE ID: 26408
 
Pollutant: PCBs (Polychlorinated biphenyls)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 2
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 Lawson Valley Creek station 909SLAW02 during the months of June 2005, and April 2006, for PCBs analyses. None of the 2 samples showed excessive concentrations.
Data Reference: Monitoring data for Region 9
 
SWAMP Data: Non-SWAMP
 
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
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Water samples were collected at Lawson Valley Creek station 2, 909SLAW02; (Latitude 37.7540, Longitude -116.7788).
Temporal Representation: Water samples were collected on June 2005 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