Final California 2010 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name: Moro Canyon Creek
Water Body ID: CAR9011100020081210154547
Water Body Type: River & Stream
 
DECISION ID
16321
Region 9     
Moro Canyon Creek
 
Pollutant: Nitrogen
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
 
Regional Board Conclusion: 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 four samples exceed the Basin Plan water quality objective for nitrogen.

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 the four samples exceed the Basin Plan water quality objective for nitrogen 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 3.11/4.11] of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
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.
 
USEPA Action (if applicable):
 
 
Line of Evidence (LOE) for Decision ID 16321, Nitrogen
Region 9     
Moro Canyon Creek
 
LOE ID: 26193
 
Pollutant: Nitrogen
LOE Subgroup: Subgroup Missing
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 2
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: Two of the four samples collected at Moro Canyon Creek 2 Station (901SJMCC2) (Latitude 33.5624, Longitude -117.8182) from October 2002 to May 2003 showed excessive nitrogen concentrations (SWAMP, 2007).
Data Reference: Monitoring data for Region 9
 
SWAMP Data: SWAMP
 
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.

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
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Water samples were collected at Moro Canyon Creek 2 Station (901SJMCC2). (Latitude 33.5624, Longitude -117.8182).
Temporal Representation: Samples were collected in October 2002; 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's 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
16322
Region 9     
Moro Canyon Creek
 
Pollutant: Phosphorus
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
 
Regional Board Conclusion: 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. Four of the four samples exceed the Basin Plan water quality objective for phosphorus.

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. Four of the four samples exceed the Basin Plan water quality objective for phosphorus 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 3.11/4.11] of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
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.
 
USEPA Action (if applicable):
 
 
Line of Evidence (LOE) for Decision ID 16322, Phosphorus
Region 9     
Moro Canyon Creek
 
LOE ID: 26194
 
Pollutant: Phosphorus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 4
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: All four samples collected at Moro Canyon Creek 2 Station (901SJMCC2) (Latitude 33.5624, Longitude -117.8182) from October 2002 to May 2003 showed excessive phosphorus concentrations (SWAMP, 2007).
Data Reference: Monitoring data for Region 9
 
SWAMP Data: SWAMP
 
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.

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
 
Evaluation Guideline:
Guideline Reference: Water Quality Control Plan for the San Diego Basin
 
Spatial Representation: Water samples were collected at Moro Canyon Creek 2 Station (901SJMCC2). (Latitude 33.5624, Longitude -117.8182).
Temporal Representation: Samples were collected in October 2002; 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's 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
16319
Region 9     
Moro Canyon Creek
 
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: Source Unknown
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Regional Board Conclusion:
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. Four of the four 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 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. Four of four samples exceeded the water quality objective for Selenium 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 3.11/4.11] of the Listing Policy, no additional data and information are available indicating that standards are not met.


State Board Review and Conclusion:
The Regional Board staff incorrectly assessed selenium as a conventional pollutant and applied table 3.2 of the listing Policy. Selenium is a toxicant and should be assessed using Table 3.1 . State Water Board staff has corrected this error and revised the recommendation to List for selenium. The revised recommendation 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. Four of the four 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 for 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. Four of four samples exceeded the water quality objective for selenium and this exceeds the allowable frequency under Section 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: 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.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the following changes to the decision:
The water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 16319, Selenium
Region 9     
Moro Canyon Creek
 
LOE ID: 26195
 
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 (conventional plus toxic pollutants)
Data Used to Assess Water Quality: All four samples collected at Moro Canyon Creek 2 Station (901SJMCC2) (Latitude 33.5624, Longitude -117.8182) showed excessive selenium concentrations according to results from the Surface Water Ambient Monitoring program. Samples were collected from October 2002 through May 2003.
Data Reference: Monitoring data for Region 9
 
SWAMP Data: Non-SWAMP
 
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
 
Spatial Representation: Water samples were collected at Moro Canyon Creek 2 Station (901SJMCC2). (Latitude 33.5624, Longitude -117.8182).
Temporal Representation: Samples were collected in October 2002; 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's 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
16320
Region 9     
Moro Canyon Creek
 
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: Unknown Nonpoint Source | Unknown Point Source | Urban Runoff/Storm Sewers
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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.

One line of evidence is available in the administrative record to assess this pollutant. Four of the four samples exceed the Basin Plan water quality objective for toxicity.

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. Four of four samples exceed the Basin Plan water quality objective for toxicity 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.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 16320, Toxicity
Region 9     
Moro Canyon Creek
 
LOE ID: 26197
 
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: Four samples were collected at Moro Canyon Creek 2 Station (901SJMCC2) (Latitude 33.5624, Longitude -117.8182) from October 2002 to May 2003 for the Surface Water Ambient Monitoring Program. Selenastrum Capicornutum alga growth test: - All four samples were considered toxic; Ceriodaphnia dubia survival and reproduction test: One of the two samples was toxic; Hyalella azteca; None of the two samples was toxic.
Data Reference: Monitoring data for Region 9
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: 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.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
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: Water samples were collected at Moro Canyon Creek 2 Station (901SJMCC2). (Latitude 33.5624, Longitude -117.8182).
Temporal Representation: Samples were collected in October 2002; January 2003, April 2003, and May 2003.
Environmental Conditions:
QAPP Information: Quality control of this study was conducted in accordance with the California's 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