| Water Body Name: | Los Coches Creek |
| Water Body ID: | CAR9071400020081210155144 |
| Water Body Type: | River & Stream |
DECISION ID |
16697 |
Region 9 |
Los Coches Creek |
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| 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. Four 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. Four of the 4 samples exceeded the Basin Plan objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy (not enough samples were collected). 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 decision be approved by the State Board. |
| USEPA Action (if applicable): | |
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| LOE ID: | 26189 | ||||
| Pollutant: | Nitrogen | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Total | ||||
| 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: | Four of four samples collected at Los Coches Creek station (907SDLCO2) from May 2004 to April 2005 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 (RWQCB, 2007).
A desired goal in order to prevent plant nuisance in streams and other flowing waters appears to be 0.1 mg/L total phosphorus, P. These values are not to be exceeded more than 10% of the time unless studies of the specific water body in question clearly show that water quality objective changes are permissible and changes are approved by the Regional Board. Analogous threshold values have not been set for nitrogen compounds; however, natural ratios of nitrogen to phosphorus are to be determined by surveillance and monitoring and upheld. If data are lacking, a ratio of N:P = 10:1, on a weight to weight basis shall be used (RWQCB, 2007). |
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| Objective/Criterion Reference: | Water Quality Control Plan for the San Diego Basin | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | Water samples were collected at Los Coches Creek station 2 (907SDLCO2). | ||||
| Temporal Representation: | Samples were collected in May 2004, September 2004, February 2005, and April 2005. | ||||
| 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 |
16698 |
Region 9 |
Los Coches Creek |
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| 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. Two of the 4 samples exceed the water quality objective. According to Table 3.2 of the Listing Policy the minimum sample requirement is five. 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 4 samples exceeded the Basin Plan 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. |
| 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 (not enough samples). |
| 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): | |
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| LOE ID: | 26190 | ||||
| Pollutant: | Phosphorus | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| 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 four samples collected at Los Coches Creek station 2(907SDLCO2) from May 2004 to April 2005 showed excessive phosphorus concentrations (SWAMP, 2007). | ||||
| Data Reference: | Monitoring data for Region 9 | ||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | As described in San Diego Basin Plan; inland surface waters, bays and estuaries and coastal lagoon waters shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growths cause nuisance or adversely affect beneficial uses (RWQCB, 2007).
From the Basin Plan: For inland surface waters-streams and other flowing waters, with all beneficial uses, the water quality objective for total phosphorus is 0.1 mg/L (RWQCB, 2007). |
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| Objective/Criterion Reference: | Water Quality Control Plan for the San Diego Basin | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | Water samples were collected at Los Coches Creek station 2 (907SDLCO2). | ||||
| Temporal Representation: | Samples were collected in May 2004, September 2004; February 2005; and April 2005. | ||||
| 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 |
16566 |
Region 9 |
Los Coches Creek |
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| 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: | 2019 |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 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. Three 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 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. Three of the 4 samples exceed the CTR value for Se 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. |
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| LOE ID: | 26191 | ||||
| Pollutant: | Selenium | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Dissolved | ||||
| Beneficial Use: | Warm Freshwater Habitat | ||||
| Number of Samples: | 4 | ||||
| Number of Exceedances: | 3 | ||||
| Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants) | ||||
| Data Used to Assess Water Quality: | Three of four samples collected at Los Coches Creek station 2 (907SDLCO2) from May 2004 to April 2005 showed excessive phosphorus concentrations (SWAMP, 2007). | ||||
| Data Reference: | Monitoring data for Region 9 | ||||
| SWAMP Data: | 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: | |||||
| Spatial Representation: | Water samples were collected at Los Coches Creek station 2(907SDLCO2). | ||||
| Temporal Representation: | Samples were collected in May 2004, September 2004; February 2005; and April 2005. | ||||
| 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 | ||||