| Data Used to Assess Water Quality: |
Three water samples were collected at Cloverdale Creek station 4, 905SDCDC4. Sample dates were January 2003, April 2003, and May 2003. All three samples showed excessive sulfate concentrations according to results in California's Surface Water Ambient Monitoring Program Report, 2007. |
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DECISION ID |
17643 |
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| Pollutant: |
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 |
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| 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 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 three 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. Three of the three 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. |
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| 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. |
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| SWRCB Board Decision / Staff Recommendation: |
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| USEPA Decision: |
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| LOE ID: |
9026 |
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| Pollutant: |
Total Nitrogen as N |
| LOE Subgroup: |
Pollutant-Water |
| Matrix: |
Water |
| Fraction: |
Not Recorded |
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| Beneficial Use: |
Warm Freshwater Habitat |
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| Number of Samples: |
3 |
| Number of Exceedances: |
3 |
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| Data and Information Type: |
Fixed station physical/chemical (conventional plus toxic pollutants) |
| Data Used to Assess Water Quality: |
Three water samples were collected at Cloverdale Creek station 905SDCDC4 on January 2003, April 2003, and May 2003. All three samples showed excessive nitrogen concentrations (SWAMP, 2007). |
| Data Reference: |
Monitoring data for Region 9 |
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| 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). |
| Objective/Criterion Reference: |
Water Quality Control Plan for the San Diego Basin (9). |
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| Evaluation Guideline: |
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| Guideline Reference: |
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| Spatial Representation: |
Water samples were collected at Cloverdale Creek station 4, 905SDCDC4; (Latitude 33.0905, Longitude -117.0197). |
| Temporal Representation: |
Samples were collected on January 2003, April 2003, and May 2003. |
| Environmental Conditions: |
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| 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. |
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DECISION ID |
6097 |
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| Pollutant: |
Total Dissolved Solids |
| Final Listing Decision: |
Do Not Delist from 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: |
List on 303(d) list (TMDL required list)(2006) |
| Revision Status |
Original |
| Sources: |
Unknown Nonpoint Source | Unknown Point Source | Urban Runoff/Storm Sewers |
| Expected TMDL Completion Date: |
2019 |
| Impairment from Pollutant or Pollution: |
Pollutant |
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| Weight of Evidence: |
303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed. |
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| RWQCB Board Decision / Staff Recommendation: |
No new data were assessed for 2008. The decision has not changed. |
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| SWRCB Board Decision / Staff Recommendation: |
N/A |
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| USEPA Decision: |
|
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Lines of Evidence (LOEs) for Decision ID 6097 |
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| LOE ID: |
4449 |
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| Pollutant: |
Total Dissolved Solids |
| LOE Subgroup: |
Pollutant-Water |
| Matrix: |
Water |
| Fraction: |
Not Recorded |
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| Beneficial Use: |
Agricultural Supply |
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| Number of Samples: |
0 |
| Number of Exceedances: |
0 |
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| Data and Information Type: |
Not Specified |
| Data Used to Assess Water Quality: |
Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006. |
| Data Reference: |
Placeholder reference pre-2006 303(d) |
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| Water Quality Objective/Criterion: |
Unspecified |
| Objective/Criterion Reference: |
Placeholder reference pre-2006 303(d) |
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| Evaluation Guideline: |
Unspecified |
| Guideline Reference: |
Placeholder reference pre-2006 303(d) |
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| Spatial Representation: |
Unspecified |
| Temporal Representation: |
Unspecified |
| Environmental Conditions: |
Unspecified |
| QAPP Information: |
Unspecified |
| QAPP Information Reference(s): |
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DECISION ID |
6096 |
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| Pollutant: |
Phosphorus |
| Final Listing Decision: |
List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: |
List on 303(d) list (TMDL required list)(2006) |
| Revision Status |
Original |
| Sources: |
Unknown Nonpoint Source | Unknown Point Source | Urban Runoff/Storm Sewers |
| Expected TMDL Completion Date: |
2019 |
| Impairment from Pollutant or Pollution: |
Pollutant |
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| Weight of Evidence: |
303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed. |
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| RWQCB Board Decision / Staff Recommendation: |
No new data were assessed for 2008. The Regional Board will update this decision when new data and information become available and are assessed. |
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| SWRCB Board Decision / Staff Recommendation: |
N/A |
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| USEPA Decision: |
|
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Lines of Evidence (LOEs) for Decision ID 6096 |
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| LOE ID: |
4448 |
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| Pollutant: |
Phosphorus |
| LOE Subgroup: |
Pollutant-Water |
| Matrix: |
Water |
| Fraction: |
Not Recorded |
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| Beneficial Use: |
Warm Freshwater Habitat |
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| Number of Samples: |
0 |
| Number of Exceedances: |
0 |
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| Data and Information Type: |
Not Specified |
| Data Used to Assess Water Quality: |
Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006. |
| Data Reference: |
Placeholder reference pre-2006 303(d) |
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| Water Quality Objective/Criterion: |
Unspecified |
| Objective/Criterion Reference: |
Placeholder reference pre-2006 303(d) |
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| Evaluation Guideline: |
Unspecified |
| Guideline Reference: |
Placeholder reference pre-2006 303(d) |
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| Spatial Representation: |
Unspecified |
| Temporal Representation: |
Unspecified |
| Environmental Conditions: |
Unspecified |
| QAPP Information: |
Unspecified |
| QAPP Information Reference(s): |