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DECISION ID |
6434 |
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| Pollutant: |
Pathogens |
| 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 |
Revised |
| Sources: |
Source Unknown |
| Expected TMDL Completion Date: |
2019 |
| Impairment from Pollutant or Pollution: |
Pollutant |
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| Weight of Evidence: |
This pollutant is being considered for removal from the section 303(d) list under section 4.2 of the Listing Policy. Under this section 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. Sevnteen log mean datapoints exceed the water quality objective.
Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the 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. Seventeen of 75 log mean datapoints exceeded the water qualityy objectiv and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are 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 removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded. |
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| SWRCB Board Decision / Staff Recommendation: |
N/A |
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| USEPA Decision: |
|
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| LOE ID: |
27162 |
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| Pollutant: |
Fecal Coliform |
| LOE Subgroup: |
Pollutant-Water |
| Matrix: |
Water |
| Fraction: |
None |
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| Beneficial Use: |
Water Contact Recreation |
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| Number of Samples: |
75 |
| Number of Exceedances: |
17 |
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| Data and Information Type: |
Water column surveys (e.g. fecal coliform) |
| Data Used to Assess Water Quality: |
This assessment uses data collected and analyzed by Lahontan RWQCB staff in 2000, 2001, 2002 and 2008. It . focuses on violations of the 20/100 mL limit. Data were evaluated as 30-day normalized log means. There were 75 log mean datapoints, with 17 datapoints in violation of the 20/100 mL limit. |
| Data Reference: |
2009. Determination of Fecal Coliform Violations of Lahontan Basin Plan Water Quality Objectives: Data Reduction Procedure |
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2008 Nonpoint Source (NPS) Fecal Coliform Data (colonies per 100 ml) for Trout Creek above Highway 50 |
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| Water Quality Objective/Criterion: |
The Lahontan Basin Plan's objective for coliform bacteria states:
"Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock waste.
The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected a evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected." |
| Objective/Criterion Reference: |
2007. Water Quality Control Plan for the Lahontan Region (as amended). |
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| Evaluation Guideline: |
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| Guideline Reference: |
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| Spatial Representation: |
Data were collected at one station at Highway 50. |
| Temporal Representation: |
The data used were collected in 2000, 2001, 2002 and 2008. |
| Environmental Conditions: |
Trout Creek joins the Upper Truckee River near the south shore of Lake Tahoe. |
| QAPP Information: |
The data were collected and analyzed using the Lahontan RWQCB's quality assurance protocols. |
| QAPP Information Reference(s): |
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DECISION ID |
6432 |
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| Pollutant: |
Iron |
| 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: |
Erosion/Siltation | Natural Sources | Urban Runoff--Non-industrial Permitted |
| 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 6432 |
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| LOE ID: |
4643 |
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| Pollutant: |
Iron |
| LOE Subgroup: |
Pollutant-Water |
| Matrix: |
Water |
| Fraction: |
Not Recorded |
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| Beneficial Use: |
Municipal & Domestic 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 |
6433 |
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| Pollutant: |
Nitrogen |
| 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: |
Atmospheric Deposition | Erosion/Siltation | Pasture Grazing-Riparian and/or Upland | Urban Runoff--Non-industrial Permitted |
| 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 6433 |
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| LOE ID: |
4644 |
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| Pollutant: |
Nitrogen |
| LOE Subgroup: |
Pollutant-Water |
| Matrix: |
Water |
| Fraction: |
Not Recorded |
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| Beneficial Use: |
Cold 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): |
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DECISION ID |
6435 |
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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: |
Atmospheric Deposition | Erosion/Siltation | Pasture Grazing-Riparian and/or Upland | Urban Runoff--Non-industrial Permitted |
| 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 6435 |
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| LOE ID: |
4646 |
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| Pollutant: |
Phosphorus |
| LOE Subgroup: |
Pollutant-Water |
| Matrix: |
Water |
| Fraction: |
Not Recorded |
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| Beneficial Use: |
Cold 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): |