| Water Body Name: | East Walker River, above Bridgeport Reservoir |
| Water Body ID: | CAR6303005020011214105850 |
| Water Body Type: | River & Stream |
DECISION ID |
20662 |
Region 6 |
East Walker River, above Bridgeport Reservoir |
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| Pollutant: | Fecal Coliform |
| Final Listing Decision: | List on 303(d) list (being addressed by action other than TMDL) |
| Last Listing Cycle's Final Listing Decision: | List on 303(d) list (being addressed by action other than TMDL)(2010) |
| Revision Status | Original |
| Sources: | Natural Sources | Other Urban Runoff | Pasture Grazing-Riparian and/or Upland | Recreational and Tourism Activities (non-boating) |
| Expected Attainment Date: | 2027 |
| Date TMDL Approved by USEPA: | This listing is being addressed through Lahontan RWQCB Resolution R6T-2007-0019, Waiver of Waste Discharge Requirements for Grazing Operations in the East Walker River Watershed (Bridgeport Valley and Tributaries) of the Lahontan Region. Nonpoint source management measures for grazing operations are to be implemented under Ranch Water Quality Management Plans. The waiver includes a time schedule, milestones and a monitoring and reporting program. An interim target, a 30-day average log-normalized fecal coliform concentration of no more than 200 fecal coliform colonies per 100 mL, is expected to be attained within the five year lifetime of the waiver. The water quality objective is expected to be attained through continued implementation and improvement of management practices. The waiver is subject to renewal. |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Staff Conclusion: | Regional Board Conclusion:
This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for removal from the section 303(d) list under section 2.2 of the Listing Policy. Under 2.2 of the Policy, a minimum of one line of evidence is needed to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. 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. There is sufficient justification to place it in the Being Addressed portion of the 303(d) list because a regulatory action other than a TMDL (a conditional waiver of waste discharge requirements) is expected to result in attainment of the standard. The waiver was adopted by the Lahontan RWQCB on June 13, 2007 and is now being implemented. |
| Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle. |
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| LOE ID: | 27588 | ||||
| Pollutant: | Fecal Coliform | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 17 | ||||
| Number of Exceedances: | 8 | ||||
| Data and Information Type: | Water column surveys (e.g. fecal coliform) | ||||
| Data Used to Assess Water Quality: | The East Walker River segment above Bridgeport Reservoir was placed on the Section 303(d) list in 2002 for pathogens as a result of sampling in 2000 and 2001 by the U.S. Geological Survey. At least 8 of 17 monthly fecal coliform samples from the Highway 395 station, and at least 6 of 14 samples at the Bridgeport Reservoir station exceeded the 40 colonies per 100 mL limit. Fecal coliform counts ranged from "K3" to "K60" colonies per 100 mL. Some of the sampling results were reported with a "K" code indicating that the bacteria count was outside of the acceptable range or ideal count of 20-60 colonies per plate. Samples without K codes ranged from 8 to 270 colonies per 100 mL.These USGS data were part of the longer study referenced as Rockwell and Honeywell. | ||||
| Data Reference: | Administrative Record of Lahontan RWQCB's 2001-2002 Section 303(d) List Update Process Resolution R6T-2002-0002 | ||||
| 2007. SWAMP Data for the West Walker River and East Walker River Hydrologic Units | |||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | The Lahontan Basin Plan's regionwide Water Quality objective for coliform bacteria states: "Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. 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 as 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: | Water Quality Control Plan for the Lahontan Region (as amended) | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | One station, East Walker River above Bridgeport Reservoir, was sampled. | ||||
| Temporal Representation: | Samples were collected monthly between April 2000 and June 2001. | ||||
| Environmental Conditions: | The East Walker River originates in the Hunewill Hills east of the Sierra Nevada crest. It flows through Bridgeport Valley and the town of Bridgeport before entering Bridgeport Reservoir. | ||||
| QAPP Information: | The study was done using USGS quality assurance procedures. | ||||
| QAPP Information Reference(s): | |||||
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| LOE ID: | 4606 | ||||
| Pollutant: | Pathogens | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Not Recorded | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 0 | ||||
| Number of Exceedances: | 0 | ||||
| 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) | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Unspecified | ||||
| Objective/Criterion Reference: | Placeholder reference pre-2006 303(d) | ||||
| Evaluation Guideline: | Unspecified | ||||
| Guideline Reference: | Placeholder reference pre-2006 303(d) | ||||
| Spatial Representation: | Unspecified | ||||
| Temporal Representation: | Unspecified | ||||
| Environmental Conditions: | Unspecified | ||||
| QAPP Information: | Unspecified | ||||
| QAPP Information Reference(s): | |||||