Draft 2008 California 303(d)/305(b) Integrated Report

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name: Swauger Creek
Water Body ID: CAR6304001220011130122006
Water Body Type: River & Stream
 
DECISION ID
6426
 
Pollutant: Pathogens
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 (TMDL required list)(2006)
Revision Status Revised
Sources: Natural Sources | Onsite Wastewater Systems (Septic Tanks) | Pasture Grazing-Riparian and/or Upland | Range 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
 
Weight of Evidence: 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.

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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 be placed the Being Addressed portion of the section 303(d) list because the RWQCB has determined that an existing program is reasonably expected to result in the attainment of the water quality standard in a reasonably specified time frame.
 
SWRCB Board Decision / Staff Recommendation: N/A
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 6426
 
LOE ID: 27589
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 16
Number of Exceedances: 5
 
Data and Information Type: Water column surveys (e.g. fecal coliform)
Data Used to Assess Water Quality: Swauger Creek was placed on the Section 303(d) list in 2002 as a result of sampling in 2000 and 2001 by the U.S. Geological Survey. At least 5 of 16 monthly fecal coliform samples exceeded the 40 colonies per 100 mL limit. Fecal coliform counts ranged from 1 to 250 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. 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.
 
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: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station was sampled.
Temporal Representation: Buckeye Creek was sampled monthly between April 2000 and June 2001.
Environmental Conditions: Swauger Creek originates in the Sweetwater Moutnains and flows south and southeast near Highway 395 before joining Buckeye Creek west of Bridgeport Reservoir. Livestock grazing is the main human land use in the watershed.
QAPP Information: The study was done using USGS quality assurance procedures.
QAPP Information Reference(s):
 
LOE ID: 4637
 
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)
 
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):
 
DECISION ID
6427
 
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 | Highway/Road/Bridge Runoff | Natural Sources | Nonpoint Source | Pasture Grazing-Riparian and/or Upland | Range Grazing-Riparian and/or Upland | Streambank Modification/Destabilization | Surface Runoff
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
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.
 
RWQCB Board Decision / Staff Recommendation: No new data were assessed for 2008. The decision has not changed.
 
SWRCB Board Decision / Staff Recommendation: N/A
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 6427
 
LOE ID: 4638
 
Pollutant: Phosphorus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
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)
 
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):