Final California 2020 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name: Mono Lake
Water Body ID: CAL6010008019980806094326
Water Body Type: Saline Lake
 
DECISION ID
80208
Region 6     
Mono Lake
 
Pollutant: Salinity/TDS/Chlorides
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)(2016)
Revision Status Original
Sources: Crop-Related Sources
Expected Attainment Date: 2019
Implementation Action Other than TMDL: SWRCB water rights decision 1631

SWRCB Decision 1631 establishes conditions to control lake level and salt concentrations. Salt concentrations are not solely due to natural causes. Fifty years of water diversions caused a 45 foot drop in lake level, which caused increases in salt concentrations above those caused by natural sources. SWRCB Decision 1631 established a restored lake level of 6391 feet to meet water quality standards (SWRCB, 2003).
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board 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 revieewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows:

This pollutant is being considered for listing under section 2.2 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. A remedial program other than a TMDL has been developed, approved, and is being implemented. This program is expected to result in attainment of the standard. This water segment-pollutant combination was moved off the section 303(d) list during the 2002 listing cycle.

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 in the Water Quality Limited Segments Being Addressed portion of the section 303(d) list.

After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
Regional Board Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 80208, Salinity/TDS/Chlorides
Region 6     
Mono Lake
 
LOE ID: 736
 
Pollutant: Salinity/TDS/Chlorides
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Inland Saline Water Habitat
Aquatic Life Use: Wildlife Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: SWRCB Water Rights Decision 1631 will address the problem. SWRCB Decision 1631 establishes conditions to control lake level and salt concentrations. Salt concentrations are not solely due to natural causes. Fifty years of water diversions caused a 45 foot drop in lake level, which caused increases in salt concentrations above those caused by natural sources. SWRCB Decision 1631 established a restored lake level of 6391 feet to meet water quality standards (SWRCB, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation:
Temporal Representation:
Environmental Conditions:
QAPP Information: QA Info Missing
QAPP Information Reference(s):