California Code of Regulations
Title 23 - Waters
Division 4 - Regional Water Quality Control Boards
Chapter 1 - Water Quality Control Plans, Policies, and Guidelines
Article 6 - Lahontan Region
Section 3959.4 - Lake Tahoe Total Maximum Daily Load (TMDL) and Implementation Plan for Fine Sediment Particles, Total Nitrogen, and Total Phosphorus
On November 16, 2010, the Regional Water Quality Control Board, Lahontan Region (Lahontan Water Board) adopted Resolution No. R6T-2010-0058, amending the Water Quality Control Plan for the Lahontan Region. The State Water Resources Control Board approved the amendment under State Water Resources Control Board Resolution No. 2011-0022, on April 19, 2011.
Resolution No. R6T-2010-0058 establishes an amendment to the Water Quality Control Plan for the Lahontan Region to incorporate a TMDL and TMDL implementation plan for fine sediment particles, total nitrogen, and total phosphorus for Lake Tahoe.
The TMDL is the sum of wasteload allocations for point sources, load allocation for nonpoint sources, and a margin of safety in protecting Lake Tahoe's deep water transparency. The major pollutant load sources include: urban (developed) upland runoff, atmospheric deposition, forest (undeveloped) upland runoff, and stream channel erosion. The most cost effective and efficient load reduction options for the atmospheric deposition, forested upland, and stream channel erosion sources are to continue with existing programs. Because the most significant and quantifiable load reduction opportunities are within the urban uplands source, the TMDL implementation plan emphasizes actions to reduce fine sediment particle and associated nutrient loading from urban stormwater runoff. Lahontan Water Board staff has developed the tools and protocols to quantify, track, and account for pollutant loads associated with urban runoff.
The Lahontan Water Board staff will evaluate progress towards meeting the TMDL in periodic milestone reports and will annually track actions taken to reduce loads from the major pollutant load sources. The estimated timeframe to achieve the TMDL-required load reductions and meet the numeric target is 65 years after the TMDL is approved by the US Environmental Protection Agency. This requires that estimated fine sediment particle, phosphorus, and nitrogen loads be reduced by 65 percent, 35 percent, and 10 percent, respectively.
1. New section summarizing amendments to basin plan filed 6-21-2011; amendments approved by State Water Resources Control Board Resolution No. 2011-0022 on 4-19-2011; amendments approved by OAL pursuant to Government Code section 11353 on 6-21-2011 (Register 2011, No. 25).
