BEsT MANAGEMENT PRACTICEs HANDbooK - Tahoe BMP

Board in California and the Nevada Department of Environmental Protectionin Nevada.Make sure all hazardous materials are properly contained, controlled, and managed.The primary pollutants of concern are:Sediment: Land disturbance is the primary cause of elevated sediment supply. 26Identify sediment sources on-site. Erosion control practices BMPs such asrevegetation, slope stabilization, and protection of sensitive areas should beimplemented at the source. There are several methods to quantitativelyestimate the sediment supply including RUSLE, MUSLE, and SWMM. Thesecalculations should be done by a qualified professional or consultant. Refer toChapter 1, Urban Hydrology for more information on these formulas.A. Fine Sediment: Specifically fine sediment particles less than 16 microns, isof primary concern because it remains suspended in the water columnfor a long time, contributing significantly to loss in Lake Tahoe waterclarity. Once fine sediment gets entrained in stormwater it may bedifficult and expensive to treat.B. Coarse Sediment: Typically found in areas with heavy applications ofroad abrasives, stream or channel bedload transport, or gullies anddrainage system development, especially where discharge is directly to aSEZ or stream. 27 Install a pre-treatment system to catch coarse sedimentbefore stormwater discharges to an infiltration system or further26SWQIC, 2004, Formulating and Evaluating Alternatives, Appendix A-4, pg A-81,http://www.trpa.org/documents/Final_FEA.pdf27SWQIC, 2004, Formulating and Evaluating Alternatives, A-4, Pg. A-80,http://www.trpa.org/documents/Final_FEA.TRPA BMP HandbookCHAPTER 2: Site Analysis2012 Page 2-25