AWWA SYM53641

The Lake Tahoe Experience Watershed controls are not new to the Lake Tahoeregion, which is located in the Sierra Nevada Mountains and shared by Nevada andCalifornia. The unique clarity of Lake Tahoe is threatened by previous andongoing land use practices despite extensive water quality controls legislated atthe national, state and local levels. The emergence of the first bi-stateenvironmental agency, federally mandated in 1969 in the form of the TahoeRegional Planning Agency, has seen draconian steps taken to reduce the rate ofdevelopment, impose ordinances requiring extensive use of Best ManagementPractices, and facilitate extensive environmental restoration projects through a$900 million environmental improvement program. Yet slowing the rate ofdegradation of the lake water quality is still in question. The Safe DrinkingWater Act Amendments of 1986 have encouraged five public water purveyors to adopta jointly prepared watershed sanitary survey and management plan for the purposeof mitigating microbial contamination. Implementation of the plan is required tomaintain a permitted exemption to filtration under the Surface Water TreatmentRule. With respect to a potable water supply, the extreme clarity of Lake Tahoein conjunction with existing and proposed watershed controls appear to form aneffective first barrier in the multi-barrier treatment chain to assure a safe andcost-effective water supply for water purveyors utilizing surface water intakes. Includes 15 references, table, figures.