Evaluation of membrane filtration for Los Angeles' open reservoirs

摘要

The Surface Water Treatment Rule (SWTR) (USEPA, 1991) affects four of the open distribution reservoirs in the city of Los Angeles, Calif.―Upper and Lower Hollywood reservoirs, Lower Stone Canyon Reservoir, and Encino Reservoir. The reservoirs receive conventionally treated surface water from the Los Angeles Aqueduct Filtration Plant (LAAFP). Because these reservoirs are subject to potential contamination from stormwa-ter runoff, the California Department of Health Services (CDHS) has identified them as unprotected, requiring compliance with the SWTR. CDHS mandated that the Hollywood reservoirs be in compliance by November 2001, the Encino Reservoir by January 2003, and the Stone Canyon Reservoir by December 2004. The reservoirs are large and irregularly shaped, so covering them or completely diverting stormwater runoff was not a feasible approach to achieving SWTR compliance.