LADWP Board of Commissioners Approves Plan to Remove Silver Lake Reservoir from Drinking Water Distribution System; Project Includes Small Hydro Facility; Silver Lake Reservoir Will Be Maintained with Non-potable Water.

LOS ANGELES -- In order to meet federally mandated water quality regulations, the Los Angeles Department of Water and Power (LADWP) Board of Commissioners has approved a project to remove Silver Lake and Ivanhoe reservoirs from service as an active potable water storage facility. The project calls for building a replacement 110-million-gallon underground water storage reservoir and a 4-megawatt hydroelectric generating facility on property known as the Headworks Spreading Grounds, located north of Forest Lawn Drive. Silver Lake Reservoir will be maintained with non-potable water.

"This project will ensure that LADWP continues to provide the most healthful, high-quality water possible to the City's 4 million residents," Board President Mary D. Nichols said. "Additionally, this project has a number of environmental benefits, including construction of a new source of renewable energy through a small hydroelectric plant."

The U.S. Army Corps of Engineers is also studying the feasibility of creating a wetlands habitat on a portion of the Headworks site adjacent to the Los Angeles River. The wetlands site is owned by the City's Department of Recreation and Parks and would be operated by the Bureau of Sanitation. The entire Headworks Spreading Grounds is bounded by the Los Angeles River to the north, the 134 Freeway to the east and Forest Lawn Drive on the south.

The Board's May 17 action included approval of the Environmental Impact Report, which was available for public review between August 4, 2005 and September 19, 2005, and approval of the Silver Lake Reservoir Complex Storage Replacement Project. In addition to the buried water storage tank and hydroelectric facility, this new project will include two drinking water regulator stations, and a bypass tunnel and pipeline around the Silver Lake and Ivanhoe reservoirs.

LADWP worked closely with neighborhood councils, community groups and all other stakeholders in the Silver Lake and Griffith Park communities on the project, which has been in the planning stages since the 1990s.

The project is required to isolate Silver Lake and Ivanhoe reservoirs from potable water service in order to comply with the federally mandated Long-Term 2 Enhanced Surface Water Treatment Rule and the Stage 2 Disinfection Byproducts Rule. Both of these rules require more frequent monitoring and new, more stringent limits for certain constituents and disinfection byproducts such as trihalomethanes (THMs) and Haloacetic acids (HAA5).

The Long-Term 2 Enhanced Surface Water Treatment Rule contains specific provisions to reduce contamination risks caused by storing water in open-air reservoirs. This provision has the biggest impact on LADWP because the agency has historically stored water in open-air reservoirs that now must be covered or bypassed.

"The Department's approach is to simultaneously meet both standards by converting our primary disinfectant from chlorine to chloramines, and by covering, or bypassing, the six remaining open reservoirs in the LADWP Distribution System," said LADWP General Manager Ron Deaton. "Basically, this represents a whole new way of moving water around the City." In addition to Silver Lake and Ivanhoe, the remaining open reservoirs include Santa Ynez, Elysian, Upper Stone, and Los Angeles reservoirs.

LADWP has already complied with the first Surface Water Treatment Rule through bypassing four open reservoirs and removing them from the water distribution system. These included Upper and Lower Hollywood Reservoir, Encino Reservoir, and Lower Stone Canyon Reservoir.

The Silver Lake Reservoir Complex Storage Replacement Project is expected to cost approximately $217 million and will now be moving into the design phase. It is anticipated that the majority of the Construction process will occur between 2009 and 2015.