Valley-Based Emergency Water System Nearing Completion

Los Angeles water officials are nearing completion of a new complex of drinking water wells in the San Fernando Valley that will help sustain water service should an earthquake cut supplies delivered by aqueduct.

The Department of Water and Power chose today, the 22nd anniversary of the Sylmar earthquake, to announce that the $27-million Tujunga well field project will be ready for operation by the end of this month, providing a larger cushion for the city in the event of a severe earthquake, drought or other supply emergency.

The project includes a corridor of 12 new wells between the Hollywood Freeway and Canterbury Avenue in Pacoima. The wells, which will draw water from depths of 450 to 780 feet, will be connected to a complex of pumps and chlorination equipment in the 8800 block of Arleta Avenue in Pacoima.

“The addition of this facility allows the city greater access to this underground emergency water supply,” said Duane Buchholz, a design engineer for the DWP, which supplies water to about 3.5 million people.

Most of Los Angeles’ water arrives via aqueducts from the Owens Valley and State Water Project, but roughly 15% comes from city wells in the eastern San Fernando Valley.

Without the Tujunga wells, officials said that in an emergency, they could extract up to 150,000 acre-feet of ground water per year--about 25% of the city’s annual consumption.

The Tujunga wells will add 70,000 acre-feet of emergency pumping capacity, temporarily allowing the city to rely on Valley ground water for more than one-third of its needs. Officials said this water--combined with water stored in local reservoirs--could sustain the city for several months if all outside supplies were cut.

An acre-foot of water is enough to supply the annual water needs of two average families.

Water officials said the Tujunga project is also an attempt to outflank a plume of chemically tainted ground water that has forced them to close some existing wells.

The contamination resulted from past spills and improper storage and dumping of industrial solvents, particularly the common de-greasers trichloroethylene and perchloroethylene.

The DWP is working with the U.S. Environmental Protection Agency to clean up the ground water under the federal Superfund program.

Ground water in the Valley flows in a generally southeasterly direction. The Tujunga wells were installed upstream to avoid contamination.