The Los Angeles Metropolitan Board of Directors has authorized construction of $140.4 million of new ozone facilities at the district’s oldest treatment plant. The new facilities will use ozone to replace chlorine as the primary disinfectant at Metropolitan’s F.E. Weymouth Water Treatment Plant in La Verne.
20 years ago, Los Angeles identified ozone disinfection as a more effective treatment process. The board has a plan to convert all five Metropolitan treatment plants to ozone technology because it is the most beneficial and cost-effective way to improve and protect the quality of drinking water served to 19 million Southern Californians.
The Weymouth plant is among the largest water filtration facilities in the nation. The plant treats a blend of waters from the district’s Colorado River Aqueduct and the State Water Project for the central area of Metropolitan’s distribution system in Los Angeles and Orange counties.
Metropolitan will construct the initial phase of facilities at Weymouth, with a capacity to treat 260 million gallons a day with ozone, and up to 345 million gallons per day under certain conditions. The phasing of the ozone processes will allow the district to expand the plant’s ozone treatment capabilities in the future.
Metropolitan initiated the changeover to ozone treatment in 1994 to comply with anticipated federal regulations and to offer a greater margin of safety in its imported supplies. A colorless gas, ozone has been used as a water disinfectant in Europe and parts of the United States for more than a century.
The Metropolitan Water District of Southern California is a cooperative of 26 cities and water agencies serving nearly 19 million people in six counties. The district imports water from the Colorado River and Northern California to supplement local supplies, and helps its members to develop increased water conservation, recycling, storage and other resource-management programs.