Water reclamation and reuse is becoming an integral part of the water picture for Los Angeles County, home to 10 million people. Hundreds of sites across the county are receiving reclaimed water in lieu of drinking water for a variety of non-potable applications, with hundreds more scheduled to be brought on-line over the next few years. In response to increasing demands for water, limitations on imported supplies and persistent droughts, the Central Basin Municipal Water District, in cooperation with the Sanitation Districts of Los Angeles County and 29 other public agencies and private entities (see list at bottom), have developed the Century and the Rio Hondo Water Reclamation Programs.

A looped system of 65 miles of dedicated pipelines utilizing two pump stations to deliver up to 22,000 acre-feet of reclaimed water per year from the two largest Sanitation Districts' Water Reclamation Plants (WRPs) was planned, designed and constructed by the Central Basin Municipal Water District. These integrated systems will supply tertiary-treated effluent to a number of municipal and private water purveyors who could not have accomplished such a feat individually.

The idea of reclaiming useful water from wastewater is not new. The Sanitation Districts began planning for a network of water reclamation facilities as far back as 1948. Following the construction of the prototype Whittier Narrows WRP in 1962, four similar plants were added in the 1970's, providing a total of nearly 200 million gallons per day of capacity.

Environmental and economic benefits beyond water reclamation will be realized statewide as a result of these programs. The use of reclaimed water augments the imported river water supply from the Sacramento Delta, an environmentally sensitive waterway populated with various endangered species. And with the reduced pumping of imported water comes energy savings of up to 66 million kilowatt hours per year, equivalent to 35,800 barrels of oil. This will result in the reduction of air pollutant emissions by up to 50 tons annually.

Regional reclaimed water projects such as the Century and Rio Hondo are the next step in the evolution of water reuse, as the Los Angeles area heads toward a planned basin-wide system linking numerous sanitary agencies and regional and local water purveyors in a highly flexible and reliable reclaimed water distribution system to complement and supplement the precious, limited drinking water supply.

The Century and Rio Hondo reclaimed water distribution systems are interconnected, providing for two, independent water supplies to enhance reliability, flexibility and system pressure and flows for numerous cities. A newly constructed 21,000 gallon per minute pump station will deliver San Jose Creek WRP effluent, while a converted four million gallon potable resevoir will provide both daily operational storage of reclaimed water and a emergency backup potable water supply, for no additional capital expenditures.

By early 1996, the 100th of the anticipated 200 reuse sites had begun receiving reclaimed water, which is used for irrigation of parks, golf courses, schools, nurseries, freeway and street medians and slopes and other greenbelt areas. In addition, various industries, such as the Tuftex Carpet Mill (left), will use reclaimed water for carpet and textile dyeing, metal finishing, concrete mixing and cooling tower supply.

The 100 million gallon per day San Jose Creek WRP in Whittier will provide tertiary treated reclaimed water from the north to the Rio Hondo System, while the 37.5 million gallon per day Los Coyotes WRP in Cerritos (right) will provide a similar effluent from the south to the Century System.

List of Participants in the Century and Rio Hondo Water Reclamation Projects

• Bellflower-Somerset Mutual Water Company
• California Domestic Water Service
• California Water Service Company
• Montebello Land and Water
• Park Water Company
• Peerless Water Company
• Pico Water District
• San Gabriel Valley Water Company
• South Montebello Irrigation District
• Southern California Water Company
• Suburban Water Systems
• Metropolitan Water District
• City of Bellflower
• City of Commerce
• City of Compton
• City of Cudahy
• City of Downey
• City of Huntington Park
• City of Los Angeles
• City of Lynwood
• City of Montebello
• City of Norwalk
• City of Paramount
• City of Pico Rivera
• City of Santa Fe Springs
• City of South Gate
• City of Vernon
• City of Whittier