Common Questions
Recycled water is highly treated wastewater that has gone through multiple levels of treatment to make it suitable for beneficial reuse. While the type and treatment will vary depending on how the water is used, all recycled water must meet stringent health standards set by the California Department of Public Health and the United States Environmental Protection Agency.
Recycled water is safe for a broad range of uses depending upon the level of treatment. Most commonly, recycled water is used for irrigation including parks, playgrounds, cemeteries, golf courses, freeway landscapes, and nurseries; for industrial and commercial uses including cooling towers, commercial laundries, concrete mixing, soil compaction, and flushing toilets and urinals; for public benefit; and for environmental applications such as fish hatcheries, wetland augmentation, and habitat restoration. Recycled water also can be highly purified with additional advanced treatment steps and used to replenish groundwater supplies.
Yes. To ensure health and safety, recycled water is highly regulated by multiple governmental agencies. Like drinking water, recycled water is required to be regularly monitored and tested to ensure it consistently meets the quality standards set by the California Department of Public Health. Los Angeles has decades of experience safely using recycled water for irrigation and other purposes throughout the city.
In reality, all water is recycled water. The water on earth today is the same water that has always existed on the planet: cleansed and recycled again and again over millennia through the natural water cycle. Today, we can emulate this natural cleansing cycle only faster and even more effectively by using water treatment and purification technology. Recycled water undergoes different processes according to the intended use.
Recycled water in Los Angeles is, at a minimum, tertiary treated, which means it has three levels of treatment. The process begins with wastewater supplied from the sewer system. First, the majority of organics and solids are screened and settled out. Second, the water undergoes biological treatment that neutralizes most remaining organics and contaminants after which any residual impurities are chemically coagulated and removed. Third, the water undergoes filtration and disinfection. The resulting tertiary treated recycled water is approved for beneficial reuse. With additional advanced treatment steps, including microfiltration, reverse osmosis, ultraviolet light ,and hydrogen peroxide disinfection, the water is purified and used for groundwater replenishment. The advanced-treated water is cleaner than any other water source used for this purpose.
In Los Angeles, water treatment for recycling occurs at four facilities operated by the City of Los Angeles Department of Public Works, Bureau of Sanitation: Donald C. Tillman Water Reclamation Plant, Los Angeles-Glendale Water Reclamation Plant, Hyperion Wastewater Treatment Plant, and Terminal Island Water Reclamation Plant.
Throughout the nation and indeed the world, available water resources cannot keep pace with growing water supply needs. In the United States, the gap between water supply and demand is particularly a challenge in semi-arid areas like the Southwest. Los Angeles is a prime example. Historically, most of Los Angeles’ water has been imported from sources located hundreds of miles away – the Eastern Sierra watershed, the Sacramento-San Joaquin Delta, and the Colorado River. In recent years, these supplies have diminished as a result of multiple issues restricting imported water such as environmental commitments, court rulings, and supply limitations; continuing dry weather; along with the potential impacts of climate change. There are simply no new supplies to tap so Los Angeles must look locally to attain a reliable water supply.
The City of Los Angeles treats more than 400 million gallons of wastewater each day to make it clean enough to release into the ocean and other water bodies. Rather than discard this valuable resource that has been effectively treated, it is far more economically and socially responsible to put it to beneficial use. Recycled water is water that is already available to us, which makes it a dependable source.
Angelenos have excelled at conserving water. Prior to 2009 when Phase III of the Water Conservation Ordinance implemented mandatory conservation, Los Angeles used about the same amount of water as it did in the 1980s, despite a population increase of nearly one million people. Additional aggressive conservation is part of the city’s strategy for water reliability. Even when all of the fixture and plumbing changes have been made and residents and businesses have reduced their use of water for irrigation, conservation can achieve only a portion of the additional water that’s needed. Thus, conservation is only one of the methods to ensure a reliable water supply for Los Angeles. The other initiatives include recycled water, stormwater capture, groundwater cleanup, groundwater storage, and green building initiatives.
Availability of recycled water in the City of Los Angeles is driven by a site’s proximity to existing recycled water distribution pipes through a dedicated system of purple pipes that are separate and distinct from the potable water system. Currently, there are approximately 45 miles of purple pipe in the city. In the San Fernando Valley, recycled water is used: for irrigation at Woodley, Encino, Balboa, and Van Nuys golf courses and the campus of Van Nuys High School, the grounds of St. Elisabeth Church, and Church on the Way; for cooling towers at the Valley Generating Station; and to provide water for the Los Angeles River, Japanese Gardens, Lake Balboa and Wildlife Lake. In the Center City, recycled water is used for irrigation at Griffith Park, Universal Studios, the Los Angeles Zoo, Cypress Park, Taylor Yard Park, Lakeside Golf Course, as well as Forest Lawn and Mount Sinai Memorial Parks. In the Westside, recycled water originates at the Hyperion Water Treatment Plant and receives tertiary treatment through our partnership with the West Basin Municipal Water District (West Basin) and is used: for irrigation, including Phase 1 of the Playa Vista development, Loyola Marymount University, and Westchester Golf Course; for industrial processes; and in surrounding communities as distributed by West Basin. In the Harbor Area, highly purified recycled water is used to replenish groundwater by injection into the seawater intrusion barriers that protect drinking water aquifers, as well as for irrigation at the Harbor Generating Station.
Recycled water is used extensively in dozens of communities throughout Southern California including Agoura Hills, Burbank, Calabasas, Capistrano, Chino, Elsinore Valley, Encina, Encinada, Fallbrook, Glendale, Hidden Hills, Irvine Industry, Laguna, Malibu, Moulton Niguel, Oak Park, Oceanside, Olivenhain, Pomona, Puente, Rancho Santa Fe, Ramona, San Clemente, San Diego, San Elijo, Santa Maria, Santa Margarita, Santa Monica, San Vincente, Thousand Oaks, Walnut Valley, Westlake Village, multiple Orange County communities, and more. A growing number of communities in states across the nation also use recycled water, such as Nevada, Arizona, Florida, Texas, Virginia, and Georgia. In addition, recycled water is safely used in numerous countries worldwide including Singapore, Australia, Israel, and Japan.
Since recycled water used for irrigation and industry in Los Angeles is not certified for human consumption, it is transported for approved uses through its own system of purple pipes that is completely separate from the city’s drinking water system. In addition to the internationally designated purple color for recycled water pipelines, public areas that irrigate with recycled water have signs indicating this water is not approved for drinking.
LADWP’s recycled water goal is to expand from the current use of 7,000 acre-feet per year (AFY) to approximately 20,000 AFY by 2014-15. This will be accomplished by expanding the “purple pipe” network of pipes, tanks, pumps, and stations and signing new irrigation and industrial customers. Current expansion is ongoing in the San Fernando Valley and in the Harbor areas where there is existing purple pipe infrastructure and concentration of potential high-use customers.
LADWP is also exploring use of highly purified recycled water to replenish the San Fernando Groundwater Basin. California and other communities in the United States, and throughout the world, are following the example of Orange County, to replenish this water by undergoing microfiltration, reverse osmosis, and other purification steps. After being highly purified, the water will mix underground with existing groundwater and rainwater. Eventually, it will be pumped to the surface and mixed with other supplies in the City’s water distribution system. This process, called Groundwater Replenishment, is a proven alternative for expanding availability of a safe, high-quality drinking water. GWR is expected to contribute 15,000 AFY to possibly 30,000 AFY to the City’s recycled water goal of 59,000 AFY by 2035.
LADWP, in collaboration with the City of Los Angeles Department of Public Works, Bureau of Sanitation, has developed comprehensive Recycled Water Master Planning Documents that outline strategies for the most efficient and effective options for expanding use of recycled water. The Master Planning process studied multiple options for treatment and use, including groundwater replenishment and the potential to increase recycled water use in the City beyond the current goal of 59,000 AFY by 2035.
As part of the recycled water master planning effort, the LADWP has convened a Recycled Water Advisory Group to obtain input from the city’s many constituencies and serve as a conduit into their communities. In addition, the LADWP conducted Recycled Water Forums throughout the City in 2011. Information will be shared broadly over the coming years through presentations to neighborhood councils, civic groups, and community organizations; via newsletters, press, and media; the LADWP.com website; and various other forms of communication. If you would like to receive future updates and notifications about recycled water use in Los Angeles, please send us an email via our Contact Us form.