California's Water: Water Recycling Imitates Nature
Many people associate the word “recycling” with glass bottles and aluminum cans, but the fact is California water agencies and communities have been recycling water for decades with great success. With scores of new recycling projects in the planning stages, the amount of water recycled in California is expected to greatly expand in the near future.
This segment of “ California’s Water” focuses on water recycling and the important role it plays in meeting the state’s water needs. Viewers will get a look at some current uses of recycled water and learn how local agencies plan to maximize this key water supply tool in the coming years.
Water recycling, also known as reclamation or reuse, is a reliable, economically feasible and environmentally sensitive means to maximize California's water resources, assist with drought prevention, and reduce the demand on freshwater systems. Recycling programs mimic the way nature purifies water and treat wastewater so that it can be safely used to irrigate landscape, golf courses, crops and freeway medians, replenish groundwater basins, flush toilets and act as a barrier to seawater intrusion. Recycled water is also increasingly being used by industry in cooling processes, new home construction and for other purposes.
According to the California Department of Water Resources, over 525,000 acre-feet of wastewater is recycled each year. About half of that (48%) is used for agricultural irrigation. Another 20% is used for landscape irrigation, and about 12% is used for groundwater recharge.
In future years, experts predict California will recycle even more wastewater. They have set a target of achieving close to 1 million acre-feet of recycled wastewater in coming decades. That level of recycling will go a long way toward meeting the needs of the 17 million additional residents California will have by 2030.
Projects Around the State:
Many large recycling projects have been completed over the past decade. The list includes the South Bay Water Recycling program, which distributes recycled wastewater to more than 400 customers in the San Jose area for irrigation, industrial and other purposes; Irvine Ranch Water District’s ground-breaking dual water system, which supplies recycled water to commercial high rises for use in flushing toilets and urinals; a project by West Basin Municipal Water District that distributes recycled water to more than 85 customers, including Chevron and Mobile refineries; Monterey County Water Recycling Projects, which provide recycled water for agricultural irrigation to help ease demands on an overdrafted groundwater aquifer; and the Padre Dam Water Recycling Facility, which was expanded to recycle 2 million gallons/day for turf irrigation at parks, golf courses and other commercial and industrial facilities.
In addition, in the San Diego region, 16 water agencies are planning to use over 32,300 acre-feet of recycled water annually by 2010 in order to meet the region’s water supply demand. Examples of local recycled water projects include the City of Carlsbad’s new recycled water treatment and distribution system that will deliver approximately 3,000 acre-feet per year of recycled water to customers located in that seaside community. In the southern portion of San Diego County, the Otay Water District is constructing a distribution system to deliver an estimated 5,000 acre-feet per year of recycled water by 2030 purchased from the City of San Diego’s South Bay Water Recycling Plant.
Also in Southern California, Elsinore Valley Municipal Water District is using recycled water to help replenish and enhance Lake Elsinore, a natural recreational lake long plagued with severe seasonal evaporation losses. The program, which began as a pilot project in 2002, is aimed at stabilizing lake levels, improving water quality and enhancing Lake Elsinore as a regional aesthetic and recreational resource.
In Northern California, two agencies have teamed up to develop the San Ramon Valley Recycled Water Program. Jointly sponsored by the Dublin San Ramon Services District and the East Bay Municipal Utility District, the program will provide recycled water to large landscape irrigation customers including municipal parks, golf courses, business parks, greenbelts and roadways in Blackhawk, Danville, Dublin and San Ramon. The use of recycled water for landscape purposes conserves high-quality drinking water and provides users with a drought-resistant water supply.
Among the most sweeping new projects under development is a major groundwater replenishment system by the Orange County Sanitation and Orange County Water Districts. Under the plan, highly treated wastewater currently discharged into the ocean will undergo microfiltration, reverse osmosis and ultraviolet disinfection. The purified water will be equivalent in quality to distilled water and would exceed all state and federal drinking water standards. The purified water will be pumped to spreading ponds near the Santa Ana River for percolation into the groundwater basin, with some injected along the coast as a barrier to seawater intrusion.
Orange County Water District has amassed a long record of success with its acclaimed Water Factory 21, a major program in which municipal wastewater is treated and injected into the groundwater basin to prevent seawater intrusion and replenish local groundwater supplies.
Numerous other water agencies have been active players in the recycling arena – either through development of their projects or financial support for local efforts. These agencies include the Los Angeles County Sanitation Districts, Water Replenishment District of Southern California, Eastern Municipal Water District, Santa Clara Valley Water District, East Bay Municipal Utility District, Marin Municipal Water District and the WateReuse Association, both the national organization and the California section.