A new source of water for Southern California
Water is too precious to use just once. So the Metropolitan Water District of Southern California is making a major investment in a potential water recycling project that will reuse water currently sent to the ocean.
The Regional Recycled Water Program, a partnership with the Sanitation Districts of Los Angeles County, will purify wastewater to produce high quality water that could be used again. The program will start with a demonstration facility and could eventually become one of the largest advanced water treatment plants in the world.
HOW IT WORKS
The process begins with wastewater discharged from homes, businesses and industries. After the wastewater has been cleaned and treated, it flows to an advanced water treatment plant where it is further purified. The water then replenishes groundwater basins and is eventually pumped up, disinfected and used again. It could also be delivered to industrial facilities and potentially to Metropolitan’s water treatment plants and delivery system.
THE PROCESS TO PURIFICATION
Membrane Bioreactors: Microorganisms remove ammonia and other nitrogen compounds, while membranes filter tiny particles, smaller than 1/100 of a grain of sand.
Reverse Osmosis: Pressurized membranes further remove microscopic materials, such as bacteria, pharmaceuticals and salts, eliminating more than 99% of all impurities.
Ultraviolet/Advanced Oxidation Process:
Ultraviolet light and a powerful oxidant destroy any remaining viruses and trace chemical compounds.
After wastewater is cleaned and treated through multiple processes, it flows to the Regional Recycled Water Advanced Purification Center where it goes through a three-step purification process. The end result is high quality, purified water that is safe to reuse again.
BENEFITS OF THE PROJECT
The Project helps ensure regional water reliability through diversifying sources, in addition to conservation, local supply development and imported water.
STARTING SMALL AND SCALING UP
The Advanced Purification Center is a 0.5 million gallon per day demonstration facility that will generate information needed for the potential future construction of a full-scale recycled water plant. It uses a unique application of membrane bioreactors designed to significantly increase efficiency in water recycling. Scientists and engineers will test the process, utilizing full-scale treatment modules, to ensure the resulting purified water meets the highest water quality standards. Once approved by regulators, this innovative process could be used throughout California and even applied around the globe.
A full-scale regional recycled water program would produce up to 150 million gallons daily, enough to serve more than 500,000 homes. Purified water from the advanced treatment facility would be delivered through 60 miles of new pipelines to the region’s groundwater basins, industrial facilities and two of Metropolitan’s treatment plants.
Cost: $17 million for construction.
Operations began October 2019.
Cost: $3.4 billion to build, $129 million annually to operate, resulting in a water cost of $1,830/acre-foot.
Timeline: 11 years to design and build, once approved.
Milestones in Recycled Water Use
The past five decades have seen recycled water use in Southern California grow rapidly, for both irrigation and groundwater replenishment.
White Papers and Related Documents
Approach for Alternative Treatment Technology Acceptance
ABOUT THE NEW PARTNERSHIP
The Metropolitan Water District of Southern California is a state-established 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.