WaterWise Articles



Water Recycling and the Diverse Portfolio of West Basin Water District

The Edward C. Little Water Recycling Plant located in El Segundo, California currently produces about 40 million gallons of recycled water for local cities and water agencies. This makes the facility one of the largest in the world and is expected to grow to produce over 70 million gallons of recycled water.

West Basin Water District (West Basin) offers instructional tours of their facility, highlighting the technologies used to treat sewer water, the production of five different types of “designer” waters for different industrial purposes such as boiler feed and irrigation, which contain different levels of purity and mineral compositions. Pure water can corrode metal pipes so the purest water produced for high-pressure boiler feed must be piped in plastic.

2016 Earth day paris acords

Photo by Efrain Esparza

The first technology demonstrated during the tour filters water through a series of giant, tubular microfiltration units called “straws.” The straws have outlets, which allow water to pass through 300 times thinner than a human hair.

The water that passes from these straws continues on through tubular units of the more commonly known reverse osmosis system that uses thin-film composite membranes that only allow molecules of water or smaller to pass through.

2016 Earth day paris acords

Photo by Efrain Esparza

At this point, some of the water, in order to comply with current California Health code standards, passes through units that have multiple UV lamps to eradicate any organic molecules that may have passed through.

2016 Earth day paris acords

Photo by Efrain Esparza

Once the water has been filtered and treated, the majority of it is pumped back into nature at varying depths as part of the Seawater Barrier system along the southern California coast. The pumped recycled water prevents seawater from entering groundwater systems and replenishes underground groundwater reservoirs. The rest of the water is piped or shipped to West Basin’s local industrial and commercial customers. Current laws in California do not allow for recycled water to be made available for residential use but as the drought becomes more severe, it may become a necessity.