Los Coyotes Water Reclamation Plant

The Los Coyotes Water Reclamation Plant (WRP) is located at 16515 Piuma Avenue in the city of Cerritos and occupies 34 acres at the northwest junction of the San Gabriel River (605) and the Artesia (91) Freeways. Twenty of the 34 acres are occupied by the Iron Wood Nine Golf Course, which is built on adjoining Sanitation Districts' property. The plant was placed in operation on May 25, 1970, with an initial capacity of 12.5 million gallons per day and consisted of primary treatment and secondary treatment with activated sludge.


The Los Coyotes WRP provides primary, secondary, and tertiary treatment for 37.5 million gallons of wastewater per day (see flow diagram below). The plant serves a population of approximately 370,000 people. Click of the diagram to read about the wastewater treatment and water reclamation process.

Over five million gallons per day of the recycled water is used at over 270 sites. Reuses include landscape irrigation of schools, golf courses, parks, nurseries, and greenbelts; and industrial use at local companies for carpet dying and concrete mixing. The remainder of the recycled water is discharged to the San Gabriel River.  To learn more about the Sanitation Districts' recycled water programs, browse the Sanitation Districts' water reuse program and the current resources and information page.