Los Coyotes WRP - Cerritos, California Wastewater Treatment Plant

Los Coyotes WRP is a major wastewater treatment facility located in Cerritos, Los Angeles County, California. It serves a population of approximately 370,000, classifying it as a large agglomeration under US regulatory standards. The plant is part of the region's critical water infrastructure, managing municipal wastewater from residential and commercial sources. As a US facility, Los Coyotes WRP operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the California State Water Resources Control Board. For a plant of this scale, secondary treatment is the minimum standard, with potential requirements for advanced treatment to protect sensitive receiving waters. The designed capacity is 1.00 million gallons per day, indicating a substantial treatment capability. The plant's treated effluent is discharged into local water bodies that ultimately drain to the Pacific Ocean via the Los Angeles River or San Gabriel River systems. This discharge supports downstream aquatic habitats and contributes to regional water quality management. The facility plays a key role in protecting the coastal environment and public health in the greater Los Angeles area.

The plant discharges into the Los Angeles River watershed, which flows through urbanized Los Angeles County before reaching the Pacific Ocean at Long Beach. This coastal ecosystem supports diverse marine life, including fish and bird species, and is an important migratory corridor. The discharge must meet stringent water quality standards to protect downstream habitats and recreational uses.