Lancaster WRP Wastewater Treatment Plant, Los Angeles County, California

Lancaster WRP is a municipal wastewater treatment plant located in Los Angeles County, California, serving a population of approximately 160,000. The facility is situated in the Santa Clarita Valley region, an area characterized by a Mediterranean climate with hot, dry summers and mild winters. As a large agglomeration serving over 150,000 people, the plant is subject to stringent regulatory requirements under the US Clean Water Act. The National Pollutant Discharge Elimination System (NPDES) permit program, administered by the California State Water Resources Control Board, governs discharge limits and treatment standards. Plants of this scale typically employ advanced secondary or tertiary treatment to meet water quality standards. The plant's treated effluent is discharged into the Santa Clara River, which flows westward through Ventura County and empties into the Pacific Ocean near Oxnard. The Santa Clara River is one of the last major free-flowing river systems in Southern California, supporting diverse aquatic habitats and providing critical water resources for agriculture and ecosystems.

The plant discharges into the Santa Clara River, which flows approximately 83 miles to the Pacific Ocean. The river supports a variety of sensitive aquatic species, including the endangered Southern California steelhead trout. Downstream, the river's estuary provides important nursery habitat for marine fish and supports migratory birds along the Pacific Flyway.