San Elijo WRF - Encinitas, California Wastewater Treatment Plant

San Elijo Water Reclamation Facility (WRF) is a municipal wastewater treatment plant located in Cardiff-by-the-Sea, Encinitas, San Diego County, California. The plant serves a population of approximately 26,600 residents in the coastal community. As a US facility, San Elijo WRF operates under the Clean Water Act National Pollutant Discharge Elimination System (NPDES) permit program, which sets effluent limits to protect water quality. For a plant of this scale serving a coastal community, advanced treatment is typically required to meet stringent discharge standards, especially for nitrogen and pathogen removal. The plant's treated effluent is discharged into the San Elijo Lagoon, a coastal wetland that drains to the Pacific Ocean. The lagoon is an ecologically sensitive habitat supporting diverse aquatic life and migratory birds. The plant plays a critical role in protecting this coastal ecosystem from nutrient pollution and other contaminants.

San Elijo WRF discharges into the San Elijo Lagoon, a coastal estuary that flows into the Pacific Ocean. The lagoon is part of the Southern California Bight, a region known for its rich marine biodiversity. The plant's operations are crucial for maintaining water quality in this sensitive coastal environment, which supports fish, birds, and other wildlife. Nutrient removal is particularly important to prevent algal blooms and hypoxia in the lagoon and nearshore ocean waters.