Tapia WRF Wastewater Treatment Plant, Unincorporated Santa Monica Mountains, California

Tapia WRF is a wastewater reclamation facility serving the Unincorporated Santa Monica Mountains area in Los Angeles County, California. The plant serves a population of approximately 89,500, placing it in the medium-to-large agglomeration category under US regulatory frameworks. As a US facility, Tapia WRF operates under the Clean Water Act, with National Pollutant Discharge Elimination System (NPDES) permits issued by the California State Water Resources Control Board or the Los Angeles Regional Water Quality Control Board. For a plant of this scale, secondary treatment is typically required, and advanced treatment may be necessary for discharge to sensitive waters or for water reuse. The plant's treated effluent likely discharges into a tributary of the Los Angeles River or directly into the Santa Monica Bay via local creeks. The receiving waters ultimately flow to the Pacific Ocean, supporting coastal ecosystems and recreational areas along the Southern California coast.

Tapia WRF discharges into the Santa Monica Bay watershed, which drains the Santa Monica Mountains and flows into the Pacific Ocean. The bay supports diverse marine life, including kelp forests and fish populations, and is a key recreational area. The plant's location within 50 km of the coast means its discharge can affect nearshore water quality and coastal habitats.