What to know
- We continuously analyze wastewater across four treatment facilities to ensure safe, high-quality operation.
- Plant engineers use immediate laboratory test results to optimize biological and chemical treatment processes 24/7.
- Extensive testing verifies that recycled water is completely safe for irrigating local parks, golf courses, and greenways.
- Purified water from Terminal Island is tested and injected into the Dominguez Gap Seawater Intrusion Barrier to prevent ocean saltwater contamination.
Program Overview
At LA Sanitation & Environment (LASAN), we operate four water reclamation facilities that together process over 400 million gallons of wastewater every day:
- Hyperion Water Reclamation Plant (HWRP)
- Donald C. Tillman Water Reclamation Plant (DCTWRP)
- Los Angeles-Glendale Water Reclamation Plant (LAGWRP)
- Terminal Island Water Reclamation Plant (TIWRP)
Daily laboratory monitoring at each plant ensures full compliance with Waste Discharge Requirements (WDR) and National Pollutant Discharge Elimination System (NPDES) permits issued by the United States Environmental Protection Agency (US EPA) and the Los Angeles Regional Water Quality Control Board (LARWQCB). By delivering immediate test data to plant operators, our scientists help fine-tune biological treatment processes, protect aquatic receiving waters, and produce clean recycled water for our community.
Process Control Testing
Plant process control technicians perform continuous testing on incoming wastewater, active biological aeration basins, and final effluent. Key laboratory parameters include:
- Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD)
- Total Suspended Solids (TSS) and settleable solids (using Imhoff cones)
- Oil, grease, and heavy metals
- Organic priority pollutants
- Microorganism community health (monitoring bacterial filaments and stalked ciliates)
- Acute and chronic aquatic toxicity
Recycled Water Compliance
LASAN tests recycled water to verify compliance with California Title 22 Recycled Water regulations. This high-quality recycled water is safely distributed across the City of Los Angeles to irrigate parks, golf courses, and street greenways.
At Terminal Island's Advanced Water Purification Facility (AWPF), recycled water undergoes advanced purification before being injected into the Dominguez Gap Seawater Intrusion Barrier. This underground barrier protects vital local groundwater drinking aquifers from ocean saltwater intrusion. All monitoring data is regularly reported to regulatory agencies and made available to the public via the California Integrated Water Quality System (CIWQS) and the California Environmental Data Exchange Network (CEDEN).
Contact Us
Have questions about recycled water testing or plant discharge permits? Call our 24-hour Customer Care Center at 1-800-773-2489 or submit an inquiry through MyLA311.