As the City’s imported water supply becomes more critical, so does the need to expand our local, sustainable water resources, including water recycling. Water recycling offers a reliable, economically feasible, and environmentally conscience way to augment the city's water supplies. Recycling programs treat wastewater so that it can be used safely for irrigation and industrial purposes, groundwater replenishment, as a barrier against seawater intrusion, and for other beneficial environmental uses.
As a result, new recycled water projects and the expansion of existing projects are in various stages of planning, design, or construction. Below is a link to the Executive Summary of the Recycled Water Master Planning document followed by a chronological history of LADWP recycling projects currently in operation, as well as new projects in which construction is planned or already underway.
Recycled Water Master Planning – Executive Summary
Groundwater Replenishment Project
The Los Angeles Groundwater Replenishment Project, in partnership with LADWP and LASAN, will provide up to 22,000 acre-feet per year (AFY) of purified water to replenish the San Fernando Groundwater Basin. The project involves the construction of an Advanced Water Purification Facility (AWPF) at the Donald C. Tillman Water Reclamation Plant (TIWRP), producing high quality, advanced treated water surpassing regulatory requirements for surface spreading for groundwater replenishment. Construction has begun in the winter of 2024 and is scheduled to be complete by 2027.
More information on the Groundwater Replenishment Project
Pure Water Los Angeles
The Pure Water Los Angeles Program is a major water supply initiative led by LADWP and L.A. Sanitation and Environment (LASAN) to enhance the City's water resilience by transforming treated wastewater into a reliable, sustainable source of drinking water. The Program will produce purified recycled water from wastewater treated at the Hyperion Water Reclamation Plant located in Play Del Rey. In early 2025, LADWP completed the Master Plan establishing the initial planning framework for PWLA.
More information on Pure Water Los Angeles
Headworks Direct Potable Reuse (DPR) Demonstration Project
The California State Water Resources Control Board (SWRCB) Division of Drinking Water (DDW) adopted the final Direct Potable Reuse (DPR) regulations in December 2023 and went in effect in October 2024. DPR allows agencies to augment drinking water supplies with advanced purified recycled water, a critical water reuse strategy that LADWP is examining through the Headworks Direct Potable Reuse Demonstration Project. Located at the Tom LaBonge Headworks Water Complex, the DPR Pilot will evaluate various advanced water treatment process trains to produce highly purified water, meeting DPR standards. Results from the 50 gallon per minute (gpm) pilot study will inform the selected treatment train(s) for a proposed 1-MGD demonstration-scale facility. Pursuing DPR allows the City of Los Angeles to make strides in achieving 100% reuse of wastewater and continue advancing recycled water availability to diversify the Los Angeles' supply.
Harbor Refineries Recycled Water Project
The City of Los Angeles Bureau of Sanitation and Environment (LASAN), in the Department of Public works, owns and operates the Terminal Island Water Reclamation Plant (TIWRP) with its associated Advanced Water Purification Facility (AWPF) located on Terminal Island. LASAN is subjected by the State Water Resources Control Board Resolution 94-009 to implement water recycling as a means to cease discharge of water from the TIWRP into the Los Angeles Harbor. Since this resolution was adopted, the Los Angeles Department of Water and Power developed the Harbor Refineries Recycled Water Project (HRRWP) that enables LADWP to utilize their existing recycled water system in the Harbor area and the TIWRP treatment facility to produce million gallons per day (MGD) of Advanced Treated Recycled Water (ATRW).
HRRWP includes non-potable reuse projects (e.g. recycled water for irrigation, dust control, industrial use, and recreational impoundments) throughout the Los Angeles Harbor area and injection of recycled water into the Dominguez Gap Seawater Intrusion Barrier. LADWP has formed partnerships with the Water Replenishment District and industrial customers with the Valero Wilmington Refinery and Air Products & Chemicals Refinery located in Wilmington, CA. These partnerships, formalized through Recycled Water Agreements, incorporate ATRW from TIWRP into their processes.
By using ATRW, customers can reduce their reliance on potable water, saving approximately 7,800 acre-feet per year (AFY). This initiative marks a significant step forward in LADWP's ongoing efforts to achieve 100% water reuse in the Los Angeles Harbor area.
Second Dominguez Gap Connection Project
The Second Dominguez Gap Connection Project (Project) aims to eliminate imported potable water usage at the Dominguez Gap Seawater Intrusion Barrier (DGB), achieving 100% water reuse in Los Angeles Harbor and reducing wastewater discharge into the Pacific Ocean. The DGB is a series of wells that are currently used to inject imported potable water and locally sourced advanced treated recycled water (ATRW) into the West Coast Groundwater Basin, creating a pressure ridge that inhibits the flow of seawater into freshwater inland aquifers.
The Project will install approximately 3,000 feet of 24-inch diameter ductile iron pipe to supply the DGB an additional 4,000 acre-feet per year of ATRW from the Terminal Island Water Reclamation Plant (TIWRP), utilizing over 50% of TIWRP's product water, eliminating potable water usage at the DGB, all while protecting the West Coast Groundwater Basin's groundwater supplies from saltwater contamination. The additional supply of ATRW to the barrier will leave imported potable water for approximately 48,000 customers.