At the A.K. Warren Water Resource Facility in Carson, a demonstration plant is already turning wastewater into 500,000 gallons of purified water every day, and it is doing so as a proof of concept for something far bigger. The Grace F. Napolitano Pure Water Southern California Innovation Center is the testing ground for a project that officials say could eventually serve 1.5 million Angelenos with locally recycled water.
According to CalEPA
, the state agency highlighted the milestone this week, noting that California is working to protect its water supply from climate change and that the California Water Boards have provided over $2 billion statewide for water recycling projects. The Carson facility uses a three-stage process combining membrane bioreactors, reverse osmosis, and ultraviolet and advanced oxidation treatment, according to the
Groundwater Resources Association
That process is part of the demonstration effort before full-scale construction begins.
From Demonstration Plant to Regional Powerhouse
The numbers behind the full build-out are staggering compared to the current pilot. Once fully constructed, the Pure Water Southern California project is projected to produce 150 million gallons of purified water daily — about 155,000 acre-feet annually — enough to serve 1.5 million Southern California residents and generate nearly 50,000 new jobs, per the Governor's Office of Land Use and Climate Innovation. The program is a joint partnership between the Metropolitan Water District of Southern California and the Los Angeles County Sanitation Districts.
Carson was chosen as the site in part because of the sheer volume of untapped wastewater already flowing through it. The A.K. Warren facility has a design capacity of 400 million gallons of wastewater daily, according to the Los Angeles County Sanitation Districts.
A Name Honoring Decades of Water Advocacy
The innovation center's name is not incidental. The Metropolitan Water District officially dedicated and renamed its Carson demonstration plant in November 2023 in honor of U.S. Representative Grace F. Napolitano, the outlet MyNewsLA reported at the time.
That federal support has continued to flow toward the project. The California Water Environment Association reported on June 11, 2024, that the U.S. Bureau of Reclamation had provided $99.2 million in federal funding to the Metropolitan Water District to advance design work and infrastructure improvements, with federal officials announcing the funding at the Carson demonstration plant alongside state water leaders, according to the California Water Environment Association.
Regulatory Shifts Clearing the Path
None of this scale-up would be legally possible without a regulatory breakthrough at the state level. In December 2023, the California State Water Resources Control Board unanimously adopted regulations addressing direct potable reuse. Those regulations took effect in October 2024 after approval by the Office of Administrative Law.
Governor Gavin Newsom also certified Pure Water Southern California under the state's CEQA judicial streamlining process in December 2025, a move intended to limit legal challenges and prevent construction delays, per the Governor's Office of Land Use and Climate Innovation. The certification comes amid broader state climate efforts.
Carson's Project Has Company Across the Basin
Carson is part of a broader regional focus on water recycling.
Getting the purified water from Carson to the communities that need it will require substantial new infrastructure. Distributing the water will demand 40 to 60 miles of large-diameter underground conveyance pipelines and pump stations stretching north to Azusa and east to La Verne to recharge regional groundwater basins, according to Delve Underground, which outlined the project's physical footprint across multiple LA County urban centers.
