The Metropolitan Water District board voted to begin environmental planning work on what would be one of the largest advanced purified wastewater treatment plants in the world.
Metropolitan officials said the approval marks a significant milestone for the Regional Recycled Water Program, a partnership between the MWD and the Los Angeles County Sanitation Districts to reuse water currently sent to the ocean.
“Our board has shown over the past five years that we are committed to creating a drought-proof, local water supply for the region by investing in this project,” Metropolitan board Chair Gloria D. Gray said. “We all recognize our growing duty to ensure Southern California has reliable water in the face of threats from climate change and earthquakes. This project builds that resilience.”
As envisioned, the project would take cleaned wastewater from the Sanitation Districts’ Joint Water Pollution Control Plant in Carson and purify it using innovative treatment processes, producing up to 150 million gallons of water daily — the amount used by more than 500,000 homes.
The purified water would initially be used for groundwater replenishment and storage, and by industrial facilities. After additional treatment, it may later be delivered directly to Metropolitan’ss existing water treatment plants and used for drinking water, after the state develops regulations for direct potable reuse, according to an MWD statement.
The board’s vote allows Metropolitan to initiate the necessary environmental planning work, including an Environmental Impact Report and engineering and technical studies, and to continue public outreach, which will cost an estimated $30 million and take about three years.
“The information produced will be critical to provide our board with the necessary information to make a fully informed decision in 2024 whether to build this project,” Metropolitan General Manager Jeffrey Kightlinger said.
“When combined with our investments to ensure the reliability of our imported supplies from the Colorado River and the northern Sierras, we can build water security for the region for generations to come,” he said.
“Metropolitan has never before directly developed a local supply like this. It is a huge opportunity for Southern California, and an opportunity that can only succeed through a partnership between two large regional agencies like Metropolitan and the Sanitation Districts.”
At its upcoming meeting, the Sanitation Districts board will consider contributing about $5 million toward the environmental planning costs, along with undertaking additional studies to support the project, through an agreement also approved Tuesday by Metropolitan’s board.
Last year, Metropolitan allocated $17 million for a demonstration plant to test an innovative purification process that could be used in a full- scale plant.
Metropolitan is a state-established cooperative that, along with 26 cities and retail suppliers, provide water for 19 million people in six counties in Southern California. The district imports water from the Colorado River and Northern California to supplement local supplies, and helps its members to develop increased water conservation, recycling, storage and other resource-management programs.