Orange County awarded grant to increase drinking water supply

The Orange County Water District (OCWD; the District) has been awarded a $3.6 million grant from the California Department of Water Resources Integrated Regional Water Management (IRWM) grant program for use toward the construction of its Groundwater Replenishment System (GWRS) Final Expansion project. Operational since 2008, the GWRS is undergoing its second and final expansion.

This expansion will increase treatment capacity from 100 million gallons per day (MGD) to 130 MGD; enough water to meet the daily needs of 1 million people. Construction began in 2019 and will be complete in 2023.

“In addition to being a highly-reliable source of clean water, the GWRS produces some of the lowest cost water in the region,” said OCWD President Vicente Sarmiento. “The receipt of these grant funds further lowers the cost of producing GWRS water, a savings ultimately passed on to consumers.”

The GWRS is a joint project between OCWD and the Orange County Sanitation District and is the world’s largest water reuse project of its kind. The project takes highly-treated wastewater and purifies it using a three-step process of microfiltration, reverse osmosis and ultraviolet light with hydrogen peroxide. The result is water that meets or exceeds all state and federal drinking water standards. This ultra-pure water is then recharged into the aquifer to become part of the region’s drinking water supply.

OCWD is one of 10 agencies and the GWRS is one of 11 projects in the Santa Ana River Watershed to receive funding from round one of IRWM’s Implementation Grant Solicitation. The program supports integrated water resources management as well as project planning and implementation. Funding for the program comes from Proposition 1, a bond measure passed by California voters in 2014.

The GWRS Final Expansion costs are estimated to be $310 million. Additional funding for the project includes $1.1 million in grants from the U.S. Department of the Interior Bureau of Reclamation Title XVI Water Infrastructure Improvements for the Nation (WIIN) program and $186 million through the Clean Water State Revolving Fund (SRF) Loan program. Remaining costs (up to $135 million) will be paid through a loan from the U.S. Environmental Protection Agency’s Water Infrastructure Finance and Innovation Act (WIFIA) program.

For additional information about the GWRS, please visit For additional information about the IRWM grant program, visit

The Orange County Water District is committed to enhancing Orange County’s groundwater quality and reliability in an environmentally friendly and economical manner. The following cities rely on the groundwater basin, managed by OCWD, to provide 77 percent of their water demands: Anaheim, Buena Park, Costa Mesa, Cypress, Fountain Valley, Fullerton, Garden Grove, Huntington Beach, Irvine, La Palma, Los Alamitos, Newport Beach, Orange, Placentia, Santa Ana, Seal Beach, Stanton, Tustin, Villa Park, Westminster and Yorba Linda.

For more information about OCWD, please visit

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