A final expansion to the world’s largest indirect potable water reuse facility, the Groundwater Replenishment System (GWRS) is complete, producing 130 million gallons of water a day – enough water to serve nearly one million people in Orange County.
The GWRS now recycles 100 percent of local reclaimable wastewater flows. This expansion maximizes water recycling efforts and increases drinking water supplies for the region.
This historic milestone was achieved by project partners Orange County Water District (OCWD) and Orange County Sanitation District (OC San).
“We are proud to make history once again with the completion of the Groundwater Replenishment System,” said OCWD Board President Cathy Green. “The GWRS is a premier example of vision, innovation, and collaboration – all which are key components of the project’s successes over the years, further cementing our pioneering role in water reuse.”
The GWRS takes highly treated wastewater that would otherwise be discharged to the ocean and purifies it using a three-step advanced treatment process consisting of microfiltration, reverse osmosis, and ultraviolet light with hydrogen peroxide. The result is high-quality water that is pumped to recharge basins in Anaheim where it naturally percolates into the Orange County Groundwater Basin (Basin) and becomes part of the drinking water supply for 2.5 million people in north and central Orange County. GWRS water is also sent to injection wells located along Orange County’s coast to create a seawater intrusion barrier that protects groundwater supplies.
“WateReuse congratulates OCWD and OC San for proving that regional partnership can reap great rewards for the community,” said WateReuse Association Executive Director Patricia Sinicropi. Both OCWD and OC San are longtime leading members of the WateReuse Association (WateReuse). Together with local partners including OCWD and OC San, WateReuse advances laws, policies, funding, and public acceptance of water recycling to improve the resilience, health, and prosperity of communities across the United States.
Craig W. Lichty P.E., WateReuse Association President, and vice president with Black & Veatch, attended a celebration for the completed project. “The Groundwater Replenishment System is a remarkable project. It will benefit the people and environment of Orange County for generations,” he said.
The GWRS first made history when it came online in 2008, bringing water reliability to Orange County. It started producing 70 million gallons of water per day (MGD) in January 2008, increased production to 100 MGD after an initial expansion was completed in May 2015, and since inception has produced more than 400 billion gallons of water and counting. In 2023, the GWRS celebrated its 15th “crystal” anniversary.
GWRS water is pumped to recharge basins in Anaheim where it naturally percolates into the Orange County Groundwater Basin, managed by OCWD, and becomes part of the drinking water supply for 2.5 million people in north and central Orange County. GWRS water is also sent to injection wells located along Orange County’s coast to create a seawater intrusion barrier that protects groundwater supplies. It creates a new, drought-proof water supply, decreases the region’s dependence on imported water, and reduces the amount of treated wastewater sent to the ocean. For more information about the GWRS, visit www.ocwd.com/gwrs.
