The Groundwater Replenishment System (GWRS) is a collaboration between the Orange County Water District (OCWD) and OC San to beneficially reuse treated wastewater. GWRS is the world’s largest advanced water purification system for potable reuse.

OC San supplies OCWD with secondary treated wastewater from OC San Plant No. 1 in Fountain Valley to produce high-quality water as part of GWRS. The water is then pumped to the groundwater basin.

The original GWRS facility was initially constructed in 2008 and supplied up to 70 million gallons per day (MGD) of purified water. Yet the facility was designed for an ultimate treatment and conveyance of 130 MGD. Today the GWRS facility produces 100 MGD.

To produce 130 MGD, additional treated wastewater from OC San is required. This additional water will come from OC San’s Plant No. 2, which is in the city of Huntington Beach and approximately 3.5 miles south of the GWRS facility. To make this possible OC WD is expanding GWRS treatment facilities in Fountain Valley, constructing two equalization tanks and a pump station at Plant No. 2, and rehabilitating an existing pipeline between OC San Plant No. 2 and the GWRS for future water conveyance. OC San is making modifications to the Headworks System at Plant No. 2 and constructing a Low-Flow Pump Station/Plant Water Pump Station.

By 2023 the Final Expansion of GWRS will be complete and will produce the maximum capacity of 130 MGD, this will be enough water for 1,000,000 people.

To learn more about this world-renowned project please visit www.ocwd.com/gwrs.