GWRS - new water you can count on
The GWRS is the world's largest water purification system for indirect potable reuse. The system takes highly treated wastewater that would have previously been discharged into the Pacific Ocean and purifies it using a three-step advanced treatment process consisting of microfiltration, reverse osmosis and ultraviolet light with hydrogen peroxide. The process produces high-quality water that meets or exceeds all state and federal drinking water standards.
View the GWRS technical brochure (PDF)
After wastewater is treated at the Orange County Sanitation District, it flows to the GWRS where it undergoes a state-of-the-art purification process.
The process
Public tours of the GWRS are offered the first Friday of every month, or other days of the week depending on staff availability.
Book a tour
The Groundwater Replenishment System Final Expansion (GWRSFE) project will increase treatment capacity from 100 to 130 million gallons per day (MGD); enough water for 1 million million people!
Final expansion
