Orange County's Groundwater Replenishment System (GWRS)

Leading the Way in Water Reuse

Orange County Water District and Orange County Sanitation District CALIFORNIA, USA

Orange County’s groundwater replenishment system produces potable water for indirect reuse from highly treated wastewater—conserving water resources, reducing energy consumption and supporting economic vitality.

Faced with extended droughts and continued population growth, the Orange County Water District and Orange County Sanitation District embarked on the landmark groundwater replenishment system (GWRS) project—a true model of sustainability. Producing potable water for indirect reuse from highly treated wastewater, the system conserves and recovers limited water resources, reduces energy consumption and supports economic vitality.

^mgd

of reclaimed water processed by GWRS

70 ^mgd

of reclaimed water processed by GWRS

^mgd

of expandable capacity

130 ^mgd

of expandable capacity

Orange County residents served by GWRS Water

500K

Orange County residents served by GWRS Water

Public health and safety was a top priority when CDM Smith designed the 70-million-gallon-per-day (mgd) GWRS. Therefore, water is treated with microfiltration and reverse osmosis, followed by ultraviolet light disinfection, to ensure that all bacteria, emerging contaminants and viruses are removed. The treated water is then injected into an underground seawater barrier or percolated into aquifers, providing a new water source for about 500,000 people living in the area.

With a capacity expandable to 130 mgd, the GWRS is one of the largest potable reuse plants in the world.

The environment-friendly plant reduced regional power demand because less power is required to purify wastewater than to pump imported water from Northern California or the Colorado River.

The facility also reduces the amount of treated wastewater released into the ocean, delaying the need for an additional ocean outfall.

By reducing maintenance costs and providing a new water source, the GWRS facility supports the economic growth of Orange County.

Project Details

Treatment Innovation for Safe Water Supplies
Three barriers ensure that GWRS produces safe water: microfiltration, reverse osmosis, and ultraviolet light disinfection.