file under: Water, United States, Government, Water Reuse, Integrated Resources Management

Waste Not, Want Not

Orange County’s Groundwater Replenishment System Project

Faced with extended droughts and continued population growth, the Orange County Water District and Orange County Sanitation District embarked on the landmark groundwater replenishment (GWR) system 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.

 
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. 

Public health and safety was a top priority when we designed the 70-million-gallon-per-day (mgd) GWR system. 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 GWR system is the largest plant in the world using this triple-barrier approach to purify treated wastewater into drinking water. But the system offers more than size and innovation. The environment-friendly plant reduced the regional power demand—less power is required to purify wastewater than to import a similar amount of 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, and provides economic benefits to the county by reducing maintenance costs.

The pioneering advanced water treatment facility takes a previously wasted resource to help drought-proof Orange County with a safe, new potable water supply.

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Orange County Water District