Reclaiming Wastewater with Tremendous Results
Faced with declining freshwater resources, California’s Orange County Water District took an innovative approach to protect its freshwater supply. In 1976, it moved to a system whereby it purifies wastewater into drinking water.
The Orange County Water District’s Water Factory 21 launched its Groundwater Replenishment System (GWRS) with the goal of maintaining its water source through wastewater reclamation. Using a three-step advanced treatment process consisting of microfiltration, reverse osmosis and ultraviolet light with hydrogen peroxide, GWRS reclaims wastewater that would otherwise have been discharged into the Pacific Ocean.
As a result, the GWRS process produces high-quality water that exceeds all state and federal purification standards, providing good, clean water to Orange County. The system is capable of producing 70 million gallons of water each day, with a total of 23.5 billion gallons per year.
Every day, approximately 35 million gallons of this treated water is then pumped into injection wells, where it serves as a seawater intrusion barrier. The system pumps another 35 million gallons to recharge basins in Anaheim, California, where it filters through sand and gravel to blend with the Santa Ana River, gradually entering the groundwater basin to again become part of north and central Orange County’s drinking water supply. The process of re-infiltration not only helps replenish the groundwater, but also introduces an added purification step.
The District has continued making improvements to their system since 1976. For example, in 2007, the county launched the world’s largest plant devoted to purifying sewer water to increase drinking water supplies.
The actions taken by the Orange County Water District illustrate that with innovative and proactive governance, sustainable water management is possible before crisis hits.