Ground Water Replenishment System

The Initial Expansion of the Groundwater Replenishment System for McCarthy that consisted of 55 7/8” OD down to 14” OD pipe, with a mixture of Polyurethane and Carboline Plasite 4500 lined and coated pipe. The GWRS, a joint project of Orange County Water District and Orange County Sanitation District, takes highly treated wastewater that would have normally been discharged into the Pacific Ocean and purifies it through a three-step process that includes microfiltration, reverse osmosis and ultraviolet light with hydrogen peroxide. 35 million gallons of near-distilled quality GWRS water per day is pumped into injection wells where it serves as a seawater intrusion barrier. Another 35 million gallons per day is pumped in a 13-mile long pipe to OCWD recharge basins in Anaheim, California. The GWRS water then filters through sand and gravel to replenish the deep aquifers of Orange County’s groundwater basin and ultimately becomes part of the drinking water supply.