Over the past 75 years, the Orange County Water District (OCWD) has recharged water from a variety of sources. Previously used sources, such as imported water and Santa Ana River base flows are becoming less abundant and less reliable. Orange County’s recycled water; however, is a source of supply that can provide a reliable and cost effective alternative to imported supplies. Since OCWD completed the Groundwater Replenishment System (GWR System) in 2008, it has produced 186,000 acre-feet of ultra-purified wastewater that serves to protect against seawater intrusion along the coast, replenishes the aquifers, and improves the quality of native groundwater. Approximately half of these flows are recharged in the Talbert Gap Seawater Barrier and the other half is recharged in surface spreading basins in Anaheim. Recycled water produced by the GWR System is providing 15 to 20 percent of total recharge to the groundwater basin. OCWD is proceeding with plans to expand the capacity of the GWR System to produce up to 100,000 acre-feet per year, which will provide an average of 30 percent of the total recharge to the groundwater basin.
In addition to providing increased reliability, the GWR System produces very high quality water with a number of other important benefits. Imported water from the Colorado River and Santa Ana River base flows have total dissolved solids concentrations (TDS) of 600 mg/L or more. The TDS concentration of GWR System water is 70 mg/L, which helps to reduce the salt load to the groundwater basin. Another key benefit is the superior performance obtained in injection wells and surface water recharge facilities. Because there is minimal potential for clogging with GWR System water, the capacity of the surface water recharge facilities are 200 percent greater with GWR System water compared to Santa Ana River water.
