MEETING THE CHALLENGE OF PROVIDING A RELIABLE WATER SUPPLY FOR THE FUTURE, THE GROUNDWATER REPLENISHMENT SYSTEM

摘要

The Groundwater Replenishment (GWR) System is an innovative approach to keeping Orange County’s groundwater basin a reliable source for meeting the region's future potable water needs. A joint program of the Orange County Water District (OCWD) and the Orange County Sanitation District (OCSD), the GWR System is an ambitious, large-scale project that will construct an advanced recycled water treatment facility (AWTF) to treat secondary wastewater for reuse. The facility will replace the aging Water Factory 21 (WF21) which, when completed in 1976, was one of the first recycled water treatment plants in the world. Using microfiltration as pretreatment for reverse osmosis (RO) and ultraviolet radiation (UV), Phase 1 of the GWR System will produce 70 million gallons per day (mgd) of recycled water that will meet all drinking water standards. The treated water will be injected into the ground by OCWD through new and existing injection wells to supply the local seawater intrusion barrier and pumped 13 miles up the Santa Ana River to be percolated into spreading basins for groundwater recharge, improving the groundwater quality and reducing Southern California’s dependence on imported water. The facility will produce enough water to supply the needs of over 200,000 families. While OCWD will construct and operate the GWR System, the project will have far reaching impacts and benefits on OCSD as well as OCWD. OCSD is committed to good resource management and has partnered with OCWD over the years on numerous recycled water projects, including WF21 and more recently, the Green Acres Project (GAP). Participation of OCSD in the GWR System is defined in a new inter-agency operating agreement between OCSD and OCWD which, among other things, stipulates a 50/50 cost share of capital costs between the OCSD and OCWD. OCSD staff participates as active members in the GWR System design team and has helped shape favorable public perception for the project at a time when they were also gaining public input regarding the future of their ocean discharge waiver. Despite all of the additional responsibilities, there are significant benefits to OCSD, including deference or elimination of an additional ocean outfall, and support for OCSD's long-standing commitment to water reclamation.