OCWD Submits Imported Water Recharge Report

The Santa Ana Regional Water Quality Control Board (Regional Water Board) is responsible to protect the quality of surface water and groundwater in the watershed that includes the Orange County Groundwater Basin. One of the significant water quality challenges in Southern California is managing salinity in water supplies. Elevated salinity levels (total dissolved solids and nitrates) can contaminate groundwater supplies, constrain implementation of water recycling projects and cause other negative economic impacts such as the need for increased water treatment. Increased salt concentrations in groundwater can be due to fertilizer use, septic systems, and use of recycled water for landscape irrigation, to name a few. Another source can be the use of imported water for groundwater recharge operations.

Every six years, OCWD prepares a report to the Regional Water Board that evaluates future water quality conditions in the Orange County Groundwater Basin. The most recent report was completed in July 2016.

OCWD staff evaluated the impacts to water quality in the basin with varying volumes of imported water used for groundwater recharge over the next 30 years. Some of the sources of groundwater recharge, such as imported water and local surface waters, are expected to add salt to the basin. On the other hand, recycled water produced by OCWD’s Groundwater Replenishment System (GWRS) is high quality water with very low levels of salt. Due to the large volume of GWRS water recharged each year, the projection of groundwater quality is good with salt levels improving into the future. A copy of the Salt and Nitrate Projections for Orange County Management Zone, Final Technical Memorandum, July 18, 2016 can be found at http://www.ocwd.com/wp-content/uploads/final-2016-ocwd-iwr-report.pdf.