The Orange County Water District (OCWD) has been awarded a $3.6 million grant from the California Department of Water Resources Integrated Regional Water Management grant program for use toward the construction of its Groundwater Replenishment System (GWRS) Final Expansion project.
Operational since 2008, the GWRS is undergoing its second and final expansion. This expansion will increase treatment capacity from 100 million to 130 million gallons per day; providing treated water to meet the daily needs of one million people.
“In addition to being a highly-reliable source of clean water, the GWRS produces some of the lowest cost water in the region,” said OCWD President Vicente Sarmiento. “The receipt of these grant funds further lowers the cost of producing GWRS water, a savings ultimately passed on to consumers.”
Consumers in 21 cities rely on the OCWD groundwater basin to provide 77% of their water demands. Historically, the main source of water for basin replenishment had been the Santa Ana River — but water flows fluctuate from year to year due to weather patterns and water conservation programs at upstream locations. To compensate for these fluctuations in replenishment water, OCWD began importing water from other sources, first the Colorado River and later, the Sacramento-San Joaquin River Delta. But relying on these distant watersheds to recharge groundwater poses challenges, and Orange County’s future depends on reliable water supplies. The GWRS provides the region with water it can count on and serves as a model project for other regions that are, or will be, facing natural and man-made water supply challenges.
The GWRS is a joint project between OCWD and the Orange County Sanitation District and is the world’s largest water reuse project of its kind. The project takes highly-treated wastewater that would have previously been discharged into the Pacific Ocean and purifies it using a three-step advanced treatment process consisting of microfiltration, reverse osmosis, and ultraviolet light with hydrogen peroxide. The result is high-quality water that meets or exceeds all state and federal drinking water standards. This ultra-pure water is then recharged into the aquifer to become part of the region’s drinking water supply. The project is expected to be complete in 2023.