Resource Recharge Decreasing Dependency on State, River

Replenishment of California’s Groundwater Addresses Drought

Most people outside of California don’t think of it as a desert, but it is. Now, with longer periods of drought, water is an ever more critical resource, especially in Southern California.

The Orange County Water District (OCWD) has been planning and investing to bring water reliability to the region since its founding in 1933. Completion of the initial expansion of OCWD’s Groundwater Replenishment System (GWRS) has made the world’s largest advanced water purification system for potable reuse even bigger.

The GWRS includes a large treatment facility known as the Advanced Water Purification Facility (AWPF) that went into service in 2008. The maximum production capacity has now been elevated to 100 million gallons per day (mgd) with the initial expansion project. The AWPF now creates enough water for 850,000 Orange County residents and decreases California’s dependency on the State Water Project and the Colorado River.

“Black & Veatch brought a lot of creativity to the project. When we were looking to expand the project, they came up with some big ideas that we implemented that made the expansion a much better project.”

Mike Markus, General Manager, Orange County Water District

Exceeding Standards

Black & Veatch was chosen for the preliminary and final design and construction support for the GWRS initial expansion. The system supplements existing water supplies by providing a reliable, high-quality alternative to imported water to recharge the Orange County Groundwater Basin.

Until recently, hundreds of millions of gallons of treated wastewater from the Orange County Sanitation District (OCSD) were discharged into the Pacific Ocean. Both OCWD and OCSD consider this a resource and not a waste product.

Today, after wastewater is treated, it flows back into the system at the OCWD. Here, the treated wastewater undergoes an extensive purification process consisting of microfiltration, reverse osmosis and advanced oxidation consisting of hydrogen peroxide and ultraviolet light. The end product is 100 mgd of near-distilled-quality water that exceeds all state and federal drinking water standards.

The expansion serves water to an additional 250,000 residents a year.