Alternative water supply system for southern California earns top industry honour

Consultants Black & Veatch are celebrating after the Orange County Water District’s Groundwater Replenishment System (GWRS) Initial Expansion project, an alternative water supply system that bolsters water security for a large portion of southern California which they designed, was chosen to receive the prestigious Water Environment Federation (WEF) Project Excellence Award. 

The award, which is due to be presented during the WEF’s annual conference in New Orleans later this month, recognises outstanding programs and product execution in the water sector. Among other criteria, projects are evaluated on innovation, sustainability and community benefit.

The $142m expansion, completed in 2015, adds 30 million gallons per day (MGD) of capacity to Orange County’s Advanced Water Purification Facility (AWPF), the world’s largest planned indirect potable reuse system. The AWPF takes wastewater treated to secondary levels from the Orange County Sanitation District’s neighbouring Fountain Valley Plant No. 1 and uses a state-of-the-art process to produce ultra-pure water that meets or exceeds state and federal drinking water standards. The system now produces enough new water for about 850,000 people at roughly half the cost of water supplies taken in from other sources.

“The GWRS Initial Expansion is a prime example of resilient and holistic water planning,” said Cindy Wallis-Lage, president of Black & Veatch’s water business. “This is a locally controlled, essentially drought-proof system that brings reliability and supply security to the Orange County region. To expand this facility’s production while other sources of supply around the state were being restricted due to extreme, prolonged drought truly shows the power of alternative water supply solutions such as water reclamation and water reuse,” she said.

In addition to raising capacity from 70 to 100 MGD, the project presented opportunities to reduce operating costs by optimising system performance. Flow equalisation, energy recovery devices and a new corrosion-minimising lime system were implemented to help the GWRS operate more efficiently. 

Energy recovery devices were implemented in the expanded reverse osmosis system to capture energy lost during the process. They are projected to save 14 million kilowatt-hours and $1.3 million annually for the life of the system while reducing greenhouse gas emissions by an estimated 14 million pounds each year.

Construction of the original GWRS was jointly funded by both the Orange County Water District and the Orange County Sanitation District.