Five south Orange County water districts combine resources to open second water treatment plant

Looking to provide increased water supply reliability, improved water quality, sustainability and efficiency along with protection during emergencies, five south Orange County water districts have banded together to open a second water treatment plant. Irvine Ranch Water District and the Moulton Niguel, Santa Margarita, Trabuco Canyon and El Toro water districts have worked cooperatively to open the Baker Water Treatment Plant in Lake Forest.

The new facility will provide up to 28.1 million gallons per day (mgd) of drinking water to some 63,300 homes in south Orange County. The new plant is expected to become operational in January.

Currently, the five water districts rely entirely on imported water from the Diemer Water Treatment Plant in Yorba Linda, operated by the Metropolitan Water District (MWD) of Southern California. The new plant will combine water from both Lake Mathews in the Temescal Mountains, operated by MWD, and local surface water from Irvine Lake.
An original Baker Filtration Plant Water was built in the early 1970s by the Los Alisos Water District but new regulations soon rendered the facility obsolete and it was shuttered. The Irvine Ranch Water District acquired the Los Alisos district in 2001. In 2006, the five water district partners began studying the feasibility of constructing a new water treatment facility at the former Baker site.

The new plant has been built on the site of the original Baker facility. A construction contract was awarded in Dec. 2013 at an overall cost of $103.6 million. The site includes three pumping stations, a chemical building, storage, a treatment site and administrative buildings. The project has been approved by all five project partner water districts.

The five districts realized early-on that it would be necessary to work cooperatively to bring a second water source and treatment site to south Orange County. Although the water will still be imported from MWD, in the event of an emergency when the imported water might be cut off, the new Baker station can treat water directly from Irvine Lake.

“It was absolutely critical,” said Joone Lopez, general manager for the Moulton Niguel Water District. “Not one of us could have done this alone. We’re sharing not only the funding, but the resources to find a solution to enhance reliability in south Orange County.”

In addition to the increased water supply reliability, the new Baker Water Treatment Plant will also increase operational flexibility by creating redundancy within the water conveyance system. The new site will utilize advanced microfiltration treatment and ultraviolet disinfection technologies to produce water that meets standards stricter that current regulatory requirements thereby providing a consistent, high quality source of drinking water for the region. On-site recycling and treatment of waste streams have been designed within the plant which will result in a 99 percent recovery efficiency. Additionally, through the joint efforts of the partner agencies, the plant has been designed to architecturally blend in with the surrounding neighborhood.

Paul Cook, general manager of the Irvine Ranch Water District summed up the project saying, “Damaged pipes are easy to fix, but a large plant on a hill with pumps, that could be out of commission for three to six months… Two treatment plants would give south Orange County an additional option.”