Colored Water Treatment Facility Technology Replacement & Expansion Project

Cost: $16.9 million
Location: Costa Mesa, Calif.
Year: 2011-12-14
Size: 8.6 mgd
Owner: Mesa Consolidated Water District
Designers: Carollo
Contractor: MWH Constructors; Brutoco Eng. & Construction

Situated in southern California, the town of Costa Mesa has always had an issue with naturally occurring organic materials (NOMs) in its groundwater, giving it a tea-colored appearance. The offending tint is due to an ancient, submerged redwood forest located hundreds of feet below the surface, within the aquifer Mesa Water uses.

While the water remains safe to drink, the district’s existing Colored Water Treatment Facility (CWTF) has been unable to remove all NOMs. This has forced the district to import some of its water from outside sources. A new water treatment facility will increase the district’s ability to produce its own water, saving money in the process.

In January 2011, Mesa Water began the process of building a new CWTF, which first meant demolishing the current plant. With that step done, construction could begin on the new facility, complete with a state-of-the-art nanofiltration system manufactured by Biwater-AEWT. This approach makes use of membrane technology to weed out any undesirable foreign materials.

A degasifier system, provided by Jacobs Air Water Systems, is also in the plans for removal of methane and hydrogen sulfide gases, while an onboard chemical scrubber will prevent any gaseous odor from escaping into the surrounding community.

Project planners have given themselves a tight deadline for completion: The expected finish date is mid-July 2012. The construction site is fairly small, which presents its own set of challenges. In addition to the treatment facility itself, Carollo and Mesa Water are designing a 3,400-sq-ft landscaped area around it. Visitors will be able to see mature redwoods and other native plant species along numerous footpaths, complete with a gazebo.

“The facility has always produced soft, high-quality water,” said Fred R. Bockmiller, Jr., P.E., Mesa Water Board president. “The CWTF Improvements Project expands capacity, reduces energy cost and will help the district achieve its goal of being 100% locally reliable by 2012.”