New Zone 7 Water Treatment Plant Celebrated In National Engineering Competition

Innovative Technology Safeguards Users Against “Forever Chemicals”

Carollo Engineers, Inc. of Walnut Creek, Calif. has earned a National Recognition Award for exemplary engineering achievement in the American Council of Engineering Companies’ (ACEC) 59th annual Engineering Excellence Awards (EEA). The award comes for the Zone 7 Water Agency, new Stoneridge PFAS Treatment Plant in Livermore, Calif.

Carollo Engineers led the design of Northern California’s first treatment facility to use an ion exchange (IX) system to remove per- and polyfluoroalkyl substances (PFAS), commonly referred to as “forever chemicals.” Located at the Stoneridge Well, the new $16.3M facility treats up to 4,600 gallons of water per minute—equivalent to 6.6 million gallons per day—serving more than 250,000 Tri-Valley residents and businesses across Dublin, Pleasanton, Livermore, and Danville.

To optimize the treatment solution, Carollo conducted extensive Rapid Small Scale Column Tests (RSSCTs) to evaluate multiple granular activated carbon and ion exchange media options, selecting the most effective and economical approach for long-term PFAS removal. Conco-West, Inc. served as general contractor, working closely with Carollo and Zone 7 to deliver the project through an accelerated design-build approach.

Carollo Engineers provides a full range of planning, design, and construction management services.

Judging for the awards program took place in February and was conducted by a national 32-member panel of built environment leaders, along with experts from government, the media, and academia. Award criteria focused on uniqueness and originality, technical innovation, social and economic value, and excitement generated toward the engineering profession.

All 240 award winners—including 16 Honor Awards, eight Grand Awards, and the announcement of the prestigious Grand Conceptor Award for the year’s most outstanding overall engineering achievement—will take place at the 2026 EEA Gala on Tuesday, May 5, 2026, at the Grand Hyatt in Washington, DC.

About The American Council of Engineering Companies (ACEC)
The American Council of Engineering Companies (ACEC) is the business association of America’s engineering industry, representing more than 5,200 independent engineering firms and more than 600,000 professionals throughout the United States engaged in the development of America’s transportation, water, and energy infrastructure, along with environmental, industrial, and other public and private facilities. Founded in 1906 and headquartered in Washington, D.C., ACEC is a national federation of 51 state and regional organizations.