Orinda Water Treatment Plant prioritizes climate readiness
The Orinda Water Treatment Plant in California’s East Bay region is undergoing a major renovation with a focus in climate resilience. The $341 million project started in 2022 will provide and protect fresh water for 1.4 million residents in the area. The innovative design team decided to integrate ultraviolet disinfection and a chlorine contact basin to advance the plant’s water treatment processes. On the team is Carollo Engineers, Stantec, Arcadis and FlatironDragados.
The new treatment process allows for filtration to occur first to optimize disinfection to minimize formation of disinfection byproducts. While The Orinda Water Treatment Plant is on a limited lot, with barriers for expansion, the design team quickly adapted. The team took the project and its new UV disinfection system and chlorine contact basin 65 feet below the surface. The complex and advanced engineering system accounted for underground conditions and movement with a geotechnical instrumentation program . This allows the team to monitor for threatening abnormalities.
“The water moves at a consistent rate, providing uniform contact with the disinfectant,” said Peter von Bucher, P.E., a project manager and vice president at Carollo. “It’s a complicated structure, designed to create a wide point in the treatment process that increases the time that water interacts with chlorine. At the end of the process, we add ammonia, which produces chloramine – another step to help limit disinfection byproducts from forming.”
The project is scheduled for completion in 2028.
