Walnut Creek Water Treatment Plant Pretreatment Project

Project Description WCWTP Site Photo.jpg

The Walnut Creek Water Treatment Plant (WCWTP) is the primary water treatment facility serving approximately 500,000 customers in EBMUD’s east-of-hills service area, which includes portions of Pleasant Hill, Lafayette, Walnut Creek, Alamo, Danville, Blackhawk, and San Ramon Valley. The WCWTP primarily treats Mokelumne River water stored in the Sierra foothills at Pardee Reservoir, but also treats water stored locally in Briones Reservoir.

The WCWTP Pretreatment Project will add improvements to the WCWTP that will allow EBMUD to more reliably treat lower quality untreated water resulting from high rainfall runoff, wildfires, future droughts, algae blooms, climate change and emerging contaminants. The project would also improve treated water taste and odor. Hydraulic changes at the WCWTP would require modification of weir structures at the Lafayette WTP off Mt. Diablo Blvd.

Workplan and schedule   

The project would be designed and constructed in two separate phases.  Phase 1 is planned for construction from 2027 to 2030 and would allow EBMUD to more reliably treat a broader range of water quality up to a capacity of 125 MGD.  Phase 2 would allow EBMUD to treat up to the planned capacity of 160 MGD. The construction timing of the Phase 2 improvements is not firmly established but will depend on untreated water quality conditions in the future and the timing of future demands.   

EBMUD will prepare an Environmental Impact Report (EIR) for this project, beginning with a Notice of Preparation (NOP). The NOP and CEQA Initial Study will be posted to this webpage on February 28, 2022. Written comments on the project should be submitted no later than 4:30 p.m. on March 30, 2022 to: Tom Boardman, Associate Civil Engineer at 375 Eleventh Street, MS 701, Oakland, California 94607, or, by email to wcwtp.pretreatment@ebmud.com.


Kathryn Horn, Community Affairs  
Email: Kathryn.Horn@ebmud.com  
Phone: 510-287-2053   
For after-hours assistance, please contact: 1-866-403-2683

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Published studies and other resources

Document Type Size
WCWTP Pretreatment CEQA_January 2022 PDF 4.5 MB