AGS performed a preliminary geotechnical study to aid in the selection and design of the proposed 69-inch diameter water pipeline. Based on AGS’ recommendation one of three proposed alignments was selected.
Client:
East Bay Municipal Utility District
Location:
Walnut Creek - San Ramon, CA
EBMUD serves 1.2 million people in Alameda and Contra Costa Counties. Three Mokelumne Aqueducts import water from the High Sierra watershed of the Mokelumne River, 91.5 miles across the San Joaquin Valley and Delta to direct-filtration water treatment plants [WTPs] in Lafayette, Orinda and Walnut Creek. As part of EBMUD’s San Ramon Valley Water Master Plan, which extends from Walnut Creek to Stone Valley Road in Danville, a new 69-inch diameter water pipeline is planned to extend between Danville Pumping Plant and an existing 84-inch diameter pipeline under North California Boulevard near the Walnut Creek BART station.
During Phase I, AGS performed a preliminary geotechnical study to aid in the selection and design of the proposed 69-inch diameter water pipeline. Based on AGS’ recommendation one of three proposed alignments was selected. Following selection of the project route, AGS performed a final geotechnical study to develop design recommendations. The final report included geologic and geotechnical conclusions and recommendations related to tunnel design, trench design, geoseismic hazards, seismic design parameters, earthwork, and dewatering. The conclusions and recommendations presented in the Phase I report were based on estimation of the subsurface conditions, based on a literature review and a site reconnaissance only. Drilling and laboratory testing were performed specifically for this project during Phase II to provide refinement for geotechnical conclusions and recommendations.