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West Side/East Side CSO Project, Portland, OR

WCSO Contractor: Impregilo/Healy JV
ECSO Contractor: Kiewitt Billfinger Berger JV

Often referred to as the “Big Pipe Project,” the Combined Sewage Overflow project is the biggest and most expensive capital construction project in Portland’s histroy. Part of a 20 year, $1.4 billion projects, a 4.2 mile long, 16ft diameter tunnel was built to divert combined stormwater and sewage overload, going undering the Willametter River to a pump station. AZH Consultine Engineers by hired by the contractor to provide much engineering and contractor support at many stages of the construction. Our work included design and/or review of temporary structures, fabrication buildings, crane supports, large 150 ft deep shaft steel stairs, temportary pipe and bulkhead supports, retining walls, footings and much more, over a 5 year period.