Fremont Siphon Replacement and Odor Control Facility
Construct the replacement to the existing Fremont Siphon and construct a new odor control facility.
Construction of two parallel 60-inch nominal inside diameter siphon pipes, via microtunneling methods, under the Lake Washington Ship Canal. Each of the two pipes were approximately 465 feet in length.
Construction of ground support, and dewatering associated with microtunnel launch and retrieval shafts approximately 80 feet deep.
Replacement of approximately 130 linear feet of a 30-inch inside diameter combined sewer overflow outfall pipe and associated manholes
Construction of two structures and 108-inch inside diameter pipe to connect the new siphon to the existing Interceptor pipeline.