Fremont Siphon Replacement & Odor Control Fac.


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.