City of Mercer Island - Mercer Island Sewer Line and Pump Station #4 Replacement

The existing sewer line on the northwest corner of Mercer Island was installed in the mid-1950s, and is constructed of asbestos-cement (AC) material. The line has been suffering ongoing pipeline deterioration, capacity deficiencies, and other operation and maintenance problems. Manson Construction was awarded the contract to replace this portion of the sewer line with cast iron pipe and selected us to provide the diving services. This project will extend over a two-year period and involves the replacement of over 7,000 feet of pipe with 32 side sewer connections.

We are working very closely with Manson during all aspects of the project, including: installing both gravity and force main pipes, aligning and connecting the side sewer piping, assisting with hand dredging under docks and in tight areas where the derrick cannot access, and making the physical transition from the existing line to the new piping.