Manistee River Sewer Improvements

Located on the eastern edge of the Manistee River in the City of Manistee, an interceptor sanitary sewer that feeds sewage to the City’s 6th Avenue pump station was aging and in danger of failing. It was constructed on pilings which were failing, exposed to the elements, and below the water surface elevation of the Manistee River. As the Engineer of Record for the City of Manistee, Spicer Group was asked to review and analyze the problem. This included review of a previously-prepared and permitted project to replace the pump station and the east interceptor, which had not been constructed due to funding.

Spicer Group’s review identified some concerns with using the existing interceptor pipe. Also, discussions with permitting agencies, including US Army Corps of Engineers (USACE), resulted in a need to modify the sea wall construction that would be protecting the new east interceptor. The solution was to replace the existing failing east interceptor along the river with 500 feet of 15-inch PVC gravity interceptor sewer that would be protected with a 400-foot-long steel sheet pile sea wall meeting USACE standards. The new interceptor pipe and seawall were all installed without interrupting freighter traffic within the Manistee River shipping channel.

Spicer Group performed a study including flow monitoring, permitting, preliminary design, final design, bidding, construction inspection, testing, and construction administration services for the project. Due to the work being performed within the Manistee shipping channel, close coordination with MDEQ, US Army Corps of Engineers, Manistee County, the City of Manistee, and the US Coast Guard was required.