A section of a major sanitary sewer line in Clinton Township will undergo a nearly $12 million repair to prevent collapse and a sinkhole, such as one nearly a decade ago along the same line just two to three miles west in Fraser.
The 15 Mile Interceptor carries raw sewage for about 500,000 Macomb County residents. A section of the line about 1½ miles long will be repaired because of severe degradation of the steel-reinforced concrete pipe caused by corrosive sewer gas, according to a release from the county’s Public Works.
The interceptor is part of the Macomb Interceptor Drain Drainage District, which is composed of 11 communities in the county. The drainage district will fund the repair.
There will be no rate increase for the district’s half-million residents for the project, which is expected to be done by January, weather permitting. No service interruptions are expected during repairs.
Public Works Commissioner Candice Miller said there has been a loss of 1.5 inches of concrete pipe that’s “just eaten away.” Her office initiated the project to avoid a sinkhole like the one along 15 Mile in Fraser on Christmas Eve 2016, which destroyed homes and created a pit about the size of a football field.
Public works used an underground drone with artificial intelligence analysis of video footage to assess the deterioration in the Clinton Township section of the line.
It said the degradation was caused by hydrogen sulfide, a dangerous gas created by turbulence of sanitary sewage flowing in the pipe. Inspections of this portion of the pipe in the fall showed degradation happening faster than expected.
The project will cost $11.5 million and includes the lining of the 5-foot-diameter pipe along 15 Mile from two blocks east of Gratiot Avenue to just west of Groesbeck Highway, as well as 268 vertical feet of manhole risers, according to the release.
It said a steel-ribbed, PVC spiral-wound liner will be installed along the inside wall of the pipe, with the product expected to last 50 years.
The installation method requires less construction space. The interlocking PVC strip, measuring about 3 inches wide, is fed from a spool and down a manhole to the inside of the interceptor. Workers guide it by hand into a unique tool, which resembles a bicycle sprocket, that presses the liner up against the inside wall of the pipe as the device turns and locks it in place, according to the release.
The method was used for the first time in Michigan by the public works office in 2023 on the inside of a section of the 7-foot-diameter Garfield Interceptor, below Garfield Road at 21 Mile Road in Macomb Township, to prevent further corrosion. It was also used in another section of the Macomb Interceptor Drain Drainage District system along 15 Mile, just west of Groesbeck to west of Kelly Road, according to public works.
Contact Christina Hall: chall@freepress.com. Follow her on X: @challreporter.
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This article originally appeared on Detroit Free Press: Why nearly $12M is going to fix a sewer line in Clinton Township
Reporting by Christina Hall, Detroit Free Press / Detroit Free Press
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