Miller: 'Tsunami' of waste, human error caused 2016 sinkhole
Clinton Township — Engineering experts have concluded the 2016 sinkhole crisis along 15 Mile on the Fraser-Clinton Township border was a result of “human error” that occurred about two years earlier, Macomb County Public Works Commissioner announced Wednesday.
A resident on Eberlein Street made a 911 call on Dec. 24, 2016, to report a “popping” sound outside their house. The sound was of bricks breaking as the house was sinking, Commissioner Candice Miller told reporters at a morning press conference.
The Macomb Interceptor Drain at the location had collapsed, causing a 100-foot wide, 250-foot long sinkhole. It prompted the evacuation of 22 homes in the area. The repair project, initially estimated at three years, was done in less than a year. The 4,000 feet of installed pipe and related studies led to a $75 million bill.
Miller said a national underground engineering expert, Gary Brierley, has studied the incident and concluded from engineering studies that the problem resulted from earlier repair work in the area in May 2014.
A gate, which permits sewage and waste, was closed to allow workers inside the pipe, but once their work was done, the gate was opened, creating a “tsunami” of waste all at once, rather than a gradual release at the 11-foot diameter to eight-foot diameter interceptor.
“The opening of the gate is supposed to be done gradually, but records show it was opened all at once,” Miller said.
The sudden surge caused hairline fractures in the pipe, which over time, drew sand from outside the pipe into the flow and creating a “void” of supporting soil that eventually collapsed.
Miller said she agrees with Brierley’s assessment. She said no explanation has been offered for why protocol was not followed in the sewage gate opening.
“Accidents happen,” Miller said. “This is what you have insurance for, and we will be filing a claim to recover as much as reasonably possible in a settlement for our repairs. We hope the insurance company is reasonable, and if not, we will be taking this to litigation in Macomb Circuit Court.
“If I was at the insurance company, I would be sharpening my pencils.”
Dan Heaton, a spokesman for Miller, said three contractors involved in the “human error” have been notified of claims from Macomb County Public Works for a settlement of $75 million in repairs would be made with their insurance carriers.
Heaton said Wednesday he did not have the names of the insurance companies.
Miller said she would seek a reasonable settlement, which might not include full restitution.
Miller said the incident has caused her engineers to do a system-wide study of aging underground pipes in hopes of heading off similar problems elsewhere.