By SUE SUCHYTA
Sunday Times Newspapers
ROMULUS – A small sinkhole near Wick and Middlebelt roads near Detroit Metropolitan Airport was stabilized over the weekend and has not appeared to increase in size, Wayne County officials said.
The sinkhole is within the Downriver Utility Wastewater Authority. DUWA official Dick Hinshon said Wayne County contracted with Inland Pipe Rehabilitation — Great Lakes April 28 to stabilize the site, and two engineering firms, Hubbell, Roth and Clark, and Applied Sciences Inc. are providing additional support services.
Hinshon said the sinkhole is about 10 feet in diameter and four feet deep. He said the upstream service area is small and contained within Romulus. The 24-inch diameter pipe is about 22 feet below ground, and the sinkhole is near the upstream terminus of a section of the Goddard Interceptor.
While the investigation is still underway, it is suspected that hydrogen sulfide, which occurs when stagnant bacteria allows slime to occur in pipes, forms sulfuric acid and corrodes the calcium carbonate in concrete pipes.
The contractor was not able to run a camera into the pipe beyond six feet due to a clog that blocked passage of the equipment. If the clog cannot be jetted out, excavation down to the interceptor might be needed.
IPR was able to construct a bypass by April 29, Hinshon said, and was able to operate the bypass during weekend rains.
The repairs are budgeted under the fiscal year 2017 emergency sewer repair budget, which also covers the cost of the emergency response and investigation.
The Michigan Department of Environmental Quality has been notified of the situation, and the bypass pumping has, to the best of officials’ knowledge, prevented the release of waste water into the environment.
Hinshon said that given the location of the sinkhole, it is unlikely to damage any structure or road. Repair cost estimate will not be available until the extent of the pipe damage has been determined.
(Sue Suchyta can be reached at [email protected])