Sewer pipe repairs prevent sinkhole in Warren

WARREN — The discovery of a sinkhole in Warren has led to repairs that may have prevented a bigger problem.

The sinkhole was found last week on 10 Mile Road at Loretta Avenue, west of Mound Road. According to a press release from the Macomb County Public Works Office, an inspection revealed that the bottom of a 30-foot-long portion of a corrugated metal pipe beneath the road had rotted.

“A relatively small or moderate sized sinkhole is an indicator of a significant problem deep below the surface and requires prompt attention to avoid a major infrastructure problem,” the press release states.

The pipe measures 11 feet wide and serves as part of the Bear Creek Drain. Stormwater penetrated the pipe through openings caused by the rotting and as a result, some of the gravel and dirt beneath and around the pipe was washed away, which led to a sinkhole forming, the press release states.

“This sinkhole was right up next to the curb,” Macomb County Public Works Commissioner Candice Miller said in a statement. “It was already a hazard and could have quickly become significantly worse.”

Miller said the pipe was installed 60 years ago and that rotting such as this is something her office is beginning to see more frequently where small sinkholes have occurred.

A contractor was hired to install temporary internal bracing inside the pipe. Workers then used cement to fill the holes at the bottom of the pipe and sinkhole. A coat of geopolymer spray was then used on the interior of the pipe before a carbon fiber grid was installed and a second coating of spray was applied.

“The spray-lining method used by the contractor was efficient with long-term protection of the sewer without the alternative of excavation to reach the rotted pipe, tear it out and replace it with new pipe,” the press release states. “Its use by Macomb County in the Bear Creek Drain and an unrelated sewer rehabilitation project along 15 Mile Road is the first of its kind in Michigan.”

The total cost of the reconstruction and engineering was $230,000.

“It’s a reminder that we need to continue to invest in our aging underground infrastructure by inspecting it, rehabbing it when possible or replacing it when necessary,” Miller said.