Deteriorating sewer main leads to street closure

Repairs will affect a portion of Adams Street
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Times Herald Photo by Warren Bluhm

Oconto Falls officials closed off a portion of Adams Street starting June 28 after an estimated 50 yards of sand under the street fell into a sanitary sewer line.

The Oconto Falls City Council declared a state of emergency June 28 along a block of Adams Street where a deteriorating sanitary sewer main appeared to be eating away at the soil underneath the street.

Meeting in a rare emergency session, the council approved replacing approximately 900 feet of aging clay-tile sewer pipe with PVC.

DeGroot Inc. of Green Bay provided an estimate of $81,596.50 to replace the sewer main and related work. Another $11,352 to replace laterals to 13 properties will be billed back to the property owners.

The problem was discovered when the sewer line was televised, a process using a robotic camera attached to a cable to inspect the underground system. Utilities manager Greg Kuhn showed aldermen a video of an area where a portion of pipe had cracked, tree roots had grown in the joints between the pipes, and a section of pipe had given way altogether.

“Our best guess is roots had come through that crack, and when we went through with our root cutter, that grabbed a hold of the roots and then caved the pipe in,” Kuhn said.

The sewer is flowing, but it’s about half full of sand for about 300 feet, he said.

“It’s roughly 50 yards of sand that we’ve lost in the pipe, which leaves a very large void underneath the road,” Kuhn said.

The affected pipe runs down Adams Street from Caldwell Avenue to Monroe, and then under a field that is used as an ice skating rink in the winter across to Cherry Avenue.

DeGroot will do the work as soon as it can, city officials said.

That section of sewer main is old enough that its installation is not in the city’s records, which go back to the 1950s.

“Our best guess is it’s World War II-era, well past its life expectancy,” Kuhn said.

A section of Adams Street from Monroe to Union was already on the city’s street reconstruction plan for 2019 or 2020. Kuhn is recommending that the portion from Monroe to Caldwell Avenue be moved up to 2018.