City crews discovered a sanitary manhole that appeared to have a recent overflow on Tuesday.

ANN ARBOR – The city of Ann Arbor announced on Tuesday afternoon that the temporary shutdown of all lanes of S. Main Street on Monday was a result of a sanitary sewer overflow. According to the city, a contractor was working on a sanitary sewer relining project in the mid morning when it experienced a by-pass pumping failure. As a result, an estimated 10,000 gallons of sanitary sewage was released onto South Main Street. “The by-pass operation was being done to divert the sanitary sewer while the contractor cleaned the sewer main in advance of lining the pipe,” reads a news release. City of Ann Arbor staff notified the Michigan Department of Environment, Great Lakes and Energy, in observance of regulatory protocols.