ANN ARBOR – An estimated 50 gallons of sanitary sewage was released onto South Main Street on Wednesday morning after a contractor’s attempt to divert the sanitary sewer flow failed. This is the second incident to occur at the same site since Feb. 22, when an estimated 10,000 gallons of sewage was released onto South Main Street as a result of a failure during an ongoing sanitary sewer relining project. “The pipe was diverting sanitary sewer flow while the contractor cleaned the sanitary sewer main in advance of lining the pipe,” reads a news release. The contractor will be charged with all costs to the city related to the incident. The city of Ann Arbor notified the Michigan Department of Environment, Great Lakes and Energy of the incident, in accordance with protocols.