The City of Ann Arbor issued the following announcement on July 13.
On Friday, July 10, a 42-inch sanitary sewer line was broken while undergoing renovations by a city contractor. An estimated 9,000 gallons of sanitary sewage escaped the pipe into a pit created to facilitate the work and then re-entered the sanitary system through a newly constructed 30-inch sanitary sewer line. No overflows escaped the shaft leading to the new sanitary line nor at any time left the project site, which is located at Fuller and Glen Court. No workers were injured during the incident.
In accordance with regulatory protocols, City of Ann Arbor staff notified the Michigan Department of Environment, Great Lakes and Energy.
Original source can be found here.
Source: The City of Ann Arbor