ANN ARBOR, MI – The city of Ann Arbor has reported yet another raw sewage spill into the Huron River.

At about noon on Tuesday, May 16, a sanitary sewer overflow occurred in Nichols Arboretum near the entrance along Nichols Drive by the helipad next to the University of Michigan Hospital, according to the city.

“The overflow of an estimated 100 gallons was the result of a failed bypass pump that backed up flow into a broken sanitary sewer pipe,” the city stated in a news release. “This overflow discharged into the Huron River. Upon notification, the city’s contractor immediately installed a working pump.”

In accordance with regulatory protocols, the city reported the incident to the Michigan Department of Environmental Quality.

The city has been doing sewer rehabilitation work in the Arb recently.