According to a city press release,
On May 27th, 2022 around 8:45 pm, until May 27th, 2022 at around 10:35 pm, the City of Flint Water Pollution Control Facility discovered a discharge of raw sewage/filter press filtrate from the Northwest pump station.
The cause of the discharge is still being investigated since Northwest Pump Station is currently under renovations and the station is being bypassed. The discharge has now ended.
As a precautionary measure required by law, the State of Michigan Department of Environment, Great Lakes, and Energy (EGLE) has been notified, as well as officials of Flint Township and Flushing.