Officials are warning people to avoid a roughly 5-mile stretch of the Kalamazoo River after heavy rains led to the overflow of more than 570,000 gallons of partially treated wastewater.
The city of Kalamazoo says the overflow happened Tuesday as heavy rains moved across the state, causing flooding.
Department of Public Services Director James Baker tells WOOD-TV that extra water flowed into a water treatment plant.
He says two pumps were working, but an error in the system meant that it didn't alert staff that a third pump should be operating.
Baker says the water went through nearly all the treatment processes, except chlorination and filtering.
City and county officials are advising people and pets to avoid contact around the affected areas, including parts of the Kalamazoo River.