Officials in Janesville say tests found E. coli bacteria after flooding overwhelmed sewage treatment plants upstream on the Rock River.
City officials say anyone who touches the flood water that's now so common in southern Wisconsin should scrub with soap and water to prevent the possibility of becoming ill with E. coli.
According to warden Jon King with the state Department of Natural Resources, there are lots of places with the same problem. He says there have been at least 150 of the releases and probably more that haven't yet been reported to the DNR.
It just shows the danger lurking in flood water.
The other big hazard, according to King, is getting caught in the rapidly flowing water, which can easily carry a person away.
Two people have died in Wisconsin after their vehicles went into flood water.