So far this year 25 public beaches on Lake Michigan have had closures due to high bacteria levels. As sewers and septic tanks age, they can leak human waste into streams and lakes - which can make people sick. Some cities and towns are trying to fix this old infrastructure.
But there’s a problem - how do you find out which pipes are leaking? A company founded in Michigan, Environmental Canine Services, uses dogs to sniff out wastewater.