Listen to today's Environment Report.
Researchers have found some kinds of chemicals are harder to filter from water.
These compounds belong to a family called highly fluorinated chemicals. They’re used to make carpets, clothes and cookware stain and water repellant.
They’ve also been used in firefighting foam at military bases and airports. Those chemicals from firefighting foam have contaminated drinking water around the country, including drinking water wells near the former Wurtsmith Air Force Base near Oscoda.