A look at the 3M lawsuit

The state's lawsuit claimed that 3M knowingly contaminated the drinking water of several east-metro communities, causing up to $5 billion in potential damage to property values, wildlife and human health. The trial, before Hennepin County District Judge Kevin Burke, was expected to last four to six weeks and draw a large audience because 3M and PFCs are the subject of more than 30 other lawsuits around the country.

The company denied wrongdoing, saying it followed the law in disposing of its industrial wastes and that it settled the matter in a 2008 agreement with the state in which 3M agreed to clean up the chemicals and pay for clean drinking water in the affected communities.

PFCs, or perfluorinated chemicals, are manufactured compounds that help consumer products resist stains, grease and water. A key ingredient in Teflon and Scotchgard, they became one of the most widely used chemicals in the world. 3M Co. began making PFCs at a plant in Cottage Grove in the late 1940s, but stopped their production in 2002.

3M dumped the chemicals legally at four sites in Washington County. They have now polluted a 100-square-mile plume of groundwater from Woodbury to the Mississippi River at Hastings.