Chemical manufacturer 3M has agreed to pay at least $10.3 billion to settle lawsuits over contamination of many U.S. public drinking water systems with potentially harmful compounds known as PFAS. The deal was announced Thursday by the company based in St. Paul, Minnesota, and an attorney representing hundreds of public water systems. 3M is a leading maker of PFAS chemicals used widely in firefighting foams and many nonstick and grease-resistant consumer products. They're described as “forever chemicals” because they don’t degrade naturally in the environment. PFAS compounds been linked to a variety of health problems, including liver and immune-system damage and some cancers.