June 22 (Reuters) - 3M Co has reached a $10.3 billion settlement with a host of U.S. public water systems to resolve water pollution claims tied to "forever chemicals," the chemical company announced on Thursday. The company said the settlement would provide the funds over a 13-year period to cities, towns and other public water systems to test and treat contamination of per- and polyfluoroalkyl substances, or PFAS. 3M, which is facing thousands of lawsuits over PFAS contamination, did not admit liability, and said the money will help support remediation at public water systems that detect PFAS "at any level."