TRAVERSE CITY, Mich. — Three chemical companies said Friday they had reached a $1.18 billion deal to resolve complaints of polluting many U.S. drinking water systems with potentially harmful compounds known as PFAS.DuPont de Nemours Inc., The Chemours Co. and Corteva Inc. said they would establish a fund to compensate water providers for contamination with the chemicals used widely in nonstick, water- and grease-resistant products, as well as some firefighting foams.Described as “forever chemicals&rdquo …