The $3.5-million upgrade to the Cascade filtration plant will help make drinking water safe again for thousands of residents after PFAS was found in two dams supplying water to the plant. The $3.5-million upgrade to the Cascade filtration plant will help make drinking water safe again for thousands of residents after PFAS was found in two dams supplying water to the plant. Water Pollution, Water, Water Supply, Government and Politics, Environmental Health Latest business news