WATER POLLUTION: Enviros sue utility over sludge dumping in Potomac River Published: Friday, February 14, 2014 Two environmental groups are suing a utility for allegedly dumping sludge and chemicals into the Potomac River. Please subscribe to Greenwire to read the full story. Username: Password: Forgot your access codes? Recover them. Not a subscriber? Sign up for a trial. Ready to subscribe? Click here.