If someone accidentally connected a wastewater pipe to your drinking water line, yes...
http://www.wral.com/news/state/story/1634438/
http://www.wral.com/news/state/story/1634438/
Cary — Vinay Jain knew his tap water tasted funny, but he wouldn't have guessed his family had been drinking treated wastewater that is supposed to be used for watering lawns.