Mike Bolf, P.E. Michigan Department of Environmental Quality Office of Drinking Water & Municipal Assistance Outline • Why are the rules necessary? • Basic concepts • Brief history backflow prevention regulations • Who do the rules apply to? • What are the program basics? • Useful references What do these things have in common? (cid:151) Lawn sprinkling system (cid:151) Air conditioning system (cid:151) Metal plating factory (cid:151) Home water purification system All have caused illness or death by accidently contaminating a public water supply! Why are these rules necessary? To protect public health What is a Cross-Connection? “A connection or arrangement of piping or appurtenances through which a backflow could occur.” Or “Any piping arrangement which allows a potable water system to be connected to a non-potable system.” Backflow The undesirable reversal of flow of water or other substances into the potable water distribution supply. It can be caused by backpressure, backsiphonage or combination of both. Backflow Backsiphonage Backpressure What’s wrong with these pictures? History of MI’s Drinking Water Regulations The Waterworks and Sewerage Systems Act 98, P.A. 1913 (cid:151) Promulgated August 15, 1913 (cid:151) Department of Health authority (cid:151) Included water supply First Cross Connection Rules (cid:151) December 1938: x-conn regulations adopted by the Advisory Council of Health (cid:151) No connection shall be installed or maintained between a potable public supply and pipes, pumps, or tanks supplied or possible of being supplied, from any non-potable source