Section R. 325.11108 - Distribution system valvesRule 1108.
(1) Sufficient valves shall be provided on distribution systems to minimize interruptions in service and minimize sanitary hazards during construction or repairs.(2) Automatic air relief and automatic vacuum relief valves, if provided on the distribution system, shall be installed and maintained to prevent contaminants from entering the distribution system.(3) Buried stop-and-waste valves on service lines and the installation of other valves with openings subject to flooding are prohibited.Mich. Admin. Code R. 325.11108