Section R. 325.10828 - Casing vents; sampling tap; relief valvesRule 828.
(1) Casing vents shall be both of the following: (a) Provided on all wells and constructed to prevent the entrance of contaminants into the well.(b) Extended to the outside atmosphere above the roof level if toxic or flammable gases are present.(2) Provisions shall be made for collection of raw water samples by installation of a proper sampling tap in a convenient location as close to each well as possible. Provisions shall be made for collection of finished water samples by installation of a proper sampling tap at each entry point to the distribution system.(3) Air vacuum relief valves, where used, shall be constructed to prevent entrance of contaminants into the well.Mich. Admin. Code R. 325.10828