Section NR 811.72 - Air-relief facilities and valve and meter chambers(1) AIR-RELIEF FACILITIES. If possible, water mains shall be constructed to avoid high points at which air can accumulate. Permanent provisions shall be installed to remove the air by means of air relief valves, hydrants, or blow-offs when high points cannot be avoided. Automatic air-relief valves may not be used in situations where flooding of the manhole or chamber may occur. The open end of an air-relief pipe shall be extended to the top of a manhole or chamber and have a screened, downward facing elbow equipped with a 24-mesh corrosion resistant screen. If a manhole or chamber vent pipe is installed, the vent pipe shall be metal, terminate downward facing a minimum of 24 inches above grade, and be covered with a rodent screen. Air-vacuum and air relief valves and associated discharge piping shall meet the requirements under s. NR 811.37 (5) (a).(2) CHAMBERS. Chambers, pits, and manholes containing valves, blow-offs, meters, or other such appurtenances constructed for use in the distribution system shall meet the following requirements: (a)Location not subject to flooding or high groundwater. If possible, chambers, pits, and manholes containing valves, blow-offs, meters, or other such appurtenances to a distribution system shall not be located in areas subject to flooding or in areas of high groundwater. If location in areas not subject to flooding or in areas of high groundwater is not possible, any valve discharge or structure vent pipes shall terminate a minimum of 24 inches above the ground surface or the high water level, whichever is the higher elevation.(b)Means to allow drainage. Chambers, pits, and manholes containing valves, blow-offs, meters, or other such appurtenances to a distribution system may not be connected directly to any storm drain or sanitary sewer, nor may any blow-offs or air-relief valves be connected directly to any sewer. Chambers shall be drained to absorption pits underground or to the ground surface where they are not subject to flooding by surface water or high groundwater. If electrical power is available, sumps with sump pumps discharging above grade with a down-turned metal pipe and a free air break over grade or over a storm sewer receptacle may also be approved by the department.(c)Installation requirements. If not installed in the road right-of-way or if installed in the road right-of-way in areas with minimal risk from damage due to traffic and maintenance equipment, larger below grade facilities or below grade facilities housing pumps and other electrical equipment shall meet the applicable booster pumping station requirements under s. NR 811.84. In addition, if installed in vulnerable areas of the road right-of-way, the facilities may be constructed with a gasketed, watertight, bolt-down cover at grade if approved by the department.Wis. Admin. Code Department of Natural Resources NR 811.72
CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.Amended by, CR 22-074: am. (1), (2) (c) Register January 2024 No. 817, eff. 2/1/2024