Wisconsin Administrative Code › Department of Natural Resources › NR 800 - Environmental Protection - Water Supply › Chapter NR 811 - Requirements For The Operation And Design Of Community Water Systems › Subchapter X - Distribution Systems › Section NR 811.72 - Air-relief facilities and valve and meter chambers

Current through June 24, 2024
(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.