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 V - Pumping Equipment and Appurtenances › Section NR 811.35 - Pitless units

Current through June 24, 2024
Pitless units shall be installed in a manner to provide
					 equivalent security, sanitary protection, accessibility, and operational
					 flexibility to an above grade pump discharge installation and in accordance
					 with the requirements of this section and as shown in Figure No. 7 in the
					 Appendix.
(1) TERMINATION. Pitless
				  units shall terminate a minimum of 12 inches above a concrete floor as required
				  by ss.
				  NR
				  811.12(1) and
				  811.32(1) (a). If the
				  vent assembly is built into the pitless unit, the portion of the pitless unit
				  where the bottom of the vent assembly is located shall be terminated a minimum
				  of 24 inches above the concrete floor. Pitless units shall be provided with a
				  protective concrete collar where they pass through the concrete floor as
				  required by s.
				  NR 811.32(1)
				  (c). The exterior exposed conduit pipe for
				  the pump wiring shall be rigid steel and the conduit pipe incorporated into the
				  concrete collar.
(2) ENCLOSURE. The
				  exposed portion of a pitless unit shall be surrounded by a weather resistant,
				  watertight, locked, and vented enclosure secured to a concrete floor as
				  required by s.
				  NR
				  811.25(1) (i). The top surface of the
				  concrete floor shall be located a minimum of 6 inches above the finished
				  grade.
(3) APPURTENANCES. The top
				  of the pitless unit shall be sealed sanitarily in accordance with s.
				  NR 811.32(1)
				  (b), provided with a well vent and water
				  level measuring equipment in accordance with s.
				  NR 811.36, and
				  shall be provided with a frost-proof down-turned metal smooth end sampling
				  faucet terminating above the top of the pitless unit and a minimum of 12 inches
				  above the concrete floor of the enclosure unless the sampling faucet is
				  installed remote from the pitless unit in accordance with sub. (6)
				  (h).
(4) DISCHARGE PIPING.
				  Discharge piping from a pitless unit shall meet the following requirements:
(a) The discharge piping from the pitless
				  unit shall be directed to a separate building located above grade where all of
				  the applicable pump discharge piping appurtenances shall be installed in
				  accordance with s.
				  NR 811.37
				  and Figure No. 7 in the Appendix.
(b) The discharge piping from the pump in the
				  well to the above grade pump discharge piping shall remain pressurized at all
				  times. No provisions for drain back of the discharge piping may be allowed. A
				  shut-off valve shall not be installed in the buried portion of the pitless unit
				  discharge piping unless approved by the department as part of a pump-to-waste
				  installation.
(c) The buried
				  portion of a pitless unit discharge piping along with any joints or fittings
				  shall be ductile iron, steel, or plastic piping meeting at minimum the AWWA
				  pressure class 150 water main standards required under s.
				  NR
				  811.69. Plastic piping shall not be used in areas
				  where soil or groundwater contamination may be present. Plastic piping shall be
				  transitioned to metal piping within 12 inches above the floor of the building
				  into which it will be directed, under par. (a), unless minimum schedule 80 PVC
				  pipe is installed in the building as allowed under s.
				  NR 811.28(5)
				  (b).