Section 812.31. Pitless adapters and pitless units.

  Pump installers or persons installing pumps shall use pitless adapters or pitless units approved by the department to make subsurface connections to wells. Nonpressure conduits may not be used, unless a variance is granted by the department.

(1)   Department approval criteria. The design criteria on which pitless adapter or pitless unit approvals are based include, but are not limited to, materials of construction, thickness of pipe or tubing, thickness of other component parts, method of fabrication, method of connection and the integrity of the seal to the well casing pipe. The department may require additional standards and tests, including minimum pressure test performance, that the department deems necessary to demonstrate the sanitary integrity of any adapter or unit submitted for department approval. A list of approved models is available from the department. Pitless receiver tanks, factory-assembled pitless units, both short and full length models are depicted in figures 25 to 28.

(2)   General requirements.

(a) A pitless subsurface pipe connection to a well casing pipe shall be made with an approved weld-on, clamp-on, bolt-on or bolt-through pitless adapter or with an approved pitless unit, except that a bolt-through adapter may only be installed for a well constructed with polyvinyl chloride well casing pipe that has a permanently attached well screen. A clamp-on, bolt-on or bolt-through pitless adapter may only be installed for a well that will serve a single family residence. Weld-on adapters or pitless units shall be welded or threaded to the well casing pipe according to sub. (3) or (4) . All welding shall be performed in accordance with s. NR 812.18 . A pitless adapter or pitless unit shall be installed according to any approval conditions and according to the manufacturer's instructions.

(b) The inside diameter of a pitless unit may not be smaller than the inside diameter of the well casing pipe. No part of a pitless adapter may extend into the inside of the well casing pipe, except that a bolt-through pitless adapter may be installed for a well with polyvinyl chloride well casing pipe having a permanently attached screen.

(c) An above-ground discharge shall be provided for all school and high capacity wells except that an approved pitless unit or an approved weld-on pitless adapter may be installed if the welded or threaded joints are pressure tested for leakage as depicted in figure 29 or by a comparable testing procedure. The adapter or unit joints shall be tested and proven watertight under a pressure of not less than 14 psig. The pressure shall be maintained for at least 30 minutes. The pump installer shall notify the department at least 24 hours before testing, so that a department employee may witness the test.

(d) An above-ground discharge shall be provided for crystalline (granite) bedrock wells approved for installation of 25 or less feet of well casing pipe. When installing the above-ground discharge, the required neat cement grout surrounding the well casing pipe may not be removed.

(3)   Pitless unit connections to steel well casing pipe.

(a) When a well casing pipe is not terminated at the desired depth for the installation of an approved factory assembled pitless unit, the well casing pipe shall be cut off at the desired height, and the pitless unit may be welded or threaded and coupled to the top of the well casing pipe by one of the following methods:

1. Cutting off the well casing pipe squarely, providing a bevel for the top of the well casing pipe and welding the beveled end of the unit to the beveled end of the well casing pipe.

2. Cutting threads on the top of the well casing pipe with a pipe die and threading a full-standard recessed coupling watertight to the threaded end of the unit and to the top of the well casing pipe.

3. Welding a pipe nipple, having threads on one end, beveled on the other end and meeting the requirements of s. NR 812.17 (2) , to the cut off top beveled end of the well casing pipe and threading a full-length standard recessed coupling watertight to the threaded end of the unit and to the nipple. The top of the well casing pipe and the bottom of the pipe nipple to be welded shall both have beveled ends. If the pitless unit has female threads, the unit may be threaded watertight directly to the threaded end of the nipple.

4. Reaming out the threads of a full standard recessed coupling, at least 1/3 the length of the coupling, and welding the coupling to the top of the cut-off well casing pipe with a fillet weld on the inside or the outside contact surface of the coupling.

(b) When installing an approved factory assembled pitless unit, the following restrictions shall be followed:

1. The threaded lower end of a pitless unit may not be welded to the cut-off end of a well casing pipe.

2. The threaded ends of a short model, factory-assembled pitless unit may not be welded to the top of a cut-off well casing pipe nor to the section of riser pipe extending from the unit to ground grade, except that the unit may be welded to the cut-off well casing pipe and to the riser pipe if the ends of the unit, the well casing pipe, and the riser pipe are cut and beveled according to par. (a) 1.

3. Factory-assembled pitless units, including those fabricated with pitless receiver tanks, may not be connected to the well casing pipe by means of a compressible joint.

(4)   Pitless unit and pitless adapter connections to thermoplastic well casing pipe.

(a) Steel well casing pipe, pitless units or pitless adapters may not be welded after they are attached to thermoplastic well casing pipe. The thermoplastic coupling shall be threaded onto the pitless unit before it is solvent cemented to the top of the thermoplastic well casing pipe. This is depicted in Figure 31.

(b) Only approved lubricant specifically intended for use with thermoplastic well casing pipe may be used with threaded couplings used for pitless units and pitless adapters. A threaded joint shall be tightened no more than one full turn using a strap wrench.

(c) Threaded couplings may only be used for installation of pitless units or pitless adapters after placement of the well casing pipe.

(d) The portion of the well casing pipe above a short length pitless unit shall be steel or thermoplastic well casing pipe meeting the requirements of s. NR 812.17 .

(e) When thermoplastic well casing pipe is extended above the ground surface, the thermoplastic pipe may be contained in a pumphouse or in an oversized steel pipe extending from below the frost depth to the top of the thermoplastic pipe.

(f) A permanent tag bearing the message “plastic well casing pipe" shall be attached to the top of the well.

(5)   Pitless receiver tanks. Pitless receiver units shall be approved by the department.

(a) Steel buried tanks that are part of an approved pitless unit shall have a minimum wall thickness of 1/4-inch and shall have an identifying seal, label or plate showing the manufacturer's name and model number.

(b) An approval shall be obtained for the installation of a buried pitless receiver tank having a gross volume greater than 1,000 gallons.

History: Cr. Register, January, 1991, No. 421 , eff. 2-1-91; am. (intro.), (1), (2) (a), (b) and (d), (3) (a) 3., (5) (a) and Figure 28, cr. (5) (intro.), Register, September, 1994, No. 465 , eff. 10-1-94; CR 13-099 : am. (2), (4) (e) Register September 2014 No. 705 , eff. 10-1-14.

Note

In areas especially prone to lightning strikes to wells having submersible pumps, the department will grant variances to the prohibition against nonpressure conduits. Microsoft Windows NT 6.1.7601 Service Pack 1 - See PDF for diagram Figure 23. Examples of sanitary well seals. Microsoft Windows NT 6.1.7601 Service Pack 1 - See PDF for diagram Figure 24. Well seals for high capacity wells with submersible pumps. Microsoft Windows NT 6.1.7601 Service Pack 1