NR 812.26(5)(b)(b) Removal of obstructions prior to filling and sealing. All debris, pumps, piping, ungrouted liner pipe, and any other obstruction known to be in the well or drillhole shall be removed if possible before the well or drillhole is filled and sealed. When a pump is stuck within the well, a reasonable attempt shall be made using the best available technology to pull it out. If the pump cannot be pulled, a tremie pipe shall be placed in the well to a depth just above the top of the pump and neat cement grout shall be pumped in to entomb the pump and fill and seal the entire well.

NR 812.26(5)(c)(c) Circulation of drilling mud in fractured formations. In a highly fractured or highly permeable geologic formation, sodium bentonite drilling mud may be circulated in the drillhole or in the well prior to the filling and sealing procedures.

NR 812.26(5)(d)(d) Use of a tremie pipe. The sealing material to be used to fill and seal a well or drillhole greater than 3 inches in diameter shall be placed through a tremie pipe or by means of a dump bailer except when bentonite chips or bentonite pellets are used. Tremie pipe shall meet the requirements specified in s. NR 812.11 (2). The bottom end of the tremie pipe shall be submerged in the filling and sealing material as the grouting proceeds.

NR 812.26(5)(e)(e) Wells or drillholes with inadequate grouting or sealing of the annular space. Wells or drillholes with inadequate grouting or sealing of the annular space outside the well casing pipe or liner shall be filled and sealed. Techniques are situation dependent and may include reaming a new annular space outside the well casing pipe, use of pressure grouting methods, or perforation of the well casing pipe. When perforation of the well casing or liner pipe is undertaken, it shall be done in accordance with the requirements specified in par. (i).

NR 812.26(5)(f)(f) Termination of filling and sealing material. The well casing pipe and filling and sealing material may be terminated as much as 3 feet below the ground surface or to a depth below any future building foundation at the time of the filling and sealing procedure.

NR 812.26(5)(g)(g) Perforation of casing or liner. Well casing or liners with ungrouted annular spaces that cannot be removed from the well or drillhole shall be perforated or ripped in place prior to filling and sealing. When an ungrouted casing or liner is perforated or ripped in place prior to filling and sealing, it shall be completed in accordance with all the following procedures:

NR 812.26(5)(g)1.1. The casing pipe or liner shall be perforated using projectiles fired perpendicular to the length of the string of pipe. The perforations shall extend completely through the casing or liner pipe. As an alternative, the casing pipe or liner may be vertically ripped.

NR 812.26(5)(g)3.3. Each perforation shot shall be a minimum of 0.4 inches in diameter. Each rip shall have a minimum width of 0.25 inches and a minimum length of 12 inches.

NR 812.26(5)(g)4.4. The orientation of each successive perforation shot or rip shall be rotated by 90 degrees along the string of pipe.

NR 812.26(5)(g)5.5. After the well casing or liner has been perforated or ripped, the well shall be filled completely with neat cement from the bottom up to the ground surface. The well shall be filled both inside and outside the string of casing or liner pipe using a pressure grouting method in accordance with the requirements specified in s. NR 812.20.

NR 812.26(5)(h)(h) Well or drillhole casing pipe. Except as provided under par. (i), (j), or (k), the well casing pipe or drillhole casing pipe shall be left in place when a well or drillhole is filled and sealed. When the well or drillhole casing pipe is removed under par. (i), (j), or (k), the well or drillhole shall be completely filled and sealed with the sealing material as the well casing pipe is pulled or before it is pulled. Any concrete or neat cement grout that settles in the well or drillhole when the well or drillhole casing pipe is removed shall be replaced.

NR 812.26(5)(i)(i) Dry drillholes. Well casing pipe may be removed from a dry drillhole and reinstalled in a well on the same property within 30 days of original drillhole construction.

NR 812.26(5)(j)(j) Reconstruction ordered by the department. Well casing pipe may be removed from a well or drillhole as part of reconstruction ordered or requested by the department. The well casing pipe may only be reinstalled on the same property if the reconstruction takes place no later than 120 days after the original construction.

NR 812.26(5)(k)(k) Dewatering wells or drillholes. Well casing pipe may be removed from a dewatering well or a drillhole. The removed well casing pipe may only be reused for dewatering wells.

NR 812.26(5)(L)(L) Gravel packs. When a well has a gravel pack that extends up to or within 20 feet of the ground surface, at least the top 20 feet of the gravel pack shall be jetted out or removed in some other manner. Once the gravel pack has been removed, the open annular space shall be filled and sealed with neat cement grout or concrete applied with a pressure method injected through a tremie pipe.

NR 812.26(5)(m)(m) Well pits. When a well terminating in a pit is filled and sealed, the pit shall also be filled and sealed, except when the pit is an alcove or if the pit will only be used for the purpose of housing valves and the pit complies with s. NR 812.36 (1). The filling of a well pit shall meet all of the following requirements:

NR 812.26(5)(m)4.4. The pit shall be filled and sealed with clean native soil less permeable than the soil surrounding the pit.

NR 812.26(5)(n)(n) Nonpressurized conduits. When wells having nonpressurized conduits are filled and sealed, the basement end of the conduit shall be permanently sealed with a watertight cap or seal.

NR 812.26(6)(a)(a) General. Once obstructions have been removed from a well or a drillhole, the well or drillhole shall be filled and sealed, from the bottom up with the use of a tremie pipe, except where the use of a tremie pipe is specifically exempted. As allowed in this section, all materials used to fill and seal wells and drillholes shall meet the specifications of s. NR 812.11 (15).

NR 812.26(6)(b)(b) Use of bentonite chips or pellets. Bentonite chips or pellets may be used to fill and seal wells and drillholes, subject to all of the following restrictions:

NR 812.26(6)(b)2.2. The total depth may not be deeper than 500 feet and the number of feet of standing water in the well or drillhole may not be more than 350 feet.

NR 812.26(6)(b)3.3. Bentonite chips or pellets may not be used for any well or drillhole filled with drilling mud or bentonite slurry.

NR 812.26(6)(b)4.4. Any bentonite chips or pellets placed below the water table shall be screened and poured in a manner that prevents bridging.