Section 312IAC13-10-2. Permanent abandonment of wells

   (a) A well abandoned before January 1, 1988, must be sealed at or above the ground surface by a welded, threaded, or mechanically attached watertight cap. The well shall be maintained so the well does not become a source or channel of ground water contamination. A well that poses a hazard to human health must also be plugged under subsection (c). A cased or uncased bucket well or a hand dug well (other than buried slab construction) that was abandoned before January 1, 1988, shall be closed in conformance with one (1) of the following procedures:

(1) Covered with a reinforced concrete slab:

(A) at least four (4) inches thick; and

(B) having a diameter larger than the nominal diameter of the borehole or the well casing.

(2) Equipped with a properly reinforced cover:

(A) constructed of pressure treated lumber;

(B) having dimensions larger than the nominal diameter of the borehole or well casing; and

(C) protected against the water with roofing or other water repelling materials that are properly maintained to ensure the integrity of the cover.

Closure shall not be performed under this subdivision, however, if the cover is in direct contact with ground water or surface water.

(3) Closed as otherwise approved by the division.

  (b) A well drilled before January 1, 1988, and abandoned before January 1, 1994, shall be as follows:

(1) Sealed at or above the ground surface by a welded, threaded, or mechanically attached watertight cap.

(2) Maintained so the well does not become a source or channel of ground water contamination.

A well that poses a hazard to human health must also be plugged under subsection (c).

  (c) A well abandoned after December 31, 1987, shall be plugged by a water well driller or water well pump installer with an impervious grouting material to prevent the following:

(1) Migration of materials or fluids in the well.

(2) Loss of pressure in a confined aquifer.

  (d) A well drilled after December 31, 1987, and not equipped with casing must be plugged by a water well driller within seventy-two (72) hours after completion.

  (e) This subsection applies as follows to a cased or uncased well abandoned after December 31, 1987:

(1) The plugging material must consist of one (1) or a combination of the following:

(A) Neat cement with not more than five percent (5%) by weight of bentonite additive.

(B) Bentonite slurry, which can include polymers designed to retard swelling.

(C) Pelletized, medium grade, or coarse grade crushed bentonite.

(D) Other materials approved by the commission.

(2) The following methods apply:

(A) Cement and bentonite slurries shall be pumped into place in a continuous operation with a grout pipe introducing the plugging material at the bottom of the well and moving the pipe progressively upward as the well is filled.

(B) Plugging materials other than neat cement or bentonite slurry shall be installed in a manner to prevent bridging of the well or borehole. The well or borehole shall be measured periodically throughout the plugging process to ensure that bridging does not occur.

(3) The following procedures apply:

(A) An abandoned well shall be disconnected from the water system. Any substance that may interfere with plugging shall be removed, if practicable.

(B) A well, other than:

(i) a monitoring well;

(ii) a dewatering well; or

(iii) an uncased borehole;

shall be chlorinated before abandonment as provided in 312 IAC 13-9-1.

(4) Unless otherwise approved by the department, a cased well shall be plugged as follows:

(A) With neat cement, bentonite slurry, or medium grade or coarse grade crushed or pelletized bentonite from the bottom of the well to within two (2) feet below the ground surface.

(B) The well casing shall be severed at least two (2) feet below the ground surface, and a cement plug larger in diameter than the borehole shall be:

(i) constructed over the borehole; and

(ii) covered with natural clay material to the ground surface.

(5) An uncased well (other than a borehole drilled by a bucket rig or a dewatering well governed by subdivision (8) or (9)) shall be filled with:

(A) natural clay materials;

(B) neat cement;

(C) bentonite slurry; or

(D) medium grade or coarse grade crushed or pelletized bentonite;

from the bottom of the borehole to a depth of not less than twenty-five (25) feet below ground surface. The borehole shall be filled with neat cement or medium grade or coarse grade crushed or pelletized bentonite from a depth not less than twenty-five (25) feet below ground surface to within two (2) feet below ground surface. The remaining borehole shall be filled with natural clay material to ground surface.

(6) A cased or uncased monitoring well shall be plugged from the bottom of the well or borehole to the ground surface with a:

(A) bentonite slurry; or

(B) pelletized or coarse grade crushed bentonite.

(7) A bucket well shall be plugged as follows:

(A) A bucket well installed as buried slab construction shall be filled with gravel from the bottom of the well to within ten (10) feet below the ground surface. Neat cement, bentonite slurry, or pelletized, medium grade, or coarse grade crushed bentonite shall be installed in the casing or well pipe from not less than ten (10) feet below the ground surface to within two (2) feet below the ground surface. The well pipe shall be:

(i) severed at least two (2) feet below the ground surface; and

(ii) covered with a cement plug larger in diameter than the well pipe.

The remaining hole shall be filled with natural clay material to the ground surface.

(B) Bucket well construction:

(i) using casing with an inside diameter of less than twelve (12) inches extending the entire length of the borehole; and

(ii) equipped with a well screen;

shall be abandoned under subdivision (4)(A).

(C) An uncased borehole drilled by a bucket rig shall be filled with natural clay material:

(i) from the bottom of the hole to the ground surface; and

(ii) thoroughly tamped to minimize settling.

(D) For other than buried slab construction, a bucket well shall be filled with gravel from the bottom of the well to at least five (5) feet below ground surface. The top section of the concrete or tile well casing shall be removed to cause the top of the well to terminate below ground surface. The well shall be filled with at least one (1) foot of:

(i) neat cement;

(ii) bentonite slurry; or

(iii) pelletized, medium grade, or coarse grade crushed bentonite;

from at least five (5) feet below ground surface to the top of the well casing. The well casing shall be covered with a cement plug larger in diameter than the borehole. The remaining hole shall be filled with natural clay material to ground surface.

(8) If a dewatering well casing is removed following use, the remaining borehole shall initially be filled with granular, pelletized, medium grade, or coarse grade crushed bentonite a minimum of one (1) foot thick. The remainder of the borehole shall be:

(A) filled with natural earth materials obtained during the drilling process to the ground surface; and

(B) thoroughly tamped to minimize settling.

(9) If a dewatering well casing is removed following use and the well site will be excavated as part of the construction project, the remaining borehole shall be:

(A) filled with natural earth materials obtained during the drilling process to the ground surface; and

(B) thoroughly tamped to minimize settling.

  (f) The division shall be notified in writing of a well abandonment within thirty (30) days after plugging is completed. (Natural Resources Commission; 312 IAC 13-10-2; filed Nov 22, 1999, 3:34 p.m.: 23 IR 773; readopted filed Aug 4, 2005, 6:00 p.m.: 28 IR 3661; filed Jul 14, 2006, 1:23 p.m.: 20060809-IR-312050341FRA; errata filed Apr 13, 2010, 2:06 p.m.: 20100428-IR-312100231ACA; readopted filed May 20, 2011, 3:28 p.m.: 20110615-IR-312110002RFA; filed Dec 20, 2011, 1:55 p.m.: 20120118-IR-312110332FRA)