(1) In addition to appropriate material required under subchapter 3, any plan for underground mining must include the following:

(a) a detailed description, with appropriate drawings, of permanent entry seals and down-slope barriers designed to ensure stability under anticipated hydraulic heads developed while promoting mine inundation after mine closure for the proposed mine plan area;

(b) descriptions, including appropriate maps and cross-section drawings, of the proposed disposal methods and sites for placing waste and excess spoil generated at surface areas affected by surface operations and facilities. Each plan must describe the geotechnical-investigation, design, construction, operation, maintenance and removal, if appropriate, of the structures and be prepared according to ARM 17.24.313, 17.24.320, 17.24.505, 17.24.510, and 17.24.520;

(c)(i) a complete subsidence control plan for the proposed operation which must include:

(A) a map of the proposed underground workings;

(B) the proposed technique of coal extraction, such as longwall, room and pillar, hydraulic mining, or other methods;

(C) a description of the sequence and timing for the development of the underground workings;

(D) a description of the physical and geological conditions, such as depth of cover, seam thickness, and lithology of overlying strata, affecting the subsidence potential;

(E) an analysis of the amount and lateral extent of planned or controlled subsidence anticipated, using acceptable geotechnical practices, including specific methods proposed for the control of subsidence;

(F) a survey, including a map at 1":400' scale or larger as determined by the department and a narrative, which shows the location and type of all structures, renewable resource lands, and domestic water supplies within the permit area and adjacent areas, and whether subsidence, if it should occur, could cause material damage or diminish the reasonably foreseeable use of such structures or lands, or could contaminate, diminish, or interrupt such domestic water supplies; and

(G) of the structures and domestic water supplies identified in (1)(c)(i)(F) (the structure survey requirements of ARM 17.24.911(4) notwithstanding), a survey of the condition of all non-commercial buildings or occupied residential dwellings and structures related thereto, and a determination, in accordance with ARM 17.24.304(1)(e) and (1)(f), of the quality and quantity of all domestic water supplies.

(I) The applicant must submit copies of the results of this survey and determination to the surface owner of the land where the above structures and domestic water supplies are found, as well as to the department.

(II) If the applicant cannot make this survey and determination because the surface owner will not allow access, the applicant must notify the surface owner, in writing, of the effect that denial of access will have on the rebuttable presumption of causation of subsidence as stated in ARM 17.24.911(8)(b). This notification must be documented in the application;

(ii) If the plan shows that no such structures or renewable resource lands, or domestic water supplies exist, or that no such material damage or diminution of the reasonably foreseeable use of such structures or lands, and no contamination, diminution, or interruption of such water supplies would occur as a result of mine subsidence, and if the department agrees with such conclusion, no further information must be provided in the application under this section;

(iii) In the event the survey shows such structures, renewable resource lands, or water supplies exist, and that subsidence could cause material damage or diminution of value or foreseeable use of the land or contamination, diminution, or interruption of such water supplies, or if the department determines that such damage or diminution or contamination, diminution, or interruption could occur, the application must include the following information:

(A) a detailed description of the measures to be taken to prevent subsidence and subsidence-related damage, including:

(I) the anticipated effects of planned subsidence, if any, and a map of the proposed underground mine workings which shows the location and extent of the areas in which planned-subsidence mining methods will be used and that identifies all areas where the measures in (1)(e)(i)(C) will be taken to prevent subsidence-related damage;

(II) measures, if any, to be taken in the mine to prevent subsidence including, but not limited to, such measures as backstowing or backfilling of voids, leaving support pillars of coal, and areas in which no coal removal is planned, including a description of the overlying area to be protected by leaving coal in place;

(III) measures to be taken on the surface to prevent material damage or diminution of the value or the reasonably foreseeable use of structures or the surface, including such measures as reinforcement of sensitive structures or features, installation of footers designed to reduce damage caused by movement, change of location of pipelines, utility lines, or other features, relocation of movable improvements to sites outside the angle-of-draw, and monitoring to determine the commencement and degree of subsidence so that other appropriate measures can be taken to prevent material damage in accordance with ARM 17.24.911. For areas where planned subsidence is proposed, written consent or request by the owners of non-commercial buildings and occupied residential dwellings and structures related thereto that material damage prevention measures should not or need not be taken may be provided in lieu of a description of prevention measures to be taken;

(B) a detailed description of the measures to be taken to mitigate the effects of any material damage or diminution of value or foreseeable use of lands that may occur, including one or more of the following:

(I) restoration or rehabilitation of structures and features, including approximate land-surface contours, to premining condition;

(II) replacement of structures and water sources adversely affected by subsidence;

(III) purchase of structures prior to mining and restoration of the land after subsidence to a condition capable of supporting and suitable for the structures and foreseeable land uses; and

(IV) purchase of non-cancelable insurance policies payable to surface owner in the full amount of the possible material damage or other comparable measures;

(C) a detailed description of measures to be taken to determine the degree of material damage or diminution of value or foreseeable use of the surface, including such measures as:

(I) the results of presubsidence surveys of all structures and surface features that might be materially damaged by subsidence;

(II) monitoring proposed to measure deformations near specified structures or features or otherwise as appropriate for the operation;

(D) any other information that the department deems necessary to demonstrate compliance with ARM 17.24.911;

(d) location of each water and subsidence monitoring point;

(e) location of each facility that will remain on the proposed permit area as a permanent feature, after the completion of underground mining operations;

(f) a description of the design, operation and maintenance of any proposed processing waste disposal facility, including flow diagrams and any other necessary drawings and maps, for the approval of the department and the mine safety and health administration;

(g) a description of the source and quality of waste to be stowed, area to be backfilled, percent of the mine void to be filled, method of constructing underground retaining walls, influence of the backfilling operation on the active underground mine operations, surface area to be supported by the backfill, and the anticipated occurrence of surface effects following backfilling, including:

(i) a description of the source of the hydraulic transport mediums, method of dewatering the placed backfill, retention of water underground, treatment of water if released to the surface; and

(ii) a description of each permanent monitoring well to be located in the backfilled area, the stratum underlying the mined coal, and gradient from the backfilled area.

(h) a complete description, where applicable, of any hydraulic mining or transport system for coal, including:

(i) the source of the hydraulic medium;

(ii) methods for dewatering the coal;

(iii) methods for control or containment of water underground; and

(iv) treatment of water to be released at the surface, if any.

(2) The requirements of (1)(g) and (h) also apply to pneumatic backfilling operations, except where the operations are exempted by the department from requirements specifying hydrologic monitoring.

History: 82-4-205, MCA; IMP, 82-4-222, MCA; NEW, 1980 MAR p. 725, Eff. 4/1/80; AMD, 1989 MAR p. 30, Eff. 1/13/89; TRANS, from DSL, 1996 MAR p. 2852; AMD, 1999 MAR p. 811, Eff. 4/23/99; AMD, 1999 MAR p. 2768, Eff. 12/3/99; AMD, 2004 MAR p. 2548, Eff. 10/22/04; AMD, 2012 MAR p. 737, Eff. 4/13/12; AMD, 2024 MAR p. 258, Eff. 2/10/24.