30 CFR 784.30 - When must I prepare a subsidence control plan and what information must that plan include?
(a)Pre-subsidence survey. Each application must include -
(1) A map of the proposed permit and adjacent areas at a scale no smaller than 1:12,000. The regulatory authority may require a larger-scale or more detailed map. The map must show the location and type of -
(i) Structures, renewable resource lands, wetlands, streams, and water bodies that subsidence may materially damage or for which the value or reasonably foreseeable use may be diminished by subsidence; and
(ii) Drinking, domestic, and residential water supplies that could be contaminated, diminished, or interrupted by subsidence.
(2) A narrative indicating whether subsidence, if it occurred, could cause material damage to or diminish the value or reasonably foreseeable use of such structures, renewable resource lands, wetlands, streams, or water bodies or could contaminate, diminish, or interrupt drinking, domestic, or residential water supplies.
(i) A survey of the quantity and quality of all drinking, domestic, and residential water supplies within the permit area and adjacent area that could be contaminated, diminished, or interrupted by subsidence.
(ii) You, the applicant, must pay for any technical assessment or engineering evaluation used to determine the premining quantity and quality of drinking, domestic, or residential water supplies. You may use publicly available assessments conducted for research purposes by a university or government agency, provided those assessments are updated to reflect any changes that have occurred since completion of the study.
(iii) You must provide copies of the survey and any technical assessment or engineering evaluation to the property owner and to the regulatory authority.
(b)Conditions under which no subsidence control plan is needed. You do not need to submit a subsidence control plan if the survey conducted and information provided under paragraph (a) of this section show that -
(2) There would be no material damage or diminution in value or reasonably foreseeable use of structures, lands, or features protected under § 817.121(c) through (e) of this chapter, and no contamination, diminution, or interruption of water supplies protected under § 817.40 of this chapter would occur as a result of mine subsidence, provided that the regulatory authority agrees with this conclusion.
(c)Subsidence control plan.
(2) The subsidence control plan must contain the following information:
(i) A description of the method of coal removal, such as longwall mining, room-and-pillar removal or hydraulic mining, including the size, sequence and timing of the development of underground workings.
(ii) A map of the underground workings that describes the location and extent of the areas in which planned-subsidence mining methods will be used and that identifies all areas where the measures described in paragraphs (c)(2)(iv), (v), and (vii) of this section will be taken to prevent or minimize subsidence and subsidence-related damage; and, when applicable, to correct subsidence-related material damage.
(iii) A description of the physical conditions, such as depth of cover, seam thickness and lithology of overlying strata, that affect the likelihood or extent of subsidence and subsidence-related damage.
(iv) A description of the monitoring, if any, needed to determine the commencement and degree of subsidence so that, when appropriate, other measures can be taken to prevent, reduce or correct material damage in accordance with § 817.121(c) of this chapter.
(v) Except for those areas where planned subsidence is projected to be used, a detailed description of the subsidence control measures that will be taken to prevent or minimize subsidence and subsidence-related damage to the extent technologically and economically feasible. Those measures may include, but are not limited to:
(A) Backstowing of voids;
(B) Leaving support pillars of coal;
(D) Taking measures on the surface to prevent or minimize material damage or diminution in value of the surface.
(vi) A description of the anticipated effects of planned subsidence, if any, including impacts to wetlands, streams, and water bodies that support the value and reasonably foreseeable uses of surface lands.
(vii) For those areas where planned subsidence is projected to be used, a description of methods to be employed to minimize damage from planned subsidence to non-commercial buildings and occupied residential dwellings and structures related thereto; or the written consent of the owner of the structure or facility that minimization measures not be taken; or, unless the anticipated damage would constitute a threat to health or safety, a demonstration that the costs of minimizing damage exceed the anticipated costs of repair.
(viii) A description of the measures to be taken in accordance with §§ 817.40 and 817.121(c) of this chapter to replace adversely affected protected water supplies or to mitigate or remedy any subsidence-related material damage to land, wetlands, streams, water bodies, and protected structures.