30 C.F.R. § 817.121 : Mineral Resources — OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR — PERMANENT PROGRAM PERFORMANCE STANDARDS — PERMANENT PROGRAM PERFORMANCE STANDARDS-UNDERGROUND MINING ACTIVITIES — What measures must I take to prevent, control, or correct damage resulting from subsidence?

(a) Measures to prevent or minimize damage.
(1) You, the permittee or operator, must either-
(i) Adopt measures consistent with known technology that prevent subsidence from causing material damage to the extent technologically and economically feasible, maximize mine stability, and maintain the value and reasonably foreseeable use of surface lands; or
(ii) Adopt mining technology that provides for planned subsidence in a predictable and controlled manner.
(2) If you employ mining technology that provides for planned subsidence in a predictable and controlled manner under paragraph (a)(1)(ii) of this section, you must take necessary and prudent measures, consistent with the mining method employed, to minimize material damage to the extent technologically and economically feasible to non-commercial buildings and occupied residential dwellings and structures related thereto unless-
(i) You have obtained the written consent of the owners of those structures; or
(ii) The costs of those measures would exceed the anticipated costs of repair. This exception does not apply if the anticipated damage would constitute a threat to health or safety.
(3) Nothing in this part prohibits the standard method of room-and-pillar mining.
(b) You must comply with all provisions of the subsidence control plan prepared pursuant to §784.30 of this chapter and approved in the permit.
(c) Repair of damage to surface lands and waters.
(1) To the extent technologically and economically feasible, you must correct any subsidence-related material damage to surface lands, wetlands, streams, or water bodies by restoring the land and water features to a condition capable of maintaining the value and reasonably foreseeable uses that the land was capable of supporting before the subsidence-related damage occurred.
(2) When correction of subsidence-related material damage to wetlands or a perennial or intermittent stream is technologically and economically infeasible, you must implement fish and wildlife enhancement measures, as approved by the regulatory authority in a permit revision, to offset the material damage.
(d) Repair or compensation for damage to non-commercial buildings, occupied residential dwellings and related structures.
(1) You must promptly repair, or compensate the owner for, material damage resulting from subsidence caused to any non-commercial building or occupied residential dwelling or structure related thereto that existed at the time of mining.
(2) If you select the repair option, you must fully rehabilitate, restore, or replace the damaged structure.
(3) If you select the compensation option, you must compensate the owner of the damaged structure for the full amount of the decrease in value resulting from the subsidence-related damage. You may provide compensation by the purchase, before mining, of a non-cancellable, premium-prepaid insurance policy.
(4) The requirements of paragraph (d) of this section apply only to subsidence-related damage caused by underground mining activities conducted after October 24, 1992.
(e) Repair or compensation for damage to other structures. To the extent required under applicable provisions of state law, you must correct material damage resulting from subsidence caused to any structures or facilities not protected by paragraph (d) of this section by either repairing the damage or compensating the owner of the structures or facilities for the full amount of the decrease in value resulting from the subsidence. Repair of damage includes rehabilitation, restoration, or replacement of damaged structures or facilities. Compensation may be accomplished by the purchase before mining of a non-cancellable, premium-prepaid insurance policy.
(f) Information to be considered in determination of causation. The regulatory authority must consider all relevant and reasonably available information in determining whether damage to protected structures was caused by subsidence from underground mining.
(g) Adjustment of bond amount for subsidence damage.
(1) When subsidence-related material damage to land (including wetlands, streams, and water bodies), structures or facilities protected under paragraphs (c) through (e) of this section occurs, or when contamination, diminution, or interruption to a water supply protected under §817.40 of this part occurs, the regulatory authority must require the permittee to post additional performance bond until the repair, compensation, or replacement is completed.
(2)
(i) For structures protected under paragraphs (d) and (e) of this section, the amount of additional bond required under paragraph (g)(1) of this section must equal the-
(A) Estimated cost of the repairs if the repair option is selected.
(B) Decrease in value if the compensation option is selected.
(ii) For water supplies protected under §817.40 of this part, the amount of additional bond required under paragraph (g)(1) of this section must equal the estimated cost to replace the protected water supply, unless the conditions described in §817.40(a)(4) of this part apply.
(iii) For surface lands and waters to which paragraph (c) of this section applies, the amount of additional bond required under paragraph (g)(1) of this section must equal the estimated cost of restoring the land and waters to a condition capable of maintaining the value and reasonably foreseeable uses that they were capable of supporting before the material damage from subsidence occurred.
(3)
(i) The requirements of paragraph (g)(1) of this section do not apply if repair, compensation, or replacement is completed within 90 days of the occurrence of damage. The regulatory authority may extend the 90-day time frame, provided that the total time allowed does not exceed one year, if you demonstrate, and the regulatory authority finds in writing, that repair of subsidence-related material damage to lands, waters, or protected structures or replacement of an adversely impacted protected water supply within 90 days would be unreasonable because-
(A) Subsidence is not complete;
(B) All probable subsidence-related material damage to lands, waters, or protected structures has not yet occurred; or
(C) All reasonably anticipated changes that may affect an adversely impacted protected water supply have not yet occurred.
(ii)
(A) If you have not completed correction or repair of subsidence-related material damage to surface lands or waters or replaced adversely impacted protected water supplies within 2 years following the occurrence of that damage, the regulatory authority must initiate bond forfeiture proceedings under §800.50 of this chapter and use the funds collected to repair the surface lands and waters or replace the protected water supplies.
(B) Paragraph (g)(3)(ii)(A) of this section does not apply if-
(1) The landowner refuses to allow access to conduct the corrective measures; or
(2) You demonstrate, and the regulatory authority finds, that correction or repair of the material damage to surface lands or waters is not technologically or economically feasible. In that situation, you must complete the enhancement measures required under paragraph (c)(2) of this section.
(h) Prohibitions and limitations on underground mining.
(1) You may not conduct underground mining activities beneath or adjacent to-
(i) Public buildings and facilities.
(ii) Churches, schools, and hospitals.
(iii) Impoundments with a storage capacity of 20 acre-feet or more or bodies of water with a volume of 20 acre-feet or more.
(2) The prohibitions of paragraph (h)(1) of this section do not apply if the subsidence control plan demonstrates that subsidence will not cause material damage to, or reduce the reasonably foreseeable use of, the features or facilities listed in paragraphs (h)(1)(i) through (iii) of this section.
(3) The regulatory authority may limit the percentage of coal extracted under or adjacent to the features and facilities listed in paragraphs (h)(1)(i) through (iii) of this section if it determines that the limitation is necessary to minimize the potential for material damage to those features or facilities or to any aquifer or body of water that serves as a significant water source for any public water supply system.
(i) If subsidence causes material damage to any of the features or facilities listed in paragraphs (h)(1)(i) through (iii) of this section, the regulatory authority may suspend mining under or adjacent to those features or facilities until the subsidence control plan is modified to ensure prevention of further material damage to those features or facilities.
(j) The regulatory authority must suspend underground mining activities under urbanized areas, cities, towns, and communities, and adjacent to industrial or commercial buildings, major impoundments, or perennial streams, if it finds that the mining activities pose an imminent danger to inhabitants of the urbanized areas, cities, towns, or communities.
(k) You must submit a detailed plan of the underground workings of your mine in accordance with a schedule approved by the regulatory authority. The detailed plan must include maps and descriptions, as appropriate, of significant features of the underground mine, including the size, configuration, and approximate location of pillars and entries, extraction ratios, measures taken to prevent or minimize subsidence and related damage, areas of full extraction, and other information required by the regulatory authority. The regulatory authority may hold the information submitted with the detailed plan as confidential, in accordance with §773.6(d) of this chapter, upon your request.

30 C.F.R. § 817.121

48 FR 24652, 6/1/1983, as amended at 60 FR 16749, 3/31/1995; 65 FR 79670, 12/19/2000; 81 FR 93418, 1/19/2017

EFFECTIVE DATE NOTE: At 64 FR 71653, Dec. 22, 1999, § 817.121, paragraphs (c)(4)(i) through (iv) were suspended, effective Dec, 22, 1999.