§ 817.102 - Backfilling and grading: General requirements.

§ 817.102 How must I backfill surface excavations and grade and configure the land surface?

(a) You, the permittee or operator, must backfill all surface excavations and grade all disturbed areas in compliance with the plan approved in the permit in accordance with § 784.12(d) of this chapter

Backfilling and grading: General requirements.

(a) Disturbed areas shall be backfilled and graded to -

(i) They are compatible with the approved postmining land use and are needed

(1) Restore Achieve the approximate original contour as the final surface configuration, except in the following situations:

(i) Sites for which the regulatory authority has approved a variance under § 785.16 of this chapter.

(ii) Remining operations on previously mined areas, but only to the extent specified in § 817.106(b) of this part.

(iii) Excess spoil fills constructed in accordance with § 817.71 or § 817.74 of this part.

(iv) Refuse piles constructed in accordance with § 817.83 of this part.

(v) Permanent impoundments that meet the requirements of paragraph (a)(3)(ii) of this section and § 784.35(b)(4) of this chapter.

(vi) The placement, in accordance with § 784.35(b)(3) of this chapter, of what would otherwise be excess spoil on the mined-out area to heights in excess of the premining elevation when necessary to avoid or minimize construction of excess spoil fills on undisturbed land.

(vii) Regrading of settled and revegetated spoil storage sites at the conclusion of underground mining activities, provided the following conditions are met:

(A) The settled and revegetated storage sites are composed of spoil or non-acid-forming or non-toxic-forming underground development waste.

(B) The spoil or underground development waste is not located so as to be detrimental to the environment, the health and safety of the public, or the approved postmining land use.

(C) You demonstrate, through standard geotechnical analysis, that the spoil or underground development waste has a 1.3 static safety factor for material placed on a solid bench and a 1.5 static safety factor for material not placed on a solid bench.

(D) The surface of the spoil or underground development waste is revegetated in accordance with §§ 817.111 and 817.116 of this part.

(E) Surface runoff is controlled in accordance with § 784.29 of this chapter and §§ 817.43 and 817.45 of this part.

(F) The regulatory authority determines that disturbance of the existing spoil or underground development waste would increase environmental harm or adversely affect the health or safety of the public.

(G) The spoil is not needed to eliminate the highwall or to meet other regulatory program requirements.

(2) Minimize the creation of uniform slopes and cut-and-fill terraces. The regulatory authority may approve cut-and-fill terraces only if -

as provided in paragraph (k) of this section;

(2) Eliminate all highwalls, spoil piles, and depressions, except as provided in paragraph (h) (small depressions) and in paragraph (k)(2) (previously mined highwalls) of this section;

(3) Achieve a postmining slope that does not exceed either the angle of repose or such lesser slope as is necessary to achieve a minimum long-term static safety factor of 1.3 and to prevent slides;

(4) Minimize erosion and water pollution both on and off the site; and

(5) Support the approved postmining land use.

(b) Spoil, except as provided in paragraph (l) of this section, and except excess spoil disposed of in accordance with §§ 817.71 through 817.74, shall be returned to the mined-out surface area.

(c) Spoil and waste materials shall be compacted where advisable to ensure stability or to prevent leaching of toxic materials.

(d) Spoil may be placed on the area outside the mined-out surface area in nonsteep slope areas to restore the approximate original contour by blending the spoil into the surrounding terrain if the following requirements are met:

(1) All vegetative and organic material shall be removed from the area.

(2) The topsoil on the area shall be removed, segregated, stored, and redistributed in accordance with § 817.22.

(3) The spoil shall be backfilled and graded on the area in accordance with the requirements of this section.

(e) Disposal of coal processing waste and underground development waste in the mined-out surface area shall be in accordance with §§ 817.81 and 817.83, except that a long-term static safety factor of 1.3 shall be achieved.

(f) Exposed coal seams, acid- and toxic-forming materials, and combustible materials exposed, used, or produced during mining shall be adequately covered with nontoxic and noncombustible materials, or treated, to control the impact on surface and ground water in accordance with § 817.41, to prevent sustained combustion, and to minimize adverse effects on plant growth and the approved postmining land use.

(g) Cut-and-fill terraces may be allowed by the regulatory authority where -

(1) Needed to conserve soil moisture, ensure stability,

or

and control erosion on final-graded slopes, if the terraces are compatible with the approved postmining land use; or

(

ii

2) Specialized grading, foundation conditions, or roads are required for the approved postmining land use, in which case the final grading may include a terrace of adequate width to ensure the safety, stability, and erosion control necessary to implement the postmining land-use plan.

(

3) Eliminate all highwalls, spoil piles, impoundments, and depressions, except in the following situations:

(i) You may construct or retain small depressions if -

(A) They

h) Small depressions may be constructed if they are needed to retain moisture, minimize erosion, create

or

and enhance wildlife habitat, or assist revegetation

; (B) They are consistent with the hydrologic reclamation plan approved in the permit in accordance with § 784

.

22 of this chapter; and

(C) You demonstrate that they will not result in elevated levels of parameters of concern in discharges from the backfilled and graded area.

(ii) The regulatory authority may approve the retention of permanent impoundments if -

(A) They

(i) Permanent impoundments may be approved if they meet the requirements of §§ 817.49 and 817.

55 of this part; (B) They

56 and if they are suitable for the approved postmining land use

; and

.

(

C) You demonstrate compliance with the future maintenance provisions of § 800.42(c)(5) of this chapter.

(D) You have obtained all necessary approvals and authorizations under section 404 of the Clean Water Act, 33 U.S.C. 1344, when the impoundment is located in waters subject to the jurisdiction of the Clean Water Act, 33 U.S.C. 1251 et seq.

(iii) You may retain highwalls on previously mined areas to the extent provided in § 817.106(b) of this part.

(iv) You may retain modified highwall segments to the extent necessary to replace similar natural landforms removed by the mining operation. The regulatory program must establish the conditions under which these highwall segments may be retained and the modifications that must be made to the highwall to ensure that -

(A) The retained segment resembles similar landforms that existed before any mining and restores the ecological niches that those landforms provided. Nothing in this paragraph authorizes the retention of modified highwall segments in excess of the number, length, and height needed to replace similar landforms that existed before any mining.

(B) The retained segment is stable. Features that result in the creation of talus slopes for wildlife habitat are acceptable if they meet the requirements of paragraph (a)(3)(iv)(A) of this section.

(C) The retained segment does not create an increased safety hazard compared to the features that existed before any mining.

(D) The exposure of water-bearing strata, if any, in the retained segment does not adversely impact the hydrologic balance.

(v) You may retain settled and revegetated spoil storage sites under the conditions specified in paragraph (a)(1)(vii) of this section.

(4) Achieve a postmining slope that does not exceed either the angle of repose or such lesser slope as is necessary to achieve a minimum long-term static safety factor of 1.3 and to prevent slides.

(5) Minimize erosion and water pollution, both on and off the site.

(6) Support

j) Preparation of final-graded surfaces shall be conducted in a manner that minimizes erosion and provides a surface for replacement of topsoil that will minimize slippage.

(k) The postmining slope may vary from the approximate original contour when approval is obtained from the regulatory authority for -

(1) A variance from approximate original contour requirements in accordance with § 785.16 of this chapter; or

(2) Incomplete elimination of highwalls in previously mined areas in accordance with § 817.106.

(l) Regrading of settled and revegetated fills to achieve approximate original contour at the conclusion of underground mining activities shall not be required if the conditions of paragraph (l)(1) or (l)(2) of this section are met.

(1)

(i) Settled and revegetated fills shall be composed of spoil or non-acid- or non-toxic-forming underground development waste.

(ii) The spoil or underground development waste shall not be located so as to be detrimental to the environment, to the health and safety of the public, or to the approved postmining land use.

(

b) You must return all spoil to the surface excavations from which the spoil was removed. This requirement does not apply to -

(1) Excess spoil disposed of in accordance with § 817.71 or § 817.74 of this part.

(2) Spoil placed outside surface excavations in non-steep slope areas to restore the approximate original contour by blending the spoil into the surrounding terrain, provided that you comply with the following requirements:

(i) You must remove all vegetation and other organic matter from the area upon which you intend to place spoil for blending purposes. You may not burn these materials; you must store, redistribute, use, or bury them in the manner specified in § 817.22(f) of this part.

(ii) You must remove, segregate, store, and redistribute topsoil, in accordance with § 817.22 of this part, from the area upon which you intend to place spoil for blending purposes.

(3) Settled and revegetated spoil storage sites under the conditions specified in paragraph (a)(1)(vii) of this section.

(c) You must compact spoil and waste materials when necessary to ensure stability or to prevent the formation of acid or toxic mine drainage, but, to the extent possible, you must avoid compacting spoil, soil, and other materials placed in what will be the root zone of the species planted under the revegetation plan approved in the permit in accordance with § 784.12(g) of this chapter.

(d)

(1) You must cover all exposed coal seams with material that is noncombustible, nonacid-forming, and nontoxic-forming.

(2) You must handle and dispose of all other combustible materials exposed, used, or produced during mining in accordance with § 817.89 of this part in a manner that will prevent sustained combustion, as approved in the permit in accordance with § 784.12(j) of this chapter.

(3) You must handle all other acid-forming and toxic-forming materials -

(i) In compliance with the plan approved in the permit in accordance with § 784.12(n) of this chapter;

(ii) In compliance with § 817.38 of this part;

(iii) In compliance with the hydrologic reclamation plan approved in the permit in accordance with § 784.22(a) of this chapter; and

(iv) In a manner that will minimize adverse effects on plant growth and the approved postmining land use.

(e) You must dispose of any coal mine waste placed in the surface excavation in accordance with §§ 817.81 and 817.83 of this part, except that a long-term static safety factor of 1.3 will apply instead of the 1.5 factor specified in § 817.81(d)(2) of this part.

(f) You must prepare final-graded surfaces in a manner that minimizes erosion and provides a surface for replacement of soil materials that will minimize slippage.

iii) Stability of the spoil or underground development waste shall be demonstrated through standard geotechnical analysis to be consistent with backfilling and grading requirements for material on the solid bench (1.3 static safety factor) or excess spoil requirements for material not placed on a solid bench (1.5 static safety factor).

(iv) The surface of the spoil or underground development waste shall be vegetated according to § 817.116, and surface runoff shall be controlled in accordance with § 817.43.

(2) If it is determined by the regulatory authority that disturbance of the existing spoil or underground development waste would increase environmental harm or adversely affect the health and safety of the public, the regulatory authority may allow the existing spoil or underground development waste pile to remain in place. The regulatory authority may require stabilization of such spoil or underground development waste in accordance with the requirements of paragraphs (l)(1)(i) through (l)(1)(iv) of this section.

[48 FR 23370, May 24, 1983, as amended at 48 FR 41735, Sept. 16, 1983; 81 FR 93418, Dec. 20, 2016; 82 FR 54999, Nov. 17, 2017]