4 Va. Admin. Code § 25-130-817.102

Current through Register Vol. 41, No. 6, November 4, 2024

Section 4VAC25-130-817.102 - Backfilling and grading; general requirements

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

(1) Achieve the approximate original contour, except as provided in subsection (k) of this section;

(2) Eliminate all highwalls, spoil piles, and depressions, except as provided in subsection (h) (small depressions) and in subdivision (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 subsection (l) of this section, and except excess spoil disposed of in accordance with 4VAC25-130-817.71 through 4VAC25-130-817.75, 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 4VAC25-130-817.22.

(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 4VAC25-130-817.81 and 4VAC25-130-817.83 as provided in subdivisions (1) and (2) of this subsection, except that a long-term static safety factor of 1.3 shall be achieved.

(1) Disposal of coal processing waste and underground development waste in the mined-out area to backfill disturbed areas shall be in accordance with 4VAC25-130-817.81.

(2) Disposal of coal processing waste and underground development waste in the mined-out area as a refuse pile and not to backfill disturbed areas shall be in accordance with 4VAC25-130-817.81 and 4VAC25-130-817.83. The division may approve a variance to 4VAC25-130-817.83 (a) (2) if the applicant demonstrates that the area above the refuse pile is small and that appropriate measures will be taken to direct or convey runoff across the surface area of the pile in a controlled manner.

(f) Exposed coal seams, acid- and toxic-forming materials, and combustible materials exposed, used, or produced during mining shall be covered with a minimum of four feet of nontoxic and noncombustible materials, or treated, to control the impact on surface and ground water in accordance with 4VAC25-130-817.41, to prevent sustained combustion, and to minimize adverse effects on plant growth and the approved postmining land use. Acid- and toxic-forming materials shall not be buried or stored in proximity to any drainage course.

(g) Cut-and-fill terraces may be allowed by the division where:

(1) Needed to conserve soil moisture, ensure stability, and control erosion on final-graded slopes, if the terraces are compatible with the approved postmining land use; or

(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.

(h) Small depressions may be constructed if they are needed to retain moisture, minimize erosion, create and enhance wildlife habitat, or assist revegetation.

(i) Permanent impoundments may be approved if they meet the requirements of 4VAC25-130-817.49 and 4VAC25-130-817.56 and if they are suitable for the approved postmining land use.

(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 division for:

(1) A variance from approximate original contour requirements in accordance with 4VAC25-130-785.16; or

(2) Incomplete elimination of highwalls in previously mined areas in accordance with 4VAC25-130-817.106.

(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 subdivision (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.

(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 4VAC25-130-817.116, and surface runoff shall be controlled in accordance with 4VAC25-130-817.43.

(2) If it is determined by the division 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 division may allow the existing spoil or underground development waste pile to remain in place. The division may require stabilization of such spoil or underground development waste in accordance with the requirements of subdivisions (l)(1)(i)-(l)(1)(iv) of this section.

4 Va. Admin. Code § 25-130-817.102

Derived from VR480-03-19 § 817.102, eff. December 15, 1981; amended, eff. June 28, 1982; October 28, 1982; December 14, 1982; October 11, 1983; December 27, 1983; May 8, 1984; June 22, 1984; August 2, 1984; October 16, 1985; January 7, 1987; July 22, 1987; November 25, 1987; October 12, 1988; December 26, 1990; July 1, 1991; July 17, 1991; November 20, 1991; July 7, 1992; May 5, 1993; October 19, 1994; Virginia Register Volume 11, Issue 26, eff. October 18, 1995.

Statutory Authority

§§ 45.1-161.3 and 45.1-230 of the Code of Virginia.