1. (a) Applicability. This section applies to all operations for which the regulatory authority has approved a permit under § 785.14 of this chapter.

2. (b) Performance standards.

   1. (1) You, the permittee, must comply with all applicable requirements of this subchapter and the regulatory program, other than the approximate original contour restoration requirements of § 816.102(a)(1) of this chapter and the thick overburden requirements of § 816.105 of this chapter.

   2. (2)

      1. (i) You must retain an outcrop barrier, consisting of the toe of the lowest coal seam and its associated overburden, of sufficient width to prevent slides and erosion. You must construct drains through the barrier to the extent necessary to prevent saturation of the backfill.
      2. (ii) The outcrop barrier requirement in paragraph (b)(2)(i) of this section does not apply if the proposed mine site was mined prior to May 3, 1978, and the toe of the lowest coal seam has already been removed.
      3. (iii) You may remove a coal barrier adjacent to a head-of-hollow fill after the elevation of the fill attains the elevation of the coal barrier if the head-of-hollow fill provides the stability otherwise ensured by the retention of a coal barrier.
      4. (iv) The regulatory authority may allow removal of the outcrop barrier required by paragraph (b)(2)(i) of this section if the regulatory program establishes standards for and requires construction of a barrier comprised of alternative materials that will provide equivalent stability.
   3. (3) The final graded slopes must be less than 1v:5h, so as to create a level plateau or gently rolling configuration. The outslopes of the plateau may not exceed 1v:2h except where engineering data substantiate, and the regulatory authority finds in writing and includes in the permit under § 785.14 of this chapter that an alternative configuration will achieve a minimum static safety factor of 1.5.
   4. (4) You must grade the plateau or gently rolling contour to drain inward from the outslope, except at specified points where it drains over the outslope in stable and protected channels.
   5. (5) You must place sufficient spoil on the mountaintop bench to achieve the approved postmining land use. You must place all spoil material not retained on the mountaintop bench in accordance with the excess spoil disposal requirements of § 816.71 or § 816.74 of this chapter.
   6. (6) You must prevent damage to natural watercourses in accordance with the finding made by the regulatory authority under § 785.14 of this chapter.

[81 FR 93445, Dec. 20, 2016]