(a) Applicability. This section applies only where the thickness of all overburden strata multiplied by the swell factor for those strata plus the thickness of any waste materials to be returned to the mined-out area is less than the combined thickness of the overburden and coal seam or seams prior to removing the coal to the extent that there is insufficient material to restore the approximate original contour. Specifically, there is insufficient material to achieve a surface configuration that -

1. (1) Closely resembles the surface configuration of the mined area prior to any mining; and
2. (2) Blends into and complements the drainage pattern of the surrounding terrain.

(b) Performance standards. Where thin overburden as described in paragraph (a) of this section occurs within the permit area, you must backfill all mined areas and grade all disturbed areas in accordance with the plan approved in the permit under § 780.12(d) of this chapter. At a minimum, you must -

1. (1) Use all spoil and waste materials available from the entire permit area to attain the lowest practicable grade that does not exceed the angle of repose.
2. (2) Comply with the requirements of paragraphs (a)(2) through (f) of § 816.102 of this part.
3. (3) Ensure that the final surface configuration blends into and complements the drainage pattern of the surrounding terrain to the extent possible.