(a) Timing of backfilling and grading.
  (1) Contour mining. Rough backfilling and grading shall follow coal removal by not more than 60 days or 1,500 linear feet. The Commission may grant additional time for rough backfilling and grading if the permittee can demonstrate, through a detailed written analysis under §12.145(b)(3) of this title (relating to Reclamation Plan: General Requirements), that additional time is necessary.
  (2) Open pit mining with thin overburden. Rough backfilling and grading shall occur in accordance with the time schedule approved by the Commission, on the basis of the materials submitted under §12.145(b)(3) of this title (relating to Reclamation Plan: General Requirements), which shall specifically establish in stated increments the period between removal of coal and completion of backfilling and grading.
  (3) Area strip mining (cyclic excavation). Rough backfilling and grading shall be completed within 180 days following coal removal and shall not be more than four spoil ridges behind the pit being worked, the spoil from the active pit being considered the first ridge. The Commission may grant additional time and/or distance for rough backfilling and grading if the permittee can demonstrate, through a detailed written analysis under §12.145(b)(3) of this title (relating to Reclamation Plan: General Requirements), that additional time and/or distance is necessary.
  (4) Area strip mining (continuous excavation). Rough backfilling and grading shall occur in accordance with the time schedule approved by the Commission, on the basis of a detailed written analysis by the permittee under §12.145(b)(3) of this title (relating to Reclamation Plan: General Requirements) and any additional information which the Commission may require.
(b) Method of backfilling and grading.
  (1) Except as specifically exempted in this subchapter (relating to Permanent Program Performance Standards), all disturbed areas shall be returned to their approximate original contour. All spoil shall be transported, backfilled, compacted (where advisable to insure stability or to prevent leaching) and graded to eliminate all highwalls, spoil piles, and depressions.
  (2) Backfilled material shall be placed to minimize erosion, to minimize water pollution both on and off the site, and to support the approved postmining land use.
  (3) The postmining graded slopes need not be of uniform slope.
  (4) Cut-and-fill terraces may be used only in those situations expressly identified in §12.385 of this title (relating to Backfilling and Grading: General Grading Requirements).

Source Note: The provisions of this §12.384 adopted to be effective April 7, 1997, 22 TexReg 3093.