LAC 43:XV.5411. Backfilling and Grading: Thin Overburden

A. Thin Overburden―insufficient spoil and other waste materials available from the entire permit area to restore the disturbed area to its approximate original contour. 1. Insufficient spoil and other waste materials occur where the overburden thickness times the swell factor, plus the thickness of other available waste materials, is less than the combined thickness of the overburden and coal bed prior to removing the coal, so that after backfilling and grading the surface configuration of the reclaimed area would not: a. closely resemble the surface configuration of the land prior to mining; or b. blend into and complement the drainage pattern of the surrounding terrain. B. In surface mining activities carried out continuously in the same limited pit area for more than one year from the day coal removal operations begin and where the volume of all available spoil and suitable waste materials over the mine plan area is demonstrated to be insufficient to achieve the approximate original contour of the lands disturbed, surface mining activities shall be conducted to meet, at a minimum, the following standards: 1. haul or convey, backfill and grade, using all available spoil and suitable waste materials from the entire mine area, to attain the lowest practicable stable grade, to achieve a static safety factor of 1.3, and to provide adequate drainage and long-term stability of the regraded areas and cover all acid-forming and toxic-forming materials; 2. eliminate highwalls by grading or backfilling to stable slopes not exceeding 1v:2h (50 percent), or such lesser slopes as the office may specify to reduce erosion, maintain the hydrologic balance, or allow the approved post-mining land use; 3. haul or convey, backfill, grade and revegetate in accordance with §§5417-5423 to achieve an ecologically sound land use compatible with the prevailing use in unmined areas surrounding the mine plan area; and 4. haul or convey, backfill and grade to ensure impoundments are constructed only where: a. it has been demonstrated to the satisfaction of the office that all requirements of §§5319-5347 have been met; b. the impoundments have been approved by the office as suitable for the approved post-mining land use and as meeting the requirements of this Chapter and all other applicable federal and state laws and regulations.