312 Ind. Admin. Code 25-1-62
Authority: IC 14-34-2-1
Affected: IC 14-34
Sec. 62.
"Head-of-hollow fill" means a fill structure consisting of any material, other than a coal processing waste and organic material, placed in the uppermost reaches of a hollow where side slopes of the existing hollow measured at the steepest point are greater than twenty (20) degrees or the average slope of the profile of the hollow from the toe of the fill to the top of the fill is greater than ten (10) degrees. In fills with less than two hundred fifty thousand (250,000) cubic yards of material, associated with steep slope mining, the top surface of the fill will be at the elevation of the coal seam. In all other head-of-hollow fills, the top surface of the fill, when completed, is at approximately the same elevation as the adjacent ridge line and no significant area of natural drainage occurs above the fill draining into the fill areas.
312 IAC 25-1-62