(b) backfill by one of the following materials, followed by surface revegetation:i. earth, sand, gravel or stone;
ii. residues of a mineral nature from aggregate material extraction;
iii. sludge generated by sedimentation basins used in aggregate extraction or dimension stone processing processes, with a dryness equal to or greater than 15% and that, when tested by a laboratory accredited by the Minister under section 118.6 of the Act, contains no free liquid; or
iv. particles of a mineral nature recuperated by an air cleaning system and resulting from the crushing and screening of aggregate material and fragments of cement concrete or brick, with the exception of firebrick;