27—60.75(208) General mining activities.

1. 60.75(1)  Topsoil and overburden stockpiles. Topsoil shall not be buried or mixed with nontopsoil materials. All stockpiles (topsoil and overburden) shall be seeded and stabilized if they are to remain in place for a period of time in excess of 12 months.
2. 60.75(2)  Erosion control. Affected areas which will not be disturbed by future operations shall be graded, disked, mulched, fertilized, and seeded as necessary within a period of nine months to attain substantial and appropriate grass, legume, shrub, tree, crop, or other acceptable species and to ensure viable erosion control.

3. 60.75(3)  Setback.

   1. a. A minimum excavation setback distance of 25 feet shall be maintained from all registered site boundaries to protect the adjacent property from erosion or damage which might result from mining activities.
   2. b. In areas where excavation depth exceeds 25 feet, a minimum excavation setback distance of at least 50 feet shall be maintained from registered site boundaries.
   3. c. A minimum excavation setback distance of 50 feet shall be maintained from all buildings, dwellings, public right-of-way boundaries and other man-made structures not associated with the mining operation.
   4. d. Excavation on a registered site found to be closer than the allowable minimum setback shall be in violation of this subrule. The operator shall be required to backfill, slope and stabilize to the required limits.

   5. e. The requirements of this subrule shall not apply to registered operations where mining has exceeded the setback limitation as of January 1, 1991, provided that the operator has filed adequate documentation as of July 1, 1991, detailing the area being grandfathered into these requirements.

      The operator shall be responsible for maintaining a permanent record of all documentation once approved by the division.

   6. f. The division may grant a variance from this subrule, provided the operator submits a complete application that meets the requirements of rule 27—60.85(208) at least 60 days prior to the proposed starting date of any mining within the setback limitations.