(1) Operators who disturb prime farmlands shall comply with applicable performance standards of ARM 17.24.701 through 17.24.703.
(2) Prime farmland soil removal and stockpiling operations must be conducted in compliance with 82-4-232(3) (a) and (b) , MCA. The minimum thickness of soil materials to be removed for use in reconstructing prime farmland soils must be sufficient to meet the soil replacement requirements of (3) of this rule. Prime farmland soil materials must be handled separately from other soil materials, including salvage, stockpiling and redistribution, unless otherwise approved by the department upon a finding that the other soil materials with which the prime farmland soil would be combined meet the requirements of quality set forth in 82-4-232(3) (a) and (b) , MCA.
(3) The minimum thickness of soil to be reconstructed for prime farmland must be 48 inches or a thickness equal to the depth to a subsurface horizon in the natural soil that inhibits root penetration, whichever is shallower. The department shall specify a depth greater than 48 inches wherever necessary to restore productive capacity. Soil horizons are considered inhibitory to root penetration if their physical or chemical properties restrict or prevent penetration by roots.
(4) Prime farmland soils must be removed, immediately redistributed or stockpiled, and reconstructed in a manner that results in a soil having equal or greater productive capacity than that which existed prior to disturbance. The A and E horizons or other suitable soil materials must be replaced as the surface soil layer to a thickness that will equal or exceed the thickness of this layer as it existed before disturbance.