(a) The inspections by the commission shall occur on an irregular basis at a frequency necessary to insure compliance with the intent and purposes of this chapter and the commission’s rules for the surface mining and reclamation operations covered by each permit.
(b) The inspections shall occur only during normal operating hours if practicable and without prior notice to the permittee or his agents or employees.

(c) An inspection shall include the filing of an inspection report adequate to enforce the requirements of and to carry out the terms and purposes of this chapter. The commission shall make each report a part of the record and furnish one copy of the report to the operator.
(d) Insofar as practicable, the commission shall establish a system of rotation of inspectors.