(1) Before making a final decision on an operating license application under section 111512, the department shall review the application for consistency with the requirements of part 115. The department shall notify the clerk of the municipality in which the disposal area is located and the applicant of its approval or denial of a license application within 10 days after the final decision is made.

  (2) An operating license expires 5 years after the date of issuance. An operating license may be renewed before expiration upon payment of a renewal application fee specified in section 11512 if the licensee is in compliance with part 115.

  (3) Issuance of an operating license by the department authorizes the licensee to accept waste for disposal in certified portions of the disposal area for which a bond was established under section 11523 and, for type II landfills, for which financial assurance was demonstrated under section 11523a. If the construction of a portion of a landfill licensed under this section is not complete by the time the license application is submitted, the owner or operator of the landfill shall submit a certification under the seal of a licensed professional engineer verifying that the construction of that portion of the landfill has proceeded according to the approved plans at least 60 days before the anticipated date of waste disposal in that portion of the landfill. If the department does not deny the certification within 60 days of receipt, the owner or operator may accept waste for disposal in the certified portion. In the case of a denial, the department shall issue a written statement of the reasons why the construction or certification is not consistent with part 115 or the approved plans.

  (4) The final exterior landfill slopes approved by the department, including the slope of the top of waste beneath the final cover, shall not be steeper than 25% except where necessary for either of the following:

  (a) To install berms for erosion control.

  (b) To vertically transition the side slope back to permitted final waste grades upslope from an area that has received final cover and has settled below permitted grades. The department may approve the transition slope if it does not exceed 33% and the owner or operator demonstrates, through revised engineering plans and analyses, that the steeper slope will not result in increased erosion or reduced stability in either the interim or final cover conditions. The landfill owner or operator shall provide enhanced soil erosion protection to the top surface of the transition slope to ensure interim and long-term erosion control and stability equivalent to a 25% side slope.