1. Each operator of a solid waste disposal area shall insure that the area is properly closed upon cessation of operations. Each operator shall submit a closure plan with the application for a permit. Operators of currently permitted sanitary landfills shall submit a closure plan within one year from August 13, 1986. The plan, as approved by the department, shall include at least the following:

(1) A description of how and when the area will be closed and, if applicable, a description of plans for closing portions of the area during the operational life of the area;

(2) A written estimate, in current dollars, of the cost of closure of the total area and, if applicable, an estimate of the cost of closing portions of the area during the operational life of the area in accordance with sections 260.200 to 260.245. The estimate shall equal the cost of closure at the time in the area’s life when the extent and manner of its operation would make closure the most expensive unless the closure plan demonstrates that the most expensive closure can be avoided in which case the estimate shall equal the cost of closure based upon the closure plan.

2. The operator shall amend the closure plan whenever changes in operating plans, area design or closure costs affect the closure plan. When the operator requests a permit modification to authorize a change in operating plans or area design, he shall request a modification of the closure plan at the same time.

3. The operator shall notify the department at least one hundred eighty days prior to the date he expects to begin closure. Closure shall begin within thirty days after the date on which the operator receives the final volume of waste.

4. The permittee shall provide a financial assurance instrument in such amount and form as prescribed by the department to insure that, upon abandonment, cessation or interruption of the operation of the area, an approved closure plan is completed. Operators of currently permitted disposal areas shall provide a suitable financial assurance instrument prior to January 1, 1988. Any interest which accrues to any financial assurance instrument established pursuant to this section shall remain with that instrument and shall be applied against the operator’s obligation under this section until the instrument is released by the department as provided in subsection 5 of this section.

5. The department shall inspect a solid waste disposal area, or some portion thereof as specified in the closure plan, when notified by the operator that the area has been closed. If the inspection reveals that the approved closure plan has been properly effected, the director shall authorize the release, or proportional release, of the financial instrument required under this section.

6. Operators of a solid waste disposal area as part of a permit issued under sections 444.500 to 444.905 shall not be required to submit closure and post-closure plans or provide the financial assurance instruments required under this act^*.