An owner or operator of a treatment, storage, or disposal facility shall file, as a part of the application for a license to operate, a surety bond or other suitable instrument or mechanism or establish a secured trust fund, as approved by the department, to cover the cost of closing the treatment, storage, or disposal facility after its capacity is reached or operations have otherwise terminated. In addition, the owner or operator of a disposal facility shall also file a surety bond or other suitable instrument or mechanism or establish a secured trust fund, approved by the department, to cover the cost of postclosure monitoring and maintenance of the facility. An owner or operator may use a combination of bonds, instruments, mechanisms, or funds, as approved by the department, to satisfy the requirements of this section. The bond, instrument, mechanism, or fund, or combination of these methods of assurance, shall be in an amount equal to a reasonable estimate of the cost required to adequately close the facility, based on the level of operations proposed in the operating license application, and, with respect to a disposal facility, to monitor and maintain the site for a period of at least 30 years. The bond, instrument, mechanism, or fund, or the combination of these methods of assurance, shall be adjusted periodically as determined by rule to account for inflation or changes in the permitted level of operations. Failure to maintain the bond, instrument, mechanism, or fund, or combination of these methods of assurance, constitutes a violation of this part.