(1) Once every five years an owner may request a reduction of the required bond amount upon submission of evidence to the department proving that decommissioning work, reclamation, or other circumstances will reduce the maximum estimated cost to the department to complete decommissioning and therefore warrant a reduction of the bond amount. Prior to denying the request in whole or in part, the department shall consult with the owner.

(2) The department shall review each decommissioning plan and bond amount every five years. The department may increase the amount of the bond if the facility has expanded or the cost to decommission a facility otherwise increases. The department shall notify the owner of any proposed bond increase and provide the owner an opportunity for an informal conference on the proposal. If the department determines that the bond amount must be increased, it shall provide the owner with a written justification for the increase. The owner shall increase the bond within 90 days of receiving the department's revised bond amount.