30 CFR § 800.15 - Adjustment of amount.
(a) The amount of the bond or deposit required and the terms of the acceptance of the applicant's bond shall be adjusted by the regulatory authority from time to time as the area requiring bond coverage is increased or decreased or where the cost of future reclamation changes. The regulatory authority may specify periodic times or set a schedule for reevaluating and adjusting the bond amount to fulfill this requirement.
(b) The regulatory authority shall—
(1) Notify the permittee, the surety, and any person with a property interest in collateral who has requested notification under § 800.21(f) of any proposed adjustment to the bond amount; and
(2) Provide the permittee an opportunity for an informal conference on the adjustment.
(c) A permittee may request reduction of the amount of the performance bond upon submission of evidence to the regulatory authority proving that the permittee's method of operation or other circumstances reduces the estimated cost for the regulatory authority to reclaim the bonded area. Bond adjustments which involve undisturbed land or revision of the cost estimate of reclamation are not considered bond release subject to procedures of § 800.40.
(d) In the event that an approved permit is revised in accordance with subchapter G of this chapter, the regulatory authority shall review the bond for adequacy and, if necessary, shall require adjustment of the bond to conform to the permit as revised.