The commission may release in whole or part the bond or deposit if it is satisfied that reclamation covered by the bond or deposit or a portion of the bond or deposit has been accomplished as required by this chapter according to the following schedule:
(1) when the operator completes required backfilling, regrading, and drainage control of a bonded area as provided in his approved reclamation plan, the commission may authorize the release of up to 75 percent of the bond or substitute collateral for the applicable permit area, provided the amount of the unreleased portion of the bond or substitute collateral is not less than the amount necessary to assure completion of the reclamation work by a third party in the event of forfeiture; and
(2) when the operator has successfully completed the remaining reclamation activities, but not before the expiration of the period specified for operator responsibility in Section 131.102 of this code, the commission may release the remaining portion of the bond or substitute collateral, provided that no bond is fully released until all reclamation requirements of this chapter are fully met.