Ill. Admin. Code tit. 35, § 820.405
d) Face Amount
e) The insurance policy must guarantee that funds will be available to close the GCDD recovery facility in compliance with Section 820.305. The policy must also guarantee that, once closure begins, the insurer will be responsible for paying out funds, up to an amount equal to the face amount of the policy, upon the direction of the Agency to such party or parties as the Agency specifies. The insurer will be liable when:
f) Reimbursement for Closure Expenses
3) If the Agency determines based on information available to it that the cost of closure will be greater than the face amount of the policy, it must withhold reimbursement of such amounts as it considers necessary until it determines that the owner or operator is no longer required to maintain financial assurance. In the event the face amount of the policy is inadequate to pay all claims, the Agency must pay claims according to the following priorities:
g) Cancellation