1. (a) Adjustment required. Except as provided in (b) of this Section, cost estimates for closure, post-closure, and/or corrective action shall be adjusted no later than April 9th of each year. The adjustment must be submitted to the DEQ for approval.

   1. (1) Recalculation of maximum costs. The maximum costs of closure, post-closure, and/or corrective action may be recalculated in current dollars using the procedure in Part 5 of this Subchapter (relating to determination of cost estimates).

   2. (2) Use of inflation factor. If there are no significant changes to the closure or post-closure plan, corrective action plan, or facility conditions, cost estimates may be adjusted by use of an inflation factor derived from the most recent annual "Implicit Price Deflator for Gross National Product" or the "Implicit Price Deflator for Gross Domestic Product" published by the U.S. Department of Commerce in its Survey of Current Business in the year for which the adjustment is being made.

      1. (A) The first adjustment shall be made by multiplying the approved cost estimate by the inflation factor. The result is the adjusted cost estimate.
      2. (B) Subsequent adjustments shall be made by multiplying the latest adjusted cost estimate by the latest inflation factor.
   3. (3) Place in operating record. The approved adjusted cost estimates shall be placed in the operating record.

2. (b) Corporate test or guarantee as financial assurance mechanism. When the corporate test (OAC 252:517-17-81) or guarantee (OAC 252:517-17-82) is used as the financial assurance mechanism, the cost estimates for closure, post-closure, and/or corrective action shall be adjusted no later than 90 days after the close of the corporate fiscal year.

   1. (1) Required information. The financial strength information specified in OAC 252:517-17-81(c) shall be submitted to the DEQ for approval.
   2. (2) Extension allowed. The DEQ may provide up to an additional 45 days to submit the information upon demonstration that 90 days is insufficient time to acquire audited financial statements.
   3. (3) Place in operating record. The approved adjusted cost estimates shall be placed in the operating record.

Added at 33 Ok Reg 1469, eff 9-15-16

Amended at 35 Ok Reg 1293, eff 9-15-18