|(a) The owner or operator of a municipal solid waste management unit required to undertake a corrective action program under §330.415 of this title (relating to Implementation of the Corrective Action Program) shall prepare a detailed written cost estimate, in current dollars, of the cost of hiring a third party to perform the corrective action program. The corrective action cost estimate shall account for the total costs of corrective action activities as described in the corrective action plan for the entire corrective action period. The owner or operator shall submit the cost estimate for financial assurance with the corrective action plan. Financial assurance shall be required for each separate corrective action program established for a municipal solid waste unit. (1) The corrective action cost estimate and the amount of financial assurance provided under subsection (b) of this section shall be increased if changes in the corrective action program or unit conditions increase the maximum costs of corrective action. (2) A reduction in the cost estimate and the amount of financial assurance for corrective action provided under subsection (b) of this section may be approved if the cost estimate exceeds the maximum remaining costs of corrective action at any time during the remaining corrective action period and the owner or operator has provided written notice to the executive director that includes a detailed justification for the reduction of the corrective action cost estimate and the amount of financial assurance. The owner or operator may request a reduction in the cost estimate and the financial assurance as a modification to the corrective action plan. (b) The owner or operator of any municipal solid waste management unit required to undertake a corrective action program established under §330.415 of this title shall establish financial assurance for the costs of the most recent corrective action program in accordance with Chapter 37, Subchapter R of this title (relating to Financial Assurance for Municipal Solid Waste Facilities). Continuous financial assurance coverage for each corrective action program shall be provided until the facility is officially released in writing by the executive director from all requirements of the corrective action program after completion of all work specified in the corrective action plan.