|(a) An owner or operator subject to this subchapter shall establish financial assurance for the plugging and abandonment of each existing and new Class I well, Class III well, Class I salt cavern disposal well and associated salt cavern, or as otherwise directed by the executive director, in a manner that meets the requirements of this section, in addition to the requirements specified under Subchapters A - D of this chapter (relating to General Financial Assurance Requirements; Financial Assurance Requirements for Closure, Post Closure, and Corrective Action; Financial Assurance Mechanisms for Closure, Post Closure, and Corrective Action; and Wording of the Mechanisms for Closure, Post Closure, and Corrective Action) and §331.143 of this title (relating to Cost Estimate for Plugging and Abandonment). (b) An owner or operator subject to this subchapter may use any of the following mechanisms as specified in Subchapter C of this chapter to demonstrate financial assurance for plugging and abandonment: (1) trust fund (fully funded or pay-in trust), except that the executive director will respond in writing within 60 days to requests for reimbursement made in accordance with §37.201(j) of this title (relating to Trust Fund); (2) surety bond guaranteeing payment; (3) surety bond guaranteeing performance; (4) irrevocable standby letter of credit; (5) insurance; (6) financial test; or (7) corporate guarantee. (c) Owners or operators shall comply with §37.31 of this title (relating to Submission of Documents), except that evidence of financial assurance shall be submitted at least 60 days prior to commencement of drilling operations for new wells and for salt cavern disposal wells. All financial assurance mechanisms shall be in effect before commencement of drilling operations. For converted wells and other previously constructed wells, financial assurance shall be provided at least 30 days prior to permit issuance and be in effect upon permit issuance. (d) Owners or operators using a financial test or corporate guarantee must comply with §37.141 of this title (relating to Increase in Current Cost Estimate) except that mechanism increases must be made within 90 days after the close of each succeeding fiscal year.