Owners or operators subject to this subchapter may use the following financial assurance mechanisms:(1) a certificate of insurance to demonstrate automobile liability coverage; and(2) an MCS 90 form or letter of credit to demonstrate pollution liability coverage. The letter of credit is subject to the requirements specified in §37.231 of this title (relating to Irrevocable Standby Letter of Credit), except:(A) whenever the terms "closure," "post closure," "corrective action," or "current cost estimate" are cited, replace with "pollution liability"; and(B) in §37.231(h) of this title, the following statement will be added: "Failure to obtain alternate insurance coverage and submit evidence of such coverage to the executive director before the effective date of the cancellation will result in revocation of the registration."