(a) Exemptions pursuant to § 66.31(a) (1), (2), (3), and (5) will cease to be effective upon termination or revocation of the order on which the exemption is based.

(b) Exemptions pursuant to § 66.31(a)(4) will cease to be effective when the order or decree is terminated or revoked, or the inability to comply ceases to be for reasons entirely beyond the control of the source owner or operator as defined in § 66.31(c).

(c) Exemptions granted pursuant to § 66.32 or § 66.33 shall terminate at the time specified in the exemption.

(d) The Administrator shall notify the source owner or operator, in writing, that the exemption has terminated, and shall specify the date from which the penalty shall be calculated. The notice shall be transmitted as required by § 66.12. The source owner or operator shall respond to this notice within 45 days of its receipt and in the form provided in § 66.13.