(a) The Administrator may, on his own initiative, review any determination by a State or its agent that a source owner or operator is or is not in compliance with applicable legal requirements or is or is not entitled to an exemption, to determine whether that determination conforms to the requirements of the Act and part 66 (as modified by § 67.11).

(b) The Administrator shall review any such determination upon receipt of a petition alleging that the State's determination does not conform to the requirements of the Act and part 66 (as modified by § 67.11). Such petition must be filed within 20 days of issuance of the State's decision.

(c) The Administrator shall give notice in writing to the State or local agent, to the owner or operator of the source, and to the petitioner of his intent to review the determination. Such notice shall be given within 90 days of the Administrator's receipt of the State or local agent's determination. Unless otherwise provided, such notice shall not withdraw EPA's delegation of authority to the State or local agent over the particular facility in question.

(d) No such State determination shall become final until the expiration of 90 days after the Administrator's receipt of the notice required by § 67.11(b)(5).

(1) If the Administrator does not issue a notice of intent to review within that period, the State determination shall, upon expiration of such period, constitute final action of the Administrator under section 120 of the Act.

(2) If the Administrator issues a notice of intent to review within that period, the State determination shall not become final until the Administrator takes final action after reviewing the determination.

(e) Except as otherwise provided, a State determination shall be approved if there was a reasonable basis in law and in fact for making the determination.