(a) Any party adversely affected by a final decision may file a petition in the appropriate United States Court of Appeals for review of the decision under 42 U.S.C. 3612(i). The petition must be filed within 30 days after the date of issuance of the final decision.

(b) If no petition for review is filed under paragraph (a) of this section within 45 days after the date of issuance of the final decision, the findings of facts and final decision shall be conclusive in connection with any petition for enforcement.