(a) A petition for review of a proposed assessment of a civil penalty must be filed within 30 days of receipt of the proposed assessment; or

(b) If a timely request for a conference has been made pursuant to 30 CFR 723.18 or 845.18, a petition for review must be filed within 30 days from service of notice by the conference officer that the conference is deemed completed.

(c) No extension of time will be granted for filing a petition for review of a proposed assessment of a civil penalty as required by paragraph (a) or (b) of this section. If a petition for review is not filed within the time period provided in paragraph (a) or (b) of this section, the appropriateness of the amount of the penalty, and the fact of the violation if there is no proceeding pending under section 525 of the Act to review the notice of violation or cessation order involved, shall be deemed admitted, the petition shall be dismissed, and the civil penalty assessed shall become a final order of the Secretary.