Any penalty imposed or abatement or remedial action ordered by the Commission or the Executive Director shall be paid or completed within such time period as shall be specified in the civil penalty assessment or order. The Executive Director and Commission counsel are authorized to take such additional action as may be necessary to assure compliance with this subpart. If a proceeding before a court becomes necessary, the penalty amount determined in accordance with this part shall constitute the penalty amount recommended by the Commission to be fixed by the court pursuant to section 15.17 of the compact.