(a) The Commission shall issue its final decision within 90 days after the date of the recommended decision or within 90 days after the date when objections to the recommended decision are filed or within 90 days after the conclusion of briefing by the parties, whichever comes later, unless the recommended decision is to dissolve or make permanent a temporary closure order issued under §573.4 of this chapter, in which case the Commission shall issue its decision within 30 days of the recommended decision.

(b) The Commission shall serve its final decision upon the parties.