A specially benefited zone may be terminated by joint action of the Governor and the designating municipality. The designating municipality shall conduct at least one public hearing within the zone before adopting its ordinance of termination. The mayor of the designating city or the chair of the governing body of the designating county shall execute with the Administrator a joint agreement for termination of the zone. The termination of a specially benefited zone does not become effective until at least 6 months after the execution of the terminating agreement, which must be filed in the Office of the Secretary of State.