(a) The Department and the Commission shall work cooperatively with each other and with other entities in the federal and State governments to ensure that the policies embodied in the Federal Act, the Illinois Gas Pipeline Safety Act, this Act, the Illinois Oil and Gas Act, the Public Utilities Act, and the rules adopted thereunder are fully effectuated. The Department and the Commission shall take steps to avoid the duplication of efforts while at the same time ensuring that all regulatory obligations are fulfilled. As long as the Department submits to the Secretary of Transportation annually the certification described in 49 U.S.C. § 60105(a), and the certification is not rejected under 49 U.S.C. § 60105(f), the Department shall have jurisdiction over the downhole portion of underground natural gas storage facilities subject to this Act. The Commission shall retain jurisdiction over all other portions of the underground natural gas storage facilities.
     (b) Nothing contained in this Act is intended, nor shall it be construed, to limit or diminish the authority of the Department under the Illinois Oil and Gas Act or the Commission under the Public Utilities Act.