This Act shall not apply in any municipality that provides for the registration of recyclable metal purchased by resolution, ordinance or regulation that substantially complies with the substantive provisions of this Act or any rule or regulation hereunder with the exception of the penalty provisions. The fact of such nonapplication shall be evidenced by a certificate of exemption issued by the Department of State Police or such department as may succeed to its functions, if it finds that a municipal resolution, ordinance, or regulation meeting such requirements is being enforced. The certificate of exemption shall be available for inspection in the office of the municipal clerk. This Act does not apply in municipalities with populations of 1,000,000 or over.