225 ILCS 320/36

Governmental units which are authorized to regulate plumbing and the fixtures, materials, design and installation methods of plumbing systems may adopt a minimum code of standards pursuant to local ordinance at least as stringent as the minimum code of standards promulgated by the Department, or may by ordinance or resolution, adopt the minimum code of standards, promulgated by the Department. The minimum code of standards promulgated by the Department may be incorporated in the ordinance or resolution by reference.