225 ILCS 720/3.12
Surface mining shall not be permitted within five hundred feet from active and abandoned underground mines except as provided in this Section. The Department may permit an operator to mine near, through or partially through an abandoned underground mine or closer than five hundred feet to an active underground mine if (1) the nature, timing, and sequencing of the approximate coincidence of specific surface mine activities with specific underground mine activities are jointly approved in accordance with law under laws concerned with surface mine regulation and the health and safety of underground miners, and (2) such operations will result in improved resource recovery, abatement of water pollution, or elimination of hazards to the health and safety of the public.
225 ILCS 720/3.12