Section 225 ILCS 720/4.09 - HydrologyThe operator shall minimize the disturbances of the prevailing hydrologic balance at the minesite and in associated offsite areas and to the quantity of water in surface and ground water systems both during and after underground coal mining operations and during reclamation by-
(a) avoiding acid or other toxic mine drainage by such measures as, but not limited to- (1) preventing or removing water from contact with toxic-producing deposits;(2) treating drainage to reduce toxic content which adversely affects downstream water on being released to water courses;(3) casing, sealing, or otherwise managing boreholes, shafts, and wells to keep acid or other toxic drainage from entering ground and surface waters; and(b) conducting underground mining operations so as to prevent, to the extent possible using the best technology currently available, additional contributions of suspended solids to streamflow or runoff outside the permit area (but in no event shall such contributions be in excess of requirements set by applicable State or Federal law), and avoiding channel deepening or enlargement in operations requiring the discharge of water from mines.