Operating 239 mines without environment clearance: In September 2011, CAG criticised CIL for operating 239 mines in seven coal producing subsidiaries, which existed prior to 1994, without environmental clearance.[28][29] These mines included 48 open-cast, 170 underground and 21 combined mines. In its report, the CAG also pointed out that of the 18 sample open-cast and eight underground mines, ten mines had undertaken capacity expansion without environmental clearances.