225 ILCS 705/31.29

In a gassy mine, all workings which are abandoned after the effective date of this Act, or the date such mine was classified a gassy mine, whichever is later, shall be sealed or ventilated. If such workings are sealed, the sealing shall be done in a substantial manner with incombustible material; however, some other type of material may be used provided prior approval has been obtained from the Mining Board. One or more of the seals of every sealed area shall be fitted with a pipe and cap or valve to permit the sampling of gases and the measuring of hydrostatic pressure behind such seals. For the purposes of this Section, workings within a panel shall not be deemed to be abandoned until such panel is abandoned.