Ill. Admin. Code tit. 62, § 245.1000 – Plugging and Restoration Requirements

a) The permittee shall perform and complete plugging of the well and restoration of the well site in accordance with the Illinois Oil and Gas Act and any and all rules adopted under that Act (62 Ill. Adm. Code 240.Subpart K). The permittee shall bear all costs related to plugging of the well and reclamation of the well site.
b) If the permittee fails to plug the well in accordance with this Section, the owner of the well shall be responsible for complying with this Section. (Section 1-95(a) of the Act)
c) Special Plugging Requirement
If the permittee stimulates the geologic formation in accordance with the permit using a high volume horizontal hydraulic fracturing process, then once commercial production ceases from the well and it is time to plug the well, in addition to all the other requirements, the permittee shall initiate the plugging process using a circulation method starting at the top of the geologic formation stimulated installing a cement plug at least 100 feet above the top of the geologic formation.
d) Upon completion of the requirements of this Subpart J, the Department will release the permit in accordance with Section 245.350.