220 ILCS 15/3
Upon the filing of the application specified in Section 2 hereof, the Commission shall set a date for a hearing thereon, and said corporation shall thereupon cause notice of said hearing to be given by publishing notice thereof at least once each week for three successive weeks in some newspaper of general circulation in the county or counties wherein the gas is proposed to be stored, the first such publication to be at least 21 days prior to the date of the hearing. Any order approving the proposed storage project shall not be operative against any privately owned interest in any tract of land, unless notice of said hearing be sent at least 21 days prior thereto by registered mail to the record owner thereof to his last known address as disclosed by the records of the Tax Collector of the county wherein such land is located, proof of which shall be made by affidavit filed in the proceeding.
220 ILCS 15/3