Ill. Admin. Code tit. 8, § 675.30
b) A written notification to the local unit of government with a public water supply well located within one mile of a proposed high capacity well shall be made to the chief executive officer of the local unit of government. The notification shall be mailed within five (5) working days of having received written notification of the proposed high capacity well by the land occupier or owner. The letter of notification to the local unit of government shall contain the following information: