225 ILCS 725/19.4
The fact that any person has initiated or supported a proceeding before the Department or has remedied or attempted to remedy the condition of any well under the authority of this Act shall not be construed as an admission of liability or received in evidence against such person in any action or proceeding where responsibility for or damages from surface or subsurface pollution, or injury to any fresh water or oil or gas bearing formation is an issue, nor shall such fact be construed as releasing or discharging any action, cause of action, or claim against such person in favor of any third person for damages to property resulting from surface or subsurface pollution, or injury to any fresh water or oil or gas bearing formation, to the extent that any such action, cause of action or claim may have existed prior to the initiation or support of such proceeding or such remedying or attempted remedying of the condition of such well.
225 ILCS 725/19.4