415 ILCS 30/6b
Except as provided in Section 14.2 of the Environmental Protection Act, the owner of every potable water supply well which has been contaminated due to the actions of the owner or operator of a potential primary or potential secondary source or potential route shall be provided an alternative source of potable water of sufficient quality and quantity, or treatment of the waters from such well to achieve a sufficient level of quality and quantity appropriate to protection of the public health, or such other remedy as may be mutually agreed upon by the well owner and the owner or operator of the potential source or potential route. For purposes of this Section, contamination shall mean such alteration of the physical, chemical or biological qualities of the water as to render it unfit for human consumption, or to otherwise render it unfit for use as potable water as measured by applicable groundwater quality standards which are adopted by the Pollution Control Board. All costs of providing alternative or treated potable water supplies under this Section shall be borne by the responsible owners and operators of the contamination source and route. This Section shall apply only to actions of an owner or operator which occur after the effective date of this Section and for which there is adequate reason to believe that a relationship exists between the potential source or potential route and the contaminated well.
415 ILCS 30/6b