225 ILCS 730/3
All geophysical logs and well drilling reports supplied to the Geological Survey in accordance with the provisions of this Act, all sample descriptions compiled by the Survey from examination of drill cuttings or cores, and all completion reports received from the Department of Natural Resources shall be available for public inspection except as to the information that the permittee of the well requests be kept confidential. The requirement that the Geological Survey keep certain information confidential shall not prohibit the use of the information for research purposes, provided the Survey does not publish specific data or identify the well from which the data were taken or interpreted. No such information shall be kept confidential for more than 2 years from the date the permit was issued.
225 ILCS 730/3