615 ILCS 5/18d
No agreement permitting the right to take earth, stone, sand or gravel, or combination or combinations thereof, coal, gas, oil or other mineral or substance, shall be made which by its terms permits such a taking for a period of over 5 years.
Every person, firm and corporation, with whom any such agreement is made by the Department of Natural Resources, shall furnish said Department a surety bond, for the use of the People of the State of Illinois, with good and sufficient sureties and in such amount as is acceptable to such Department, to secure the payment of the amounts agreed upon for the taking of such earth, stone, sand, gravel, minerals, substances, or the building of any causeway, harbor or mooring facilities for watercraft, and to save the State of Illinois harmless to any damages caused by any such person, firm or corporation in connection with the taking of any such earth, stone, sand, gravel, minerals, substances, or the use and occupation of State owned lands for watercraft facilities.
Every person, firm, corporation, municipal corporation, political subdivision or governmental unit or agency thereof which by any agreement is permitted to take any such earth, stone, sand or gravel, minerals or substances, and is required to make compensation therefor, shall report to the Department of Natural Resources, on or before the fifteenth day of each calendar month, the amount of such earth, stone, sand, gravel, minerals, or substances taken by him, them or it during the next preceding calendar month and make payment therefor.
Payment for earth, stone, sand or gravel or combination or combinations thereof so taken, shall be for each cubic yard of such material based upon quantities determined by the Department of Natural Resources by means of commonly used engineering methods of measurement of such earth, stone, sand or gravel.
Payment for coal, gas, oil or other minerals or substances shall be at the price per pound, ton, cubic foot, gallon, cubic yard or other commonly used applicable unit of weight or measure at the unit price bid by the highest responsible bidder based upon quantities determined by the Department of Natural Resources by means of commonly used engineering methods of measurements of such coal, gas, oil or other minerals or substances.
The Department of Natural Resources has the right of access to and the right of examination during reasonable business hours of all books, records, papers and memoranda of any person, firm, corporation, municipal corporation, political subdivision or governmental unit or agency thereof, with whom it has any such agreement permitting the taking of any such earth, stone, sand, gravel, coal, gas, oil or other minerals or substances for compensation.
615 ILCS 5/18d