620 ILCS 5/39
Subject to the provisions of Section 41, all contracts for the acquisition, construction, development, improvement, operation and maintenance of air navigation facilities in this State made by the Department, with the exception of the construction of military housing as part of an agreement with the U.S. Air Force to rebuild Cardinal Creek Housing and 2 grade schools as it relates to the Scott Joint-Use Airport in St. Clair County, which shall be the responsibility of St. Clair County utilizing building and bidding procedures as it deems appropriate, either on behalf of this State or as the agent of any municipality or other political subdivision, when acting at the express request of such municipality or other political subdivision, shall be awarded, made and entered into as are contracts for the performance of State work or for the construction of improvements constructed by the State of Illinois; provided, however, that where the acquisition, construction, development, improvement, operation and maintenance of any air navigation facility is financed wholly or partially with Federal monies, the Department, in behalf of the State or of any municipality or other political subdivision thereof, may let contracts and cause the performance thereof in the manner prescribed by the Federal authorities, acting under the laws of the United States, and any rules or regulations made thereunder, notwithstanding any other State law to the contrary.
620 ILCS 5/39