(30 ILCS 557/10)
If a contract between a contractor and a
governmental entity for an improvement exceeds $75,000, all of the
following provisions apply to that contract:
(1) If a contractor discovers one or both of the following physical
conditions at the surface or subsurface of the site, the contractor must notify
governmental entity of the condition, in writing, before disturbing the
(A) A subsurface or latent physical condition at the
site differing materially from conditions indicated in the contract.
(B) An unknown physical condition at the site of an
unusual nature differing materially from the conditions ordinarily encountered and generally recognized as inhering in work of the kind provided for in the contract.
(2) If the governmental entity receives notice from the contractor under
subdivision (1), the governmental entity must promptly investigate the physical
(3) If the governmental entity determines that the physical condition (i)
does materially differ from the conditions indicated in the contract or
ordinarily encountered in
the work of the kind provided for in the contract and (ii) will cause an
increase or decrease in the costs or time needed to perform the contract, the
governmental entity must make an equitable adjustment to and modify the
contract in writing.
(4) The contractor may not make a claim for additional costs or time because
of a physical condition at the site, unless the contractor has provided notice
to the governmental entity under subdivision (1).
(5) The contractor may not make a claim for an adjustment
after the contractor has received a final payment under the contract.
(Source: P.A. 91-647, eff. 11-30-99.)