As I have stated before, differing site condition claims remain fairly common. They can also one of the most difficult claims for a contractor to prove at trial. There are two types of differing site condition claims–Type I and Type II.
Generally, a contractor may make a Type I differing site condition claim where the contractor encounters a subsurface or latent physical condition at the project site that differs materially from the conditions indicated in the parties’ contract.
Under a Type II claim, a contractor may assert a differing site condition claim where there are unknown and unusual physical conditions at the project site that differ materially from those ordinarily encountered and generally recognized as inherent in work of the character provided for in the parties’ contract.
The United States Court of Federal Claims recently considered a contractor’s $10.5 million differing site condition claim in Nova Group/Tutor-Saliba, Joint Venture v. United States.