A geotechnical report provided by the owner indicated that soils excavated for a parking garage would consist of silty clays that were suitable for use as structural fill under a new building to be erected on the site. The contractor's bid relied upon using that excavate for fill. However, on performing the excavation, no silty clays were found. Shale was found instead. Because this shale was unsuitable for fill, the contractor had to purchase fill from a borrow pit and haul it onto the site at her own expense. The contractor made a site visit before bidding. The shale formation was concealed under at least one foot of top soil and could not have been discovered during that site visit. The owner-contractor agreement is silent about differing site conditions.

Is the owner responsible for the cost of the fill material?