Barely a day goes by without a major newspaper article speculating on the shutdown of Big Bertha, the tunnel boring machine presently stuck underground only 1,000 feet into the two-mile long SR 99 Alaskan Way Viaduct Replacement Project. It now appears that Big Bertha will be inactive until September 2014. The tunneling crews are digging a 120-foot deep pit to fix the bearings and seals on the cutter head of Big Bertha. In the meantime, much of the work on the project has come to a halt. Before Big Bertha can be rescued, dozens of boring probes need to be made to see if ancient Native American artifacts or other archaeological items exist in the area where the 120-foot deep pit is being excavated.
Last month, contractors working in the South Lake Union neighborhood (where Amazon employees enjoy their morning espresso) discovered an ice age mammoth tusk that was at least 16,000 years old. Paleontologists have removed the tusk to the University of Washington’s Burke Museum of Natural History and Culture. The discovery of the mammoth tusk and possible Native American artifacts raises the question as to whether these unforeseen subsurface conditions are “differing site conditions” and thereby compensable events for the contractor.
The plans and specifications for the projects certainly did not disclose a mammoth tusk or Native American artifacts might be uncovered at the particular site. As a result, in order to obtain compensation for the unforeseen subsurface condition, the contractor would have to show that what was encountered was a Type II differing site condition. A Type II differing site condition is one that “differs materially from those ordinarily found to exist and generally recognized as inherent in construction activities of the character provided for in the contract documents.” Read our article on differing site conditions Differing Site Conditions.
In this instance, the mammoth tusk would seem to qualify as a Type II differing site condition, but it may be questionable whether Native American artifacts – particularly in the coastal Puget Sound area – are Type II differing site conditions. Ultimately, the contract provisions of the particular project will dictate whether the uncovered fossils or artifacts qualify as differing site conditions. For example, the AIA General Conditions (2007) in § 3.75 specifically recognize human remains and archaeological sites may qualify as a differing site condition and provide the contractor with the means for an equitable adjustment if those unforeseen subsurface conditions are encountered.
Comment: When the contractor discovers human remains, archaeological sites, wetlands, mammoth tusks, etc. not indicated in the contract documents, it should always promptly notify the owner or architect/engineer of the discovery and suspend operation until the owner provides direction as to how to proceed. Prompt written notice of the conditions is particularly essential if the contract contains strict notice and claim provisions.