Lump Sum Bids Based Upon Undefined Quantities: Who Bears the Risk?

On a summary judgment motion, a U.S.D.C. court out of South Dakota addressed the question of a subcontractor who contracted for undefined quantities of work on a lump sum basis, then performed over 50% more work than the parties originally contemplated.  The case is United States ex rel. Black Hills Hydro-Turf, Inc..., 2012 U.S. Dist. LEXIS 187530 (December 19, 2012), and the court essentially held that in such a case, yes, the subcontractor would bear that burden.  However, because it was not clear from the pleadings exactly what the work consisted of, and whether any of it was outside the scope of the parties' original contract, the court denied summary judgment on the part of the defendant general contractor.