Madison Rock Services, Inc. agreed to work as a subcontractor on a sewer project, which Strandemo Paving, Incs was the general contractor. For drilling and blasting a certain amount of rock, Madison Rock Services was to be paid $29 per cubic yard or a time-and-materials basis, whichever is less. From the beginning, Madison experienced problems. The primary obstacle was a heaving concentration of water, which according to the custom of the industry, Madison should have controlled but did not. Madison was compelled to use more costly and time-consuming methods than anticipated, and it was unable to complete the work on time. Madison asked Strandemo to pay for the rest of the project on a time-and-materials basis. Madison signed a modification of the original agreement. On completion of the work, Strandemo refused to pay Madison the balance due under the modification. Madison filed suit in a court against Strandemo