Orion, a mining company in Canada, is considering a mining project that will have an

initial cost of $25 million and generate revenues of $18 million per year for three

years. During the fourth year, the mine will be shut down and there will be

substantial clean-up costs to restore the land to its original state, (a process that will

be completed during the fourth year.) Orion is also considering an alternative mining

project which will cost $12 million and generate revenues of $6 million per year for

four years but which does not involve clean-up costs. Orion's weighted average cost

of capital is 12%. What must be the clean-up costs on the first project for Orion to

be indifferent between the two projects?