Letter: Border Wall Construction Question

The continuous stream of heavy trucks hauling gravel and steel columns through Ajo on their way to border wall construction sites raises at least one puzzling question. Obviously, enormous quantities of water are required to install these columns, yet the trucks are not hauling water. Recent revelations are that the private contractor is drilling wells to obtain water from the immediate construction area. The question: How much is the contractor paying for the public water he's consuming? Inasmuch as water in this desert area is a scarce commodity, then according to the laws of the free market, it ought to command a premium price. Getting an answer to the question of the price paid by the private contractor for the public water has proved exceedingly difficult. No-one seems to know or to be willing to divulge the answer. Perhaps another reader knows the answer to this not unimportant question?