I agree with esshup on the good dirt. If you collect any good topsoil on your property while using heavy equipment, try to keep it separate from your sand spoils as much as you reasonably can.
It is way easier to make attractive surroundings with good dirt that you only have to move 50 yards, compared to trucking in topsoil.
P.S. Have you taken any good water samples from your pond and submitted them to a lab to check the levels of the known contaminants on the property? I would hate to see you spend a lot of money on a pond project, only to find out that your pond water cannot support fish, or that you cannot eat any of the fish you catch.
Further, if the pond property is "contaminated" to some government standard, but not so contaminated that it would affect recreational usage, then I would warn that piling up sand MIGHT facilitate the release of essentially immobile contaminants into your pond water or new hunting cabin yard.
Contaminants in ground water can become static and stay in place near the site of the original pollution source. Especially if there is very little gradient for movement or subsurface flow of the ground water. However, if you excavate water-laden sand that is polluted and place it in spoils piles above grade, then the sand will be subject to flushing by each subsequent rain event. Over time, you may wash all of the contaminants out of the piled sand and mobilize them into your pond water. (Depending on the type of contaminant and some other variables.)
