Pine Barrens (New Jersey)
Because there is so much sand and acid in the soil, people did not want to make farms in the Pine Barrens.  But the water in the Pine Barrens was very pure.  Sea captains liked to take water from the Pine Barrens with them on long trips because it did not go bad quickly.  The iron in the soil and tannin chemicals from the cedar trees kept bacteria from turning the water bad.