So I was watching PBS Nature on Evolution. They were showing some chimpanzees who were living in a very hot weather and they went looking for water. Soon they came upon a pond of water which looked dark and dirty with dead stuff, with various mosquitoes etc swarming around the water. The chimpanzee examined it and decided not to drink it. Instead it proceeded to dig a 3 to 4 inch wide hole and probably a 5 to 6 inch deep one close to the pond. Pretty soon clean beautiful water starts forming in the hole it had dug - pretty much filtered by the sand. It then proceeded to drink it along with its kids. I thought this was a neat idea to try in the wild. I mean we have all come up with questionable water and usually decide not to take the water because of the quality - I have done this many times in some sections of CT and AZT. I am going to try this next time I come across a questionable pond/lake!!