This filter is supposed to be one of the better ones (supposed to be) I think that where the water is taken is of more concern than what the filter will take out. If I know that we will be stopping to camp in a short time Greg you have seen the Google Maps water is in abundance in the BOB. It wouldn't be hard to get the water as high in the source and then bring it back and BOIL THE CRAP OUT OF IT let it cool and then run it thu the filter. John the Forest Service. guy spends many days in the forest each spring summer fall and only uses iodine and a filter. Ive been sick in 3rd world countries and dont want to take a chance.