>>188725Just get a Lifestraw. Bloody incredible.
I carry around one/two of those stainless steel water bottles, and a lifestraw. My last couple of camp-hikes had plenty of running water not far from the trail, so i could just fill up, and drink at will.
It's distributed all over to third-world countries, and is extremely effective at purifying and filtering water that's otherwise unsafe to drink. Should last you a year of full use - a tip though, if after your trip you'll have a long hiatus, leave the lid open for a while before you store it away so it can air out.
http://en.wikipedia.org/wiki/LifeStraw 
