OK, but I'm hiking in the Cascade Mountains, not Bangladesh, or Africa, or a "developing nation." It is all snow melt spring runoff or fresh out of the ground. Understand, that I just added in my observations regarding personal hygiene being the culpret (sp?) for much illness in the mountains around here. As it turns out, I (almost) always filter my water and I always have my scouts filter their water. We use the MSR Miniworks.