“Hikers drink water from runoff and other nearby water sources. Disease anyone?”
Honestly? Anyone drinking surface water without treating it first, is looking for disease regardless.
http://www.dhpe.org/infect/giardiasis.html
The Giardia parasite is found in every region of the United States and throughout the world. Giardiasis occurs often in mountainous areas where water supplies from lakes, ponds, or streams have become contaminated with animal droppings or human waste.
If you people really want to not be a burden to nature then maybe you would reconsider living because every day you spend on this earth eating, drinking, clothing yourself, housing yourself, warming yourself, cooling yourself, entertaining yourself and defecating you are a burden.