Drinking contaminated water in the backcountry can spell a quick end to your backcountry camping trip. Pathogens can contaminate any water supply and are invisible to the naked eye so it's always wise to purify any water before drinking.

These microscopic disease-causing organisms are commonly referred to as germs. This is a broad category that includes bacteria, viruses, fungi and parasites. The main waterborne pathogens to worry about are Protozoa, Bacteria, Virus, and Multicellular Parasites.

There are plenty of good water filters on the market to rid your water of pathogens and many are small and light enough for multi-day backcountry camping trips. MSR has put out a handy guide about water treatment which will educate you on the dangers of contamination and help you decide what kind of water filter to purchase. Read MSR's Water Treatment Guide here.