Water Purification: Myths vs. Reality

There is a dangerous myth in the outdoor community that high-altitude water is "pure." As a Colorado native, I can tell you: a moose doesn't care about elevation when it relieves itself upstream.

Understanding the difference between filtration and purification is critical for anyone venturing more than a few miles from a tap.

Filtration vs. Purification

Filtration physically removes particulates and protozoa (like Cryptosporidium and Giardia) and most bacteria. It works like a sieve.

Purification kills or removes viruses (Hepatitis A, Norovirus) in addition to everything else. In North America, filtration is usually enough. But if you are prepping for a disaster scenario where sewage infrastructure fails, you need purification.

The Boiling Standard

The gold standard remains boiling. A rolling boil for 1 minute (3 minutes above 6,500 feet) kills everything. It's 100% effective, but it consumes fuel and time.

Chemical Treatment

Chlorine dioxide drops (like Aquamira) are superior to iodine, which tastes terrible and is less effective against Crypto. They are lightweight and reliable, but take time to react—up to 4 hours for cold, dirty water.

Mechanical Filters

Ceramic and hollow-fiber filters (Sawyer, Katadyn) are excellent for backcountry travel. However, they can freeze and crack in winter conditions, rendering them useless without you knowing. Always sleep with your filter in your sleeping bag during winter months.

My personal setup? A Sawyer Squeeze for quick drinking, backed up by boiling capability (stainless container) for true redundancy.