Water treatment in the Enchantments

You’ll need lots of water on the trail, both to drink and to cook your dehydrated meals. Fortunately, there is no shortage of water sources in the Enchantments. Even in the middle of summer, you won’t go more than a mile or so on the trail without crossing a stream. When you camp, you’ll almost certainly be within walking distance of a lake.

However, it isn’t safe to drink this water without treating it somehow. Even in high alpine environments like the Enchantments, water usually contains pathogens and can make you sick if you drink it untreated.

There are numerous ways to treat water for drinking, and they have various pros and cons.

Types of pathogens

First, it’s important to understand that there are three major categories of pathogens in untreated North American water:

• parasite cysts (such as Cryptosporidium and Giardia)
• bacteria (such as Salmonella and E. Coli)
• viruses (such as norovirus and rotovirus)

Generally, parasitic cysts are the greatest threat to backpackers, followed by bacteria. Viruses pose less of a concern, mainly because while most cysts and bacteria can be transmitted between many kinds of animals, most viruses that affect humans also come from humans. The most likely way to catch a virus while hiking is to drink water that’s been tainted with another hiker’s poop, which is why it’s so important to dig a good cathole and poop far away from water sources (or better yet, use one of the many backcountry toilets).

Why do we care that there are different types of pathogens in backcountry water? Because some water treatment methods are effective against only some of these types.

Types of water treatment

Boiling kills all pathogens. Since you’re probably already planning to boil water to cook your dinners and breakfasts, you won’t need any further treatment. If you plan to boil your drinking water too, you’ll need to let it cool first—either in your cookpot or a heat-proof water bottle.

Water filters can remove parasites and bacteria from water, but not viruses (they’re small enough to pass through typical filter membranes).

Chemical treatments come in various forms. Iodine tablets and chlorine treatments are effective against bacteria, viruses, and some parasites, but are notably ineffective against Cryptosporidium. Chlorine Dioxide (not to be confused with elemental Chlorine) is the only chemical treatment that’s effective against all pathogens.

Our recommended system

Since cysts and bacteria are generally the greatest threat to hikers when drinking water in the backcountry, our favorite method of water treatment is a filter which removes these. Modern filters are lightweight, convenient, and leave no aftertaste in your water (unlike most chemical treatments).

A filter will not remove viruses, but we think that in most conditions in North America this is an acceptable risk. You can reduce the risk of ingesting viruses by avoiding water sources which are more likely to have been contaminated by human waste, such as lakes near campsites.

Our favorite filter is the thru-hiker favorite Sawyer Squeeze. We, like many others, use it paired with a reused Smartwater bottle. The bottle weighs just 38 grams (one-fifth as much as a Nalgene!) and the Squeeze screws right onto the top. You drink straight from the filter by squeezing the bottle gently. If you prefer, you can bring a second Smartwater bottle and squeeze all the water out of the “dirty” bottle and into the “clean” one, then drink from the clean one (just don’t mix them up!).

As a backup for your filter, we recommend that you carry Chlorine Dioxide tablets or drops. Popular choices are Aquamira drops or Katadyn Micropur tablets. A few of these weigh hardly anything, and will come in handy if your filter breaks or gets lost.