Treat or Not To Treat The Water?—Conservative vs Relaxed Philosophies


The choice I have made this year is to drink unfiltered water. I find it quite liberating to leave my city-bred paranoia (and one more technological artifact) behind, and go ahead and indulge myself in one of nature's great treasures—clean, clear mountain snowmelt, or better yet, a spring flowing straight from the rock. Most of the people in the world will never in their lifetimes see water as pure as the water most of us are taught to filter religiously.

—unknown author

As for those who drink straight from the source without filtration or purification, I suspect you've never gotten gut-wrenching, high-fever, diarrhea-running sick, 30 miles from the trail head. One of those and you stop taking chances.

—unknown author

Central Issues Addressed In This Article

Should I assume all backcountry sources of water are contaminated and take the appropriate treatment steps or should I take a more situational approach? What are the pros and cons of taking a conservative and highly disciplined approach to water treatment in the backcountry versus taking a more relaxed, laissez-faire approach? What are the best sources of backcountry drinking water?


Water contamination can be grouped into three types: biological, chemical and aesthetic. Chemical contamination is commonly found in the frontcountry and is ordinarily not a problem in the backcountry with the exception of being around mining sites. Aesthetic contamination is material suspended in the water that may not cause illness itself, but looks unattractive and can interfere with removal of the other two. The most common aesthetic water contaminations in the backcountry are algae, silt, glacial flour, or volcanic ash. Biological contamination is the primary focus of this article. Biological contaminants are generally grouped into three types: parasites (or protozoa), bacteria, and viruses. Parasites (or protozoa) are the primary concern in backcountry areas of North America.

With this background, what about the treatment of backcountry water, especially for parasites? Surprisingly, it is common to find backcountry travelers on both sides of this issue. There are many who seldom treat or filter their water, who claim to have gone for years without problems. There are some who religiously treat all of their water sources and still get sick. Having said this, most hikers these days seem to be routinely treating their water most of the time in the backcountry. This is also the position of most hiking and backpacking book authors. The most balanced treatment of this topic I have come across is from REI’s online Expert Advice resource: Is Water Treatment Necessary?

At first take, the central issue seems to be technological: are there effective, lightweight, easy to use and relatively inexpensive treatment methods available for hikers? The answer to this question is an obvious yes. For a detailed overview of nine different types of water treatment currently available for the backcountry, click on this link: Treatment Options.

Upon closer analysis, this topic should be viewed as both a scientific and a philosophical issue. The scientific issue revolves around available studies regarding the types and levels of water contamination. When I say that this issue can be viewed philosophically (i.e., opposing positions with interesting arguments supporting a wide range of positions), I am sure some would disagree by saying that there is no real issue: if there is any doubt at all, treat. If this is your position, read no further. If your mind is not already made up and you are interested in a serious philosophic debate, read on.

Assuming this is a serious issue (of whatever kind), what is the most defensible approach? Should I treat or not? Before debating these approaches, let’s first clarify and define the positions. I start by offering working definitions for the two approaches. I then offer thumbnail sketches of a full range of philosophical positions.

Working Definitions—Two Competing Approaches

Here are behaviors common to the two competing approaches. The sum of these behaviors will provide a good working definition for each approach.

Conservative, Highly Disciplined Approach:

  • Treat or disinfect all water sources by filtering, ultraviolet purification, chemically disabling harmful organisms or boiling.
  • Be careful not to contaminate already treated water.
  • Carry backup methods of treatment in case the primary method fails.
  • Be careful where the water to be treated is drawn.

Relaxed, Laissez-faire Approach:

  • Undertake a careful study of potential water resources in advance of a trip in order to draw primarily from pristine sources.
  • Carry extra water between pristine sources, if necessary.
  • Treat water drawn from sources close to trailheads, from sources close to domestic or wild herds of animals or from heavy concentrations of hikers.
  • Trust that most backcountry sources are not contaminated when you get any distance away from trailheads.
  • Carry emergency treatment methods in case the reality in the field turns out to be different from what was expected.

Philosophies of Water Treatment: A Continuum

Within the conservative and relaxed approaches defined above is a full range of options and attitudes on this subject. This is not a black/white, either/or issue. The following thumbnail sketches are intended to go from one end of a continuum to the other.

 —Be suspicious of all water sources. Treat or disinfect all water, even that carried to the trailhead (i.e., coming from known and dependable private or municipal water systems).

 [Plus eight more distinct water treatment philosophies identified]


 The above paragraphs provide a preview of the complete article (approximately 19 pages) available as a free download.  Click on one of the following to download in either a Word or PDF format.

To Treat or Not To Treat The Water—Conservative vs. Relaxed Philosophies? – Word Format

To Treat or Not To Treat The Water—Conservative vs. Relaxed Philosophies? – PDF Format

The sub-topics listed below are developed in the complete article:

Working Definitions—Two Competing Approaches 

Philosophies of Water Treatment: A Continuum

Reader Participation: Philosophy of Water Treatment

In Favor of Relaxed or No-Treatment Approaches

In Favor of Conservative, Disciplined Treatment of Backcountry Water

Conclusions and Final Thoughts About Treatment

Avoiding Poor Sources of Drinking Water

Additional Issues for Reflection