I take a fairly relaxed attitude towards water treatment because I have made life decisions that allow living near and hiking in many relatively uncontaminated backcountry wilderness areas. Generally, it is easy to carry enough purified water from home to get far enough into backcountry wilderness areas beyond most contaminated sources. By referring to uncontaminated areas, I mean that my research has lead me to believe that any contaminants in these backcountry areas (especially protozoan cysts) are in such minute quantities that they are unlikely to cause serious problems. Part of this attitude is based on the belief that I have a fairly strong immune system to deal with potential contaminants. If my general health declines and I become more susceptible to illness, I would have to reconsider. Most important, I am willing to change my relaxed attitudes based upon new information.
Part of my more relaxed attitude towards water treatment is because I believe I have developed a better understanding about which water sources to trust and not to trust. Here is the link to a short article on the results of my research: Avoiding Poor Sources of Drinking Water. For example, most hikers assume that if a water source is clear and cold and running briskly that it has a low probability of being contaminated. This common attitude is not defensible. I carefully plan my trips around my knowledge of potential water sources
Having said all this, I occasionally take trips into areas that might have been compromised. I also take trips with those who feel strongly about water treatment and who insist on treating all of our drinking water. In both cases I willingly participate in treating all of our group water containers. On these trips, we carry not only a primary, but also backup water treatment methods.
As a backup, I always carry chemical water treatments (usually chlorine dioxide) if I can’t find dependable sources of water. However, in using chemicals one needs to be careful about the timing: use the chemicals before getting desperate. It is good to carry chemical water treatments for another reason: treated water is an effective hand and surface sanitizer as well as a potential source for cleaning wounds in the field.
Since it is likely that more people get sick in the backcountry from poor personal hygiene than from questionable sources of drinking water, I have become quite conservative about personal hygiene. I seldom share food with others for the same reason. I do what I can to encourage others to take their personal hygiene seriously in the backcountry.
To get a sense of the reasoning behind the above conclusions about backcountry water treatment, consult a much longer article on this topic. The sub-topics listed below are developed in this complete article: To Treat or Not To Treat The Water?
Working Definitions—Two Competing Approaches
Philosophies of Water Treatment: A Continuum
Reader Participation: Philosophy of Water Treatment
Arguments in Favor of Relaxed Approaches
In Favor of Conservative, Disciplined Treatment Backcountry Water
Conclusions and Final Thoughts About Treatment
Avoiding Poor Sources of Drinking Water
Additional Issues for Reflection