Faecal Contamination of Drinking Water in Wilderness Areas
A report available from the Sustainable Tourism Cooperative Research Centre titled Human Waste Contamination At Huts And Campsites In The Back Country Of Tasmania prepared by Kerry Bridle, Jamie Kirkpatrick & Julie von Platen illustrates the nature of the problem in environments considered to be pristine. They note that:
"Water quality around many of the huts
and campsites along walking tracks around the State may not pass
Australian water quality guidelines ... Research into water quality
around some of the major overnight locations in the Tasmanian
Wilderness World Heritage Area (WHA) showed that ... very few places
passed NWQMS (1996) guidelines for drinking water quality..."
The conclusion is that
"...poorly buried faecal waste is a public health risk to walkers. While soil and vegetation may not be adversely affected by increased nutrient levels, contamination of soils and water from faecal pathogens does occur. Pathogens can remain in the soil for over 12 months, even where deposits are no longer visible."
Although the report looked at human faecal contamination, it is important to remember that native wildlife is also a source of contamination and that herbivores can also spread Giardia. Since these pathogens are invisible to the naked eye the water may look very inviting but could have the potential to make the camping trip a very miserable one indeed.
It is very important that all water be purified before being used. "Used" in this context means not just drinking or cooking with water but also activities such as washing fruit and vegetables, and brushing teeth. The methods of water purification most commonly employed are boiling, chemical sterilisation, or some form of mechanical purification.
Boiling is a simple method but requires fuel to heat the water, a boiling time of around 10 minutes, and then involves a waiting time while the water cools - unless, of course, you are making a hot beverage. If you are hiking, then the time to heat and cool the water must be factored into any estimates of the total hiking time. Boiling can be effective in killing pathogens but does not remove many other contaminants. Further, if you are hiking at altitude the boiling point of the water is lowered and could possibly not be high enough to kill all pathogens.
Chemical sterilisation involves adding a chemical to the water (e.g, sterilisation tablets) or passing the water through a chemically treated device such as a sterilising straw and allowing the chemical to kill any bacteria. The effectiveness of this method depends on the chemical used, the strength at which it is administered, and the length of time over which it is allowed to act. Chemical sterilisation suffers from the disadvantages of adversely affecting the taste of the water, not removing other contaminants, and requiring sufficient time to work.
Mechanical purification, if done properly, avoids the disadvantages of the other two methods. A well-designed water purifier suitable for camping or hiking use is lightweight, does not require chemicals or electricity and purifies water when it is required without any waiting time. Ideally it also provides some method of allowing the user to determine whether it is operating correctly, i.e., that the purifier is not passing through any contaminants to the output water. Such water purifiers do exist and it is worthwhile seeking them out before embarking on the next camping or hiking trip. They can provide peace of mind knowing the water you are drinking, or brushing your teeth with, is safe - and tastes great.