Backcountry users have three options for obtaining safe drinking water: filtration, pasteurization by heating, and halogenation with iodine or chlorine. If you use filtration, be sure to check the specifications of your filter (they do not all filter the same organisms) to be sure it does what you want it to do. If you disinfect your water by heating, make sure you get it to a rolling boil. Anywhere in the continental United States, that much heat should quickly kill the protozoas, bacterias, and viruses that harm humans.

Both filtration and pasteurization are relatively safe and simple. They are also slow and, in the case of filters, rather expensive, especially when providing water for more than a handful of people.

For these reasons, many outdoor programs rely on chemical treatments to provide adequate supplies of water for participants. The following list describes the most popular methods:

Laundry Bleach: 4%-6% sodium hypochlorite

Two drops per quart of water. Let stand for thirty minutes. Water should have slight chlorine odor; if not, repeat dose and let stand an additional fifteen minutes.

Halazone Tablets

Five tablets per quart of water. Let stand for thirty minutes. Defective Halazone tablets have an objectionable odor.

Tincture of Iodine, 2%

Five drops per quart of clear water, ten drops per quart of cloudy water. Let stand for thirty minutes.

Potable Aqua (Globuline-tetraglycine hydroperiodide)

One table per quart of clear water. Let stand for ten minutes. One tablet per quart of cloudy water. Let stand for twenty minutes. If water is very cold, let stand for thirty minutes.

Polar Pure (USP grade iodine crystals sold in a one-ounce glass bottle)

Add water to the bottle to make an iodine solution that you then add to your drinking water. Specific instructions and a temperature chart are printed on the bottle. Has the advantage of being very stable for long periods.

This article reprinted with the permission of the Wilderness Medicine Newsletter, a bi-monthly publication which focuses on the recognition, treatment, and prevention of wilderness emergencies. Subscription rates are $20 for one year, $37 for two years. Please address all correspondence to: Wilderness Medicine Newsletter, 1208 St. Francis Rd., Bel Air, MD 21014.

Please Read The Website Disclaimer!
Copyright 1986-2012, The Survival & Self-Reliance Studies Institute (SSRsi), All Rights Reserved
Site conceptualized, designed, created & maintained by MEG Raven
Snail Mail: SSRsi, PO Box 2572 Dillon, CO. 80435-2572