Water Purification for Backpackers

There was a time not so long ago that people wandering out among the wilderness could stop by a flowing creek or stream and take a drink of the refreshing water, but these days, it's not advised due to any number of possible organisms that might be present. The Environmental Protection Agency (EPA) has given estimates that at least 90 percent of the water in the world is polluted or contaminated by chemicals, bacteria or viruses. This isn't a very comforting thought. So what do you do if you want to go hiking or backpacking and you run out of fresh water?

Luckily, there are several effective methods of purifying water. However, backpackers and hikers also need to be careful when dealing with contaminated water even when not drinking it. Infections can happen if the water is on the hands and then someone handles food or otherwise allows their hands to get into their mouths. Always wash hands thoroughly after touching stream or creek water. Washing up with contaminated water is never a good idea. One of the best ways to prevent infection is by boiling the water. Most pathogens will be killed at temperatures above 185 degrees Fahrenheit, so just to be sure, it's a good idea to let the water boil (212 degrees Fahrenheit) for a couple of minutes. If boiling isn't possible, there are chemical methods to purify the water. Backpackers can buy purification kits that contain either iodine or chlorine and will disinfect the water. There are liquids and tablets available. Most of these have expiration dates, so care must be taken not to use expired kits. Some are also sensitive to the temperature of the water and may not be completely effective at certain temperatures. The colder the water, the more difficult it will be to purify.

With the chemical treatment, the water will need to sit for half an hour or more to assure that the contaminants are killed. If using the tablets, they must be allowed to completely dissolve. Some parasites like Giardia won't be killed effectively if the water is too cold. In cases of cold water, twice as much of the chemical treatment might be needed. Iodine has to be kept in a dark bottle because it's sensitive to light and will lose effectiveness otherwise. Water at or above 68 degrees Fahrenheit is best and about 5 drops of iodine for every quart of water is a good rule to follow. However, some people are allergic to iodine, so they should never use this method. There are special iodine treatment bottles available at most backpacking supply stores. Iodine treatment also comes in tablet form.

There are also several different types of water filters available, but these have varying sizes of filters, most of which won't be small enough to filter out viruses. Giardia, however, will probably be effectively strained out. For filtering Giardia, a 5 micron screen will be needed, but bacteria will need a 0.2-0.5 micron filter. Whatever treatment system is preferred, it's probably a good idea to carry a backup treatment as well, just in case.