Should I Drink It?
An Overview of Water Purification
By Tim Sprinkle
I'd venture to guess that anyone who's spent time hiking, camping, or paddling with their parents in the last 30 years knows "The Deer Story." The way I remember it, unsuspecting hikers #1 and #2 are heading through the woods when #1 decides that he needs to refill his water bottle. He then proceeds to dip into the babbling mountain brook nearby and take a long, cool drink. #2 needs water too, but is a little concerned with the supply (Where is it coming from? How clean is it?), and decides to wait until later. Lo and behold, a few minutes up the trail, the pair comes across a deer lying dead and bloodied in the stream; the same stream that hiker #1 just drank from.
The moral of the story is that water is a shaky proposition in the backcountry. Just because you're miles from nowhere doesn't mean that your water supply can't be polluted, infested, or worse. And in this age of toxic waste leaks, unpleasant bacterial and viral infections, and all sorts of nastiness, there really is no good reason not to carry something to purify your water.
The most common waterborne problems in the United States are Giardia, Cryptosporidium, and E Coli; all nasty little buggers that can quickly add an unpleasant footnote to an otherwise fun trip. Beyond the borders, you can add at least a dozen more threats including Salmonella, Hepatitis A, and others so whatever water purification method you choose needs to be able to kill as many of these as possible. As with anything, these methods all have their pros and their cons, so it's important to learn as much as you can about the options on the market and make informed choices to best meet your needs.
The classic backcountry purification method, it's long been held that boiling water for ten minutes (plus a minute for each 1,000 feet of elevation) will kill anything dangerous in it. It's more or less true, and it remains the simplest and most foolproof way to purify water. And since you're going to be bringing a stove and cook pot along anyway, there's really nothing extra to pack. But, the sterile taste of boiled water, the time it takes to heat and cool the water, and the fuel that the operation requires, leave it as a last resort for most people in this day and age.
At once the most popular and least effective treatment solution, no self-respecting gear head these days can venture out the front door without the de rigor hand pump water filter. The good news is, as long as the filter's pores are small enough and the element is kept clean, they are generally effective against most bacteria and parasites. And since many also come with a pre-filter screen, you can even pump directly from a water source and avoid contaminating your bottle. The result is a quick, easy solution that doesn't alter the taste of your water.
The bad news is that filters are largely ineffective against viruses. Not generally a concern stateside, but if you're traveling abroad, a filter alone is generally not the best choice (although this can be countered by treating the water with iodine as well as filtering it.) And remember, the current crop of pump filters still only filter the water, they don't purify it. An easy solution, but far from perfect. (The exception, of course, if the First Need Deluxe, a filter-style pump system that's actually rated as a purifier and meets EPA standards against cysts, bacteria and viruses.)
Quick and effective, chemical drops can kill most viruses, bacteria, and protozoa except for the ever-popular Crypto. Their high portability factor just a few drops can purify gallons of water make them a tempting and popular solution for paddlers and backcountry hikers alike. But, there are a few caveats that make chemical treatment less than ideal.
The first is taste. Iodine in particular leaves a strong, metallic taste in the water. It's not so bad for cooking, but drinking it straight can be a little tough to stomach. There are ways around this (Kool Aid, citrus flavor, etc…) but it's important to consider what you can tolerate taste-wise before you head out on the water. Second is its effectiveness. Chemical solutions are largely variable depending on the water temperature and the amount that you're purifying, and also often require the water to be pre-filtered to remove sediment or cloudiness. This means that it can literally take hours to treat a large sample of water. The third problem depends on the person drinking the water. While rare, it's not unheard of for iodine and chlorine to trigger reactions. Plus, chemicals like these are not things that you want to build up in your body. Using them as infrequently as possible is generally a good thing.
Inactive against Crypto an increasing threat in U.S. waters chemicals that can cause problems in the body, and variable effectiveness are enough to convince me to keep the chemicals at home. But, that said, drop solutions are great as an emergency backup method. And the tiny bottles certainly won't take up too much space in your gear bag.
So, there you have it. Three water purification methods, three sets of pros and cons. It's far from a black and white situation, so the best thing to keep in mind when shopping for a backcountry water solution is that nothing's perfect. Choose the method that makes the most sense for what you're doing.
Tim Sprinkle writes and paddles around his home in central Virginia. His work has appeared in Seakayaker, Paddler, and a number of other publications.