Backpacking Water Treatment

backpacking filtering drinking water

If you don’t treat your drinking water when hiking or backpacking, you’re risking the possibility your high sierra adventure will end in intestinal distress. Even under ideal circumstances and in the most remote corners of the wilderness, there is still some risk associated with drinking straight out of pristine alpine lakes, tarns, rivers and streams. Here are several options that will ensure your drinking water will be safe from the likes of Giardia, Lamblia, Cryptosporidium and more.


If you’re camping below treeline and decide to have a campfire, or if you have easy access to an alternative form of fuel, boiling can be an excellent way to be sure your water is safe to drink. Boiling is the most tried and true method of killing microscopic nasties, but it does consume a significant amount of fuel. In backpacking situations, boiling is not ideal as a primary treatment option. However, in fire permit areas where wood is available, fires are a decent option albeit this approach can result in your drinking water tasting like wood smoke. To avoid a sour burnt taste from a wood fire, decant the water from one bottle to another, or, mask the taste by seeping herbal tea-bags or mixing in a powdered drink mix such as Crystal Light.

How Long To Boil: There appears to be some disagreement over just how long you need to boil water before it is safe to drink. Some agencies recommend five minutes or even longer, especially at higher altitudes. Others say that a strong rolling boil at any altitude will suffice. The Centers for Disease Control recommends three minutes to make sure everything is really and truly dead, including hardy viruses (more a problem in developing countries than in the American back country).

Iodine Tablets & Drops:

Iodine has some compelling advantages – it’s lightweight, reliable and easy to use. But iodine tablets do not kill the most recent arrival on the microbial scene: Cryptosporidium, which causes Giardia-like symptoms and has no cure (the disease runs its course in 7 -10 days). Iodine treatment products are available in liquid form, crystals or tablets. Read the directions for how much to use and how long to wait before consuming treated water – higher doses of iodine and longer wait times are required in cold or especially dirty water. To mask the flavor, you can drop in tablets made by Potable Aqua, add a piece of lemon peel (it’ll freshen several liters) or use tea-bags / powdered drink mixes as mentioned above. Note: it’s not a good idea to use iodine for days on end, however it is an excellent idea to carry a few tablets to use as an alternative if your filter fails and/or when boiling is not an option.

Portable Water Filters:

Few pieces of backpacking equipment are more vilified than are the many categories, makes and models of water filters. Think of filters as microscopic strainers. They give you clean, great tasting water – and no residue of floaties staring at your from your water bottle. To choose a filter, first look at the”absolute” pore size, which should be 1 micron or less for hiking in North America: That’ll take care of both Giardia and Cryptosporidium. For hiking abroad, you may also need a filter that can handle viruses.

Avoiding Clogging: Clogging is one of the biggest problems when it comes to water filters. You can help prevent it by keeping the filter element as clean as possible. Selecting a good, clear water source with low turbidity is the best avoidance measure. If that’s not an option, allow clouded water sit for a while so that the suspended particles settle to the bottom. If your device didn’t come with a pre-filter of its own, alternatively you can pre-filter water through a piece of fabric such as a bandanna or cotton t-shirt. If you’re filtering directly from the water source, use a float to keep your intake tube off of the river, stream or lake bottom.

Unclogging Your Filter: Filters clog because they do their job: The gunk that clogs them is gunk you’d otherwise be drinking. Make sure you take your filter’s directions into the field with you. Some ceramic filters can be cleaned by scrubbing the element with an old toothbrush. Others can be wiped clean. Some filters can be backwashed, which is a temporary solution. Reverse the intake and output tubes, then pump backwards so the water flushes the gunk out of the filter element. After backwashing, you must run clean water that has been treated with iodine or bleach through the filter and its hoses.


“Backpacking Water Treatment” is a Guest Blog post contributed by “ERIC” at, October 2003