Oct 16

Water Purification

Katadyn Vario Water FilterI found this great article over on hitthetrail.com, it provides a nice overview of some of the techniques used to purify water and some of the dangers that might lurk even in the most crystal clear mountain stream.  As preppers the topic of Bugging Out is often discussed, heading to the hills to get away from populated areas during times of extreme civil unrest.  If that scenario plays out it will be important to understand the dangers associated with consuming untreated water and how to purify water to avoid getting sick.  The chances of dying from contaminated water while out in the bush are probably far higher than the chances of getting into a shoot out with looters hell bent on destruction.

Water Purification

This section discusses water purification; it’s purpose and the equipment required to achieve clean, healthy water. The primary methods for purification include boiling, chemical treatment, ultra violet treatment, and water filters. These are discussed in more detail below.

Unfortunately, the days of simply cupping your hands into a creek for a safe drink of water are over. Water purification is no longer just for water sources that look questionable; you should use some type of purification before drinking from any water source in the wilds. In this section I will discuss the different methods for purifying your water, and the various diseases you can prevent by doing so. For complete coverage on this subject, I highly recommend the hilarious, but very informative and readable book (you may want to sit down for this—pun intended!), How to Shit in the Woods by Kathleen Meyer. And women, there is even a chapter just for us, “For Women Only: How Not to Pee in Your Boots.” Ms. Meyer even discusses safeguards for international travel.

First, let’s discuss what evils can be lurking in that crystal-clear looking water! Giardiasis is the most common and widespread disease and is caused by microscopic parasitic cysts called giardia. No surface water source is guaranteed to be unaffected by these cysts, including clear-looking mountain headwaters. This intestinal disease is spread through oral-fecal transmission and is carried by humans and animals. If you’ve seen the water filter ads in some of the outdoor magazines, you will see that animals are not often concerned with where they urinate or defecate. And much of our public lands are used for grazing livestock, and they aren’t very particular either.

Unfortunately, some humans are just as careless. Without the precaution of staying at least 200 feet away from any water source and properly disposing of human waste, fecal matter can contaminate a widespread area. For proper disposal of human waste, see the section Backcountry Etiquette.

Giardiasis has an incubation period of seven to twenty-one days and must be diagnosed by a physician analyzing the victim’s stool for giardia’s microscopic cysts. Some of the symptoms for giardiasis include bloating, diarrhea, headache, vomiting, flatulence, cramping, low-grade fever, and loss of appetite . . . need I go on? It is not pleasant by any means. I know; I got giardia in Grand Canyon National Park.

Beavers (along with humans and other animals—domestic and wild) are known carriers of the disease, and believe it or not, Grand Canyon has beavers. My filter clogged up and I needed water, so not having a way to purify water, I drank right out of the stream. One thing to remember if you are in the same situation; always drink the water. You can be treated for giardia later; DEATH from dehydration is harder to treat! Because of this situation, I now carry purification tablets as well as a filter. The additional ounce in weight is well worth the safety net it provides.

Cryptosporidium is the next villain to be on the watch for, and it’s quickly becoming a serious problem in many areas, not just in the woods. Like giardia, it is another microscopic cyst with the same transmission methods and many of the same symptoms. This particular parasite is even becoming a threat in our municipal water supplies because of its high resistance to chlorine.

In 1993, Milwaukee had an outbreak of the waterborne cryptosporidium in its municipal water supply, which ended up affecting around 40,000 people! As a desert dweller, I can’t stress enough how important water is and to respect it, take care of it, and never waste it. Kansas State University has a wonderful site on this particular villain although it is rather technical.

Now on to water purification. There are several effective methods for purifying your water.

  • Boil the water – This is the good old standby. The main disadvantage of boiling your water is carrying enough fuel to provide ample water for your trip. It also makes the water taste flat. Water must be boiled for five (5) minutes to be considered safe to drink.
  • Chemical Disinfectants – Iodine or chlorine. Some of the most popular and effective brands are Potable Aqua TabletsPolar Pure Water Disinfectant, and Aquamira Water Treatment Drops. As I mentioned above, cryptosporidium is very resistant to this type of purification, so it is questionable how much longer this will be effective as our water sources become more contaminated.One of the main problems with using iodine or chlorine is the taste they give the water. If using iodine, one effective method for reducting the taste of the iodine is to add vitamin C to neutralize it, but only after the treatment itself has been completed.
  • Filtration– This is the method I’ve used for years. The flavor is maintained, or even improved, by the use of water filters. However, with the arrival of UV light for sterilization, I’m considering adding to my equipment. For a complete rundown on the different filters available, costs, specifications and the pros and cons of different brands, be sure to pick up the copy of Kathleen Meyer’s book mentioned above. Unfortunately, there is no such thing as the perfect water filter. They can not filter out viruses, and not all of them treat bacteria. Here in the United States, filters usually provide plenty of protection; however, if you plan on traveling abroad, think seriously about the capability of treating water for viruses as well. Hepatitis, among many other diseases, is a very real threat when traveling to certain countries. There have been several situations where I didn’t trust that the water filter was enough. In those cases, I filled my collapsible bucket with water and disinfected it with iodine tablets. After the time needed for treatment, I neutralized the water and then filtered the treated water. It tasted great and I felt pretty well protected.Because there is no perfect water filter for every situation, be sure to compare and buy one suited to your needs. Where will you be using it most? How often will you use it? How easy is it to use by yourself? How comfortable is it to use? These are all very important considerations; pumping can be extremely tiring, but your health and welfare rely on it. An important consideration is the ability to clean the filter in the field. Also the availability of replacement filter cartridges. What good is it to get a great filter that you will never be able to find the parts for? My personal favorites are the MSR Miniworks EX Water Filter and the MSR SweetWater Microfilter Water Filter. They are designed so they are quite comfortable to pump, they pump at decent flow rates, and most importantly they are field-cleanable! Katadyn has been making water filters for years, and in fact, river companies have been using them for their commercial trips. But their expensive price tag has kept them out of my pack. Well, Katadyn now makes excellent filters that compete in the same range in the filters named above and are all highly rated. I have not personally tested them but have no doubt that they perform excellently. These include the Katadyn Hiker PRO Water Microfilter (which appears to be the old Pur Hiker – an excellent filter) and the Katadyn Vario Multi Flow Water Microfilter. Katadyn makes larger filters as well, but the two mentioned here are the truly small ones made for lightweight backpacking.

Ultraviolet (UV) Light – Compared to the other treatments, this is a relatively new process for treating water in the backcountry, but it is fast becoming a favored choice of many outdoors enthusiasts and travelers due to its light weight, small size and ability to kill viruses. Innovations in design have minimized the size and weight of these water treatment devices, making them an excellent choice for the backcountry. The SteriPEN Adventurer Opti Handheld UV Water Purifier has some excellent features geared specifically for those of us who need something durable and lightweight as well as effective. It weighs only 3.6 ounces with the included batteries and will purify .5 liter/16oz of water in 48 seconds, or 1 liter/32oz in 90 seconds. It will destroy viruses, bacteria and protozoa, but it is less effective in murky water. The UV lamp life is good for 8,000 treatments. The filter won top honors in the 2011 Backpacker Magazine Editor’s Choice Awards. SteriPen UV purifiers have also been tested by the Water Quality Association (WQA) against the U.S. EPA Microbiological Water Purifier Standard, and have received the WQA’s Gold Seal, signifying that the products purify water safely and effectively.

If you will be treating water that isn’t clear, it is imperative that you filter the water through the optional SteriPEN Prefilter or fabric, such as a bandana or cheesecloth, before using the SteriPen. Besides needing to treat clear water, another drawback of this type of filtering is having to use batteries. However, they are lightweight and easy enough to carry an extra set. The SteriPEN is powered by 2 CR123 batteries which are available in disposable (good for about 100 treatments) or rechargeable (lasts about 40-80 treatments). The batteries can now be a non-issue with the Steripen Adventurer Optic UV Water Purifier with Solar Charging Case!

Here are several more tips for water usage in the backcountry:

  • When brushing your teeth, be sure to use purified water. It only takes several giardia cysts to start your very own colony! You will not get it by washing with the water unless you happen to swallow water while cleaning up! The cysts have to gain entry into your intestines to infect you.
  • Remember that you do not need to treat water used in cooking or hot drinks as long as it comes to a rolling boil before you drink it; boiling will kill the waterborne pathogens that can wreak havoc in your intestines. The water needs to boil for five (5) minutes to be considered completely safe.
  • Filtering your water directly from a stream or pothole can be very difficult, what with trying to keep the intake hose out of the silt at the bottom but still submerged. I recommend using a collapsible backpacking bucket. They are available in many places now. Coleman, L. L. Bean, and REI (Recreational Equipment Inc.) all have their own for sale. I don’t take any trips without my bucket. A bucket allows you to scoop water without disturbing the silty bottom of the stream or pothole, keeping the water cleaner for easier filtering. I can fill the bucket from the water source, even lowering it into areas I couldn’t otherwise reach, and take it back to camp to filter in comfort. If the water is silty, the bucket allows the sediment to settle out so it can be filtered from the cleaner top layer. This will keep your filter running smoothly much longer. The bucket also comes in handy for washing yourself, your clothes, and your dishes well away from water sources that could be contaminated by the wastewater.
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    • Mike on November 20, 2012 at 10:02 PM
    • Reply

    HI, I am working on increasing my water storage. I have a swimming pool that holds nearly 30,000 gallons. It would be a good source of grey water…toilets, washing clothes, etc., The question I have is, “How can I make this supply of water safe for drinking an cooking without boiling?”

    I’ve read several articles and am getting varying viewpoints. Can you point me in the right direction for reliable and solid information. Thanks, Mike

      • PJ on November 20, 2012 at 10:20 PM
      • Reply


      If you don’t want to boil the pool water to make it safe for consumption, a good filtration system like the Berkey should do the trick. From their FAQ page:

      In case of an emergency, can I take water from our pool and filter it with my Berkey system? Will all the chlorine be removed?

      Yes. The Berkey water filter systems can make chlorinated pool water safe for consumption. However, keep in mind that such a use will cause the elements to wear faster. So, you should only do so in case of emergency.

      Here’s the link: http://www.berkeyfilters.com/berkey-answers/berkey-water-filter-faq/

      I have several filtration systems, the Berkey being one of my favorites. (Replacement filters are good items to have on hand as well). Is there any reason why boiling water is not an option for you? Either way thanks for the great question and I hope my answer was sufficient.


    • donald on October 30, 2013 at 5:30 PM
    • Reply

    I’ve seen oodles of articles on commercial filters, and a lot about how to make you own in a SHTF situation, but has anyone thought about using fish tank filters? I haven’t been able to find specs on one yet, but those things have to be able to filter out ammonia from the fish excrement… I’m not talking about it being the “one stop shop” of water purification, but if you have a means of making power, or if you can fabricate a gravity feed to go through all the steps a tank filtration system uses…..


      • PJ on October 30, 2013 at 5:39 PM
      • Reply


      I guess that certainly is a possibility, but for the price of a fish tank filter I’d rather purchase a dedicated one that has been proven safe to use for humans. That said in a pinch it could be better to use the fish tank filter than nothing at all.

  1. Your website is so organized, and your posts are always common sense, congratulations for making the difference.

    Thanks for sharing this 🙂

  2. I agree with you. The quality of our drinking water is very important. I live in an area where the water quality is very poor. Therefore, I purchased a big berkey water filter. As you said the installation was very easy. Though the water flow is a little slow, it is not a big problem.

  3. Water is very vital in human life that’s why we have to be extra careful when it comes to this one.
    chemicals and heavy metals that can easily contaminated our drinking water are dangerous in our health making it not advisable for human consumption. But how will you know if your water is safe to drink? In my case, I don’t like taking chances. that’s why I made sure we are drinking safe water in the aid of berkey water filter. filters heavy metals and other contamination.

    1. it’s not a bad thing if you invest on a good home water purification system. it will benefit your family’s health and safety. R.O water system is great as it removes toxins and contaminants

    2. Water is essential for health, hygiene and the productivity of our community. water treatment process may vary on the water condition that you have in your area. its better to invest on a good water treatment. it will benefit you by providing safety to you and your family.

  4. Water pollution is very serious now, especially in developing countries. Even the tap water contains many contaminants, such as chemicals, heavy metals, virus and baceria, and other contaminants. If you continiue to drink the contaminated water, it is harmful to our health. I don’t trust any forms of water from the public and I install a ro system to get filtered water to drink and cook.

  5. I say these evils really need to be purified and I’m glad we have a lot of options to make, not just things but specifically our water, clean. I think you have good points worthy to be shared here. Thanks for an informative article!

  6. I am happy to have found this article about water purification. It is interesting to learn of all of the harmful things that can be hiding in the water that we drink. It is good to be aware and to be cautious when dealing with water. I think that it would also be a good idea to invest in a water filter for the home if necessary.

  7. I’m not so sure I’d trust anything other than boiling to purify water, at least in a SHTF scenario. I’d just be worried that a filter would miss something or other, you know? With boiling you know nothing in there is gonna survive to cause you trouble.

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