When I first started hiking and backpacking in the 1960s and 1970s few people bothered to treat their backcountry water in the USA. If it looked good it probably was good and we drank from streams and lakes without a second thought to the quality of the water in them. Unfortunately this is no longer the case and serious illnesses can be contracted by failing to treat the water you drink. Since I have not yet experienced TEOTWAWKI , I will describe my experiences with different water treatment methods from the viewpoint of a hiker and backpacker. I think that in most cases you will agree with me that a backpacker’s water needs and treatment of choice will not be very different from a prepper trying to make his way cross country or possibly cross city to his home or retreat.
When cases of Giardia began to be reported in the 1980s I began to treat my backcountry water with iodine tablets . Iodine was the Army’s standard water treatment chemical for individual soldiers (canteen cases even had a little pouch on the outside for the bottle). The tablets are quick and easy to use; just pop two in a quart of water and wait 30 minutes (longer is better, especially with cold water) before drinking. Iodine tablets are cheap, compact, failure proof and lightweight to carry. They also turn your water and water containers brown and do not taste very good. I treated a lot of water with iodine. My wife complained about the taste, my kids complained about the taste, I thought about complaining about the taste but nobody ever got sick from bad water.
Iodine still holds some advantages for the prepper. The bottles are relatively cheap ($5-7), readily available at places like Wal-Mart (packaged as Coghlan’s Emergency Germicidal Drinking Water Tablets) and other big stores that have a camping department and fit in almost any pack or container. One bottle treats 25 quarts of water. An unopened bottle has a shelf life of four years. More recently it is possible to buy iodine tablets with an extra bottle of taste neutralizer. Sold as Potable Aqua P.A. Plus  this combination is said to be effective at hiding the taste of the iodine. While I haven’t actually tried this version yet I do have several sets in my survival gear – just in case. I can live with whatever taste might remain but not without the water!
(If you really want to save on cost and weight you might consider a bottle of Pure USP grade iodine crystals; marketed as Polar Pure . One small four ounce bottle will treat up to 2,000 quarts of water. The crystals last indefinitely; some Appalachian Trail “thru hikers” complete their 6 month 2,200 mile journey on one bottle of Polar Pure and have leftovers for their next long distance adventure.)
Note: If you want to neutralize the unpleasant taste of the iodine from either tablets or crystals you can use any powdered citrus drink or simply crush up a Vitamin C tablet and add to the water after the required waiting time has passed.
Moving up from iodine tablets I bought a Katadyn Hiker PRO pump microfilter . This is pretty much the standard filter system in use among many hikers and campers. There are better (cheaper, faster, more efficient) systems available but this specific model seems to be carried in most outdoor and Army-Navy shops. Again, you can even buy them In Wal-Mart!
Special Note: check the details of any pump system you buy: micro filters treat giardia, cryptosporidium and similar bacteria in water but not viruses. Usually this is not a problem in the continental USA; if you are travel outside the country you should consider water purifiers which also eliminate viruses. If you are really concerned about the quality of the water you are getting out of a micro filter you can always treat it with chemicals too. If you dose with chemicals first the filter will remove any objectionable taste.
The Hiker filter (you can buy a Hiker purifier or replace the standard microfilter with a purifier class filter is desired) is relatively heavy and seems to take forever to un-package and connect the input and output hoses to the correct ports on the filter body (it is important not to mix hoses or contaminate the output hose with “bad” water) and get started. It takes a minute or two of pumping to filter a quart of water. It is much easier if you have two or three extra hands to hold the output hose, water bottle, input hose and pump assembly while treating water. The pumping action itself is somewhat tiring and it helps to trade off assignments if you have many quarts to filter.
If you get the idea I do really not like pump filters you are correct. They are heavy and a hassle to use; it helps if you are an octopus. However they work well (when they are not clogged) and are an effective way to treat relatively large amounts of water in a short time. I use a Hiker filter when backpacking with my two adult sons. We filter 9-12 quarts of water each night for dinner and to refill our 3-liter water reservoirs for the next day’s hiking. It takes some time but the cold, clear, pure water taste is worth it for larger parties. (Note to self: As I write this it becomes obvious that maybe a gravity filter system would work better for my needs. It does all the work by itself and can effectively filter all the water we need for the next day’s hiking. I will have to look into this as there are several gravity filter systems available that look ideal for my needs).
The big advantages of pump-type filters are two- fold: great tasting water and (almost) immediate drinking water availability. The disadvantages include the weight of the system and the hoses and associated hassles of setting them up, pumping water and then packing them away. In addition, pump filters clog when you least expect them to and being mechanical they are subject to failure for a variety of reasons.
Besides chemical treatment and mechanical filters a relatively new water treatment option uses UV light to make sterile all the harmful things in wilderness water. [JWR Adds: The UV light does not kill all of the microbes. Rather, it renders them incapable of reproducing, so they simply pass through your digestive tract without multiplying.]
I bought a Steripen UV water purifier  after watching a thirsty Appalachian Trail thru-hiker arrive at a mountain stream and treat his drinking water in under a minute (1/2 liter bottle). I was impressed by the speed and efficiency the way the Steripen handled the job. While I fussed with my Hiker filter he treated and drank several bottles of water with an efficiency I envied, packed back up and headed out. I wanted one!
Using such a system allows a traveler to immediately treat just the water he needs now and use other methods to treat water to be carried and consumed later. In the case of the Appalachian Trail hiker he treated his water reservoirs with Polar Pure allowing the chemicals to work while he hiked. The concept of being able to immediately treat and drink the water when you need it and then allow time for a chemical treatment to neutralize all the bugs in the water you are carrying is indeed an attractive approach to a prepper on the move.
I chose the Classic model Steripen for my personal use. There are smaller and lighter units but the Classic uses four AA batteries while the lighter models use more specialized and expensive CR-123 cells. Using AAs makes sense from a standardization point of view and I use them in my flashlights and weather radio as well. As a backpacker I figured I could buy AA batteries just about anywhere in the world – this same principal would be equally important in a SHTF situation. I always try to avoid special, hard to find batteries in all my outdoor gear – it is too much hassle trying to find them when you need them. I was disappointed however to discover that the Steripen really puts a drain on ordinary alkaline batteries – you get only about 10-20 one quart treatments with them before they are exhausted. You really need either lithium or rechargeable NiMh cells to work efficiently. Since all my backpacking trips are short duration a single set of rechargeables lasts me through a typical weekend outing. Availability of these more specialized batteries might be a concern for the traveling prepper or maybe not if you go the rechargeable route as many have suggested in this blog.
We took a pair of Steripens on our annual “three guys” backpacking trip and discovered that filtering 10 quarts of water at a time was more of a hassle than anticipated. We had to do a quart bottle at a time and sometimes the Steripens did not want to work on the next bottle – perhaps they needed to ‘cool off” after a treatment? It was slow methodical work and somewhat annoying. We went back to using the Hiker filter for these trips.
An alternative approach to instantly treating water with a UV system is the personal water filter, either contained in a water bottle such as the Bota Outback Water Filter  or the Katadyn MyBottle Microfilter  (don’t they make this in more subdued colors?) or an individual filter straw like the Frontier Emergency Water Filter System Straw . Either system allows quick and easy water treatment on the go: simply scoop up a bottle full of water, replace the top and drink/suck clean Pure water. I have an older model filter bottle that I use so I can’t comment specifically on these particular versions but if water is plentiful this is by far the easiest way to replenish on the move. Drink your fill and then top off your spare water containers with water and treat with the chemical of your choice (see below).
If you use your filters for hiking and camping it is important to properly clean them before storage. Simply add 4-6 drop of chlorine bleach to a quart of water and filter it through the system. Remove the filter element and allow all the parts to dry thoroughly before putting them away.
Whether you use pump filters, bottle filters or UV light systems to filter your water you must always have a back up for when these devices fail; and fail they will. Filters are very prone to clogging and of course being mechanical can also break when you least expect them to. The Steripen requires batteries and even though the bulb itself has a life expectancy of over 3,000 treatment the device is mechanical and probably would not survive being dropped onto rocky ground etc. Remember, one is none and two is one.
I used to carry a bottle of ordinary chlorine bleach as back up. I re-purposed a small eye dropper container and after washing it out filled it with unscented Clorox bleach. I only used this a couple times as the container leaked within the plastic bag I had it stored and risked damaging my clothes and other gear. Four drops per quart is the standard dose; let sit at least 30 minutes for average water at average temperatures, longer for cloudy water or cold temps. You should still smell the chlorine when you open the bottle. If you cannot smell the bleach please add 4 more drops, shake and wait an additional 30 minutes. As with all chemical treatments be sure to open the screw top slightly and allow the treated water to wash away any contamination that may reside on the lid and threads from when you filled the bottle originally.
BTW, chlorine is still a very useful tool for disinfecting water on a large scale. A single teaspoon of bleach will treat a 5 gallon container of water at a very low price. A bottle of plain, unscented bleach (Clorox is a good example) should be in the emergency stores for ever survivalist. Since many municipalities treat their city water with chlorine most people will not even object to the taste!
I now carry Katadyn MicroPur MP1 tablets  as my primary back up water treatment. The MicroPur tablets release chlorine dioxide when dissolved in water; the same chemical used to disinfect many municipal water supplies. Each tablet treats one quart of water and is individually wrapped in a tough, durable foil package. Instructions are simple: tear open the foil package and drop into a quart of water. The FDA mandated instructions tell you to wait four hours before drinking but a little on- line research revealed that this is a worst case scenario for very cold, very turbid (cloudy) water. If your water is clear and not ice cold than you can wait 30 minutes and drink without a worry. I carry a number of foil packets in all my first aid and survival kits. They are very useful when day hiking and the water you carried from home runs out. I pack a minimum of 6-8 tablets in a kit; they are my backup for getting home hydrated and healthy. I really like the MicroPur tablets and recommend them as a lightweight, compact and very effective water treatment technique.
I hope this review of some of the available methods I have used for treating questionable water is of use to you. A quick review of on-line camping and survival stores will reveal many additional options for treating “bad” water. For example I have heard good reviews for Aquamira solutions  – I met another pair of Appalachian Trail thru hikers using this two part solution to treat all their water on the way from Georgia to Maine. Aquamira also makes water treatment tablets similar to the MicroPur system – I use the MicroPur MP1’s because they are readily available in the stores I frequent but you might find the Aquamira better for your use. My advice is to consider your requirements, research the choices available and select a technique/system that works for you. Actually you need to select TWO systems to be truly prepared; but then you already knew that didn’t you?