The modern world has become so accustomed to having clean drinking water on tap that we don’t often think of what we would do if we turned on the tap and no water came out. Water is such an important resource, with humans unable to go for more than a few days without water that water security should be at the top of everybody’s preparedness checklist. The safest bet is to have clean water stored away for an emergency, see our article on water storage here, but if that isn’t an option, or you run through your water storage, you’ll be glad you know how to make your water safe.
Even the cleanest looking water can have microorganisms living in it, and these microorganisms can range from harmless to deadly. Most of the more dangerous microorganisms will simply make you sick, usually causing some variable degrees of diarrhea, vomiting and stomach pains. These bacteria and parasites are rarely fatal, but can often cause extreme discomfort for several weeks.
There are three main methods used to treat water to kill off bacterias and parasites: boiling, filtering, and chemical treatments. We’ll discuss these three methods, as well as another method of using UV light, in this article.
Boiling:
The old reliable method of treating water is to simply boil it. Boiling water is probably the most surefire way to kill all the living creatures that tend to make us sick, and in most cases it is very low cost. The CDC suggests that at sea level you need to boil water for a minute to kill all organisms, while at higher altitudes it would be longer, for example at 6500 feet you would need to boil the water for three minutes.
The benefits of boiling water are pretty straightforward, it’s extremely effective at killing off harmful organisms, and it doesn’t require any specialty equipment. If you’ve got a metal pot (don’t use plastic, or plastic lined water bottles) and a fire or working stove you can boil water.
The downsides of relying on boiling water is that if you find yourself in an emergency where you’ve lost access to water, there’s a good chance you may have lost access to electricity as well. Building a fire isn’t always an option, or at least it’s not always a good option, so if you want to rely on boiling water as your source of treated water you may want to invest in a camper stove that you can use if you’ve lost power.
The other potential downsides of boiling water is that while it does kill the harmful organisms, it doesn’t filter out any other particles. If you’re pulling your water from streams or lakes you may find that you get dirt or debris in your water, and while after boiling it may be safe you may find it contains sediment textures and has an off putting taste.
If you plan on using boiling as your method you may want to invest in a good camp stove if you don’t have one already, so that you have a reliable source of heat and a stable surface for your pan. Some tips if you do need to boil water on a camp stove. Using a lid retains a lot of heat, allowing you to boil water with less time and fuel. The type of pan you use makes a difference, with thicker cast iron pans absorbing a lot of heat before that heat transfers to the water. More surface area of the pan
Filters:
For the purpose of this article the water filters we’re talking about are generally smaller portable water filters, although you can get some pretty heavy duty filters out there. These water filters work the same way that your colander works, by forcing water through some very tiny holes that other things can’t fit through. To filter out the microorganisms this generally means that they run the water through holes less than 1 micron thick, where there are 1000 microns in a millimeter (or 25400 in an inch).
Not every filter out there is going to filter out all the microorganisms. Many kitchen type filters, like Brita water filters, aren’t built to filter out microorganisms, but are designed to make your already safe water taste cleaner. Brita’s website even specifically says “Do not use with water that is microbiologically unsafe…”, although there is some evidence that they remove some of the microorganisms. There is a certification process, and if you are lucky you can look for filters that are certified as NSF 53 or NSF 58 certified, however you can also look for micron size on the filters.
The benefits of filters are that they are usable without power or fire. You can get portable ones that you can take with you, for example a life straw portable filter can fit in a pocket and can filter hundreds of gallons of water. In addition filters filter out other particles, like sediment, that other treatments don’t, making your water taste better as well.
The down sides of filters is that they don’t last forever, most filters have a recommended amount of gallons they can process before you need a new filter. The worse quality the water you put through, the quicker your filter will need to be cleaned or replaced. Filters are also usually rated in the 99.99999 % effective category for bacteria, but aren’t effective against a handful of viruses, such as novovirus, hepatitis A, and others.
In terms of pure emergency preparedness something like a LifeStraw can come in handy, and they are particularly recommended for traveling, or bug out bags. The LifeStraw works as a straw where you stick one end in the water source while sucking on the other end. That’s not everybody’s cup of tea, but there are a number of other different filter types. You can find gravity fed filters where you fill up water from a source and have gravity push the water through the filter, allowing you to fill containers up for storage purposes. A pump action filter lets you drop an inlet hose into your water source, pump it through the filter and into whatever container you have available.
Chemical Treatments:
There are a handful of different chemical treatments available to help purify your water. The most common chemicals are chlorine, chloramine, chlorine dioxide, and iodine. You can find these chemicals in either liquid, pill, or powder variations. If you search for water purification tablets, powder, or drops you’ll find examples of these treatments. Most of the water that we drink from the faucet has been chemically treated, and contains small, safe, amounts of the chemicals.
One of the primary benefits of chemical treatments is that they are very portable. A bottle roughly the size of your thumb can contain enough chemicals to treat several gallons of water. Water treated with chemicals can also stay treated for storage purposes. If you boil water as soon as the water is done boiling any contact it has with any microorganisms can allow the organisms to begin multiplying, while a chemical treatment will stay in the water and can continue preventing organisms from spreading.
The downside of chemical treatments is that the chemicals do have expiration dates, which is usually in the range of 1 – 5 years. Chemical treatments also generally take a little bit of time, with most recommending waiting about 30 minutes after you mix the chemicals in. There is also going to be a chemical taste that goes along with the process. Chemical treatments also have a ratio of water to chemical that you need to maintain to get proper results. Like boiling chemical treatments also don’t filter out any other particles, which can leave your water with sediment or other unwanted tastes.
There are tablets that are designed to purify about a water bottle’s worth of water a time, such as Iodine tablets or Aquatabs tablets. These are extremely portable, and are quite easy to use.
You can get more potent tablets that are designed to purify gallons at a time. Check out this powder that not only purifies water, but also is said to separate the dirt out of water. I’ve never tried this myself, but the videos look impressive and it is highly rated.
UV Treatments:
I’ve treated water by boiling, by filter, and with chemicals, but I have to confess I’ve never used a UV treatment. The UV treatments I have seen advertised are usually in the form of a wand, or pen shaped light that you would stir through the water, with the UV rays killing any smaller organisms. According to the CDC these UV lights are effective, at least on small quantities of clear water. Cloudy water is less effective because smaller particles can block the light from getting to the germs.
In theory you can also purify water with sunlight. The method would involve putting clear water in a clear container, plastic or glass, and leaving it in the sunlight for up to six hours. This would probably be my least trusted method, but I might try it if I had no other alternative. It’s not something I ever hope to test out, and I think I’d much rather prepare myself with a good filter or chemical treatment.
Personally I would lean towards boiling water as my preferred method, but having some other treatment available, either a filter or chemical (or both) for a more portable solution.