How to Purify Contaminated Water

Let’s dive to the reader question right off the bat today. Here’s the question Alan asked us by email:

Alan’s Water Purification Question

I reside in a very agricultural area that also has some semi-large towns.  The largest environmental issue here is agricultural runoff.  I cannot think of  a single waterway, creek, river, pond, whatever that is not affected by either runoff or seepage from septic systems or sewer systems.  How then to purify water with such a heritage?

Our Response: Purifying Contaminated Water Tips & Tricks

Good question, Alan! It’s always interesting to get questions from individuals who are surrounded by environments vastly dissimilar from my own. Here in Canada, gaining access to potable water is not something I have ever considered a problem. Both freshwater and rain water are, here, so plentiful that the topic almost goes altogether out of mind. But of course, this isn’t the case for many who live in different parts of the world from myself. Having access to clean, drinkable water is and of course really should be the most important concern if you’re in a location where this resource may not be plentiful. It’s of course another reminder to always study your environment and the unique factors it presents that may be a roadblock to your survival and short and long-term sustenance.

So I’ll start off by saying it loud and clear – I don’t have any firsthand experience with contaminated water, let alone needing to purify it to the point where it’s drinkable for survival purposes. This is largely, as I’ve said, due to the fact that my location is quite good for access to drinkable water. Where I am, there are at least 2 wonderfully clean brooks within just a short, 20 minute walk from my place of residence. Based on my lack of experience, I had to do quite a bit of research into this topic, and what I found is exactly what I thought. As this excellent wikipedia article shows – cleaning contaminated water is both a complex and multifaceted issue that frankly, I am nowhere near qualified to find an end-all-be-all answer to. Getting clean water from a dirty source is a billion dollar industry – and if giant corporations have trouble with solving it considering their access to huge amounts of cash, I don’t think I’ll be of too much use.

That being said, it is possible to separate what you can do for basic survival from the technically common or “proper” way to do things. If you’re sitting at home and need to start a fire, you just pull out a lighter. This is the most common, proper technique to use these days. However, in a survival situation, we all know that doing this isn’t always possible, so we discuss other ways one can get fire even if they don’t have access to the technically “best” and most common way – in this example’s case, a lighter.

With that in mind, I will just tell you what I would personally do in a survival situation where I needed to get drinkable, clean water for my own personal survival. This is not something I think professionals would do. My recommendation is almost certainly nowhere near optimal on an industrial level and to get clean water for an entire town from a polluted source of water, say, but frankly, it’s the answer I am most comfortable with giving after a few hours of research and my own limited experiences with the topic at hand. So here we are…

How I would attain drinkable water for survival purposes

In a survival situation you need water primarily for hydration, but for extended survival, or being able to live long-term, you will need a source of (relatively) clean water for many uses that we take for granted here in our life-is-good-we-get-water-from-a-tap world. You’ll need clean water for things like washing clothes and dishes, basic hygiene (bathing, brushing teeth, etc.), and keeping your plants/animals hydrated as well. Going a day without access to tap water is not too difficult. Try a month, however, and tell me how hard your life suddenly becomes! Emergency purification is not at all realistic for everyday use – you can’t sit there purifying water with a small personal filter enough to be able to take a shower with regularly. As a result, I would suggest a 2 pronged approach with regards to water management: 1. Making due with passive sources of somewhat clean water for miscellaneous tasks, as well as, 2. Properly treated water for actual hydration.

1. Setting up passive sources of attaining clean water

Of course the environment you’re in sounds pretty terrible in terms of natural sources of water. The exception to this is of course rainfall, as that’s good, clean water to drink pretty much everywhere in the world (unless you just dealt with a nuclear apocalypse, but that’s an emergency situation we’ll deal with another day).

Rainfall is, unfortunately, quite unpredictable, so you’re not going to want to depend on waiting for the rain to fall to be able to collect it when you need it. Start collecting rainfall plenty before you need it with some sort of eaves run off system feeding into a cistern/barrel. There are some excellent ones on Amazon, or you can DIY them by using cheap barrels you bought second hand or found lying around the house, and if your family isn’t the prepping type, and thus don’t approve of the “ugly” ones, there are some better looking ones as well that they’ll be certain to be okay with having in their garden. Whether you’re shopping or making one yourself, try to get a hold or create one of these that has a spout, as that just makes getting the water out of the container easier.

Once installed, you’re all set to go. This is actually one of, if not the the single best, solution for passive water collection. You can also add a well to your property, grab some large empty containers and stick them around your garden to use as extra rain barrels (they might not fill up as quickly as the ones near the downspout, but they’ll fill up nonetheless!). Regardless of how you do it, setting up a system to collect rainwater is an easy step that can boost your supply of potable water without requiring a huge investment.

Of course, this system won’t work out too well if you live in the desert, but seeing as you’re dealing with agricultural runoff, I presume this is not your particular case!

2. Purifying contaminated water for at-home survival/prepper purposes

For personal consumption, I would go with a reverse osmosis solution like this highly rated one here, on top of getting the source water from a homemade well. The soil will filter the larger contaminates, and the reverse osmosis process couple with ultraviolet disinfection can take care of the rest on a large enough scale for a homestead without requiring an overly complicated (or expensive) solution.

Obviously these require electrical power, so consider throwing in a backup generator and ideally some solar panels on the roof, and you’ll be set to go. But in the case where you’ve got to decide whether to bug in or to bug out in case of an emergency, you’re pretty much going to want to stay put where you are and not even consider the alternative if all the water around you is polluted to the level you say. Not fun to have your options limited for you, but in a case like yours, it does seem to me the safest option.

3. Purifying contaminated water for on-the-go survival purposes

For a water filters with on-the-go use, a portable membrane filter like the LifeStraw (reviewed here) or the Sawyer mini system would work

Of course, if you’re talking long-term dependency, you will want a more permanent set up that doesn’t depend on filters with quite an inherently limited lifespan. So while these options definitely are okay for short term use, if you’re planning for long term struggles with water contamination, they’re not going to do the trick.

I hope this answer is satisfactory! It took me some time to ponder what I would suggest, as, like I said, not only have I never been in such a situation, but I have never really had to think about it either considering water is literally all around me and in survival, my number one priority (especially now that winter is coming) is fighting the cold and the risk of hypothermia, not any sort of lack of clean water.

So I am really out of my comfort zone when it comes to these queries. With that said, it’s always good to be forced to think about things from someone else’s perspective, and even though I have never been in your situation, I do think the method I outlined is relatively good when it comes to a short and long term survival plan. I definitely learned quite a bit in my research! So thank you for the question, Alan.

Do You Have Advice Concerning Water Purification?

If anyone has any extra advice/experiences/thoughts for Alan, please comment below and, who knows, maybe the perfect solution will crop up!

If you have a survival, preparedness, or gear related question you’d like us to answer, don’t hesitate to let us know! Find out how to reach us via the contact page. Although we don’t publish every question we’re asked on the blog, we try our best to respond to each and every one we receive.

In case you’re interested, you can also view our past responses to reader questions here.