Water in the Wild

Humping lots of water can be a chore on long expeditions, so sourcing and purifying safe drinking water is a critical survival technique. Here we explain the basics.

Finding a Water Source

If you've read our blog on Free Survival Apps then one of the quickest and easiest ways to find water sources is to use a map to find both still and running sources of water. If using the app, hit the BackCountry Navigator XE world vector map and water points will show up in bright blue.

Water Myth: Running water is safe to drink. This is absolutely not true. While drinking running water is better than drinking stagnant water, it can still contain bacteria, viruses, parasites and contaminants that can lead to gastroenteritis and diarrhea; so always look to purify your drinking water.

Rainwater is the safest natural source of water, but the most important factor is how it's contained. If you're able to collect rainwater in your own container e.g. water bottle, then it's safe to drink straight away. Fashion a funnel system from a clean tarp or plastic to speed up the collection. To be double-safe boil the water later to purify.

Surface water that you haven't contained yourself can become stagnant after 12 hours, where the pH level drops and it becomes an incubator for bacteria, in addition to attracting flies, mosquitoes and other nasties, which carry additional pathogens. You can spot stagnant water as it usually sits still, looks green or brown and gives off a terrible odor. This isn't always the case though, as sediment can sink to the bottom and it can appear clear at the top. If in doubt then avoid it altogether.

Reservoir lakes are usually situated higher than homes and businesses and are reasonably protected from different forms of contamination, so bacteria levels are usually low. Fish, leaves, dirt and other surrounding contaminates can create some bacteria and algae, although retain low pH levels. While we would recommend purifying all water, these sources can be some of the safest sources to provide long term supply.

Low land rivers and canals can be the most dangerous sources of water, as they are a breeding ground for bacteria and tend to have a cocktail of solid and dissolved contaminants, all of which may not be obvious with how the water is flowing or sat. If you have to drink water from a river, then find the highest point you can to reduce the volume of contaminants, as even in open spaces feces from animals can have your stomach in a whole world of trouble, very quickly.

Atmospheric water collection can be imperative where there's no rain. By cooling fog or water vapor in the air, usually by a ballooned and tied plastic bag, you can capture small amounts of water in extreme circumstances. This can be incredibly time consuming, depends entirely on the atmosphere and yields small amounts of water, so it's unlikely to be a sustainable way to survive.

Deep groundwater sourcing and Seawater distillation or reverse osmosis techniques usually require pump systems to work properly, so we may cover some of those techniques in another blog for those caught near or on the sea, or looking to source a sustainable source of water at a fixed location.

Purification

If you've seen our product review of LifeStraw Go, then you'll know that there are many similar products that offer both filtration and carbon systems that help purify your water; so if you're looking for a simple solution that works for several scenarios then this can be a worthwhile investment to instantly benefit from safe and cold drinking water. For the rest, we'll run through the three most common and popular techniques for purifying water for drinking.

• Boiling. The safest way to purify water is to boil it. At a boiling temperature most organisms can't survive, so harmful bacteria is killed. This also includes parasites, viruses and most pathogens. Carry a mess tin or metal cup, light a fire and wait for the bubbles; once cooled it's safe to drink. If you don't have, or can't find a boiling container e.g. a metal/tin can, then concave stones or even plastic bottles can be alternative boiling containers (we'd advise further research on how to do this safely). The biggest downside of boiling water from a questionable source is the taste, so for planned adventures we'd recommend a sachet of a powdered energy drink in your favorite flavour - in a pinch, then a pinch of salt for every litre of water can help with the taste.

• Tablets. Available in powdered, tablet or droplet forms, water purification tablets can be a quick and easy way to purify your water, without the rigmarole of boiling and enjoy an almost instant cold drink. Oasis are the most popular brand of water purification tablets and usually work out at 3-5p per 167mg tablet, has a typical shelf life of 3-4 years and purifies 20-25 litres of water. For a 500 tablet pack on Amazon, you'll have enough tablets to purify over 10k litres of water, so they'll run out of date before you'll likely use them all! As the active ingredient in these tablets is chlorine the amount you use is important. Too little and the water isn't safe, too much and it can have a horrible taste. We'd advise you grab a few small packets of different brands and test to taste.

• Filtering. A necessary step for questionable water is filtering. There are many methods to filtering water and this will likely depend on what you have at your disposal, to create multiple levels of filtration, to pick out different nasties. Sand is a great filtering material, but unless you're by a beach or your backyard sandpit then you're likely out of luck. Our favorite filter setup includes pebbles, grass, dirt, gravel, sand, charcoal and fabric (as many as you can get your hands on - coffee filters also work well). Layer the filter materials on top of each other in your container and slowly pour your water in the top - a up-turned plastic bottle, with cloth tied around the opening and an open base, cut for filling, works best. Repeat the process if you like and always boil the water after.

The National Academies of Sciences, Engineering and Medicine suggest that an adequate daily fluid intake of fluid intake is 3.7 litres for men and 2.7 litres for women. Under survival scenarios, where water sources may be scarce then a minimum of 1 litre per day is required to keep dehydration at bay, but only where resting in shelter, as 600ml are lost through urination, 400ml through skin and 200ml through exhaling, so dehydration is inevitable; and eventually death if you are without water for 3 days.

Stay hydrated, especially in hot weather or when active and always make sure to source water from safe sources and purify before you drink. Find multiple sources of water for survival and create a system of purifying water, so you have a sustainable source.

Now go and grab yourself a drink. All that reading must have made you thirsty!