Filtration & Purification in the Mountains:
Why You Should Clean Your Drinking Water
If you’ve been adventuring in the mountains for a while, you have probably shared this experience with thousands of other folks out there:
You’re 15km into a 7km hike that your friend assured you was “easy.” It's forty-something degrees and you have just taken your last sip of water, which is warm enough for afternoon tea. Scummy streams and muddy puddles are starting to look pretty appealing… and that’s when you realise that you probably shouldn’t have skimped on a water purification system!
WHY DO WE NEED TO CLEAN WATER?
Although we often like to think that the human body is invincible, there are many things out there to get us. When we talk about the danger of unsafe drinking water, there are three main concerns we need to look out for: viruses, bacteria and protozoa. While some of the microorganisms within these groups can be beneficial for our health, others can cause serious illnesses, including the hepatitis virus, E.coli bacteria and Giardia protozoa.
There are some rather scary stats that demonstrate the dire need for clean drinking water: diarrhoea caused by waterborne diseases has long been aleading cause of deathfor children under five years old, and it is estimated that 1.4 million people die globally each yeardue to inadequate water, sanitation, and hygiene (WASH) services, with diarrhoeal diseases being a major contributor.
And as much as we’d like to believe that fresh spring water straight from the source is perfectly safe for consumption, that is unfortunately not always the case. Even in places like the Drakensberg and Magaliesberg, where you can find beautiful, crystal-clear water running directly out of the mountain, there is always a risk of contamination in the great outdoors. I have personally seen a number of unfortunate animals who have met their end upstream, polluting the water flowing over the carrion and down the mountain. In the dry season or drought, streams can be reduced to stagnant puddles that breed harmful microorganisms, which are then flushed into the stream when the rains arrive.
This might all seem a bit overdramatic – plenty of people drink water straight from mountain streams without any filtration or purification and they’re totally fine, right? You’ll just have to decide for yourself if saving some cash and space in your pack is worth the risk of potentially waging war on your digestive system and getting seriously ill in the wilderness.
FILTRATION vs PURIFICATION
There are two primary methods for turning hazardous water into safe drinking water out in the mountains: filtration and purification – but what is the difference between the two?
Water Filtration
Filtration is the process of sending water through a series of physical barriers to remove particulates and impurities. The smaller the holes in the filter barrier, the more effective the filter will be at cleaning water. There are several types of filters with varying levels of effectiveness; when it comes to outdoor adventuring, we typically use filters with inline, pump or straw-type designs:
Inline Filters
Inline filters, like the MSR Thru-Link, can be added to any hydration pack or sit between two reservoirs. Water is typically gravity-fed, with the dirty water sitting high, running down through the filter into a bottle or clean water reservoir. An inline filter can also be added to the pipe of a hydration reservoir. With this system, as you drink from the mouthpiece, it pulls water directly through the filter, providing fresh, clean water.
Pump Filters
Pump filters, such as the Katadyn Hiker Pro, have a more complex design with additional working parts compared to inline filters. These components include an intake hose, a hand pump, and an internal filter cartridge. This system allows you to draw water directly from the source and filter it into your chosen storage container. Pump filters are particularly useful when the water source is shallow, making it difficult to fill your reservoir directly.
Straw-type filters
Straw-type filters, like the Sawyer Mini Filter, are very simple, lightweight and easy to use. These comprise a filter that is directly connected to a mouthpiece, allowing you to either drink directly from any water source or, with the use of an adapter, add it to your regular water bottle filled with unfiltered water.
Most of the filters in the above categories use activated carbon in combination with either a ceramic filter or a hollow glass fibre. The activated carbon reduces bad tastes, smells and chemicals like iodine or chlorine, while the ceramic and fibre components filter out the unwanted microscopic contaminants that can make us sick. Most filters have a pore size of about 0.2 microns, which is sufficient to filter out 99.9999% of bacteria and protozoa. If you need to filter out viruses you’ll have to kick it up a notch with a filter like the MSR Guardian, which has a pore size of just 0.02 microns.
Water Purification
Water Purification is the act of eliminating contaminates to ensure that the water is safe for human consumption; this is typically done through the use of activated carbon, chemicals such as chlorine and iodine, or ultraviolet lights.
All purification products will provide specific guidelines for how much you’ll need to use to purify your water, how long the purification will take, and how long the water will remain disinfected. In most cases it takes just a small amount of product for a large volume of water, the process doesn’t take too long, and the water remains disinfected for an impressively long time – winning!
Chlorine and iodine are two of the most common choices for water purification, as they kill bacteria, protozoa and viruses; both are available in tablet and liquid form. However, if you add too much chlorine your water might not only become unsafe, but will also taste like a public swimming pool, and prolonged or excessive use of iodine can severely impact the human body, specifically the thyroid. That being said, these products are designed to keep us safe, so as long you stick to the manufacturers’ instructions you should be just fine.
Alternatively, some products use zinc, silver and/or copper ionisation for water purification, such as the Aqua Salveo Water Disinfectant Drops. Many adventurers swear by these, and you can get good bang for your buck, with just 3 drops needed per litre of water.
Ultraviolet light purification, i.e. exposing unfiltered water to UV light, is also an option. For this to be effective, the water should be as clear as possible with no obstructions so that the UV rays can reach the entirety of the water. The quantity and quality of water will dictate how long it will need to be exposed to UV for complete purification. You should also consider that, while disinfectant drops and tablets are relatively affordable, UV purification can be fairly expensive.
The benefit of all of the above purification methods is that they effectively kill the three big nasties; the drawback is that they don’t filter out any unpleasant tastes, smells or particulates.
©Scott Rinckenberger Photography | MSR
WHICH ONE IS BEST FOR YOU?
As you can see, there are plenty of diverse options available, and whichever is best for you will depend on your own unique needs and preferences – here are a few things to consider when making your choice:
- What is the water quality like in the area you’ll be visiting? Are you likely to encounter bacteria, protozoa AND viruses, or just the former two?
You probably won’t find viruses in most remote wilderness areas, but there is a high risk of viruses in any wilderness area that has a human settlement upstream, which means you’ll need to be prepared with a cleaning system that can handle all three big bosses. - How many people will you be providing water for? Straw-type filters are best for single-person use, while pump and inline filters can push through between 1 and 3 litres per minute, making them ideal for personal or group use.
If you want to be extra thorough, you can purify the water first and then filter it, which is a bit of a mission… but that little extra bit of work is always worth your health and happiness!
To leave you with a final thought – plenty of people have been drinking unfiltered mountain water for decades, and many have never had even one bad experience. On the other hand, some have had their adventures ruined and their minds scarred by horrendous tummy incidents, and even serious illnesses, that could have been easily avoided with the use of the above solutions.
So… do you want to risk it?
Check out our water filtration & purification solutions here, and stay safe out there!
Photos courtesy of Hennie van der Merwe, MSR, Sawyer and Katadyn.