“Water, water everywhere, Nor any drop to drink.”
- The Rime of the Ancient Mariner, Samuel Taylor Coleridge
It’s the great paradox of the outdoors: enough water to fill your bottles twice over, but drinking it will literally bowel you over. Thanks to diseases and our bodies evolving into squishy balls that can’t take a protozoa, slurpin’ from the riverbank is a risky business. Being unprepared to purify water risks dehydration and sickness, two big players in the ruin-your-good-time gang.
Purifying water isn’t the kind of thing you want to get wrong when the closest dunny is back at the servo in town. But it is confusing and each method has pros and cons that depend on the kind of adventure you’re getting yourself into.
Here’s how to stay moist in the sunburnt country:
Choosing A Water Source
You’ll want to start with the cleanest water you can find, these tips will help you get the best the bush has to offer:
- Look for the clearest water possible, it sounds obvious but scrounging around for less sediment is easier on your filter, you might not have to use it at all!
- Take water from fast flowing sources over stagnant ponds or puddles; pathogens have less time to develop.
- Know your area! Take a look at a map before you head out and you’ll know about landfills or mines that might contaminate your water source.
- Farm animals are kind of gross – avoid farmland watercourses where possible.
Filters
Sometimes you don’t have to second guess the water quality, a simple glance will confirm that you’ve found some dirty bush juice. There’s nothing healthy or enjoyable about drinking microchunks – so get yourself a microfilter.
Pump Filters
The Katadyn Hiker Pro has pores small enough to filter out bacteria, protozoa and cysts along with the big boys: algae and spores and dirt. It’s also got a piece of carbon that reduces bad smells and sounds high tech enough to impress your mum. It won’t stop viruses though, so you’ll still need to treat your water, or level up to the military-spec MSR Guardian
Pros
- Greatly increase your available water sources.
- Prepare janky water for further treatment.
Cons
- Most filters can’t filter out viruses and require further treatment.
- Pumping, so much pumping.
- Somewhat heavy (but possibly essential weight)
Gravity Filters
Think pumps are for chumps? Rather hang a bag off a tree and let old man gravity do the work? Yeah, me too.
You might be thinking of the lethargic pace of the drip coffee maker at your local bean house right now but don’t stress, these things are quick. In fact at a rate of 1.5 litres a minute, the 2 litre Platypus Gravity Works will be done before you can say “pumping is for plebs”.
Gravity filters clean water in much the same way as pump filters and strain out the same nasties (basically everything but viruses). Unless you’re Popeye, they’re the smart choice for dirty water in the backcountry.
Pros
- Doing nothing while your water teams up with Newton to filter itself.
- Reservoirs double as water storage vessels.
- Simple system with easy backflushing maintenance.
- Lightweight
Cons
- Doesn’t filter out viruses and might require further treatment.
- High quality, high-flow filters don’t come cheaply.
Ultralight Filters
If you’re a hardcore weight saver, the size and weight of the above might have you thinking about going al natural and sippin’ from the source. But whether you’re trail running, mountain biking or ultralight hiking, nothing is worse for your runs than “the runs”.
Katadyn’s BeFree bottle is just 59 grams with a fill-up-and-go design the size of your fist. You can drink straight from the bottle and it’s flexible so it rolls up when empty. For even more versatility, the MSR TrailShot can pump into your bottle, or you can dip the end in the water and drink directly from the pump like a lizard.
Pros
- Did I mention that they don’t weigh very much?
- Not too expensive
- Stashable
- High flow
Cons
- The filters aren’t fine enough to remove viruses – why are you running through such a sketchy area?
- Designed for personal use.
Treatments
Now that your water actually looks drinkable, it’s time to get all Magic School Bus on the microscopic nasties the filters might have missed.
Katadyn Micropur Tablets
Scrambling down to a creek in the Budawangs I passed a woman lugging two full bottles.
“What’s the water like?” I asked.
“Nothing Katadyn can’t fix!” she replied and bounded up the hill towards camp.
She wasn’t far wrong. Katadyn Micropur tablets are so synonymous with hiking that I’m surprised I haven’t seen it tattooed. If you’re new to the tablet game here are the #hacks to ensure you’re not left thirstin’:
- Drink all of your water when you get to a water source, fill up, drop a tablet in and note the time. You won’t be thirsty ‘til they’ve done their work.
- You can boil water at camp, no need to “drop tabs” an hour out from sunset.
- Chuck some tabs in before you head to bed so it’s ready for the next day.
Pros
- Super lightweight and cheap
- Kills most nasties including bacteria, viruses and Giardia.
- An easy backup
Cons
- Significant waiting time
- Won’t tackle Cryptosporidium, but it’s large enough to be removed by the above filters.
- Limited by supply (but packs last a surprisingly long time)
- Only works in clear water, if it’s turbid (full of sediment) you’ll need a filter (see below).
UV Light
Earlier I mentioned that name-dropping “carbon” sounded pretty techy – well grab your labcoats because we’re stepping it up with UV light. Water Purification technology that used to be reserved for governments and industry can now happen inside your bottle, futuristic as.
Back in 1999 SteriPEN released a portable UV lamp that looked kind of like a magic wand and the first Harry Potter book hit the best-seller list, pretty sus if you ask me. All you have to do is wave it around in a litre of water for 90 seconds, say expelliarmus under your breath and boom, drinkable water.
For the less magically inclined, Camelbak’s All Clear bottle integrates a UV lamp into its lid that’ll purify water in 60 seconds.
Pros
- The quickest, most comprehensive treatment method available.
- Annihilates bacteria, viruses, cryptosporidium and Giardia, no further treatment required.
- Lightweight and reusable
Cons
- Battery powered – might mean backup batteries for long trips.
- You’ll need crystal clear water to begin with or it’s time to crack out the filter.
Boiling
“Or you could just boil it.” as any backcountry veteran might say. Bringing water to a rolling boil for 1 minute (or 3 if you’re over 2000m up, looking at you Kozi) will kill any lurking pathogens. However it’s weighty, slow and leaves you with a hot bottle of water that’s less than ideal in summer months.
That being said, you’ll probably already have a stove with you for cooking and the right bit of gear can go a long way. The Jetboil Flash can boil half a litre of water in 2.5 minutes and weighs half a kilo including a 100g gas cannister. Jetboil’s are big on efficiency too: you’ll get 12 litres boiled from one 100g cannister.
Pros
- Kills every pathogen
- You need to take a stove anyway
- Coffee
Cons
- You’ll have to wait for the water to cool down
- Dirty water will still require filtering.
- Limited by the fuel you take with you
In Partnership With
Keeping it sustainable and safe when hiking
How to Stay Safe in the Bush (and Keep your Mum Happy): The Ultimate Hiking Safety Guide
Leave No Trace: 10 Tips To Tread Softly in Our Wild Places
How To Stay Safe Around Water // Swimming Hole Safety
My vote goes to the Sawyer filters! Super light weight, works with gravity, filters to 0.01 micron and fits generic plastic bottles!
I’ve heard good things about the Sawyers, Mitch Stewart couldn’t stop raving about them after hiking the Dusky Track!
In comparison to what you have shared, we are a fan of the Fill2Pure travel filter bottles. They are the simple ‘fill and go’ style, but they filter out the viruses and bacteria. So much more practical and efficient, when compared to the cumbersome and inconvenient multi-step process options. They have saved us on a few occasions when we have unknowingly drank bad water… there are a few other similar options on the market but the Fill2Pure are a better price point.
Excellent article! I really appreciate this and is something I’ll be sharing with my outdoor classes.
One small correction about boiling: as soon as the water starts to boil, it has surpassed the temperature required to kill off pathogens. So the adage of 1min at sea, 3min at altitude, is no longer relevant. The WHO has a table published about pathogens and what temperature and for how long at such temperature they become inactivated.
Thanks Duke!
I found a fair bit of conflicting information about boiling water. I agree with you, but settled on suggesting the safest possible option. I’ll look up the table you’ve mentioned. Cheers!
Also, in a pinch, a sock filled with gravel, sand and charcoal (from a campfire) will make an excellent sediment filter – you can run water through it til clear and then boil.
Now you’re talking. Genius Constance…i’d probably choose your sock over Jeremy’s too!