What is the best way to sanitise water in the bush?

Minimising the risk of illness in the wild is extremely important. One of the easiest ways to turn an adventure into a nightmare is getting sick by drinking contaminated water on the track.

Guest Post by Sara Freeland

Of course, you can mitigate some risk by choosing your water source wisely; generally, running water is better than stagnant water; upstream is better than downstream, and it’s important to consider whether any livestock or wildlife pass through the area as their fecal matter can contaminate the water.

But sometimes, your only option might be to sanitise the water you collect. So what is the best method?

To purify water, there are 4 main options; boiling, water purification tablets, water filters and UV light devices. We’ve unpacked the pro’s and con’s below, to help you make the best decision next time you’re heading out into the wild.


Roll boiling for 3 minutes

Pros Cons
– Very effective in killing germs and bacteria

– Does not require additional equipment

– Does not require a wait-time, like some water filters or purification tablets

– Does not remove all pollutants, odours and silt/sediment

– Can be time-consuming to boil large amounts of water, using lots of fuel

– Water is hot, needing time to cool before it can be safely drunk


Water purification tablets (e.g. Aquatabs)

Pros Cons
– Easy to find and lightweight to carry

– Requires no special equipment or fuel sources

– Good for small, individual containers such as drink bottle and bladders

– Does not remove sediments or silt

– Requires time to purify, commonly 30 minutes

– May leave a chemical, chlorine taste behind

– May lose effectiveness over time if tablets are stored for too long


Water filters/Straws

Pros Cons
– Removes most sediments and silt

– Can purify exactly the right amount of water needed (no wastage)

– Treatment is easy and water is instantly drinkable

– Requires additional equipment

– Filters require regular maintenance and cleaning to stay effective

– Some can be a manual process, pumping or squeezing which takes time and effort


UV light devices (e.g. Steri-pen)

Pros Cons
– A very high rate of accuracy, often sanitising water to 99.5%

– Lightweight to carry and easy to use

– One pen device can last a lifetime, with over 8000L per bulb

– Quick to sanitise, often taking less than 1 minute to do 1 L

– Expensive to buy

– Requires battery charge, so it’s necessary to always carry a back-up solution just in case

– Does not remove any sediment. Dirty water will need to be strained first

– Can be tricky to use in water bladders or water bottles with narrow tops, as the UV light needs to be completely submerged to operate.


Overall, the filtration system you choose will be a personal choice, based on your hiking location and your access to fresh water, the size of your group and the length of your trip. Whichever you choose, make sure you follow the instructions 100% to ensure happy bellies and a successful hiking adventure.

Sara Freeland owns and operates Freeland Hiking Co. an expedition adventure company based in Sydney, Australia. Head to to find out more.

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