There is little more refreshing than drinking fresh cool water straight from the source while hiking, while some water in the New Zealand outdoors is still safe to drink, there is also no way of identifying which water contains infection causing Bacteria, Viruses and Protozoa.
In the late 90’s having already seen the unpleasant effects of Giardia and Cryptosporidium on unlucky hikers, and being aware of a rising rate of Giardia in New Zealand,(*1) I started purifying all water before drinking while hiking.
Methods of Purifying water
Like many people new to hiking, I started with the cheapest and easiest method of purifying my drinking water, before moving on to more advanced methods as my hiking needs and experience changed;
The traditional method of a rolling boil for at least 3 minutes. (*2)
Use a cloth or filter paper pre filter (or letting the water settle) first) clears the water of sediments, before maintaining a rolling boil over a heat source.
- Kills or inactivates Protozoa, Bacteria, Viruses.(Basically pasteurization)
- At least you don’t have to pump right ?
- Cheap on gear
- Fuel expenditure
- You will have to wait for the water to cool for drinking
- How big is your billy compared to your drink bladder
This method is generally used as an emergency back up to your main method . First filtering your water to remove sediment, then adding purification tablets;
- Light weight
- No taste (Can’t vouch for the Chlorine – but the Iodine had an after taste?)
- Works for Viruses, Bacteria, and some Protozoa
- Do you really want the added chemicals?
- 30 minutes – 4 hour treatment time depending on chemical
- Most Chemicals have an expiry date on the package… do they work after that?
- Some Protozoa are resistant to chlorine and Iodine
This method involves placing the intake hose in to your water source, and then hand pumping the water up to the filter where its forced through a ceramic carbon filter. (*3) Pre treating with a chemical method as well as pre filtering is wise where the water source is undesirable.
- If you choose to pre treat with the chemical method the carbon element will remove any taste/ chemical
- Water is cool and tastes like the source
- Fully field maintainable (you can break it right down to clean or repair)
- No battery power or charging required
- The ceramic element is rated to 2000litres.
- Great for taking the “gym” to the out doors – see disadvantages;-)
- Advertised at flow rate of 1 litre/min, requiring 85 pumps. ( didn’t take long for the arm to get sore!)
- I recall around 30minutes of pumping to refill my 3 litre drink bladder;-) ( who needs the gym!)
- 3-400gms total weight – more once the ceramic filter is wet(takes several days to fully dry)
- The filter doesn’t like dirty water, it still works but will get harder until you clean it.
- Removes 99.9999% Bacteria and protozoa only – NOT viruses ( although that’s not a problem in New Zealand)
- More expensive then tablets
4.)Ultra Violet light Sterilisation
Purifying is as simply as screwing the pre filter onto to compatible bottle, filling the bottle, insert UV pen and agitate and treat, before pouring in to my drink bladder.
- Fast: approx. 2 minutes a litre
- The water is cool and tastes of the source
- Destroy Bacteria, Protozoan, Cysts, Viruses
- Auto power off and water cut out sensor
- Screws onto a number of 1 litre bottles (I know it fits Nalgene everyday wide mouth and Camelbak Eddy )
- Battery, timer, UV life and fault notification
- UV pen and pre filter = 190 gm with out batteries
- Easy and Fast
- Requires batteries (without solar charging this could be a problem)
- Considered expensive – although the price has come down from when I brought.
- UV light life rated at 8000 activations (device warning approaching limit)
- Event of Device failure ( I’ll resort to boiling if this happens)
- Can’t be used directly on drink bladders – must be treated in a rigid vessel (I carry a compatible CamelBak drink bottle for camp)
The future… Do I need a step 5.?
Looks like Technology is still improving beyond Ultra Violet…. Electrolytic Water Purification?
(*2) At altitudes below 1000m the boiling time is 1 minute at a rolling boil, above 1000m’s this lengthens to 3 minutes.
(*3) Some drink bottles and drink bladders screw directly onto the base of the pump. If your using a Camelbak quick connect bladder you can also make a hose to connect the outlet to the hose port on the bladder to avoid spilling.
(*4) I use the Steripen Classic because, while a little heavier then other Steripen’s the batteries are removable and compatible with my other electronics and charging system.
- Keeping healthy outdoors
- Emergency Disinfection of Drinking Water
- Boil Water Response – Information for the Public Health Professional