Water purification methods

[AndyW]

I haven't done too many trips yet where water has been an issue.

However, I'm planning some longer ones and have been wondering about the best methods. I was thinking along the lines of MSR or Katadyn filters but am now wondering about the new Steripen.

They are Ultraviolet lights. Battery powered, one version even has a small solar charger. They seem to recommend about 1 min of this in a litre of water and all the nastys have been taken care of

Anybody else tried these yet?

 

[leon-1]

They are Ultraviolet lights. Battery powered, one version even has a small solar charger. They seem to recommend about 1 min of this in a litre of water and all the nastys have been taken care of

Anybody else tried these yet?

The physics behind them seems to be sound from the studies that have been made on them, but they are not filters. Water that has not been filtered and as such has particulate matter still in it reduces the effectiveness of these pens meaning that the exposure time has to be increased significantly.

They should be used after water has been filtered as they are effectively a form of active sterilisation, not of filtration. If you remember;

Qualify: Selection of the water source, does your water source provide that which you require (quantity and Quality).
Clarify: The process of filtration to reduce particulate matter.
Purify: This is the active sterilisation be it through heat, chemicals or light.

The final one is consume, but if you use the above for a guide / checklist then you should have no problems.

 

[DavidW]

I had never heard of the Steripen until a week ago , it turned up on a web page I had followed looking for tent pegs. The Steripen is an intesting device.

Here are some of the links I found with information about them. The first link also has a short section comparing the Steripen to other filtration devices.

http://www.thetravelinsider.info/travelaccessories/steripen.htm
http://www.ldpcampingfoods.com/SteriPEN.htm
http://www.ecopro.biz/faqs.php

A thread on backpackinglight suggest that in the future an LED version could be available. Which would be more rugged , more energy efficient , reduce the price to about half the current price and also last through more treatments. The problem faced is making an LED which can produce the short wavelengths of UV needed to purify water. The current Steripen uses a lamp which would have to be replaced after treating about 1,250 gallons of water . While an LED Steripen would be expected to last a life time or about 500,000 gallons. This is according to the CEO of the manufacturing company. See this link

http://www.backpackinglight.com/cgi...um_post/4059/29067/forums/thread_display.html

fwiw

David

I .... I was thinking along the lines of MSR or Katadyn filters but am now wondering about the new Steripen.

They are Ultraviolet lights. Battery powered, one version even has a small solar charger. They seem to recommend about 1 min of this in a litre of water and all the nastys have been taken care of

Anybody else tried these yet?

 

[OzaawaaMigiziNini]

When doing my traditional bushcraft, I just boil my water. Here in Canada the main concern is Giardia, which is killed after just a minute of rapid boiling. I don't care for the smokey taste so I usually add a few bags of tea, or make some bush tea (cedar, mint, bearberry or sumac).

As for all around hiking, I carry an MSR Swee****er filter, with all the gadgets that come with one. I love them, versatile, and field managable...

In my survival kit I carry 90-120 Katadyn Micro-pur tablets. They're the only tablets approved by the FDA in America. They can basically purify any water, and are the preffered purification tablets used by my mentor and his company www.survivalinthebushinc.com. I don't use them unless I really really need to of course, that's why they're in my survival kit.

 

[Voivode]

I can tell you that in the Norwegian mountains it is 99,99% safe to drink directly from lakes or streams without boiling and filtering. I think that goes for most such places.

There is no reason whatsoever to boil it there, I think you are culturally biased on this subject. Elma, ilovemybed and C_Claycomb can testify on this.

I'm not certain who you are addressing here, but I'll take it up. Absolute statements make me immediately suspect. Are you claiming that there has never, ever been a case of any waterborne pathogen contracted from your wild spaces? And are you guaranteeing there never will? I don't think anybody can or should make those sorts of claims. I obviously can't attest to the purity of the water in the Norwegian mountains, and I don't doubt that your wild spaces are good and clean. But that doesn't preclude a mountain goat from falling off a waterfall into the river below and rotting away. Or a bear having a poo by the river. Or another trekker washing their dishes directly in the river. Substitute your fauna, but the point remains; unless you're taking it from a source, you can't say it's 100% clean.

We have areas that see heavy hiker and backpacker traffic. You couldn't pay me to ingest the waters that touch those trails and camp sites without some kind of treatment. We also have areas that are isolated and rarely see a human at all. I would be willing to make your bet that 99.99% of the time, that water is as good as gold. The fact remains that if I'm in those isolated areas I'm there on foot, and it took me at least a day or two to get there. If I did get seriously sick, I'm in a world of hurt and now I've become a burden for my friends. Why take that risk when all I have to do is take some simple precautions?

It is probably so in many other places too. Before the deforestation began, Amazonian indians drank directly from the great river. In a working ecosystem, without too much environmental degredation and overgrazing it will more than likely be safe to drink.

I agree with you 100%, and in the bad old days, nobody out here thought twice about dipping from a mountain stream and some still don't. As you say, damaged ecosystems cause water quality problems and if there is no human activities upstream, you're very, very unlikely to have any problem. That does not mean you will never have a problem though as "natural" sources of pathogens still exist.

 

[xylaria]

I live in the midlands and the area where i live is surrounded by towns and cities. If i got water from a stream which has traveled through a dirty old town, is it still safe to drink if you boil it? And what about farm chemicals?

I wouldn't take water from the trent once it is south of stoke. The pot industry used cadium lead and tin in pigments for years and it is in the soil. The trent is 50% effluent by the time it gets to nottingham. There is alot of wells and springs and around here, and most of them are marked on OS maps. I do take water from certain wells without treatment.

 

[torjusg]

But that doesn't preclude a mountain goat from falling off a waterfall into the river below and rotting away. Or a bear having a poo by the river. Or another trekker washing their dishes directly in the river. Substitute your fauna, but the point remains; unless you're taking it from a source, you can't say it's 100% clean.

Those things you are talking about there are generally (emphasis on that) to spread out to have an impact. There has been instances when a dead elk has been laying in a stream or something, but then the water usually smells foul, which should be a warning sign. I have also heard about one single case of giardia (the European variation being far less potent than the American one). But of all the literally thousands of times I have drunk from a stream I have never gotten ill.

But as a general rule, it is safer to drink directly of big lakes and rivers rather than small streams, as any natural pathogens will appear in lower concentration. More than likely to a so little degree that your immune system can handle it. This does however not apply to the lowlands, where the bigger rivers and lakes often are polluted by humans. Then the small streams are often safer, as they are less likely to be contaminated.

 

[Greg]

I prefer to Filter and sterilze / boil depending on the circumstanses, I suffered a severe case of the trots whilst on exercise in Scotland, Appleby to be exact, I had drunk from a high mountain fast flowing stream taking the old saying that drinking from a fast flowing stream in the mountains is ok.
I became proof of not to trust that saying!
I was in hospital for 3 days with a drip in my arm and under meds before it cleared up, not funny my backside didn't stop being sore for about a week after!!

 

[AndyW]

The physics behind them seems to be sound from the studies that have been made on them, but they are not filters. Water that has not been filtered and as such has particulate matter still in it reduces the effectiveness of these pens meaning that the exposure time has to be increased significantly.

They should be used after water has been filtered as they are effectively a form of active sterilisation, not of filtration. If you remember;

I realise I say I'm looking at them in place of filtration but I mean in place of the "high end" filters such as the Katadyns. The kit available here does state that it includes a "pre filter". I'm obviously only guessing but am taking it that the two combined will filter out particulate matter and the the gadget will do the rest instead of boiling or adding chemicals.

Or am I just expecting too much from this stuff?

Andy

 

[Voivode]

Those things you are talking about there are generally (emphasis on that) to spread out to have an impact. There has been instances when a dead elk has been laying in a stream or something, but then the water usually smells foul, which should be a warning sign. I have also heard about one single case of giardia (the European variation being far less potent than the American one). But of all the literally thousands of times I have drunk from a stream I have never gotten ill.

But as a general rule, it is safer to drink directly of big lakes and rivers rather than small streams, as any natural pathogens will appear in lower concentration. More than likely to a so little degree that your immune system can handle it. This does however not apply to the lowlands, where the bigger rivers and lakes often are polluted by humans. Then the small streams are often safer, as they are less likely to be contaminated.

I agree with you, but only to a point. These examples I give are indeed going to be rare (well, except for maybe the jackass washing his dishes) events but they happen. I just take issue with absolute statements about things, that's all. I have also never suffered for dipping from a river or stream, but that doesn't mean I never would and that's a risk I just don't see the need to take considering the nature of my time spent outdoors and how I would like to spend the next week or two. As always, YMMV. Good to know your Giardia isn't as bad as ours; ours is very unpleasant, to say the least.

If one were to go without water treatment, I would say your rules are about as sound as you could ask. I might still be wary of those small streams, but that's just me.

 

[Voivode]

I realise I say I'm looking at them in place of filtration but I mean in place of the "high end" filters such as the Katadyns. The kit available here does state that it includes a "pre filter". I'm obviously only guessing but am taking it that the two combined will filter out particulate matter and the the gadget will do the rest instead of boiling or adding chemicals.

Or am I just expecting too much from this stuff?

Andy

No, not really. UV disinfection works best on clear water, without a bunch of particulate matter floating around in there. A simple prefilter (we use a chunk of pantyhose) will take out most of the solid bits and then the UV treatment kills pretty much everything in the water.

I seem to remember a thread a couple of months ago where we hashed out that very product and somebody pointed out a ruggedized version more suitable to outdoor travel. Maybe do a search and see what pops out?

Edit: Of course, none of these methods deal with industrial pollutants like heavy metals or effluent or the drugs passed by humans into the water supply. They are just not designed to deal with water downstream from major human operations. As long as you're operating in a wilderness-ish state, they all have merit.

 

[Brendan]

If I am not in a position to boil my water I use an Aquastar plus UV water purifier and I must say it's pretty good.
It takes 80 seconds to purify 1 liter of reasonably clear water, double that if it's cloudy.
I have 3 pump filters,2 bottle filters and an inline filter but I think the aquastar wins on weight, ease of use and you do not get any aftertaste like you would when adding chemicals.
It also has a built in led lantern and comes with a basic pre-filter.
The only downside is the 2x3v lithiums it uses but they last quite some time.

I bought mine from ebay from the US for under £50 inc postage.

 

[Thorfinn]

If the water is flowing and does not have a dirty foam anywhere i'll drink it staright. If it does i don't touch it, as it is most likely bad. If how ever it's a loch or lake i'll strain it through a hanky or a peice of muslin. And boil, I've never used steri tabs but have always had them never really needed them really. If you boiling wait till you have a 'rolling boil' when teams coming off it but it's not bubbling.

 

[Chance]

I read a review in one of the hill-walking magazines a while back. It compared all the usual filters, summarising with a cost per litre. The Katadyn came out a long way ahead, because the high initial outlay was offset by the long service period.
Of course, you'd have to be using it for several years to get the cost benefits; and there are the usual caveats about some filters not being appropriate for the processing of seawater or raw sewage.
I didn't know this when I bought mine back-when-it-was-all-fields, but is assuages some of the guilt at the price I paid.

 

[dommyracer]

If you boiling wait till you have a 'rolling boil' when teams coming off it but it's not bubbling

That doesn't make sense. A "rolling boil" means the state when all the liquid has reached boiling point and is moving, with bubbles constantly forming and breaking the surface.

In cookery its normally defined as a state where a liquid is producing bubbles that can't be put down by stirring.

A pot of water with steam coming off the top is not a rolling boil

Also, because water boils at a lower temperature at Altitude, you'll need to boil for longer if you're high up.

Boiling should kill all the known pathogens.
Make sure you keep your boiled water clean though, because if nasties are introduced to it, they will spread again - boiled water has no residual disinfectant properties.

Chemical treatments are good, but Cryptosporidium is highly resistant to chlorine and iodine.

Filters that have pores of 0.2 microns or less will normally remove all the Protozoa and Parasites (Giardia, Crypto, Campy etc), but viruses will pass through - these will need to be killed by Iodine or Boiling.

 

[Tor helge]

I drink directly from the streams and lakes. But if it was necessary to treat the water I would boil it.

The only giardia case I`ve heard about is in a water plant in Bergen. Haven`t heard that this is a problem anywhere else in Norway.


Tor

 

[S8AN]

I drank straight from a brook when younger I know thats not good but Im still here.... but just curious as to what type of cloth you use to pre filter.

ive used muslin cloth as it's very tightly woven so pulls out most crap.

over the years ive tried many different forms of water purification - the cleanest water was from boiling water then catching the steam with something overhead at an angle which then produces droplets that run into another container. a process for sure but if your fussy then it might be worth it. filtering with muslin and then boilding for 3-5 mins is my main option and its a simple to stage process no overhead bits and other containers. if you get water from a clean enough stream etc the boiling can be good enough for what you need.

 

[Scuba Pete]

I rolling boil will be suffient to kill anything in the water. What you are talking about is distillation of the water.

You should not drink distilled water, it does not contain any electrolytes (salt etc), as they are removed by the distillation. This means when you drink it you will loose far more electrolytes etc from your body when you urinate. Don't get me wrong, your not going to drop dead after a glass and if you are eating well then you will be fine. However it is something to consider, esp if you have little food about.

 

[torjusg]

I rolling boil will be suffient to kill anything in the water. What you are talking about is distillation of the water.

You should not drink distilled water, it does not contain any electrolytes (salt etc), as they are removed by the distillation. This means when you drink it you will loose far more electrolytes etc from your body when you urinate. Don't get me wrong, your not going to drop dead after a glass and if you are eating well then you will be fine. However it is something to consider, esp if you have little food about.

Just curious, isn't destilling pretty much the only method available at sea?

 

[Scuba Pete]

They have solar stills, but now they have osmosis pumps, very clever really. I assume a little salt will get in the water but there is plenty to drink, heh.

In life or death situations you don’t really have a choice.

I know it has been mentioned before the importance of taking salt in your diet if you are sweating a lot. I would not want to further reduce salt levels by drinking distilled water.

There is a lot of info about it on the web, i think at one point it was widely recommended and a method to detox your system but again you need a balanced diet. From what I understand the recommendation is that you do not drink it, and certainly from a chemical point of view this is the case.

When boiling is sufficient, I would not want to reduce my electrolyte intake further.