UKC

A few years ago I experienced symptoms suggestive of Yersinia enterolotica infection following drinking water contaminated by marmot pee. As a result I bought a UV type water purifier, which I find easy to use and therefore it gets used. It is not effective in even moderately turbid (cloudy) water.

European marmots carry Y enterolitica but US 'marmots' (groundhogs) in some areas may carry Y pestis (the plague), which is usually rapidly fatal.

I read last year's thread on water purification and the US army analysis provided in a link in that thread basically says they 'don't work' ie they don't achieve 6 log reduction for bacteria and 4 log for viruses.

I checked the website for the device and the figures they quote are around 3 log reduction for bacteria.

A few thoughts:
Boiling for 1 minute remains the best way of 'sterilising' water (3 mins at altitude above 1500m) - http://water.epa.gov/aboutow/ogwdw/upload/2006_09_14_faq_fs_emergency-disin...
Water in the wild can never be assumed to be free from cantaminants
Lakes are probably safer than rivers through the dilution effect
An effective device is one which gets used

Does anyone know of an easy-to-use device (which they probably own and have used) that achieves 6 log reduction on bacteria and 4 log on viruses?

In reply to Nigel Modern:
I carry a Katadyn Vario filter which is a 0.2 micron glass-fiber filter in a pump mechanism. This should be sufficient to remove Yersinia pestis which seems to be between 0.5 and 0.8 μm in its smallest dimension. Most viri will probably pass through the filter.

This is the ideal outdoor filter, in my opinion. It is big and bulky and you do have to be careful not to contaminate the output stream or receptacle into which you are pumping the water but it is robust, easy to use and quick and it doesn't run on electricity. It also fits directly onto Nalgene wide-mouth bottles of which I own several - they, too, are excellent.

EDIT: Please post the link to the US army research for those of us who haven't a clue what the "other thread" is. Also, that document from the EPA is pretty irrelevant since it doesn't mention or consider any of the latest water filtration products on the market, today.

In reply to Xharlie:

What about watertogo.eu ?
Not used them personally but sounds like you can request data/performance sheets. Filters made for NASA (on the off chance we start drinking Mars ice water?)

I have a Sawyer Squeeze Mini (less than £30) and it's so ridiculously portable & easy to use that it's not worth considering not carrying it and goes with me for bike rides, hill walks, ski tours and camping/bothy trips. However it's also completely useless vs viruses, but they weren't the offending pathogen in the quoted marmot pee.

"The Sawyer Biological Filter removes 7 log (99.99999%) of all bacteria and 6 log (99.9999%) of all protozoa."

In reply to Nigel Modern:

Bit confused by all the marketing claims of Steripen etc

Their web site states "UV light destroys over 99.9% of bacteria, viruses, and protozoa like Giardia and Cryptosporidium" but that doesn't say Steripen does just UV light"

And that "... prove that SteriPEN exceeds the standard set forth in the U.S. EPA Guide Standard and Protocol for Testing Microbiological Water Purifiers."

I have been using a Steripen for years.


Is it safe as they claim?
Or only safe for some countries etc?
Grateful for advice.
Confused dot com

In reply to Xharlie:

http://www.dtic.mil/get-tr-doc/pdf?AD=ADA449339

The thing about the military review and most of the info about all these products is it's really just based on lab tests and expert opinion and their analysis was not just based on effectiveness but on suitability for combat secenarios unrelated to situations we find ourselves in (mostly). There's precious little actual info on actual review of case statistics ie how many people get infected, what filter were they/weren't they using etc.

Your post immediately raises one of the issues ie bulk. An effective but bulky filter system might just get left in the car, one which flavours the water might be problematic (unless it's very light and you're more concerned about mortar rounds landing about you)

General point - No purification system replaces care about your water source

In reply to moffatross:

Ta, will look at Squeeze mini

Viruses are said to be 'less of a problem' (try catching hepatitis B tho') and are definitely harder to eg filter out. Not sure how good the Steripen is on viruses but it does suffer from the size issue too in that delivered dose of UV depends on size of the bug

In reply to m0unt41n:

Marketing claims for Steripen are fine...they just use less stringent standards than the military experts...and I think the 3 log was for the 3L system which looks less effective than the 1L system, however the military review does say they do not achive the same kill rates as other systems and they regard them as 'insufficient'...based on opinion and lab testing.

In the real world lab effectiveness must be balanced with availability (you can be bothered to carry it), ease of use...etc(?)

In reply to Bluebird:
Watertogo is just a filter system. From what I have read to be effective you need filter plus sterilisation. I think same goes for Squeeze mini

In reply to moffatross:

How long to get 1L out of a Squeeze mini?

In reply to Nigel Modern:
The supplied bladder is under 1/2 litre and you can never quite fill it brim full as its natural state is to revert to a 'Flat Pack' if that makes sense ? When I'm filling a 750 ml bottle to carry away from a water source it requires 2-3 loads, and the fill and squeeze process for each load is probably about a minute. So the answer for a litre I suppose is around 4-5 minutes ...

Edit ... or you could carry 2 x 1 litre bottles with a standard thread screw top that matches the filter and be done with all the bladder refilling

In reply to moffatross:
Thank you...slower than the Steripen - speed and ease of use is its main advantage...and no (potentially) frozen filter issue.

I do find that Steripen gets used...I even 'Pen the water we will be boiling.

Hmmm...it almost certainly will deal with the Marmot issue in the Alps (that and not forgetting to pick up glacier meltwater on the way down, which was the mistake we made.

Protozoa and flukes (are these protozoa?) are quite big...so it probably nukes these relatively well and I don't really care about a bit of diarrhoea but don't want a fluke...that deals with the main UK issue(?)

Might well get a Squeeze for short hikes...but will still use the Steripen...and mostly boil. Belt and braces, once bitten and all that. I was pretty freaked when I developed bubos. It took me a couple of hours to sort out that it couln't be Y pestis

In reply to Nigel Modern:

Any moment now someone's going to tell me that I'm going to die a horrible death for using chlorine dioxide, aren't they.

In reply to climbwhenready:

Be careful out there...

In reply to Nigel Modern:

The Katadyn Vario trumps the Sawyer Squeeze and Steri-Pen in my opinion. I read a lot of stuff on both of those options before buying the Vario, a year ago, and stand by my opinion today.

Call me paranoid but I simply cannot bet drinking water on batteries. Batteries are unreliable by definition and the Steri-Pen is known to drain power from its batteries even when not in use, showing a glaring design flaw. (Sod flipping batteries. If I have to work around design flaws, I lose the convenience the device boasts.) With a mechanical device, if I end up stuck in the hills for longer than I planned, I will still have potable water.

The Vario is also a lot more usable and a lot faster than the Sawyer. It has a proper hose with a proper float on the end and, once that's in the water source, you can pump as much water as you like. You can fill several bottles and pots in which to boil your dinner in sequence and, if you have a big party, a second pair of hands makes a good production line. Less time filtering water means more time lying on the ground staring at the sunset and, if that isn't enough, less faffing with the filter means less chance of contaminating the output.

In reply to Bluebird:



The filters are great, ive drank out of some right skanky water sources and never had a problem but the bottle they come with is poor quality/design and has a tendancy to leak. Also not very good for anything but drinking from. To use them for filtering for cooking is a slow, awkward and frustrating process.

In reply to Nigel Modern:

There's also LifeStraw

http://waternlife.com/lifestraw-go-bottle.html

0.2µ

In reply to thedatastream:

Thanks guys.

I agree about batteries and I would probably use a mechanical device on longer trips, tho' nowadays we're all taking photocells to keep our devices going aren't we? Just call me 'lostwithoutaniphone' and NiMH batteries last a long time in the Steripen in my experience.

In reply to thedatastream:

Full marks for knowing how to type µ

In reply to Nigel Modern:

i have one of these

http://www.purehydration.com/

In reply to Nigel Modern:

Whats wrong with chlorination? It's what we use in the UK, the tablets are tiny and light and if you can't find a clear source, you can filter with sock or coffee filter, or allow to settle out. You should have a chlorine residual for secondary decontamination as well, uv doesn't achieve that.

In reply to Nigel Modern:
+1 for Sawyer filters. In dodgy water areas, I have one that I clip into the tubing on my camelbak/platypus etc - just scoop water & drink (requires a bit more sucking though). My parents used one to filter all their drinking water for 2 and a half years whilst living in rural west tanzania - they didn't get food poisoning once and it still works like a dream 4 years on! Of course, it may be good luck, but definitely worth a look.

In reply to Nigel Modern:

I posted the link to the US Military study originally - I agree about the lack of clinical evidence for choice of purification system, but the lab testing seemed pretty thorough to me, and the range of military requirements actually suits the use cases for the kinds of outdoor activities we're generally involved in pretty well, I thought.

The critical thing I took from the study was that for the trifecta of weight, convenience and effectiveness there's just no beating chlorine dioxide. Yes you have to wait post treatment and yes the wait can be tiresome for very cold water but for my money at least it's just too good to pass up. Why the focus on a device?

In reply to nclarey:

I agree that the lab tests are thorough but in vitro is only a guide eg Desperately thirsty man on a cold day doesn't wait etc

Will look again at ClO2...isn't there an odour issue?...I suppose I have a mild prejudice against chemical treatment - probably illogical but doesn't the army study say that filtering and chemical treatments should be used together to achieve the best results.

I keep coming back to how easy the Steripen is in use...maybe the combination of ClO2 and an easy to use device of your choice is good.

In reply to Nigel Modern:

I don't know what 6 log and 4 log mean, but this Water to Go filter/bottle claims to filter 99.9% of all contaminants, including viruses. See review: http://www.ukhillwalking.com/gear/review.php?id=5574

In reply to Nigel Modern:

ClO2 is, at least to me, completely tasteless. Give it a try. My interpretation of the study was that if you were mobile (categories C and D in the study) that ClO2 was always your best option on their weighted factors. That said, chemicals aren't going to help much with particulate matter, so a belt-and-braces approach with a filter will probably yield the most palatable water. Depends on your priorities I suppose.

The study is, however, getting a little long in the tooth now and the Sawyer filters listed above do look quite compelling. Unfortunately they don't look like a whole lot of good for winter use cases, because of the dire warnings about freezing up.

What we really need is the military to publish annual studies of these sorts of things so we can have some more confidence in the claims offered for performance! Any us.mil folks out there want to check to see if there's a more recent study that's been published?

In reply to Nigel Modern:

Just use a lifestraw, should last you forever and you can drink direct from the water source (or bottle the water and drink it through the ls).

In reply to Dan Bailey - UKHillwalking.com:

99.9% of say a few million individual bacterium still leaves a not inconsiderable amount behind!

6log would be more like 99.999999 (6DP) I think which is a considerable difference.

In reply to Removed User:

Lifestraw doesn't do viruses.

In reply to Nigel Modern:



Who and sphere guidance for emergency water treatment is that chlorination works under 5 NTU, or in clear water. As long as the water is clear it'll work, except for unlikely things like Guardia and cryptosporidium. chlorine is used in nearly all cases around the world as a residual disinfectant, it is in your tap water. All the other stuff are just filters. You still need chlorine to disinfect. Boys and toys I suppose, all that is needed are puritabs.

In reply to higherclimbingwales:

Yes, that's the issue - the residual bacteria. I'm no expert but have experience in medicine and epidemiology. It's about infective doses - pathogenic organisms act in 'packs' when disabling the immune system. A certain number of bugs are needed but this varies for different organisms, site of entry, potential host etc and knowledge about infective doses is probably inferred.

I'm intrigued as to where the judgments of what 'effective bug removal' come from ie Are the standards 6log and 4log reduction experimentally or empirically derived. It's a pretty Dr Mengele type experiment to do, so I'm guessing it's empirical ie expert opinion plus impressions from field experience.

In reply to jonnie3430:

I think the military disagrees...filtration plus disinfection

In reply to Dan Bailey - UKHillwalking.com:

99.9% might mean 6log but I'd want to see it quoted in log terms and not percentage eg I think 3-4log exceeds 99.9%. The mathematicians might correct me.

In reply to Nigel Modern:

It's worth noting that 6log reduction from highly contaminated water may still leave an infective dose of bacteria ie watch where you get your water from and don't only rely on whatever system you use

In reply to Nigel Modern:

Numbers? Agh! This is deep water for me. I'm out of my depth. I can ask Water to Go if you like

In reply to Dan Bailey - UKHillwalking.com:

testing results for the one i have are here

http://www.purehydration.com/about-us/testing-certification/

In reply to Dan Bailey - UKHillwalking.com:

99.9% of 10,000,000 = 9990000.0 so theres still 10,000 possible bacteria in the water. I should add I don't know exactly how many bacteria lives in a sample of dirty water but I think 10 million isn't a bad estimate.

at 99.9999% there'd only be around 10 bacteria left in the sample.

In reply to Nigel Modern:


But if you avoid the filtration stage by choosing clear water in the first place, you can skip the filtration phase completely. The quantities they deal with and the urgency mean they need a filtration phase for the military(and they should have CBRN proofing too). You should be able to find clear water by looking about.

In reply to Dan Bailey - UKHillwalking.com:


Well don't go drinking it Dan!

In reply to higherclimbingwales:

Just want to add another complicating factor - the claim is also highly dependent on the type of bacteria. There are some bacteria that are highly UV resistant (for example), and if the water was full of these, the claim that a large amount (6log) would be killed would not be met. For most pathogenic bacteria though, likely this can be ignored. But another reason to doubt things such as "killds 99.9% of bacteria" - what if the 0.01 left over was toxic and the rest were benign - legally the manufacturer's claim is still valid!

Another option is to use potassium permanganate to purify water. It should not be used daily, but can be used on a short term basis. It also functions as a disinfectant (dilute less), and a firestarter (mix with sugar or glycerol, not sure on ratio)

In reply to jonnie3430:

The filters also remove bacteria and protozoa depending on the pore rating for the filter

In reply to higherclimbingwales:

Thanks for the clarification of the numbers.

Your post highlights why field info is key...how many bacteria left in the water is a problem, for what bacterium? etc

In the end the military review is probably the best guide but it would be nice if they published field info as they are the ones using these systems in significant numbers for significant lengths of time.

Repeating myself for late-comers/skip-readers





Plus - US military review recommends filtration plus disinfection and reviews many available devices, some of which do both: http://www.dtic.mil/get-tr-doc/pdf?AD=ADA449339

In reply to higherclimbingwales:

makes sense

In reply to Nigel Modern:

http://katadynch.vs31.snowflakehosting.ch/fileadmin/user_upload/katadyn_pro...

The business.
Activated carbon granules assist in removing viruses due to Van der Waals forces, combined with a 0.2 uM ceramic filter.

In reply to Nigel Modern:



Just don't hit the Print Button - 666 pages

In reply to Ste Brom:

Thank you

In reply to Nigel Modern:


But you don't need to remove them as the chlorine destroys them. As i said above, you need to be wary of Chlorine resistant diseases, but they are faecal oral so as long as you aren't drinking downstream from a campsite, field of cows, etc. You'll be fine with chlorination.

In reply to jonnie3430:

I don't think you're right Jonnie...filtering and disinfection complement each other. Each potentially leaves some bugs the other will kill, though each are good on their own best results are achieved using a combination. US Army saying it, not me.

In reply to Nigel Modern:

I'm a water engineer, I've studied it for years. Get it below 5 NTU and chorinate. All you need to carry is a few packets of puritabs.

In reply to Nigel Modern:

I'm surprised no-one has mentioned Iodine. More effective/reliable than Chlorine (ie, in dealing with Giardia), downside is the taste. In practice, like others I would filter and use chemicals if I was concerned about the safety of the water. Filtration and UV also works of course, downside is reliance on batteries.

In reply to nightclimber:

According to the US.mil information the Iodine solutions aren't sufficiently effective with Giardia or Crypto. See page C-47 of the above study, referencing the Coghlan IT w/ Neut D and the tabs. As you say, also doesn't taste very good.

Seriously though, try the Chlorine Dioxide - despite the name your water will not taste like you're drinking from a swimming pool

In reply to Nigel Modern:

Hi Nigel,

Kyle from Water-to-Go here.

Just wanted to give you a bit more information about our filter technology. The filter actually uses 3 technologies which all work in their own unique way.

When we talk about pore size we refer back to standard technology. The mechanical restriction of the size of the pores has been the traditional measure of what a filter will eliminate.

This is not the case with Water-to-Go. We have a unique combination of three technologies, each performs individually but it is the combination that makes us unique.

We use traditional carbon but in a way that optimises the performance so that compared to carbon block technology, which can only remove 40-60% of Chlorine and Fluoride, WTG filters over 99.9%. We than have the combination of the two nano technologies which not only reduce the pore size to 0.7 microns, but also create a positive hydrostatic charge in the membrane which attract and traps even viruses like polio. Results at major labs in USA but importantly our results in London School of Hygiene and Tropical Medicine where we tested against polio virus. Testimony to the fact that we achieve substantial results by the combination of technologies rather than depend on just the mechanical calculation via a limited pore size.

Back to the earlier conversations about log reduction. Water-to-Go's performance has a 6 log reduction on bacteria & viruses (99.9999%) and a 4 log reduction on protozoan cysts (99.99%). We will also remove 99.9% of chemicals like chlorine & fluoride, heavy metals like Lead, copper & mercury and remove the bad taste and odour.

I hope this helps. Our testing data is available on request. Please send an email to info@watertogo.eu.

In reply to Kyle - Water-to-Go:

You need to look at your bottle designs. Im on my second lid and both have leaked dirty water through the one way valve. Ive ended up sealing it closed.

In reply to Nigel Modern:

Someone mentioned iodine. Its supposedly more effective than chlorine and destroys Giardia. Nowadays outdoor shops have stopped stocking iodine-containing tablets due to potential long term cumulative effects.
If you can get hold of iodine granules put some in the bottom of a suitable container eg graduated polypropylene bottle and top up to 20ml mark.It will form a saturated solution leaving mos of iodine undissolved .Decant 10 ml into 1L bottle of water and leave for, say, 20min. before drinking. Top up the iodine container ready for next use and repeat until no iodine solids are left.

In reply to oldie:

I have the polarpure bottles which uses iodine crystals, when in storage the iodine vapor makes it way out of the bottle, through two ziploc bags and then manage the take of the alluminium coating of my mylar bags. So beware of how you store them.

In reply to Kyle - Water-to-Go:
Thanks Kyle
PS my post about water to go was misleading. What I meant to say was '...to be maximally effective US Army recommends filtration plus sterilisation...'

I didn't intend to say water to go wasn't effective - I think I had already seen the good lab results...on the website

In reply to oldie:

Iodine drops worked fine for me. Will kill just about everything and tastes like funny lemonade. OK for short term use.

In reply to Nigel Modern:

I was under the impression that 1/2 teaspoon of Milton (or own brand baby bottle sterilising solution) per 5 litres of water left for 15 mins would kill pretty much anything? Cheap as chips.
As far as I know the advertised 99.9 isn't accurate enough to say that 0.1 survive. I always thought it was just that they weren't allowed to say 100%.

In reply to Kyle - Water-to-Go:

I've been using water-to-go for almost a year now and generally been very happy with it. Use it in the hills and especially on fell running/omm type events where the usual solution is just to drink (often not very nice looking) stream water and hope it's ok. To me, the best thing about water-to-go is it's not much heavier than a normal bottle and you use it the same way, which means I actually bother to take it. Katadyn type stuff is too heavy, and tablets are too much faff, so I know I wouldn't bother with either. The ability to safely drink e.g. tarn water allows me to fill up little and often meaning I carry less water (probably saving weight on average) and stay more hydrated as I'm not rationing my water so much. Can drink the browser water at mid-camp without fear too.

On the omm last year I only saw one or two others using water-to-go which surprised me, so you might want to try advertising more with them Kyle. One complaint though: I do wish you would produce a normal push-pull sports top as the current spout thing is annoying to drink from whilst running. I did email water-to-go to suggest this but they said they won't as this typeare more likely to get contaminated whilst filling up, don't see how myself, and I personally would much prefer it!

In reply to jonnie3430:
OK - I think I'm getting the picture.

Filtration only really needed if turbidity is an issue.

Chlorine works on the real nasties but if you slip up you might get D+V

What does chlorine do to viruses? (Looking it up as I write)...it kills them