The Science of Water

British Red

M.A.B (Mad About Bushcraft)
Dec 30, 2005
25,569
455
Mercia
Would you mind deleting that document please abushcrafter - I'd rather my works wasn't on google.

Thank you

Red
 

Staghound

Forager
Apr 14, 2008
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Powys
www.mid-waleslogbuildings.co.uk
I have just read the original article in this thread with interest. For quite a few years now we have lived in isolated houses with private water supplies, in the first case from a spring and currently from a well occasionally topped up by a nearby stream (used by farm stock) In neither case has the water been either filtered or chemically treated. With this in mind I always recommend that visitors boil water before drinking just in case, however in general we seem to be healthy and less prone to stomach bugs than many of our friends who depend on mains tap water. I also tend to be fairly blase about drinking directly from the local watercourses. Admittedly this is quite an isolated area so there is not much chemical contamination to worry about. However I wonder if there is any evidence that routine exposure to the common waterborne bugs, ie. e. coli, cryptospyridium etc. can lead to increased resistance, after all our dogs, stock and the local wildlife seem to stay healthy on the stuff?

I think in other areas I would be less casual about the water I drank.

Yours probably about to croak from cholera, liver fluke, typhus, e.coli and tapeworm:theyareon:

Steve
 

Nelis

Forager
Mar 9, 2007
112
0
45
Oudenbosch
HI Red,

Great article, nice info. A while back when I was searching for a waterfilter I indeed became very confused about all the ins and outs of the modern filters.

Now I don't want to be a knowitall, but just one little comment, as a whisky and whiskey fan I know somewhat about distillling, and I believe it are the chemicals with a higher boiling point then water that you can remove using a still. If you want to remove the chemicals with a lower boiling point, you would need a thermometer and only collect the distilled fluids as long as the water in the still is at 100 degree's (at 1 atmospheric pressure). Not before it gets to 100 degrees, and not when the water gets hotter. Even then there will be a risk of contaminating your water with chemical residu left in the condensor.

Also when I bought my filter, the people who sold it to me claimed that there are no filter devices that can remove all virusses from water, but not to worry to much about this because waterborne virusses are very rare in western europe, what are your thoughts on this ?
 

British Red

M.A.B (Mad About Bushcraft)
Dec 30, 2005
25,569
455
Mercia
Niels,

Distilling is odd. Clearly it depends if you are condensing vapour or keeping the donor liquid as to what does what.

The way I see distillation in the UK at least is its one of the only ways to reliably remove heavy metals etc. (all of them). So condensed steam will have all living contaminents killed by heat, particulates left behind and most metals etc. left behind. However the distillate could still containe alcohols and other VOCs (volatile organic chemicals)

The people who sold you your filter were plain wrong I'm afraid - Lifesaver systems are one type of portable filter for viruses and I believe there are others. I haven't used one myself (they are over £100) but I hear good things



Red
 

AJB

Native
Oct 2, 2004
1,821
8
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Lancashire
Hi Red,

That was a really good read, many thanks for the effort it must have taken to produce. Would it be possible to make your piece on fire available again, I’d like to read that.

I own a PreMac Model PWP which I have to admit I’ve never used in anger. I saw them first launched at COPEX many years ago, and when I saw it cheep I had to buy it - I’m a kit junky! Would anyone have an opinion on them? Red if you had to recommend one “perfect” (if there is such a thing) filter for back packing what would it be? There seem to be so many on the market but so few seem to cover all the bases, is this because the risks they ignore are statistically irrelevant or do they hope their users get lucky – it’s such a confusing choice (or it would be if I needed one – I just love kit)

Thanks again.
 

gregorach

Bushcrafter (boy, I've got a lot to say!)
Sep 15, 2005
3,723
26
47
Edinburgh
The PWP is perfectly adequate for almost any conceivable use, except where you need to remove chemical contaminants. Biologically, it's excellent.

There is no "perfect" filter - all have their limitations and drawbacks, whether it be inability to deal with chemical contamination, limited lifetime, weight, price, etc, etc... The question is what do you want from a filter? Me, I'm quite happy with my Pre-Mac SWP - because although it has limited capacity, and thus works out quite expensive on a per-Litre basis, it's very small and light. Other people much prefer larger / heavier / more expensive filters which have replaceable cartridges, or ceramic plate filters which don't involve replacement.

As always, it's a question of trade-offs.
 

British Red

M.A.B (Mad About Bushcraft)
Dec 30, 2005
25,569
455
Mercia
Hi Red,

That was a really good read, many thanks for the effort it must have taken to produce. Would it be possible to make your piece on fire available again, I’d like to read that.

I own a PreMac Model PWP which I have to admit I’ve never used in anger. I saw them first launched at COPEX many years ago, and when I saw it cheep I had to buy it - I’m a kit junky! Would anyone have an opinion on them? Red if you had to recommend one “perfect” (if there is such a thing) filter for back packing what would it be? There seem to be so many on the market but so few seem to cover all the bases, is this because the risks they ignore are statistically irrelevant or do they hope their users get lucky – it’s such a confusing choice (or it would be if I needed one – I just love kit)

Thanks again.


No worries

Here is the Fire article

http://www.bushcraftuk.com/forum/showthread.php?t=18056

I use a milbank bag and boil most places - failing that I have a pre-mac where size is a huge issue or where I need to suck up water from shallow pools.

Red