Water Purification - Chemisty

[Nightwalker]

Im no Chemist and I thought perhaps you wise folk could enlighten me; Whats the deal when it comes to water-purification and pesticides & chemicals etc.

Im mean really, when im out in the UK, all I ever do is collect and boil water if I want to purify it and thats about all. I've done this for a good few years now thinking 'this will kill any harmful living-bacteria & viruses' when I've never really seriously thought about pesticides or chemicals that could be in the water-source. As we know here in the UK we're never far away from farm land, so what does boiling do to pesticides/chemicals? How harmful are common pesticides that farmers may use? Surely they shouldn't be to harmful as regulators will have already planned for these chemicals reaching water-sources?

When I was a young'n I would always drink straight from a nice looking stream or spring with no purification. My father taught me good signs to look for in terms of natural-filters and fresh clean water, and so growing up out on camps & DOF I drank direct with no purification and I had never suffered and illness as a result, which I may have been lucky! Any ideas on the above questions? Thanks for your time.

 

[hedgepig]

Hmmm, good question! I wouldn't automatically assume that the regulators will have thought about the possibility of people drinking from streams. They might have concluded the potential mammalian carcinogens will only be consumed by non-human mammals in very low doses and that a small increase in the risk of cancer in these animals is acceptable.

Anyway, that is just a thought, it doesn't answer your question.

 

[bushscout1]

Not sure about the pesticides etc. but just thought I'd say you were definately lucky...

I used to do the same when mountain walking - drinking from streams to save on the amount of water I was carrying. Some years ago I did the national 3 peaks challenge (Ben Nevis, Scafell Pike & Snowdon in 24 hours), at the end of which I became sick on the journey home. This became violent vomiting & fevers which lead to my admission at the Royal Shrewsbury Hospital (still a long way from home). I ended up on a drip as I was dehydrated from the sickness & diahorrea. I had lost around 1 stone in weight - although I don't recommend it as an alternative to dieting !!

I now only drink tap water carried in or treated water - its a shame as there's a special taste to fresh mountain stream water - and I'm not refering to the sheep dung !

 

[Nagual]

Have you read Reds post on water? here it gives a fair assessment of water and various purifications. As far as your specific question to pesticides go, it's fairly interesting. I'd like to assume that most are non hazardous, being that we'd eat or consume the end product anyway, but having seen the Mark Thomas Product ep, where he exposes various farms for using very very nasy chems on organic produce, I'm not so sure. Luckily areas I go, don't have any farms contributing to the water table.

Nag.

 

[SimonM]

Like Nightwalker, I have up until recently drunk from streams. In my youth, directly, and more recently after boiling.

Sadly my "bushy" area has no potable water due to old lead mines in the area, which are leaching into the surface water. Couple this with a largeish sheep population and teh potential for liver flukes is huge. So, These days I carry in with me all the water that I need, leaving spare in the car for just in case.

Simon

 

[Nightwalker]

Not sure about the pesticides etc. but just thought I'd say you were definately lucky...

I knew someone would reply saying exactly that! sounds like you had a harsh time, I don't suppose the hospital were able to determine what bacteria or chemical it was that caused your condition?

Have you read Reds post on water? here it gives a fair assessment of water and various purifications.

I have searched and read a bit, however didn't really find much to my questions. (ps. I think your link its broken). It is interesting because as Nagual said in the end these chemicals must come down the line to us in some degree in our food, do you not think that these pesticides will be designed to be non-hazardous in very dilute amounts? :bluThinki

 

[w00dsmoke]

It's amazing how ill you can become from drinking what you think is clean water. I used to drink water from a borehole which was several hundred feet deep through glacial sand deposits (in some way sand filtered...) and one afternoon I became dizzy and collapse dwhile doing a wild flower transect. That night I had severe vomitting and runs and 2 days later could not walk (reactive arthritis in knees), I spent ten days in an infectious diseases unit attached to a drip and had 26 bags of fluid pumped into me over the next few days. It was salmonella from cattle. They don't kow if it was from water or what. I nearly died and I could not walk for 3 months afterwards without crutches.

Impurities in the environment can be SERIOUS, so we need to take care of all our hygene needs, especially HANDS and WATER.

As for chemiclas and pesticeds in the water table, I spoke to a scientist from SEPA a few years back and he told me he would NEVER drink even boiled/treated water from any source in the UK unless he was above the sheep line, he even went on to say he drank bottleed water as opposed to tap water. Maybe thats' extreme or he knew something that we don't.

 

[TheGreenMan]

The removal of chemicals from water is a bit of a tricky one, in the sense that there’s little information on the specifics of the subject, or if there is, I haven’t found it yet.

Activated carbon, will remove some chemicals from water, but I’ve yet to find any data that specifies a full list of chemicals that it will remove (actually, there are lists of chemicals that a specific filter will remove, but not a list of chemicals that it won’t remove ) and at what concentrations, and how one would know when to change the AC filter that is part of the filtration systems in some of the hand pumps available.

Reverse osmosis filters will remove chemicals effectively, but again it requires some specialist knowledge, that I don’t have.

I’ve seen a RO pump that was hand operated and so didn’t require a power source. I say it was an RO, but that’s something of an assumption on my part, the hand pump was being used to desalinate sea water during a transatlantic rowing trip. I’ve no idea where one would buy one from, but then there’s always Google

Best regards,
Paul.

 

[locum76]

do you not think that these pesticides will be designed to be non-hazardous in very dilute amounts? :bluThinki

some pesticides can build up in your body because they are fat soluble. therefore if you are exposed to them for a long period of time they can become concentrated enough for you to feel their toxic effect.

 

[w00dsmoke]

It doesn't take very much at all with some...

 

[bushscout1]

I knew someone would reply saying exactly that! sounds like you had a harsh time, I don't suppose the hospital were able to determine what bacteria or chemical it was that caused your condition?

To be honest, I can't really remember as when I was discharged I was collected by my parents but it took me a good few days more to fully recover - and a few weeks to regain my full strength & put the weight I'd lost back on. So I wasn't really aware of what the doc's said apart from "plenty of rest & boiled tap water". I seem to recall they thought it was something like Cryptosporidiosis.

 

[ems]

I've got a Pur water filtration device, and if I was going somewhere I really couldn't rely on the water source, I would definitely take it. You can get UV pens for about £80 and you put it it int he cup of water and stir it for a the set time and it sterilises your water, would be an awful lot lighter I'm sure than mine. I'd still filter it with a cloth first though.

 

[nicodiemus]

I personally would shy away from portable UV purification devices. Though UV is an incredibly effective sterilizer, by virtue of destroying DNA in the cell, i think in field conditions it's not going to be as reliable as chemical means like Iodine or Chlorine.

You can buy iodine over the counter, utterly inexpensively. Products like the one that's reviewed on the main part of the website even have temperature based dosage indicators for maximum safety.

That brings us back to the pesticide issue. In the UK, you're very rarely going to be in a location where you're not going to have ready access to drinking water, or be forced to drink from surface water near arrable land. I accept that this is not always going to be the case for intrepid bushcrafters like ourselves... I would not like to certify ANY current portable filtration system for removal of pesticides or herbicides. Many of them are fat soluble as mentioned previously, and will build up over months or years. Many can be carcinogenic.

Don't risk drinking from surface water without mechanical filtration, and don't risk it at all in agricultural land.

My two pence!

 

[Voivode]

Hey! I came back just in time to talk chemistry!

Distillation is the most thorough purification technique, assuming you do your run to catch only the water fraction. It is really the only technique to deal with chemicals (such as pesticides and other toxins) and heavy metals. No filter or boiling will remove those contaminants. Activated charcoal is somewhat effective on organic compounds, but isn't a magic bullet for cleaning water.

On the whole, chemical contaminants are the worst to try to deal with when moving around. You're best to bring your own water if you're concerned about toxins and metals.

Now, for biological contaminants like Giardia and whatnot, boiling, chemicals and filtration all do the job nicely. I'm partial to boiling, but we carry a filter unit as well.

 

[fishy1]

Interestingly, a collegue was working with activated charcoal, and found out it will take out a large amount of soluble heavy metals, even though it's not recommended as such. Maybe repeated filtering would do it.

 

[TheGreenMan]

AC is very, very interesting stuff:

http://en.wikipedia.org/wiki/Activated_carbon

http://www.activated-carbon.com/carbon.html

http://www.sutcliffespeakman.com/actifrmr.htm

http://books.google.co.uk/books?hl=...ts=sEclgwpPG3&sig=AvDCov0yoiA4lPP7su2vnfJKXoU

Best regards,
Paul.

 

[He' s left the building]

Interesting thread.

Probably a good time to introduce a couple more facts:

1. All substances (including both natural substances and man-made chemicals) have the potential to be harmful; the difference between a medicine and a poison is the dose. One drop of iodine in your water-bottle is beneficial, but 10g of iodine in the same bottle would kill you! For most trace-level water-borne contaminants, intake would probably need to be several litres per day for many years to contribute significantly to overall intake (with the exception of areas known to be grossly contaminated, such as the lead mines mentioned by SimonM).

2. Not all 'natural' substances are harmless, many natural waters contain harmful levels of heavy metals (iron, nickel) and other chemicals such as potassium. In the same way as some batches of nuts may have harmful levels of aflatoxins, some 'natural' foods/waters can be harmful to health, we must not fall into the trap of thinking that if something occurs naturally it is not harmful to health (and vice-versa, not all man-made/synthetic chemicals are harmful)

With regards to water, it really depends on the local situation. Private water supplies (for domestic and industry use) are covered by specific legislation which requires regular sampling and testing. In effect, what many of us do is become users of 'private supplies' but only on some weekends; and without the advantage of this frequent sampling/testing. More reading here: http://www.dwi.gov.uk/consumer/faq/private.htm

Therefore, most of us have no idea of the water quality of sources at our weekend retreats and training locations. Absence of local industry/agriculture may be a poor indicator of water quality (due to naturally occuring hazards which may be present in 'natural' waters). However, we are probably drinking such small amounts for such limited periods for this to be of any significant concern (we hope!!!)

Certainly for bushcraft activities in UK agricultural lowland I would be quite concerned about pesticide/fertiliser run-off from agriculture (take supplies of drinking water with you into your site) and in upland areas I would be concerned about sheep-droppings (use a good quality filter and then boil or use tablets).

Does anyone have specific examples of water quality issues they have encountered?