Author Topic: Drinking water fertiliser contamination  (Read 1978 times)

wildcaper

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Drinking water fertiliser contamination
« on: 12:20:41, 21/09/19 »
I've been wondering how much to worry about fertiliser contamination of wild water. There are a lot of good light weight ways to treat water nowadays, I have a brown bag filter to get rid of most of the junk, and arguably that with boiling or water purification tablets is about as good as it easily gets...


...and if one is high up, I see relatively little to worry about beyond that, but coastal areas, or anywhere low compared to surrounding farm land, one is surely going to be subject to quite a lot of fertiliser chemicals if nothing else, and any streams and rivers will always be lower than a lot of surrounding land so it's pretty much always a problem. I've seen rivers with horrendous algae and other growth problems and I understand this to be down to fertiliser run off from the land and it really brings it home how real the problem is.


The only way I understand we can really deal with such chemicals is activated carbon, but it appears to me from observing the how fast activated carbon removes chemicals that activated carbon filters which all operate by water flowing over/through the activated carbon, will inevitably only ever reduce contaminants.


Unless one passes water through such filters many times therefore, or sits water in such a filter, are they going to have more than a marginal effect? Will they have a sufficient effect for our purposes of filtering water from rivers and streams surrounded by intensive farming?


These are questions I'm not sure about and I would be interested to hear from anyone who has ideas on the subject.


I understand of course that we are inevitably afflicted with some chemical intake, even drinking safe tap water there will be some, but we all accept tap water as acceptable, but what is acceptable in the wild and how do we get there?


M.

ninthace

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Re: Drinking water fertiliser contamination
« Reply #1 on: 14:14:23, 21/09/19 »
Welcome to the forum from sunny Devon.
Multiple questions.  Filters that rely on pores will remove everything they are meant to remove but will eventually clog.  They are designed to remove particulates down to and including bacteria.  Active carbon filters are designed to adsorb chemical contaminants and are amazingly effective in doing so, but have a life after which they have to be replaced or regenerated.  They will remove chemical contaminants to safe levels if they are used in accordance with the instructions.
Fertilisers contain nitrogen, potassium, phosphorus and sometimes other nutrients, like zinc, needed for healthy plant growth.  None of these are toxic in trace amounts.  However, non organic fertilisers are often made by recycling from waste water treatment plants and have been found to contain traces of heavy metals which can be toxic.  Commercial water filters for walkers should remove these too, by adsorption or ion exchange.
The real threat to human health that you did not raise is pesticide and herbicide residues.  These can also be present in run off and contain known carcinogens.  Fortunately, a well designed active carbon filter should remove these too.


The moral is a commercial filter should give water safe to drink.  Its life will depend on how grossly contaminated the water is.  Fortunately there is a way to avoid all these problems - drink beer!
Solvitur Ambulando

wildcaper

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Re: Drinking water fertiliser contamination
« Reply #2 on: 17:44:34, 21/09/19 »
Haha! Of course! Beer! Is there nothing beer can't do for us?  :)


Thanks for your reply, you're right of course, pesticides are no doubt more of an issue than fertilisers, I guess my mind was focused by my experience of algae clogged rivers... from which I have never derived drinking water I must say!


It's interesting you say a (well designed) active carbon filter should remove all these, though obviously I understood active carbon was the way to go for chemical contaminants I couldn't find a way to feel confident they would really do a particularly good job.


I did an experiment with my Brita filter a couple of years ago, I used a nutrient meter (which gives you an EC / PPM based on the waters conductivity) to see what readings the tap water had, and the water after filtration. I remember it reduced the "nutrients" by an amount (I don't remember how much now, I should rerun the experiment really). Running the filtered water through multiple times reduced the EC/PPM further each time by reducing amounts. Obviously Brita filters are designed to improve already safe tap water, not make dangerous farm polluted water safe so it doesn't matter (to me anyway) if it does a somewhat incomplete job.


Perhaps I should collect some probably fairly well polluted water and measure it before and after some commercial travel filters. I'm a bit worried that an EC measure is a rather blunt instrument for this but one does not have a home laboratory sadly!

richardh1905

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Re: Drinking water fertiliser contamination
« Reply #3 on: 17:55:26, 21/09/19 »
I wouldn't drink water that has run off from arable land, simple as that.


PS - welcome to the forum :)

richardh1905

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Re: Drinking water fertiliser contamination
« Reply #4 on: 17:56:12, 21/09/19 »
..and +1 for drinking beer!

Ridge

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Re: Drinking water fertiliser contamination
« Reply #5 on: 17:59:00, 21/09/19 »
You 2 are talking more knowledgeably than I can but, what I will add is, I have drunk water from my travel tap which you would not want to get any where near even if it was filtered for particles and boiled.
Over hill, over dale. Thorough brush, thorough brier....
I do wander every where

Ridge

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Re: Drinking water fertiliser contamination
« Reply #6 on: 17:59:36, 21/09/19 »
..and +1 for drinking beer!
It's 6.00pm, what a good idea.
Over hill, over dale. Thorough brush, thorough brier....
I do wander every where

ninthace

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Re: Drinking water fertiliser contamination
« Reply #7 on: 18:15:50, 21/09/19 »
Wildcaper.  There is a world of difference in design and purpose between a Brita Filter, designed to clean up tap water, and a hiker's drinking water filter design to turn a duck pond into potable water!  The former is basically a plastic box with tiny carbon granules and the latter is a piece of hitec with multiple stages.
Solvitur Ambulando

alan de enfield

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Re: Drinking water fertiliser contamination
« Reply #8 on: 12:29:20, 22/09/19 »
I use a Sawyer water filter in conjunction with a Platypus carbon filter.
The Carbon-Filter (the white cylinder) is put 'in line' after the Sawyer.





https://www.platy.com/platypus/accessories/gravityworks-carbon-element/06700.html?


barewirewalker

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Re: Drinking water fertiliser contamination
« Reply #9 on: 11:08:41, 23/09/19 »
I always thought that the real issue with 'fertiliser contamination' was ecological rather than risk to public health. It certainly is not in the farmers interest to use such excessive levels of fertilizer that enormously high nitrate levels will leave the poor benighted walker rolling in agony on the pathside. I wonder how these rather extreme fears emerge, are they time-warped out of propaganda, issued by radical conservationists.

My concern is the dumping of scrap and other farm waste into marlpits and in my area the smaller pools, of the sort left by the last ice age. These are often very beautiful, though insignificant when compared with the popular features sought by walkers and ecologically extremely valuable.

Of course these locations are far off the righteous way, the high concentration of algae may well be due to the nitrogenous breakdown of human waste in more popular area, feeding ducks the casual discards of a slobby nation.

Were the landowner more prepared to trust, perhaps more responsible suggestions might be coming forth from less radical commentaries based of factual observations of the state of our countryside.

On the subject of chemicals, that is one of the reason for wider field margins along water courses. No one suggests that the public access to field margins should be allowed to increase 'continuity of way' and therefore improve the access network.
BWW
Their Land is in Our Country.

andyapanel

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Re: Drinking water fertiliser contamination
« Reply #10 on: 13:00:12, 23/09/19 »
My degree is Biology and I am very nervous about drinking polluted water; the nitrates can react with stomach acid and trigger gut cancer. Heaven knows how many Parasites in the water there are, too (Parasitology was my main interest)


I finally invested in a top notch water filter (https://www.ultralightoutdoorgear.co.uk/equipment-c3/water-treatment-c24/water-filters-c165/sawyer-international-select-s3-foam-water-filter-purifier-p9352)


Walking in France, where shops are like hens' teeth, is now more fun as I don't need to navigate from shop to shop to buy water and can just walk where I planned.


I used it on Offa's Dyke LDP, filling up in pools, cattle troughs and streams.
Additionally, I don't need to carry as much water as I used to, so I have shaved a kilo off there, too.

ninthace

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Re: Drinking water fertiliser contamination
« Reply #11 on: 13:26:44, 23/09/19 »
Andy - both of my degrees are in Chemistry.  Normally nitrates are removed by using a specific ion exchange resin which exchanges nitrate for chloride ion.  I cannot find a claim that the S3 filter has one and there is no mention of nitrate removal on the link you published.  Does it remove excess nitrate?
« Last Edit: 13:30:05, 23/09/19 by ninthace »
Solvitur Ambulando

fernman

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Re: Drinking water fertiliser contamination
« Reply #12 on: 13:58:44, 26/09/19 »
I'm well aware that a downside of the Steripen I use is that while it renders organisms harmless, and its 40-micron pre-filter keeps out particulates, it can't do anything with pollutants etc.
However I use it up in the hills where the bad things are unlikely, and I've yet to have any ill effects.

barewirewalker

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Re: Drinking water fertiliser contamination
« Reply #13 on: 11:29:09, 09/10/19 »
As a passing thought on this topic, the OP's title for his inquiry seems seems to over-stress harmful contaminants in naturally occurring water on fertilizer applications. It is not in the farmers interest to overuse nitrogenous fertilizer, it is expensive, but highly soluble. The traditional method of providing the necessary plant food is farmyard manure and leguminous crops as introduced by the Norfolk 5 and 7 course rotations in the 19th century.

Plant available nitrogen encourages photosynthesis, which is nature's way of locking up atmospheric carbon. It requires energy to convert atmospheric nitrogen into plant food N, so provided the energy used is renewable surely this is one of the practices that should be encouraged and not on the list off knee jerk conservation criticisms that may be hindering a sensible approach to climate change.

Andy - both of my degrees are in Chemistry.  Normally nitrates are removed by using a specific ion exchange resin which exchanges nitrate for chloride ion.  I cannot find a claim that the S3 filter has one and there is no mention of nitrate removal on the link you published.  Does it remove excess nitrate?
My chemistry may be a bit rusty, so any more informed info would be welcome. I should think that a high concentration of sheep penning close to a watercourse as risky to raising nitrogen levels. I worked with a shepherd, who grew superb tomatoes in great abundance, his secret ingredient were the sheep daggings in his water butt, which he watered the plants in their fruiting stage.

A parting remark; as walkers I think there is plenty to challenge the occupiers of our countryside about, but I think we should do it accurately, intelligently and try to compile arguments with good sense.
BWW
Their Land is in Our Country.

gunwharfman

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Re: Drinking water fertiliser contamination
« Reply #14 on: 13:00:28, 09/10/19 »
I have no knowledge of this sort of thing at all, always a worry though. I've drunk unfiltered water high up on the Tour du Mont Blanc, gallons of the stuff, it was so hot. I was caught out once in the Pyrenees, ran out of water but saw a trickle coming out of a mossy area from a rock so drank that. And more than once in the UK I've drunk from the feed pipes into cattle troughs. I do have a water filter, just a plastic tube of whatever it is inside? I just put the tube end into a cup of water and I suck the water through it. So far so good.