Rainwater safe to drink?

[Mike313]

Hi Folks,
One thing I’ve noticed from watching brushcraft videos on Youtube, is that many Youtubers head out to local woodland that is surrounded by agricultural land to make their videos. When I see someone scoop water out of a stream and I can see farmland through the trees behind them, I often wonder whether they are exposing themselves to agricultural chemicals in the water – herbicides, insecticides and fertilisers – given that these chemicals have been applied to the land year in year out for decades. Boiling will kill off the organic dangers, but won’t eliminate all the chemicals (those with a lower boiling point that water will be carried off in the steam but others will remain).
Which brings me to my question. Leaving aside the practicalities of collecting it - I was wondering if anyone had any thoughts on how safe rainwater is to drink. I typed ‘rainwater’ into the Search facility and no articles came up so I don’t think this has been dealt with on this forum before (?).
I’ve read a few articles online and some reckon rainwater is fairly safe to drink and others less so. Most point out the obvious; rainwater captured directly ‘from the sky’ into a clean container will be cleaner/safer than run-off from a roof, tree or plant. Obviously rain that has run across a roof that the crows have been pooping on, before descending a manky down-pipe into a grimy oil-drum won’t be very safe to drink!
They also point out that, in falling, rain picks up contaminants from the air, and suggest that rainwater around/downwind from chemical plants, power stations etc. might be more suspect as it might be contaminated by pollutants. Fair enough.
My initial thought (not based on any science, just gut feeling!) is that rainwater is probably ‘purer’ than ground/river/stream water since the latter is just rainwater that has been contaminated further by the soil and any chemicals that man has applied to that soil or run-off from adjacent land etc. There are exceptions, of course, such as a fresh highland spring emerging from the ground. Rainwater would probably still need to be boiled/sterilised as a precaution, but my thoughts are (a) it would probably not need to be filtered, and (b) it is likely to have less chemical contaminants.
Also, given our prevailing winds come in from the Atlantic, rain-clouds will have been formed over the ocean and will, therefore, be relatively ‘clean’ to start with.
I’d be interested to hear what other people think.
Looking forward to your comments,
Mike.
**I’d also like to mention that, as a ‘newbie’, I found British Red’s post ‘The Science of Water’ posted back in 2008 to be very informative article and would recommend it highly

 

[santaman2000]

.....My initial thought (not based on any science, just gut feeling!) is that rainwater is probably ‘purer’ than ground/river/stream water since the latter is just rainwater that has been contaminated further by the soil....

Sometimes. Sometimes the opposite. It depends on the soil in question. Some soils add the contaminates you're afraid of while other soils act as filters and actually purify the water.

I widsh I could find and link a previous thread on this subject from a few years ago. Hopefully somebody with the ability will be along shortly.

 

[Toddy]

I stood in open mouthed astonishment as a (not local) teacher on the Isle of Skye admonished a boy for opening his mouth and catching the rain. "Don't do that! it's dirty!", and I thought, "Missus, there's nothing between here and America but 2,000 miles of Atlantic Ocean, where do you think the rain's coming from ?".

Ah, but, it doesn't smell of chlorine

In general, you're right. With particular exceptions (like the ones you noted) the fresh caught rain water is cleaner than the ground water.

Rock and sand filtered ground water in wells can be superb water though.

Keep your tarp clean, hang a billy from a low point and filter out any debris from the woods around, and it's fine

Maybe be aware of what you've used to proof your tarp though....and if you've sprayed it agin insects like mozzies, midgies and ticks though.

M

 

[cbr6fs]

Like most things i think the answer would be "it depends"

Man made pollution (chemicals, gases, radiation etc) and natural pollution (volcano ash etc) will make a massive difference to how healthy rain water is to drink.

I know that earlier this year we got caught out in a downpour of biblical proportions, the rain had a very find grit it, the weather man said it was Saharan dust, no idea if that's true but our clothing was a murky brown after it had finished and my mouth felt like i had been eating sand it was that gritty.

We also had a rain spell a couple of years ago where the rain made my eyes sting, the theory was that because the government had increased the taxes on heating fuel most the houses had turned to wood burning, the air polution was terrible so i could believe it.


On both those occasions i can't imagine drinking 1 litre will have a serious detrimental affect on our health, but i can also imagine that drinking just that sort of water of a longer period of time isn't going to do us any good either.


So i think in general it's safe, and if collected safely it has to be safer than drinking from low land water sources, especially around high population areas.
I'd also use some common sense as well though.



Personally i'd still filter it.
It isn't going to be filtering out much, but to be honest it's so easy i'm of the view why not.

 

[santaman2000]

.....I know that earlier this year we got caught out in a downpour of biblical proportions, the rain had a very find grit it, the weather man said it was Saharan dust, no idea if that's true but our clothing was a murky brown after it had finished and my mouth felt like i had been eating sand it was that gritty.....

Weather is an amazing thing. Out hurricanes here begin life as a tropical wave off the African coast and travel all the way across the Atlantic to get here.

 

[cbr6fs]

Weather is an amazing thing. Out hurricanes here begin life as a tropical wave off the African coast and travel all the way across the Atlantic to get here.

It certainly is mate.

It's pretty common over here to get dirty rain like that, i've never seen it THAT bad before though.
Everything was a sandy brown after the rain storm, even the leaves on the trees.

Our little dog must eat 1kg of sand each year (fetching the ball on the beach, wet tennis ball + sand = Jack Russell with sand in her mouth) and she seems ok, so i'm not saying it's gonna kill you to drink 1 litre of it.

But it does go to show that rain ain't always pure water and it can contain any fine particles from duct to radiation.

 

[British Red]

Its not as though rainwater can contain whole shoals of sardines is it?

 

[Toddy]

........I add a correction........if you find yourself enduring a rain of sardines, then never mind the billy, just fire up the frying pan

M

 

[British Red]

What makes me laugh is the tyre tracks.....

...imagine the smell!

 

[cbr6fs]

What makes me laugh is the tyre tracks.....

...imagine the smell!

Must have been very slippy as well

 

[Quixoticgeek]

I've had a play in the past with a Kaktus as a rainwater collector. It worked really well, just be careful of the odd spider falling in it (mmmm Protein...)

I've tried using a poncho to catch rainwater, but there was something on the tarp that made it taste horrible.

Julia

 

[BushTucker]

I would say it depends on how you obtain it. I have collected rainwater on Dartmoor in the open, collected it on a laid out poncho. I would not drink it as is, if collected from down pipes or other roof channels.

But...

If I had to drink the latter then I would use a life straw or a surviva pure filter.

 

[Mike313]

Thanks for all the feedback folks!

 

[santaman2000]

....But it does go to show that rain ain't always pure water and it can contain any fine particles from duct to radiation.

To be technical,rain has to contain some particulate (usually dust) The droplets need the dust suspended in the air to have something to condense around.