how to make rainwater drinkable

  • Hey Guest, Early bird pricing on the Summer Moot (29th July - 10th August) available until April 6th, we'd love you to come. PLEASE CLICK HERE to early bird price and get more information.

treadlightly

Full Member
Jan 29, 2007
2,692
3
65
Powys
I'm interested to know what it takes to make rainwater drinkable. Is it a matter of filtering and boiling or is it more complicated than that?
 

Mesquite

It is what it is.
Mar 5, 2008
27,800
2,892
62
~Hemel Hempstead~
Depends... are you talking about rainwater stored for use in the house or out on trips?

If it's out on trips then filter and boil is fine.

Stored rainwater for the house is a bit more complicated but essentially the same by using filters and usually UV treatment to finish the job
 

Kerne

Maker
Dec 16, 2007
1,766
21
Gloucestershire
I always thought rainwater was OK to drink provided what you collected it in was clean. I don't drink from the water butts in my garden, though!
 

treadlightly

Full Member
Jan 29, 2007
2,692
3
65
Powys
I'm talking about out on trips/ in the woods. Interesting to hear Southey say he's never had a problem drinking it 'neat'. I wonder what the possible dangers of that are assuming you collect it direct from the sky, as it were, not from rivers/ streams or puddles.
 

Mesquite

It is what it is.
Mar 5, 2008
27,800
2,892
62
~Hemel Hempstead~
If you can make sure what you collect the rain water on is spotless clean as well as what you collect it in then yes, I'd drink it without filtering or boiling.

But in most woodland evironments your tarp is far from clean with various debris resting on it and this can contaminate the water plus the water coming off of trees isn't totally clean hence the filter and boil advice. Don't forget also that your tarp might have proofing agents that can leach out and into the water as well.
 

Retired Member southey

M.A.B (Mad About Bushcraft)
Jun 4, 2006
11,098
13
your house!
It is probably as cleaner source of water as your gonna get without chemical treatments, I don't treat water from transpiration bags either, just make sure what ever I'm using to collect is clean, if from a tarp then let the rain wash it before putting a can under the line, if from a guttering butt the collect from the top with a ladle rather then the bottom( just always done it that way, probably makes no diff) but then i have no issues with drinking water from mountain streams untreated, below the habitation line or from stagnant water I always filter with a milbank then bring to the boil. but rain water is IMO cool.
 

beenn

Banned
Nov 16, 2009
1,092
0
South Wales
It is probably as cleaner source of water as your gonna get without chemical treatments, I don't treat water from transpiration bags either, just make sure what ever I'm using to collect is clean, if from a tarp then let the rain wash it before putting a can under the line, if from a guttering butt the collect from the top with a ladle rather then the bottom( just always done it that way, probably makes no diff) but then i have no issues with drinking water from mountain streams untreated, below the habitation line or from stagnant water I always filter with a milbank then bring to the boil. but rain water is IMO cool.

What Southey said!
If low on water and in the rain a poncho is great to collect water, just tie 4 corners to trees and the water will run into the middle :)
 

Shewie

Mod
Mod
Dec 15, 2005
24,259
24
48
Yorkshire
I've used water, rough filtered straight off my tarp many times, it tends to taste a bit smoky at times but that's never bothered me.

What he said, it tastes smokey but it's much better than the other alternatives when you're in the middle of nowhere.
 

jenks

Member
Aug 29, 2004
18
0
county durham
I've drunk untreated water from transpiration bags without ill effects. Made them and used them on survival training in Australia. It was hot so the relatively large volume water yielded may have been due to the heat. The corner where the water collected was tied off to allow water in but reduce debris getting in, especially when you remove the bag. Something similar may work with a tarp or poncho. Before anyone brings up solar stills, they're a waste of time and effort to construct compared to the volume of water they produce, unless it's the inflatable type contained in a life-raft. Don't waste your sweat on them!
 

Retired Member southey

M.A.B (Mad About Bushcraft)
Jun 4, 2006
11,098
13
your house!
Ah but the beauty of a solar still once set up, is that you can just leave to do what it does, if there's no water going into it, it just gets hot till water goes in then it's all there waiting to give you a beautiful, thimble to cup of water a day.
 
Feb 15, 2011
3,860
2
Elsewhere
All depends on what the rain clouds have passed over. Industrialised Towns & cities can spew out via factory chimneys all sorts of harmfull chemicals & particles which wil accumulate in the clouds, form water droplets then fall with the rain. Heavy traffic exhaust fumes too will end up in the clouds too.
If the rain is comming in off the ocean without passing over major towns, cities or motorways, then it will be safer to drink.
 

santaman2000

M.A.B (Mad About Bushcraft)
Jan 15, 2011
16,909
1,114
67
Florida
Bingo on what blacktimberwolf said. Rain clouds form by the moisture condensing onto dust particles in the air. If those are pure dust particles such as are offshore or from a rural area the rainwater will be good to go (sort of; rural dust is often polluted with pesticides) If they are from over an industrial area it may well be acid rain or otherwise polluted. If that's the case (chemical pollutants) then boiling or purification tablets won't do any good as they are only intended to kill biological threats; more complicated methods are needed to remove or neutralize chemical pollutants.

Key West, Florida actually had no public water system until the 1960s (the island is a coral island with no natural fresh water supply over a hundred miles from the mainland) The locals all had metal roofs and used cisterns to collect the rainwater (untreated) for their fresh water needs until the Navy installed a pipeline to the mainland for it's fresh water needs early in the 1960s.
 
Last edited:

treadlightly

Full Member
Jan 29, 2007
2,692
3
65
Powys
Hmmmm.....the cold hand of reality....thanks Santaman and Blacktimberwolf for pointing that out. In this small island, heavily congested and industrialised as it is, I guess you can never be sure what pollutants are in the atmosphere - unless you're somewhere like Cape Wrath!
 

Wayland

Hárbarðr
I'm surprised I haven't died yet with all the contaminated air I must be breathing in.
Now it looks like the rain is going to kill me as well.
Raining.gif


It's no wonder no one ever survives life...
 

BCUK Shop

We have a a number of knives, T-Shirts and other items for sale.

SHOP HERE