Making rainwater drinkable?
Posted by kantian_drainer@reddit | preppers | View on Reddit | 69 comments
Hypothetically, how could you make rainwater drinkable?
My thinking is getting a BPA free bucket, covering the top with a window screen, sitting it outside when it rains, boiling the collected water and then running the boiled water through a lifestraw. Would this work to make rainwater safe to drink in an absolute emergency scenario?
tygerkittn@reddit
After 30 minutes of rain it's drinkable. Wait 30 minutes to let any pollutants wash down.
Fantastic-Physics718@reddit
This should be upvoted to the top. Our water association said 20. Patience, and a good long pouring rain, will get you distilled water.
TheRealBunkerJohn@reddit
You'll need to filter out multiple toxins- either due to contaminated rainwater (minor concern) or bird/animal feces (BIG concern.)
I'd first run it through a physical filter such as a Lifestraw Family/Community, and then through one with activated Carbon elements such as a Doulton (Lifestraw makes one that has carbon as well.)
If you want the ultimate filtration, have a distillation setup instead of boiling. Distill, run through carbon filter for any super-nasties. But then you need to be careful to get all your minerals from other sources.
tryatriassic@reddit
Minerals in rainwater? What are you smoking?
TheRealBunkerJohn@reddit
....Distilled water of any sort lacks minerals. This isn't a huge issue, but if your diet is limited, and are doing a lot of activity, it can have a potentially detrimental impact on your health.
tryatriassic@reddit
And what do you think rainwater is? It's literally naturally distilled water.
The notion that you need minerals from water is just an invention of companies seeking mineral water. Even the hardest water has maybe some calcium and magnesium and that's it.
techslice87@reddit
Not exactly. Rainwater picks up things as it falls and/or floats in the air. Pollution, smog, exhaust, etc, all of those get picked up by the moisture. That's how acid rain becomes a thing.
kantian_drainer@reddit (OP)
What other sources can I get the minerals from?
the_emperorDS@reddit
Liver. Minerals and vitamins in plants are not very bioavailable.
ilovetpb@reddit
Supplements maybe? Just guessing.
JimBones31@reddit
Overwhelming evidence suggests that unless there is an issue with your digestion, food is more than adequate for sourcing vitamins and minerals.
Midlife_Thrive@reddit
Food, supplements and trace mineral drops to add to your water
SherrifOfNothingtown@reddit
Food. Eat leafy greens from your garden and you'll be fine.
Fuckmepotato@reddit
Distillation only increases nitrate levels.
IsThataSexToy@reddit
Minerals come from food, not drink. A normal, varied diet has more minerals than humans need, even in stressful times. Humans can drink distilled water for their entire lives, and there is plenty of science to prove it.
TheRealBunkerJohn@reddit
In a normal environment, yes.
But if you're drinking water without minerals, and your current diet is not able to be varied (and, quite frankly, most people aren't that healthy to begin with,) it could potentially cause problems, especially if you're extremely active.
Likely problems? No. But worth considering.
Beautiful-Page3135@reddit
If you have distilled water and need to add minerals to it, use a carafe and infuse it with fruits and berries. Bonus is that it's super refreshing on a hot day, especially if served cold.
It won't replenish all the minerals, but it's not going to cause hyponatremia as fast as plain distilled water.
SherrifOfNothingtown@reddit
What purpose does each step in your process serve? Boiling the water kills bacteria. Filtering the water through a lifestraw will remove all particles over a certain size, including bacteria. Boil-then-filter is redundant, and neither boiling nor filtration will eliminate chemical contaminants.
If I was worried about chemical contamination of rainwater, I would run it through an earth filter (https://www.motherearthnews.com/diy/how-to-make-a-diy-water-filtration-system/) before either filtering or boiling it, or distill if I was really worried.
Ultimately the purification you need depends on what impurities you're worried about in your particular rain.
I personally sometimes refill my Berkey filter straight from my rain barrels, because the rain barrels are water straight off a clean metal roof so I don't even need to pre-filter it, and I've never had an issue. But if air pollution or toxic dust was a local issue, I'd be doing more to the rain before ingesting it.
cleanacc3@reddit
What about bird shit on your roof or pipes?
Haywire421@reddit
Filtering and boiling water are two different processes that serve different purposes in making water safe to drink.
Filtering removes physical impurities such as dirt, sand, and debris from the water. It can also remove some harmful bacteria and protozoa, but not all of them. Filtering alone is not enough to make water safe to drink, especially if the water source is contaminated with viruses or chemicals.
Boiling water, on the other hand, kills most types of disease-causing organisms, including bacteria, viruses, and parasites. Boiling also helps to remove some chemicals that may be present in the water. However, boiling alone may not be effective in removing certain contaminants such as heavy metals and chemicals with a boiling point higher than water.
Therefore, filtering and boiling water are complementary processes that can work together to make water safe to drink. Filtering removes physical impurities and some bacteria, while boiling kills most disease-causing organisms. Combining the two methods can help ensure that the water is safe to drink by removing a wider range of contaminants.
It's worth noting that the specific methods used to filter and boil water can vary depending on the water source and the contaminants present. It's important to follow proper procedures for both filtering and boiling to ensure that the water is safe to drink.
Don't think of it as filtering them boiling. Think of it as filtering them purifying.
hawkmanly2023@reddit
I don't know about rain water, but Ive dealt with saltwater fish.
Theres 2 basic setups you can do.
Sediment filter + carbon filter combo. A high quality setup will remove almost everything.
RODI filter. This will turn water into a lab chemical. There will be nothing left besides hydrogen and oxygen.
RODI seems to be the clear winner but it has significant drawbacks. First, it expels 2/3 of the water as waste water. This water is so contaminated you can't even use it for gardening. Straight down the drain. Second, 100% pure water is not healthy to drink. You will need to remineralize it first. The water is so pure, it will leech minerals from your body and can cause severe malnourishment. Third, its stupid expensive. Fourth, its really slow. You have to make your water well in advance because even expensive units barely trickle out.
I could go on but you get the idea. If you don't have a very specific reason to use RODI, don't. Carbon filters are good enough.
Smedley1660@reddit
Ehh, I've got a 10x12' tarp that I use as a kinda improvised Sun-Setter awning. This past weekend it was raining pretty good here in S.E. Pa. Was watching the rainwater pouring off the tarp in one particular section and decided to do an experiment. Placed a 2.5 gallon bucket right under where the water was falling and it was filled up in less than an hour. There wasn't really any visible debris in the full rain bucket and if needed I'd just filter it with my portable Katadyn filter for drinking. Or use it as is for flushing the toilet, which could make it a worthy collection method by itself, if necessary.
Jose_De_Munck@reddit
In my neck of the woods many people harvest rainwater, and pass it through a simple kitchen filter. We don´t have heavy industries anymore so this should be the cleanest water possible, faced to a deep well or underground stream.
thatsmeintheory@reddit
Reverse osmosis with UV lights. You’ll lose about a third of your water in filtration, but that should take care of chemical and biological contamination. They make them from 3 steps to 11 or 12 steps of filtration. Test the water to see what contaminants there are to make an informed decision.
MachiavelliV@reddit
Your surface area would be painfully low. Make use of your roof and gutter system (if you have one) to increase the surface area of collection.
In terms of making rain-water safe, you need to worry about two things.
Chemical contaminants (difficult to deal with) and biological contaminants (easy to deal with).
Starting with biological, pretty much any water filter that hikers use will take care of your biological contaminants. (bacteria in birdpoop, etc).
For chemical contaminants, you'll get those in a few different ways. Rain itself can contain chemicals, especially as it falls through smoke/pollution in the air.
The material of your roof can also contaminate your water. A carbon filter can reduce these things to likely an acceptable level for an emergency if you live in a 'clean' area.
One issue is that in an emergency, there may be a vast increase in pollution which might require better filtration, like reverse osmosis.
If I were to make an ideal rain collection system I would do the following:
Tap my rain spots with diverters (fiskars makes a nice one) that will divert the first few inches of water out (this will be the most contaminated) and then collect the remaining water in a food grade rain barrel.
Ideally, I would also have a small solar panel up on the roof for the next step.
Have a pump running to your rain barrel (or barrels connected together) following to a reverse osmosis system.
Still have a backup hand pump or spigot and mechanical filter of some kind as well as a few weeks of water pre-stored.
kantian_drainer@reddit (OP)
I live in an apartment sadly and that can’t change for at least a few years, so that’s not really tenable. A family members live about a 20 minute drive away though in a house that’s relatively off the grid, so perhaps I should set things up there?
What are some alternatives for apartment living?
MachiavelliV@reddit
You could try collabing with your neighbors and do some kind of roof set-up.
You could set up a tarp on retractable poles out your window to get more surface area and have that drain into your apartment and do the filtering and storage in there.
You could see if there’s a way to access the buildings gutter system and tap into it. Many taller apartments will have an internal pipe that carries rainwater directly to the sewer.
I think your best bet though would be keeping a few jerry cans of water (food safe) treated with bleach. 20 gallons of water, if used sparingly, will get you through the first couple weeks of a problem.
TaiTre2@reddit
I feel ya
Street-Slip-7395@reddit
I’d always make sure to boil it prior to consuming
YardFudge@reddit
Rain water is cleaner than most creeks, lakes, rivers… and those we mostly just filter
Sawyer filter w/ Micropur tablets backup (or similar combo, see: - https://www.outdoorgearlab.com/topics/camping-and-hiking/best-backpacking-water-filter - https://www.wideners.com/blog/water-filter-tests-for-survival - To really get into this, watch GearSkeptic on YouTube
Joyful-nachos@reddit
Charcoal (from hardwood), sand and pebble filtration system...this one is for an entire remote village but you could scale it down to meet your needs.
https://youtu.be/kazEAzGWuIc
This guy's system is the most basic in terms of a natural setup and I think if you had some ability to test or run it through a filter or RO (reverse osmosis) to ensure any bacteria are toast or removed that would help.
I've read that nothing coming off a shingle roof would be usable since there's a lot of chemicals in the asphalt. If you had a steel roof that would be likley usable.
Rubarbpie1987@reddit
If you live somewhere that the rain water isn't safe to drink then I'd move.
If you're collecting into rain barrels make sure it's food grade, screened off, black or blue barrel to keep light from growing algae and install a spigot up off the bottom. Anything heavy would settle. They also make first flush filters if you're really paranoid.
Check rainbrothers.com.
m0loch@reddit
Where you moving? https://www.usatoday.com/story/news/world/2022/08/13/rainwater-unsafe-drink-pfas-chemicals-study/10317424002/
Rubarbpie1987@reddit
That doesn't fit my context of unsafe because if its everywhere than ohh well long term risk im not going to worry about. The OPs context was for emergency drinking water as well. If someones worried about PFAS or other contaminants in an emergency situation go without water for three days your problems will go away.
This made me thirsty for some rain water.
Suprspike@reddit
Google rainwater collection systems or rain catchment.
You'll get plenty of ideas.
It's illegal in some states anf areas to collect rainwater. For the life of me I don't understand that. The water should not contain any real chemicals that would harmful you in the short term, unless you have a chemical fire nearby.
HazeGreyPrepper@reddit
I built my own Berkey style water purification system using Berkey water filters, two BPA free buckets, and a spigot set from a hardware store. I built two of them and they function fine, and at 1/2 the cost of one standard Berkey system.
OlDirtyBrewer@reddit
Yup. Did the same. There are several videos on how to do it on YouTube as well.
Top-Manufacturer9226@reddit
That's awesome.. I love my Berkey!
sarahenera@reddit
Me too!
kantian_drainer@reddit (OP)
How did you build it?
HazeGreyPrepper@reddit
Just sent you a DM with the URL to the instructions on how to do it. Hope that helps!
ErgonomicZero@reddit
Share that shit with the group! Sheesh
HazeGreyPrepper@reddit
Wasn't sure if I could since Reddit has a habit of shadowbanning people for miniscule errors, but here it goes:
https://www.instructables.com/DIY-Berkey-Water-Purifiier/
ErgonomicZero@reddit
I hear ya. Some forums just kick your post if you have a link as well
stickygumm01@reddit
Yep, they want people to stay on their platform.
InternetNo3149@reddit
I did this while in Vietnam, the water tasted like smoke and I was sick at first but stayed hydrated at least lol
Mr-Pussy-Queefer@reddit
Berkey filters can be used for this purpose. I suggest looking on their site for more information
JaniceTaterTot@reddit
You're not going to get a lot of water with that set up.
Also, you are exposing the water to birds and such pooping in the barrel.
Bigtanuki@reddit
You should be able to get about 600 gallons of water per inch of rain per 1000 sq foot of roof. So, that sounds like 60 gallons per 100 sq feet. if you can set up a 10 x 10 sheet of clean plastic you could significantly increase your water collection. You might want to consider keeping fresh water in 5 gallon containers to hold you over until it rains. The comments about the amount of expected rain bears repeating. Here in our part of California we get an average of about 15 in/yr. This last year we got 50 inches and we've had years when we got as little as 11 in.
AdministrativeCap698@reddit
I'm curious what users ZeeSolar and maryupallnight have to say about the matter....
JaniceTaterTot@reddit
... you have to say about the matter ...
AdministrativeCap698@reddit
Just waiting for my prepper group to go to level 4b before I can say anything about the matter.
JaniceTaterTot@reddit
For rain barrels?
Tight ops sec.
AdministrativeCap698@reddit
As the great maryupallnight once said, resistance is futile.
JaniceTaterTot@reddit
Wise woman.
kantian_drainer@reddit (OP)
If I have multiple buckets I don’t see how I wouldn’t get the amount the bucket can fill, unless I’m missing something
Is there a way to protect it against bird shite?
JaniceTaterTot@reddit
Because you are only getting the rain that fall in the diameter of the barrel.
If you get 20 inches of rain a year; you will only have 20 inches of water in the barrel in a year.
cropguru357@reddit
Dig a well?
kalitarios@reddit
Did you check your state resources to see if they offer classes and how-tos for water harvesting? Some states can teach you
justanothernpe@reddit
Carbon filter then boil.
Loganthered@reddit
Your best bet for collection may be a simple tarp on an angle funnelling into a barrel. Scrub it with dish detergent and only put it out when it's raining. This way you avoid rooftop or gutter contamination. You'll want another barrel for the boiled water as I don't think the filter elements can handle hot water. If my Pur filter on my faucet says to not run hot tap water through it I'd say the other ones can't handle it either. Keeping some bleach around to add to already boiled water may be good to avoid contamination. Information I've found recommends anywhere from 1/4 to 3/4 of a cup per gallon of water.
DeFiClark@reddit
Rainwater collected off a tile or metal roof is potable after boiling unless the rainwater is contaminated e.g. acid rain. Rainwater off asphalt shingles is not safe for consumption but fine for irrigation.
FuriousColdMiracle@reddit
What is it about the asphalt shingles that makes the water unsafe to drink?
DeFiClark@reddit
PAH toxins leaching.
TaiTre2@reddit
How far will aqua tabs take you? I understand that you will still need to filter it but does it replace boiling?
PennyCraneBooks@reddit
That's a bit of overkill.
I would swap the Lifestraw for a Sawyer or Berkey, and that's pretty much all you need. Unless there is some specific contaminant you're worried about, rainwater should be solid after just one filtration step.
kantian_drainer@reddit (OP)
This does not seem to be congruent with what I’ve read on this sub
silasmoeckel@reddit
Because we end up with people that are worried about microplastics when they are going to die of dehydration in a few days.
Myspys_35@reddit
Get the rainwater from a known / cleanish surface aka something that doesnt leach special ingredients to the water. Then use any type of filter to get ride of bugs and leaves and either use a filter or boil.. done