If your water source is uncertain, you should treat it first before drinking it.
One way to treat water for drinking is to add a small amount of regular bleach (chlorine). Here’s how much bleach to add, and a way to remember the quantity:
(details below)
Sawyer Products Mini Water Filtration System
When obtaining water to be purified for drinking,
avoid (if possible) water which is cloudy.
Perhaps there is another nearby access to the same body of water which may be clear.
If scooping from a body of water, try not to disturb the bottom so as not to disturb and pick up dirt or other debris into your water container.
If the water appears cloudy, filter it if possible before treatment. Use a conventional water filter, or any cloth or such filtering material to catch the floating particles as you pour from one water vessel to another.
If you cannot pre-filter a cloudy water source, let it settle in a container for a time and then gently pour off or scoop the water near the top which will be clearer. This is important because the floating ‘dirt’ particles within the water are tougher (takes longer) to penetrate while purifying with chlorine (bleach).
Indefinite shelf life:
Potable Aqua Water Purification Iodine Tablets
One best way to purify water for drinking is to boil it for 1 minute.
Once the water has reached a rolling boil, it has become safe to drink.
Note that if the water source had been contaminated with chemicals, boiling it or otherwise treating it will NOT assure that the chemical is removed.
Know your water source as best you can.
Another way to purify water is to use a small amount of regular liquid bleach.
Use regular household bleach, with the only ‘active’ ingredient ‘sodium hypochlorite’.
UPDATE: For many years, regular bleach contained a concentration of 5.25% – 6% sodium hypochlorite. Newer ‘regular’ liquid bleach may contain a concentration of approximately 8% sodium hypochlorite (about a third more than the original bleach formula).
Having recently determined how much bleach to add to a 50-gallon water tank to purify it for safe drinking, I’ve put together the following charts for your reference.
“You must be 21 to drink”
2 drops bleach per 1 quart water
Mix the following amount of bleach with water, and wait 30 minutes for it to work. The water should have just a ‘hint’ of chlorine smell.
Water – Bleach Ratio For Purifying Drinking Water
(Bleach containing 5-6% Sodium Hypochlorite)
numbers are ’rounded’
1 Quart water, 2 drops bleach
1 Gallon water, 8 drops bleach
5 Gallons water, 1/2 teaspoon bleach
10 Gallons water, 1 teaspoon bleach
50 Gallons water, 5 teaspoons bleach
Water – Bleach Ratio For Purifying Drinking Water
(Bleach containing 8.25% Sodium Hypochlorite)
numbers are ’rounded’
1 Quart water, 1 drop bleach
1 Gallon water, 5 drops bleach
5 Gallons water, 3/8 teaspoon bleach (or three 1/8th teaspoons)
10 Gallons water, 3/4 teaspoon bleach
50 Gallons water, 3.5 teaspoons bleach
LifeStraw Personal Water Filter
Note: If the water is cloudy, and if you still cannot smell any chlorine in the water after having let it sit for 30 minutes (there should be a hint of chlorine smell), the CDC (Centers for Disease Control) advises that you consider a 2nd round of treatment.
Note: According to the EPA, the maximum allowable ppm (parts per million) of chlorine bleach in drinking water is apparently 4 ppm.
Note: Generally speaking, water that has a chlorine level of 4 ppm would smell VERY strong of chlorine, whereas a ‘hint’ of smell indicates a level well below that. A chlorine test kit is the only true way to know for sure.
Note: Bleach will lose its potency (fairly quickly) over time. Generally, 6 months to a year after its expiration date may result in half strength.
Note: It is widely recognized that there are 76 drops per teaspoon.
Related: How much bleach for disinfecting surfaces (food & ;non-food surfaces)
Thank you. This is good/simple/practical/easy to remember (2 drops per quart)..
recently read a research article which stated that Antibiotic Resistant Bacteria are able to survive chlorine, at rates used in water treatment. Have not researched this, but wondering if you have suggestions which would “take out” those? Boiling comes to mind, if that were possible.
Anon – in re to antibiotic resistant bacteria in water: I’ve experienced this to some extent at a summer camp, where the lake was treated (filtered + chlorine) and used with no problems for some years, then 200 of out of 250 campers got sick within 2 days of arriving at camp. The issue was eventually identified as a cryptosporida (sp?) bloom, that was occurring in the later part of the summer. This lake is at 6800′ and just thawing out in June. The camp’s treatment plant was found to be operating within “spec”, but the solution turned out to be a much higher level of chlorine in treatment. Don’t remember how high the clorine had to be, but you could definitely taste it. Filtering was also changed, to a smaller mesh.
It’s a good idea to print this chart. In times of stress you may find it hard to remember the details. I printed several copies in order to hand out to friends and neighbors should the SHTF.
you just read my mind! printing and forward the chart to other prepper friends
This article made me finally get up and go look at my bleach bottles. The Clorox brands do not have any expiration/best by dates, only production codes. Guess I need to start marking with my purchase dates.
Learned something new (it helps to read the labels, apparently!): The ‘splashless’ variety of Clorox bleach does not list the sodium hypochlorite concentration, and in fact “is not for sanitation or disinfection. To sanitize and disinfect, use Clorox Regular Bleach.”
Bleach does lose potency over time. This is not an issue if you use it to clarify water for storage.
Avoid the scented bleaches. You should also read the label for ingredients. Last time I looked the active ingredient in, Clorox was five or six percent, store brands were half that. This means you will need to use more of the store brand.
Although I have the ability to make my own ‘regular’ bleach with calcium hypochlorite (pool shock), when I do buy regular bleach – I mark the month and year of purchase (with a Sharpie) so I know when it has reached approximate half-life (about one year later).
The rate at which regular bleach degrades to ordinary salt and water depends on the storage temperature. I once read a supposed quote from a Clorox representative which said that the decay rate is 20% per year (at room temperature). However I figure that if I presume 50% per year – I’m on the safe side.
Ken, do you have any info on possible differences between the sodium hypo in some liquid pool bleaches and the calcium hypo in the powdered shock?
Dave,
Basically the difference is the available chlorine (AC) in each type. Available Chlorine (AC) is the amount of Chlorine released in the water to disinfect.
Sodium Hypochlorite is a liquid Chlorine and typically has around 10-12% available Chlorine. Bleach, which contains Sodium Hypochlorite, only has 5-8% AC (original ‘regular’ Clorox had 5-6% while newer Clorox is slightly more concentrated with about 8% AC).
Calcium Hypochlorite is commonly seen as granular Chlorine and has an AC ranging from 40-78%.
Good idea with the chart,just copy it and put it with other important papers that should be in your bug out bag-first aid info,maps, etc.
I also keep some coffee filters,they can be used to filter out sediments prior to boiling/disinfecting water.
The 21 recipe is good. Another good item I store is swimming pool chlorine test kits. Now, it doesn’t matter so much if the bleach is old, just measure chlorine in the treated water. Test kits go on clearance at the big box stores at the end of every summer. You can generally get the simplest ones (all you need) for just a buck or two. I have 4-5 I’ve purchased over the recent years. Do the tests degrade and result accuracy compromise over time? Probably, but if you buy a kit each year, you can use the most current one to assess the accuracy of the older kits and use those up first if they still are yielding good results. I store them in the bottom of my garage refrigerator along with my stocked meds.
Calcium Hypochlorite (pool shock)
1 to 2, then 2 to 1
1 heaping teaspoon CH to a 2 liter of clear water for the mixture;
then 2 teaspoons of mixture to 1 gallon of water for purification
Store Tang for mixing to drink; clean water and Vitamin C
LOVE IT! i’ve been looking for a way to mix up my own bleach and there it is. thanks mate.
boiling is a preferred means of purification except for chemicals that “may” be present (see the chemical spill in west Virginia last year).
it does require a copious amount of energy to do this, so use the heat source for multiple uses concurrently (other cooking needs, heating your living space, ect.).
if water is known to be chemical free and filtered, you can sterilize your water whilst preparing a meal (preparing rice, beans), it sterilizes the water and cooks the food at the same time.
while cooking in water is a great way to reduce how much energy is required to sterilize your water, keep in mind that you don’t have to boil it for extended periods of time either. pathogens die in 30 minutes at 160°f, a few minutes at 185°f and are dead by the time the temperature reaches 212°f. even at high altitudes, a rolling boil for 1 minute is enough to render uncontaminated water potable. the only time it would take copious amounts of energy is if you have to treat a lot of it.
how do i know if my 55 gallon drums are clean ,for i bought them used…. I understand that i can clean with qt. of 5% bleach and use???
it all depends on what was in the barrel before you bought it. any soap solution can be cleaned by watching for suds when they stop rinse a couple times with the bleach and you should be good to go.
If it was a petroleum product you have your work cut out for you. I use alcohol to wash then soap followed with bleach. fill part way and watch for the oil film to come to the top is it does then repeat the process.
Any bio degradable product can be cleaned safely.
If it was used for a corrosive product don’t use it at all.
I live on a catchment system. They tell us the only way to make the water safe for drinking is with a UV filter. I am skeptical as I lived in Central America and boiled the water and added a few drops of bleach to every 5 gallon jug. Does the UV do anything the boiling/bleach method does not?
@Gail
I too use a catchment system. I use both a gravity filter as well as UV. Although I have a UV pen I’m saving that at the moment and am using the SODIS UV method. They say you can use a plastic bottle up to 2 liter size but I’m skeptical of plastic in the sun so I use quart size canning jars. That’s just for drinking water though. For everything else (cooking, cleaning, etc.) I just use the gravity filter. The way I see it, rainwater is already distilled so I’m just filtering out the junk from the roof and anything it may have picked up in the air on the way down. So even for drinking the UV may be overkill, but hey why risk it.
Oh and as for your question, UV does pretty much the same as bleach, it kills bacteria and viruses. But… the sun is free.
Just a bit of info, I looked into the bleach aspects of treating water and yes bleach does have a shelf life so you may not have drinkable water if your bleach was used to treat it. The pool shock method may be a better option as the dry powder has a ten year shelf life and only takes 1 GRAIN the size of a grain of salt to treat a gallon of water. The downside is this stuff is a wicked chemical and should never be exposed to petroleum products or it could blow up your house. You can buy a pound for $5-10 at a Home depot or Lowe’s or wherever, just get the stuff where the active ingredients are not algecide. That pound will treat 10,000 gallons. Look on pinterest under preppers for great information
I will be hiking the AT next year. I will be carrying a Life Straw for emergencies, but could I use the 2:1 for my drinking needs along the trail?? Don’t want to get Giardia. Thanks!! David
Your practical and easy to apply information is very much appreciated!
Great information… especially the part about the way to remember.
My question is about dissipation of the bleach when the water container is left open after treatment… I realize this will be dependent on surface area, the “bottleneck” (no pun), and such… but is there a general rule for getting predictive behavior?
I ask because while I realize that there’s a “safe threshold” for consumption, the less the better, and so I’d like to try and let it escape after it’s done it’s thing before I consume it.
Steve, It seems that many report that 24 hours is a generic period for a ‘half-life’ (you would have to research this more deeply to establish fact), but as you said – with a small opening this time may be longer. With that said, chlorine will break down much quicker with the aid of UV light (sunlight). I suspect that it will be mostly broken down within a day (gut instinct based on having had a swimming pool at a previous home – and the chlorine maintenance thereof).
Ken –
Many thanks… So it sounds like could get 2 birds with one stone out of chlorine/sun… leaving little question as to the condition of the water when all is said and done…?
I’m in a position where it’s half viable to utilize the sun as well, so that works for me.
Wish I had found this site earlier… I am “off grid mobile”, probably the best way to put it, and while obtaining clean water isn’t super difficult for me, I’m worried about the long-ish term storage that some of it is getting allowing nasties to get in or set up shop inside (tower cooler for example, valve parts etc). During winter I don’t consume as much water as during summer.
Anyhow, thanks again 😉
Steve
you say “water that has a chlorine level of 4 ppm would smell VERY strong of chlorine…” implying that your water-bleach ratios given above would be a lower ppm. Actually 5 teaspoons/50 gallon would be the equivalent of 1 part per 7680, not so??
@rg, Your calculations are correct if the bleach had 100% available chlorine. Since bleach typically has only 5% available, your answer would need to be multiplied by 20. That gives us 1 part per 153,600. This is approximately 6.5 ppm.
Great review, thanks…suggestion: time to join the scientific world and use metric units. teaspoon =5 ml, gal=3.78541. Much easier when using the metric system -like the rest of the planet 😉
3.78 L(liters) not mL, you cited 2 different units of volume but only mentioned mL, I know you get that, but others may not, agreed that it is beyond easier to work in metric as we all should; seriously, an example: 1/8 teaspoon measurement, wtf, unless one has that culinary/kitchen measuring device, impossible.
I have never understood why the rest of the planet is using metric…it’s complicated and confusing
Life is so complicated. Can’t we let this one thing be easy?
When storing water in a 55 gallon barrel should you put chlorine in as soon as it is filled or wait until use.
thanks
My opinion is that if you are storing municipal water that has already been chlorinated, adding more at the time of storage is unnecessary. If you are storing water from a home well or filtered rain water, I would add chlorine before storing. You can add more before using. To dissipate chlorinated water (get rid of that nasty taste), pour in open glass jars and leave in the sun for 30-60 min, then put the lid on and shake it up to aerate it before drinking.
I have a 1000 litre tank made from rubber. I bought it at Lee Valley last year. It was made in Australia for collecting water during droughts. By putting in the amount of bleach that you say would it be safe enough over 4 month period. Every time it rains should I add a teaspoon or two to it to make sure.
Thanks,
Henry
According to the manufacture, Liquid Clorox has a shelf life about 6 months before it begins to lose potency. As such, I have stored bottles of Clorox tablets. But how do you figure the dilution rate? Would it be x# of grams per gallon or dissolve a tablet into a gallon and use the printed figures?
In an emergency, I’ve read bromide for hot tubs can be used to purify water. Does anyone know what the dissolution rate of bromide tablets would be?
Thanks,
Arthur
Arthur, although this does not answer your question directly, it may help…
I have never seen a bottle of bleach with a date stamp. With that said, bleach may lose 20% to as much as 50% effectiveness within a year, so be sure to date your bottle upon purchase.
Bleach that has been sitting around for a year does not go bad. It simply is not as potent. (Bleach begins to ‘salt’ as it ages)
If using regular bleach to purify water, and if the bleach has been sitting around for a year, then you may simply use a bit more than the suggested formula.
The key is this… After having treated the water, you should just barely detect a hint of bleach smell from the water. If you don’t smell any, you might add a bit more.
Related: http://modernsurvivalblog.com/health/make-drinking-water-safe-with-bleach/
I thought the Clorox tablets would be great for camping. Looking at the label I saw they did not say “disinfecting” anywhere and this is the main reason I buy bleach. Called Clorox and they said they were sanitizing and deodorizing but did not disinfect. Asked her what the difference was between sanitizing and disinfecting and she said sanitizing meant you got rid of the dirt you could see. She also told me the ONLY Clorox that disinfected was “regular Clorox” and “Disinfecting CLorox”. All the others, including splashless, do not.
OK, that doesn’t make sense AT ALL.
They’re synonyms, for heaven’s sake. Sanitize, disinfect, same thing. She didn’t know what she was talking about and just spouted off. I’m dead sure that nonsense wasn’t in her script.
…and that’s exactly why I emphasize “Regular Clorox” in all related posts. Thanks for sharing what they said regarding your question.
Regular Clorox bleach is for disinfecting drinking water. I’m pretty sure that Clorox tablets, used in toilet bowls for sanitizing and odor control, contain other binding ingredients that would not be healthy to drink.
Is there a way to neutralize the bleach (I read hydrogen peroxide), I used the 5-6% ratio but I have the 8.25%, It would be useful to include it in this article in case anyone else screws up like I did.
the bleach will become less potent with time,…just like the other liquid bleach degrades after 6-9 months, but i don’t know how much or how to evaluate. I buy the concentrated on purpose because it takes less for my other needs. I do not plan on using it to treat water. I have enough trash in my body by accident, but have several different water filters. There is a formula for making concentrate and cutting it down.. since the bleach is just over 8 % and normal bleach is just over 6%, it would need to be cut by that percentage with water. or used with the strength figured…
I have a 2500 gallon holding tank and use it for drinking. I dont want stuff to start growing and i am not sure how much bleach to use.
June Nielsen
You did not state if your 2500 gallon tank was white-dark green or green-black. The dark colors are used for not having this issue but if you still wish to dump bleach into the tank there should be a chart on the internet. Otherwise if I recall correctly it is 6-8 drops per gallon for purification of water.
6-8 drops gallon with a full 2500 gallon tank is ONLY20,000 drops. There has got to be a more accurate formular my word, 20,000 drops. Insane!!
L. J. Blais,
There are about 550 drops in an ounce…
So an ounce will do about 1oo gallons.
2500÷100=25 ounces
So to be safe put in about 25-28 ounces.
You were asking about hand dug wells.
36″diameter well has about 50 gallons a foot.48″” diameter well has about 90 gallons per foot…
Just do the math for how much bleach you need…
June Nielson
I left a reply you will find this at ‘clean water store’ on the net it shows you a chart for the size of your tank an other data.
The first reply one was eaten by the cyber space gremlins. lol
I read 5 tsp for fifty gallons and did 5 tablespoons! Another unexplicable action by the senior brain. Do I need to dump them out and start over? Appreciate any help for thus old lady.
Hmmmm… Nowhere in the article does it list “tsp”. It is spelled out as “teaspoon”, “teaspoons” or “drops”.
To answer your question, yes I would start over, in my opinion.
But doesn’t bleach lose strength over it time? It would be quite horrible to waste all that water if you didn’t need it for years! Im
wondering because I did the same thing. Another senior citizen. It must be a ‘thing’
Yes, bleach will eventually break down into salt. The initial dose of bleach into the water will destroy the organic pathogens. If the water containment is secure and no pathogens enter back in, you’re pretty much good to go…
Who doesn’t know tsp stands for tea spoons??
Are you the same Patricia who said in some earlier posts that metric was complicated and confusing?
I fill my 55 gallon drums with water then add 3 1/2 tsp of regular bleach (8.25%). I do NOT plan on using this particular water for drinking, however, as we have several excellent filters. Also, instead of boiling our water we use the solar oven.
Hi All. Just looking for some suggestions on cleaning 7 gal. water containers. I’ve had the water in storage about two years and recently started to refresh the supply. After emptying the containers and inspecting the inside, I noticed lots of small, grayish-black spots on the container walls (kind of looks like a mold growth). I probably waited too long to recycle but I guess a long-handled brush is the best choice. I would probably pass the water through a gravity filter if I was to use it for drinking purposes, regardless.
Marcus, I would suggest using the following bleach formula for disinfecting (NOT for drinking) in the following article.
Disinfectant Bleach-Water Ratio
Then let it sit overnight. Shake it up. See if that gets the ‘stuff’ out.
Then drain and rinse.
You might also purchase a brush that fits down inside.
Carboy Brush
Marcus
Agreed with Ken, if ya cant find a brush that will get all the edges and spots, try dumping in a hand full of clean sand, and shake the living daylights out of it, than clean again. The sand will act as a scrubber.
Clarification; make sure you have the container 1/4 full with your cleaning water, not just the sand by itself….
I need a chart with the varying widths and depths of dug wells not ten or fifty gallon jugs!!