In our last article Emergency Water Filtration Methods we discussed and learned methods for filtering the large suspended particles from unknown quality water sources. Now we will begin to discover multiple ways of purifying this water (making it suitable for drinking), again using methods and materials found around the average home.
Why is purification necessary you ask? Our filtration process has given us water that from a visual aspect appears clear but now we need to purify the water from the things that could harm us that we cannot see. Water that comes from questionable sources can contain a variety of things that could be harmful to us and without a full laboratory to test and verify the purity of our water we should always assume the worst.
Water of uncertain quality can contain Microorganisms such as germs, bacteria, and viruses that can cause diseases such as dysentery, typhoid, and hepatitis. It can also contain parasites such as giardia cysts and cryptosporidium oocysts. It may also contain heavy metals, sodium, dissolved solids (minerals), and volatile organic contaminates (VOC’s).
So now that we understand the reasons for purification, let’s get on to the methods. There are many methods of purification but none of them are perfect, therefore the best approach is usually a combination of methods depending on your materials on hand.
First method Boiling – Boiling is one guaranteed way of removing all pathogens (germs, bacteria, viruses, and any other microorganisms). Although boiling water does not remove the heavy metals, sodium, and VOC’s. The old Rule of Thumb that water needs to boil for 5 to 10 minutes to accomplish this is not correct. One minute at a rolling boil at sea level and 1 additional minute for every 3,000 ft above sea level is sufficient, any more is just a waste of fuel.
Second method Distilling – Distilling is the process of bring water to a boil, capturing or controlling the steam and returning it to water. This method is capable of removing all pathogens, heavy metals, sodium, dissolved solids and most VOC’s. The down fall of both this first and second method is that though effective it requires a tremendous amount of fuel. Depending on your personal situation at this point in time the question is; Do you have the fuel resources available or is your fuel resources better spent on cooking and warmth? Only you can make this call and it is an important one. If winter is not here it is coming. Choose wisely based on the information you have. By the way, as a foot note distilled water has a very bland taste (our taste in water usually comes from the dissolved minerals contained in that water).
Third method a Solar Still – Although capable of removing virtually all contaminants through evaporation I will not go into discussion about a solar still at this time mainly due to the fact that the production of drinkable water is usually on the order of 1 – 2 litters/per sq. yard of surface area on a good day. Just wanted to let you know it is out there and I will include plans and details of this still and a Dug Still on our Illustrations Page.
Fourth method Solar Water Disinfection – This is a method that is commonly and currently used in 3rd world communities to disinfect (get rid of all pathogens from) filtered water supplies. To do this all you need is a sheet of corrugated plastic or tin, although not mandatory just makes it easier (possibly from a patio cover or work shed), clear plastic soda bottles 1 to 2 litter maximum size with labels removed and washed, and the Sun.
To make this process work 1) fill the clear plastic bottles with your filtered water 2) place the filled bottles on their side on the corrugated plastic or tin, it holds them in place nicely and helps reflect the UV and Infrared rays into the bottles. 3) Make sure and place the whole thing in direct sunlight. That’s it!
The UV rays from the sunlight will destroy the pathogens and the infrared rays speed up the process by heating up the water temperature. The exposure time necessary to complete this process is as follows:
a) For a sunny or partly cloudy day, at least 50% sun. Exposure time min. 6 Hours
b) For a mostly cloudy period, little to no Sun. Exposure time min. 2 Days
c) Heavily clouded and raining. Don’t waste your time, collect rainwater
Fifth method Chemical Purification – This is the method that will most commonly be used to purify our alternative water sources, but how long we can keep this up will depend on our on hand supplies.
In the average home there are possibly 3 products that we can use for purification. Those products are Regular Bleach, HTH and Iodine. I will discuss using them in that order since I listed them in the order of most likely to least likely to have on hand.
Using Bleach (the Best Method)
Let’s talk about Bleach first since it is common to most households. When I say bleach I am talking about liquid Regular Bleach so labeled on the bottle as such. That means no additives such as scents, fabric softeners, or color safe ingredients. It does not matter if it’s Clorox, Purex, or a Dollar Store off brand. On the front label it will say Regular Bleach and on the ingredient label it will say 5% or 6% sodium hypochlorite. This is what we need, and depending how much you have on hand will dictate how long we can use this method.
The main ingredient we are concerned with is chlorine (which is derived from sodium hypochlorite). Chlorine looses strength over time, and especially when exposed to air or sunshine, which accelerates that loss. So as a precaution always keep your bleach out of sunlight and always keep the cap tightly closed. Also remember when using and handling bleach to follow all Warning directions on the bottle in regards to avoiding skin contact and use in a well ventilated area.
For adult usage it is recommended by both the Red Cross and FEMA to add 8 drops (1/8 teaspoon) of household bleach to each gallon of drinking water to remove virus, mold, bacteria, fungi, and protozoa. Allow the water to sit at least 30 minutes before using. When smelled, the water should have a slight chlorine smell to it. If it does then this water is ready to drink and it is also ready to stockpile for long term storage. If the water has no odors of chlorine add 8 more drops and again wait another 15 minutes. Important we are looking for that chlorine smell to assure that our purification has worked. WARNING the above concentration is not considered safe for infants. If you need water for infants take this treated water from above and pour into a clean bowl or pan and allow to sit open for 24 hours. This exposure to the air will allow the chlorine to evaporate to safe levels. If you do not have 24 hours to wait place this bowl of water in the sunshine and stir it vigorously for a minute or two about every hour. This will accelerate the chlorine evaporation and the water should be safe for infants in about 5-6 hours. Smell the water; it should have lost the chlorine smell at this point.
A good survival tip at this point is, even if you do not use liquid bleach as a common household product. Buy at least one gallon of regular bleach to put back for emergencies and tape or tie an eye dropper to it just in case. Nobody will know you’re prepping if you don’t tell them.
Look at it this way, 1 gallon of liquid bleach can be equal to 3,800 gallons of drinkable water if the need arises and this is the recommended method for purification of water by both the Red Cross and FEMA.
Disclaimer: We are including this section strictly for educational and entertainment purposes. And as such we are not presenting this as a recommended method (just proposing an alternative). Nor are we responsible for any liabilities that result from the use of this method by others.
That being said, those of us that have pools and hot tubs have on many occasions swallowed or drank water from the pool or hot tub either accidently or otherwise and survived. During a real survival situation we may be pressed to use the things we have on hand to unsure that survival. The danger in this method is using the chemical chlorine concentrates when mixed in smaller amounts of water and I myself would not use nor recommend this method without a Chlorine test kit to verify chlorine levels before drinking. I would also mix no smaller than 55 gallon batches at a time, once verified safe, bottle and store.
So if you are one of the lucky ones that have a swimming pool or hot tub then HTH is one of the purification chemicals that you have been using all along to treat your water and probably should still have some on hand and possibly a water test kit (chlorine test).
Actually HTH is a product name; what we are looking for is dry calcium hypochlorite usually in a 70% available chlorine concentrate. This also supplies chlorine but in a much more concentrated form.
According to WHO (World Health Organization) and also FEMA (Federal Emergency Management Agency) guides on field water quality, the acceptable levels of chlorine to meet both standards of purification and still maintain safe drinking levels is 5ppm. which is also = to 5mg./L . For those that don’t know (1ppm=1mg/L).
Therefore based on these guidelines your target figure for available chlorine to shoot for is 5ppm. or 5mg/L depending on the type test kit you have. If you test below this amount add more chlorine in small amounts stir and wait at least 30 minutes and retest. The opposite is true if over this amount add small amounts of water, stir, and retest.
I am old enough to remember when this use to be in every households medicine cabinet. It was used as an antiseptic for cuts and scrapes. Many of you younger folks out there may not be familiar with it at all. But it is still an accepted method for purifying water and is still available in Drug stores.
The dosage is as follows: For a 2% USP strength tincture of Iodine
Add 20 drops to each gallon of clear water and wait 30 minutes. If the water is cloudy add 40 drops and wait 30 minutes. This again will remove all molds, fungi, bacteria, virus, and protozoa from the water. It may somewhat discolor the water itself but that O.K. that is normal. Iodine is commonly one of the ingredients used in the commercially produced purification tablets available in the market today.