Water is life. It's that simple really, without water we die. Three days is the golden standard for how long we can live without putting water into our bodies. Maybe a little longer, maybe not, depending on the circumstances. Where can we get it? How do we make it safe to drink? How much should we store?These are all common questions, and good ones.
How do you know if water is safe to drink? You don't. Assume all water is not safe to drink, no matter how thirsty you are. The LAST thing you want is diarrhea, especially when you're already dehydrated. Dysentary will kill you in a day or two. I cannot stress enough how important it is that you treat ALL drinking water. I highly recommend having a copy of the book Where There Is No Doctor. It is used in disaster situations all over the world where trained medical professionals are not available, or cannot reach people needing treatment. In was invaluable in Haiti after the earthquake. Where There Is No Doctor details many proven methods for preventative treatment, such as treating water. It's free and can be downloaded HERE.
The easiest ways to treat water in a household setting is to boil it, or sterilize it with common bleach. To use bleach mix it at a ratio of 10 drops per gallon, shake or stir it, then let it sit for 30 minutes. If you get water from outside your home, strain out any pieces of debris by running it through a coffee filter, dish cloth, sock, or something like that. Then add 10 drops of bleach per gallon, shake or stir it up, and then let it sit for 30 minutes. If you don't have any bleach in your home, get some now. It's very cheap, stores indeffinately if you keep the lid closed, and has dozens of uses in an emergency or survival situation. It should be a staple in your preparedness supplies. Once an emergency situation arises, or is expected to arise, bleach will be very hard to find.
Boiling water is pretty self explanitory, but there are a few things to keep in mind. It takes fuel to boil water. If there's no power available, and you do not have a gas fueled stove, things can get complicated. You can boil it over an open flame, and that is going to take firewood. Bring the water to a rolling boil, and let it cool off. Some people think you need to boil water for 10 minutes, I'm not one of them. Bacteria, virii, and protozoa will die at a temperature of around 180 degrees Fahrenheit. Water boils at 210 degrees Fahrenheit, if it reaches a rolling boil, everything living in the water is long dead. Save your fuel for cooking.
Lets start with water sources inside the home. Depending on the size of your hot water heater, there is between 30 and 100 gallons of potable (drinkable) water inside your hot water heater. Simply drain the tank into a storage container. Do this by first making sure the electrical power (or gas) is turned fof to the heater. Then attach a garden hose to the spigot valve on the bottom of the tank and open the valve, gravity will do the rest.
There is also between 2 and 4 gallons of water in each tank on the toilet. DO NOT drink from the toilet bowl. Remove the lid from the back of the toilet and scoop out water from the tank. This water is drinkable if you have not put some kind of toilet sanitizing cake (the blue hockey puck looking things) in it. If the water is not clear and colorless, do not drink it.
Now lets look into water sources outside the home. Swimming pools have thousands of gallons of water in them. Can you drink it? Sure, if you treat it properly. A pool is basically a pond. How can we treat it? Well....that depends on the situation. Pool water that was being pumped and filtered a day ago is in pretty good shape. Pool water that's been standing for three weeks without electricity to pump and filter it is going to be very nasty. If the water is clear, scoop it out into a bucket then take it home and treat it as described above.
If the water is not clear, move as much algea and debris away from where you plan to scoop water out as possible. Then scoop it out in small amounts from the surface. Place it in a bucket, take it home and reevaluate it's condition. If it's cloudy, strain it as described above using whatever is available. You can "shock" the water by adding 20-30 drops of bleach, shaking or stirring it up, and letting it sit for 90 minutes. You can also boil it as described above after it has been filtered.
Treat river, creek, lake, and any sources of standing water as you would treat a stagnant swimming pool. If you can't use bleach or the boiling methods, you can use UV rays from the sun. Strain the water as described above and place it in a clear plastic or glass bottle. The thinner the material of the bottle, the more UV rays can pass through into the water, and the more effective it will be. Place the bottle in full sun for at least 4 hours, longer is better. Placing it on a reflective surface when possible will make it more effective as well. I have one of those reflective windshield screens used to keep the sun from damaging your cars dashboard, I can get 16 1-liter water bottles on the screen.
It is a very good idea to have at least 3 methods of water purification at your disposal if possible. I have the ability to use chemical (bleach), boiling, UV (solar), and a backpacking water filtration system that will treat 1,000 gallons.