Make Drinking Water Safe with Bleach
Water. We can’t live without it. Not for long – only about 3 days without any source of it (including any water or moisture that is in your foods). In fact, water is the one thing that we need the most, to survive.
Far too often, survival minded preppers think of and concentrate on storing extra food, with lesser regard for storing water. For some reason, there is an underlying assumption that obtaining water during an emergency or disaster will not be a problem. For some, this may be true, especially if they live right next to a plentiful source of water. But for those that rely on a steady supply of water from their faucet, think again…
Without electricity, most homes will quickly lose their water pressure as municipal pumps will be unable to supply. Don’t count on municipal generators to keep on supplying the pumps to pump your water.
The general rule for storing water for an emergency or disaster is 1 gallon per person per day.
There are variations to this generality, ranging from a half gallon to as much as 3 gallons per person per day because there are other uses for water besides just drinking.
A problem that you will encounter during an emergency or disaster is not only obtaining water to drink, but treating it to make the water safe to drink.
A best way to treat water for drinking is to boil it first. Well, almost boiling… you don’t actually have to heat water all the way to boiling to rid it of microorganisms.
According to the Wilderness Medical Society, water temperatures above 160° F (70° C) kill all pathogens within 30 minutes and above 185° F (85° C) within a few minutes. So in the time it takes for the water to reach the boiling point (212° F or 100° C) from 160° F (70° C), all pathogens will be killed, even at high altitude. To be extra safe, let the water boil rapidly for one minute, especially at higher altitudes since water boils at a lower temperature.
If boiling is not possible, or to add a layer of protection after boiling (after cool down), another very effective way to make water safe to drink is to add a specific amount of regular household bleach. Bleach contains about 5 to 6 percent chlorine, which will disinfect the water if added in the right amount.
First things first. If the water is cloudy and contains sediment, it should be strained through a filter by using a cloth or other straining method (use your common sense here with whatever is available). Of course if you have a drinking water filter with you, you’re in good shape.
How to purify water with Bleach
According to the American Red Cross,
- Use regular liquid bleach (any brand). The only active ingredient should be sodium hypochlorite (concentration 5.25 – 6 percent). If you also see sodium hydroxide on the ingredient list, it is apparently OK and safe. Do not use bleach that contain soaps, perfumes, or dyes. Be sure to read the label. The “Regular” household bleach is usually fine for this.
- Add about 8 drops (one-eighth US teaspoon) of regular liquid bleach per one gallon of water. Use 4 drops if using a 2-liter bottle.
- Mix thoroughly and let stand for 30 minutes.
- Then, smell the water. If the water has a faint smell of chlorine, then it is OK to use. If you cannot detect any chlorine odor, add another 8 drops of regular liquid bleach (4 drops for 2-liter bottle). Let stand, and smell it again. If you still cannot smell chlorine, discard it and find another water source.
It may be useful to have a swimming pool test kit to verify the chlorine level in the water. 1 ppm to a maximum of 4 ppm is safe to drink.
Note that bleach has a shelf life, although you will probably not see a date on the bottle. Bleach loses about half its effectiveness within a year, so be sure to date your bottle upon purchase. Double the dosage if one year old. I would replace bleach that has been stored much beyond a year, just to be sure of full strength effectiveness.
Facts about chlorine level for safe drinking water
The EPA recommends a maximum (no more than) 4 ppm (parts per million) of chlorine for safe drinking water.
Ideal chlorine levels for safe water in swimming pools is between 1 – 1.5 ppm, to keep bacteria and other nastiness from growing.
Municipal tap water measured at the MSB homestead is 0.6 ppm chlorine (good enough).
It takes 45 minutes to destroy Giardia Protozoan (common cause of diarrhea) with 1 ppm chlorine level (so, let your water sit for awhile, even if using more than 1 ppm).
It is highly recommended to have a simple Pool Water Test Kit to measure chlorine levels in your stored water or renewed water.
Chlorine (which is effectively the active ingredient in general household bleach) is in all tap water systems across America and the developed countries of the world. It has no doubt saved countless lives from contamination and subsequent disease.
From the CDC, Centers for Disease Control, “If you don’t have clean, safe, bottled water and if boiling is not possible, you often can make water safer to drink by using a disinfectant, such as unscented household chlorine bleach”
Add 1/8 teaspoon (or 8 drops; about 0.625 milliliters) of unscented liquid household chlorine (5–6%) bleach for each gallon of clear water (or 2 drops of bleach for each liter or each quart of clear water).
Add 1/4 teaspoon (or 16 drops; about 1.50 milliliters) of bleach for each gallon of cloudy water (or 4 drops of bleach for each liter or each quart of cloudy water).
Stir the mixture well.
Let it stand for 30 minutes or longer before you use it.
Store the disinfected water in clean, disinfected containers with tight covers.
From the WHO, World Health Organization, “Chlorine is commonly available to households as liquid bleach (sodium hypo chlorite), usually with a chlorine concentration of 1%”
Disinfection with chlorine is the most appropriate way of ensuring microbiological safety in most low-cost settings. Bleaching powder, liquid bleach, chlorine tablets and other sources of chlorine may be used, depending on local availability. At least 30 minutes contact time should be allowed after the chlorine is added to the water before the water is drunk, to ensure adequate disinfection. The free chlorine residual (i.e. the free form of chlorine remaining in the water after the contact time) should be between 0.5 and 1.0 mg/l (0.5 ppm and 1.0 ppm).