WATER QUALITYHow to Purify Water in an Emergency

May 9, 2022

In an emergency, the normal water supply might be cut, or disrupted, or contaminated. A hurricane, flood or pipe break can mean you don’t have water or clean water. It’s valuable to have alternative ways to treat water in an emergency.

The public could be instructed to use boiled, bottled or disinfected water in certain circumstances. Water can be contaminated due to chemical, metal, bacterial, fecal or viral causes. Then, the water purification you need depends on the type of contamination, or the odor, color or taste you need to eliminate or resolve.

No matter the emergency, whether at home or not, humans must have drinkable water. A body can survive about three days with no drinkable water.


Among the simplest and most well known ways to make water safe to consume is boiling. Boiling temperatures eliminates bacteria, parasites and viruses. It won’t eliminate sediment, particles or all chemicals. Boiling water for 10 minutes is effective in creating safe, drinkable water.

If the water is cloudy, let it boil, then settle, then filter it through a coffee filter, paper towel or clean towel. After boiling, let water cool, then you can store it in clean containers and cover it. Add a punch of salt per quart or liter of water and pour it from container to container several times.



You can sanitize water with chemical tablets that contain chlorine, iodine, chlorine dioxide or other decontaminating agents. You can find these at pharmacies, most groceries or sporting goods stores. Follow the instructions with each specific brand and chemical or compound.

To sanitize water with chlorine, include one part chlorine solution to every 100 parts of water. One pint (16 ounces) of chlorine solution to 12.5 gallons of water is the same ratio. If the chlorine taste is too much, you can pour the water from one container to another multiple times, then let the water stand for a few hours before drinking.


Iodine tablets make most water safe and drinkable. It’s best to use iodine tablets as opposed to iodine which may be in a first aid or emergency kit. Pregnant women and people with thyroid problems should avoid drinking water with iodine.


If boiling water isn’t possible, you can disinfect water with bleach. Use only unscented, chlorine bleach which is marked safe for disinfection and sanitation on the label.

The steps for using bleach to sanitize water are:

  • Get a clean dropper.
  • Get liquid, chlorine bleach. It should be make safe for sanitation. It should contain 8.25% sodium hypochlorite.
  • For a gallon of water, add six drops of bleach. Double the amount of bleach if the water is cloudy, discolored or very cold.
  • Stir then let the water stand for 30 minutes. The water should have a chlorine smell. If it doesn’t, repeat another bleach dose and let it stand again.
  • If the chemical odor or taste is too strong to drink, pour the water from one container to another and let it stand for a few hours.

Survival Straws

A straw design water filter is small, light and very efficient. Newer designs can be used as you use a drinking straw. It’s possible, for instance, to connect a straw filter to a garden hose and filter the water running out of it.

Don’t expect a survival straw to filter out every particulate or bacteria in a water source. Most of these filters use an activated carbon filter. This eliminates larger bacteria and many pathogens, as well as most bad odors and tastes, from water.


Charcoal can be used to purify water. In fact, many filters and filtration systems use charcoal as a filter. Charcoal is a wonderful purifying compound because it has a unique ability to absorb sediment and contaminants while additionally improving taste. Charcoal is also simple to find because it is made wherever you burn wood.

How to Purify Water in an Emergency
Solar Water Disinfection

The process of using charcoal to filter water is relatively easy. You need charcoal, something to crush the charcoal with, and a clean container to hold the water. There are guides on the web which demonstrate how to make a charcoal purification system by using fire remains and a two-liter bottle. You can combine charcoal filtration and boiling water to combine what both methods filter out.

Solar Water Disinfection (SODIS)

Solar Water Disinfection, or SODIS, is another possible, and fairly simple, methods for getting clean water. It is so easy as a matter of fact there are several organizations that are attempting to show this method to people who are at higher risk of catching water-borne illnesses.

Basically, all you need to clean your water using this method is the sunlight, a clear, plastic container made with PET (most plastic water bottles are made out of PET, just look at the bottom of the bottle), then about six hours. Just fill up the PET bottle with water and let it stay in the sunlight for six hours. The sun’s UV-A radiation will penetrate the bottle and kill the bacteria and microorganisms in the water. The SODIS technique works in cold climates, too. If you require more info, take a look at the SODIS website.


South End Water Filtration specializes in HALO Water Filter products including the HALO H2 Zero Whole Home Water Filter. HALO systems solve hard water problems, give your family clear, great-tasting water and are totally maintenance free. We’re just a click away to help and answer any questions. South End Plumbing and South End Water Filtration will give you a free estimate. Call us at 704-486-1988 or contact us online to schedule a visit.