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Personal Water Use


After an emergency, especially after flooding, drinking water may not be available or safe to drink. As a result, residents may have to find a source of safe drinking water or know how to treat their water for use in certain activities, such as drinking, making ice, washing hands, and brushing teeth. The following information will tell you how to plan for treating and storing your water in the event of an emergency.


Create a Disaster Supplies Kit


Before an emergency, make sure you have a Disaster Supplies Kit. The CDC and the American Red Cross have prepared a list of emergency supplies that should be contained in your kit. Pack the items in easy-to-carry containers, label the containers clearly and store them where they would be easily accessible. Duffle bags, backpacks, and covered trash receptacles are good candidates for containers. In a disaster situation, you may need access to your disaster supplies kit quickly - whether you are sheltering at home or evacuating. Following a disaster, having the right supplies can help your household endure home confinement or evacuation.


Shopping List


Stored Water and Chlorine

Stored water and chlorine are important parts of your kit! You need to make sure you have a three-day supply of bottled or stored water in this kit. Do not buy store-bought water past the expiration or "use by" date on the container. Be sure to replace stored water every six months. Plan on storing the following quantities of water as part of your kit:

  • Store at least 1 gallon per person and pet per day.
  • Store at least a 3-day supply of water for each member of your family.

Your Disaster Supplies Kit should also include chlorine bleach, to disinfect your water in case your stored water supply runs out.

In an emergency, drink at least 2 quarts of water a day (3 to 4 quarts a day if you are in a hot climate, pregnant, sick, or a child). If supplies run low, don't ration water: Drink the amount you need today and look for more tomorrow. Don't risk dehydration!

Print out a copy of the following CDC Flyers to keep in your kit:


Hygiene and Sanitation Items

Collect hygiene and sanitation items for your Disaster Supplies Kit. Plan on collecting the following hygiene and sanitation items: Shampoo, deodorant, toothpaste, toothbrushes, dental floss, comb and brush, lip balm, sunscreen, contact lenses and supplies and any medications regularly used, toilet paper, paper towels, towelettes, soap, hand sanitizer, liquid detergent, feminine supplies, plastic garbage bags (heavy-duty) and ties (for personal sanitation uses), medium-sized plastic bucket with tight lid, and household chlorine bleach to be used for cleaning and sanitizing as well as drinking water treatment.


Boiling, Disinfectants, and Filters


Water can be made safe to drink by certain disinfectants and filters. Boiling and chemical treatment are two general methods used to effectively disinfect small quantities of filtered and settled water. The CDC Guide to Drinking Water Treatment for Backcountry and Travel Use covers information on the effectiveness of various water treatment methods. This guide is also available in PDF: A Guide of Drinking Water Treatment for Backcountry and Travel Use – PDF PDF Document Icon (PDF, 895.78 KB, 1 page).


Boiling

Boiling is the surest method to make water safe to drink and kill disease-causing microorganisms. If the water is cloudy, filter it through clean cloths or allow it to settle, then draw off the clear water for boiling. Boil the water vigorously for one minute (at altitudes above one mile, boil for three minutes). To improve the flat taste of boiled water, aerate it by pouring it back and forth from one container to another and allow it to stand for a few hours, or add a pinch of salt for each quart or liter of water boiled.

If boiling is not possible, chemical disinfection of filtered and settled water collected from a well, spring, river, or other surface water body will still provide health benefits; although boiling is a better way to treat water for drinking purposes.


Chemical Treatment

When boiling is not practical, certain chemicals will kill or inactivate most harmful, disease-causing organisms. For chemical disinfection to be effective, the water must be filtered and settled first. Chlorine and iodine are the two chemicals commonly used to treat water. They are somewhat effective in protecting against exposure to Giardia, but are not effective in controlling more resistant organisms like Cryptosporidium. Chlorine is generally more effective than iodine in controlling Giardia, and both disinfectants are more effective in warm water. Chlorine dioxide is also now available in some outdoor stores. This chemical has proven to be effective against pathogens, including Cryptosporidium, if manufacturer instructions are followed.


Filters

Certain types of portable water filters can also remove some harmful, disease-causing organisms from drinking water. However, most of the portable filters on the market do not effectively remove viruses, thus chemical disinfection of water is usually needed after filtering in order to make water safer for drinking. Some portable water filters designed to remove Giardia and Cryptosporidium have "absolute" pore sizes of 0.1 to 1-micrometer and, therefore, may also remove most diarrhea-causing bacteria (0.1 micrometer absolute). However, viruses are smaller than 0.1 micron and will NOT be removed by filters with a pore size of 0.1 or larger. Iodine can be added to filtered water to kill viruses that may pass through these filters.


Treatment Combinations

If boiling water is not an option, then a combination of chemical treatment and filtration discussed above is the next best way to treat water. To learn more about different filters and treatments that can remove Cryptosporidium, see the following resources from CDC:


Water Containers (cleaning and storage)


Be sure to use safe and clean containers for storing your emergency water. To prepare containers:

  • Wash containers with dishwashing soap and rinse with clean water (if available).
  • Sanitize by swishing a solution of 1 teaspoon of liquid household chlorine bleach to a quart of water on all interior surfaces of the container.
  • Rinse thoroughly with clean water (if available) before use. If clean water is not available, let containers air-dry before use.

Avoid using:
  • Containers that can't be sealed tightly
  • Containers that can break, such as glass bottles
  • Containers that have ever held any toxic substance
  • Plastic milk bottles and cartons which are difficult to clean and break down over time

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Finding Water


If you do not have a stored supply of clean water, safe drinking water may be found inside and outside the home. While searching for an alternative source of water, it is important to remember never to drink flood water, water that contains floating material or water that has an odor or dark color. If you find yourself in a situation without a stored supply of clean water, you can use water:

Inside the Home

  • Your hot-water tank
  • Pipes and faucets
  • Ice cubes

If the water from your faucet is safe to drink, but has been turned off for some reason, then you can drink the water in your pipes and hot-water tank, even if the idea seems unappealing. Remember: Learn where the water intake valve to your home is. If you hear reports of broken water or sewage lines, or if local officials recommend doing so, you would need to shut off water to your house at the incoming water valve to stop contaminated water from entering your home. If you don't drink tap water, the water in your pipes and hot-water tank may still be useful for sanitation. To use the water in your hot-water tank, be sure the electricity or gas is off, and then open the drain at the bottom of the tank. Start the water flowing by turning off the water intake valve at the tank and turning on a hot-water faucet. Refill the tank before turning the gas or electricity back on. If the gas is turned off, only a professional can turn it back on. To use the water in your pipes, identify and turn on the highest faucet in your home to let air into the plumbing. You then collect water from the lowest faucet.

If you find yourself in a situation without a stored supply of clean water, you can also use water:

Outside the Home

  • Rainwater
  • Streams, rivers, and other moving bodies of water
  • Ponds and lakes
  • Natural springs

All of these sources of water will need to be treated as described above in Boiling, Disinfectants, and Filters.

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Treating Water for Drinking


If a community or well water system with clean and safe water is not available, it is important to find safe water for drinking, preparing food, and brushing teeth. Use of unsafe water can spread a wide range of diseases including diarrhea and hepatitis. U.S. federal agencies recommend the following steps to disinfect drinking water in an emergency:

  1. Use bottled water that has not been exposed to flood waters if it is available.
  2. If you don’t have bottled water, you will need to treat your water. If the water is murky, cloudy, or colored, first filter the water through materials such as clean cloths, paper towels, or coffee filters, or allow the water to settle and then carefully pour off the clear upper portion into a clean container. It is better to both settle and filter before proceeding with treatment.
  3. Next you should boil water to make it safe. Boiling water will kill most types of disease-causing organisms that may be present. Boil the water for one minute (three minutes, if over one mile in elevation), let it cool, and store it in clean containers with covers.
  4. If you can’t boil water, you can disinfect it using household bleach. Bleach will kill some, but not all, types of disease-causing organisms that may be in the water (Chlorine and iodine are not effective in controlling more resistant organisms like Cryptosporidium). Add 1/8 teaspoon (or 8 drops) of regular, unscented, liquid 4-6% household bleach for each gallon (2 drops per liter) of clear water, stir it well, and let it stand for 30 minutes before you use it. Store disinfected water in clean containers with tight covers.

See the "shopping list" section for a discussion of the different treatments methods that can make your water safe to drink. For a more detailed explanation of water treatment, visit the Environmental Protection Agency (EPA) page on Emergency Disinfection of Drinking Water. For a more thorough explanation of chemical treatment and other types of treatment visit Traveler’s Health: Water Treatment Methods.

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Storing Water Safely


See the water containers section for information about choosing and cleaning appropriate storage containers. Store water in:

  • Store-bought, factory-sealed water containers with lids.
  • If these containers are not available, use food-grade-quality containers and lids made for storing water (should be available from sporting goods, surplus stores, and other retailers). These containers must be thoroughly washed, sanitized, and rinsed. The water you store in them, if it's from your tap, may need to be treated before being stored.
  • Final storage of filled containers should be in a cool, dark place in your home, each vehicle, and your workplace.

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Resources

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