University of Illinois Extension
Disaster Resources - University of Illinois Extension

Emergency Water Supplies

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The body's most important need is for water. About 70% of the human body is made up of water. Human beings can live longer without food than water.

Most healthy adults and children can get by on a gallon of water per day for three or four days, but each day the body needs to replace about two and a half quarts of water at a minimum.

After a natural disaster, consider all water from wells, cisterns and other delivery systems in the disaster area unsafe until tested. Each natural disaster affects water systems differently. For example, floods can submerge plumbing fixtures and water heaters. Earthquakes can break water supply and distribution lines, contaminating an entire city or regional supply instantaneously. Tornadoes can cause flash flooding and destruction of household plumbing and non-submerged water storage tanks.

In an emergency situation it is best to use bottled water if at all possible. Fresh water from neighboring municipalities not affected by a disaster may also be used. If plumbing fixtures within a household have not been affected, the water heater or water pressure tank can supply emergency gallons of water. By opening the drain valve at the bottom of the tank you can obtain water.

Boiling water during a natural disaster is sometimes more harmful than helpful. Boiling the water may concentrate unwanted chemicals such as nitrites and pesticides. Boiling water from any nearby streams, lakes or ponds is also risky. Microorganisms from either raw sewage, livestock wastes or agrichemicals may still abound in drinking water, even after boiling. Boiling water in a natural disaster is only advisable when the water supplier and/or the public health department has given the go- ahead for the population to do so. Generally this occurs after lines have been somewhat repaired and general disinfection and decontamination of water supplies and equipment are well underway. Once a BOIL ORDER has been announced, the accepted procedure is to boil the pan of water at a ROLLING BOIL (212°F) FOR ONE FULL MINUTE. Boiling the water will generally rid the water supply of microorganisms, but not such substances as nitrates/nitrites or agri-chemicals.

To protect your own and our family's public health during a natural disaster, it is best not to try and purify the water by yourself. Use bottled water supplied throughout the community or available on store shelves (if possible) until community water supplies are officially restored and certified as safe to drink. Private well owners should test their own supplies to make sure their wells are once again safe for operation after a natural disaster.

Before water services in your municipality can be turned back on, the Environmental Protection Agency or Health department in your state must inspect and sample the water to ensure it is safe to drink. The water must meet all Federal standards specified in the Safe Drinking Water Act, as well as any additional state requirements. Water-treatment operators must demonstrate that the water is properly disinfected and that a residual amount of disinfectant will remain in the drinking water once it is re-sent into consumers homes. State inspectors will also check water equipment such as pipes, storage tanks, mains and valves for breaks, cracks and failures before allowing the water system back on line. Repairs and replacements of any faulty equipment must occur before the community can once again receive a certifiably safe supply of drinking water.

Issued by Mel Bromberg, Extension specialist, Water Quality/Health Issues. February 1995.

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