Health Resource Center


Healthy Waters

Water is essential to sustain life. All human beings need an adequate, safe and accessible supply. Prior to Hurricane Katrina and the catastrophic tsunami that devastated South Asia, the quality of drinking water was a pressing global health concern, but the situation has now become even more relevant and critical. These events and their aftereffects pose many water-related health risks including waterborne disease, sanitation problems, hunger, and thirst. According to U.N. Secretary General Kofi Annan, “Access to safe water is a fundamental human need and therefore a basic human right.”

Health Politics presents the following information to help you better understand the importance of water and the challenge ahead to ensure clean, safe water for everyone. To return to the Health Politics homepage, go to www.healthpolitics.org. You might also be interested in our program that traces the history of the Red Cross.

Water and Health
The World Health Organization has done extensive work in addressing issues related to water. Please visit the World Health Organization’s Water, Sanitation and Health homepage for information about how WHO works to improve aspects of water, sanitation and hygiene where the health burden is high, where interventions could make a major difference and where the present state of knowledge is poor. Included here are important excerpts from the site:

Burden of Disease and Cost-Effectiveness Estimates
WHO has recently estimated at a global level the costs, the health benefits and the non-health benefits of a range of selected interventions to improve water and sanitation services in the 14 WHO sub-regions.

Domestic Water Quantity, Service Level and Health
The quantity of water delivered and used for households is important -- it influences hygiene and therefore public health. This WHO publication reviews the relationships between water quantity, access, and health, and provides a basis for the establishment of minimum quantity and/or access targets for domestic water supplies, which do not currently exist.

The Facts
Read recently gathered facts and figures about the relationship between water, sanitation, and health.

Water-Related Diseases and Illnesses
Water-related diseases and illnesses generally come from microorganisms and chemicals in water people drink; diseases like schistosomiasis, which have part of their lifecycle in water; diseases like malaria with water-related vectors; drowning and some injuries; and others such as legionellosis carried by aerosols containing certain microorganisms.

Click on the water-related disease below for a detailed description from the World Health Organization:

Emerging Issues in Water and Infectious Disease
New diseases, including water-related diseases, periodically "emerge" either because they are newly recognized or because their importance increases. This may be due to the microorganisms themselves evolving, to changes in the way we manage water resources and supplies; changes in the tools and methods used to study the organisms and the health effects they cause; or due to changes in the human population itself.

WHO, EPA and other agencies collaborate to address some of these challenges through an initiative on "Emerging Issues in Water and Infectious Disease". The essential issues and the overall initiative are described in a brochure.

Healthy Water is Also an Issue for the United States
Water-related problems are not limited to developing nations. The United States faces major issues of its own. According to the Environmental Protection Agency, source water is untreated water from streams, rivers, lakes, or underground aquifers that is used to supply private wells and public drinking water.

Preventing drinking water contamination of drinking water supplies is an important mission within EPA’s office of ground water and drinking water. The EPA’s Web site has basic information about the water used for drinking water and the federal, state, and local programs that assess and manage potential public health risks, including a Web Guide -- an annotated guide to EPA source water resources. Please see the Site Map for a complete list of topics.

If Disaster Strikes, What Will YOU Do?
Recent weather patterns in the United States have led to torrential rains and massive flooding. Any of us could be faced with a situation in which our access to clean water is compromised. Health Politics presents helpful tips to follow, should you find yourself in an emergency that affects your water supply.

How to Locate Safe Drinking Water
After a disaster, it is possible that water supplies will be temporarily cut off or become contaminated. Because you must have water to survive, it is important to know how to locate and purify drinking water to make it safe. The Federal Emergency Management Agency (FEMA) provides the following instructions:

Water Sources
In the home: Melt ice cubes, and use water from the hot-water tank, the toilet tank (not the bowl) and water pipes.

Hot water tank: Turn off the power that heats it, and let the tank cool. Then place a container underneath and open the drain valve at the bottom of the tank. Don't turn the tank on again until water services are restored.

Toilet tank: The water in the tank (not the bowl) is safe to drink unless chemical treatments have been added.

Water pipes: Release air pressure into the plumbing system by turning on the highest faucet in the house. Then drain the water from the lowest faucet.

Outside the home: Rain water, spring water, and water from streams, river, lakes, and coiled garden hoses can be used after it is purified.

Important Note: Avoid water from water beds as a source for drinking water. Pesticidal chemicals are in the plastic casing of the bed and chemicals have probably been added to the water to prevent the growth of algae, fungi, and bacteria. The water is safe only for hand-washing and laundering.

How to Purify Water
Boiling and chemical sterilization are two ways to purify water.

Any water that is obtained from sources outside the home or water that does not appear clear should be sterilized. Non-sterilized water may be contaminated with the parasite Giardia.

Straining water: Strain water containing sediment or floating material through a cloth or paper filter before beginning the purification process.

  • Heat sterilization: Boiling water is the preferred method of purification because disease-causing- microorganisms cannot survive the intense heat. Bring water to a rolling boil for 1 minute. Pour the water back and forth from one clean container to another to improve the taste. Adding a pinch of salt could also help.
  • Chemical sterilization: In some situations, boiling may not be an option. The alternative is to treat the water chemically. Plain household chlorine bleach may be used. Be sure the label states that hypochlorite is the only active ingredient. Bleach containing soap or fragrances is not acceptable. With an eye dropper, add 8 drops of bleach per gallon of water (16 if the water is cloudy), stir and let stand. After 30 minutes the water should taste and smell of chlorine. At this time it can be used. If the taste and smell (and appearance in the case of cloudy water) has not changed, add another dose and let stand. If after one half hour the water does not have a chlorine smell, do not use it.

Storing Your Purified Water
Store the water in a clean and sanitary glass or plastic container. Plastic containers are good because they are lightweight and unbreakable. Metal containers should be considered as a last resort because they may corrode and give water an unpleasant taste.

Water that local officials report has been contaminated with toxic chemicals or radioactive materials cannot be purified using home decontamination methods.

Disinfecting Cisterns and Other Rain-Catchment Systems After Floods
The Centers for Disease Control provides similar information to the above about making water safe for drinking. But water is needed for many other purposes besides drinking. The below excerpt of information, which can be found on the CDC’s Water Quality page, is geared to tsunami and flood victims. It describes how to disinfect cisterns and other rain-catchment systems. To view the entire list of instructions, visit http://www.bt.cdc.gov/disasters/tsunamis/waterquality.asp.

Getting Started
In many areas of the world, people get drinking water from catchment (collection) systems that trap and store rainwater. Even when these systems are constructed and used properly, they are easily contaminated by germs that can cause sickness. Some water supply systems use surfaces such as rooftops to capture and channel water to a cistern (storage tank). 

When cisterns and similar systems come in contact with flood waters, people should assume that their drinking water is contaminated.  One of the following methods can be used to disinfect cisterns and other rain-catchment systems in disaster situations on the basis of whether other sources of drinkable water are available. If fuel products or other chemical contaminants have come in contact with the cistern or rain-catchment system, or if there is a smell of fuel or other chemicals in the vicinity of the system, use only Method 1 for disinfection.

Method 1 -- If drinkable water is readily available

  1. Thoroughly clean the surface catchment area (for example, rooftop) and remove all debris.
  2. Drain the cistern or storage tank completely.
  3. Remove all debris from the tank.
  4. Without entering the tank, scrub the inside as well as you can with a stiff brush or broom and a solution of 1 cup (8 ounces; approximately 0.25 liter) of 5.25% unscented chlorine bleach (sodium hypochlorite) in 10 gallons (approximately 38 liters) of water.
  5. Refill the tank with rainwater or potable water.
  6. If you don’t know the capacity of the tank, use the following formula to determine the amount of water it will hold:  For a rectangular tank, multiply the depth of the tank (in feet) times the length (feet) times the width (feet), and multiply the result by 7.5 to get the number of gallons the tank will hold.  For a round tank, multiply the length (feet) by the square of the tank radius, multiply the result by 3.14, and then multiply that result by 7.5 to get gallons.  If neither of these methods is practical, you can estimate the capacity in gallons by making an “educated guess,” and then double the amount of bleach to be used in the disinfection solution.
    Metric: In metric units, multiply length (meters) X width (meters) X height (meters) X 1,000 = capacity in liters. For round tanks, multiply height X the radius squared (meters) X 3,140 = capacity in liters.
  7. Add 4 cups (32 ounces; approximately 1 liter) of 5.25% unscented household bleach for every 100 gallons (approximately 380 liters) of water in the holding tank.  This should give you a chlorine concentration of approximately 100 parts per million (ppm).
  8. Run water through all plumbing used for drinking water in your home until you notice a strong chlorine odor.
  9. Let the solution sit undisturbed for 24 hours.
  10. Drain the whole tank.
  11. Let the tank refill with rainwater, or fill the tank with drinkable water.
  12. Flush all piping in your home until the odor of chlorine is completely gone before you use the system again.

Method 2 -- If drinkable water is not readily available

  1. Thoroughly clean the surface catchment area (rooftop) and remove all debris.
  2. If you don’t know the capacity of the tank, use the following formula to determine how much water it will hold:  For a rectangular tank, multiply the depth of the tank (in feet) times the length (feet) times the width (feet), and multiply the result by 7.5 to get the number of gallons the tank will hold.  For a round tank, multiply the length (feet) by the square of the tank radius, multiplying the result by 3.14, and then multiply by 7.5 to get the number of gallons the tank will hold.  If neither of these methods is practical, you can estimate the capacity by making an “educated guess,” and then double the amount of bleach to be used in the disinfection solution.
    Metric: In metric units, multiply length (meters) X width (meters) X height (meters) X 1,000 = capacity in liters. For round tanks, multiply height X the radius squared (meters) X 3,140 = capacity in liters.
  3. Add 4 cups (32 ounces; approximately 1 liter) of 5.25% unscented household bleach for every 100 gallons (approximately 380 liters) of water in the holding tank.  This should give you a chlorine concentration of approximately 100 parts per million (ppm).
  4. Run water through all plumbing used for drinking water in your home until you notice a strong chlorine odor.
  5. Let the solution sit undisturbed for 24 hours.
  6. Drain the whole tank.
  7. Remove all debris from the tank.
  8. Without entering the tank, scrub the inside as well as you can with a stiff brush or broom and a solution of 1 cup (8 ounces; approximately 0.25 liter) of 5.25% unscented chlorine bleach (sodium hypochlorite) in 10 gallons (approximately 380 liters) of water.
  9. Drain all of the disinfectant solution from the tank.
  10. Let the tank refill.
  11. Flush all piping in your home until the odor of chlorine is completely gone before you use the system again

Disinfecting Wells
If you suspect that your well may be contaminated, it’s best to contact local authorities for specific advice, but click here for general instructions for disinfecting wells.