Disinfecting Water

 Before using any of these disinfection methods, let suspended particles settle to the bottom, or strain the untreated water through layers of paper towels, clean cloths or paper coffee filters. Contaminated water can contain microorganisms that cause diarrhea, vomiting, abdominal cramps, headaches, or other symptoms. You should always disinfect water of uncertain purity before using it for drinking, food preparation, or personal hygiene. 

Disinfection by Boiling

• Disinfection by boiling produces the safest water. 
• Bring water to a rolling boil for one minute. 
• Let the water cool before drinking. 
• Boiled water will taste better if you put oxygen back into it by pouring it back and forth between two containers. This will also improve the taste of stored water. 
• Using Liquid Chlorine Bleach 
• Disinfect water by adding eight drops of liquid chlorine bleach (4-6% available chlorine) per gallon of water (sixteen drops if the water is cloudy). 
• Stir, and let stand for 30 minutes. 
• If the water does not taste and smell of chlorine at that point, add another dose of bleach and let stand for another 15 minutes. 
• Using Iodine or Chlorine Tablets 
• Check the expiration date for the tablets before using. 
• Follow the package directions. 
• Usually one tablet is enough for one quart of water. 
• Double the dose if the water is cloudy. 
• Disinfecting Drinking Water

Contaminated drinking water can contain microorganisms that cause diarrhea, vomiting, abdominal cramps, headaches, or other symptoms. You should always disinfect water of uncertain purity before using it for drinking, food preparation, or personal hygiene.
Well Contamination


If the area around your well gets flooded or if you suspect that your well is contaminated, you need to disinfect the water in the well before using it for washing and at the tap before using it for drinking water or for cooking. You should continue disinfection at the tap until the water is tested and found suitable for drinking. Contact your local health department for information about testing your well. Changes in the water's appearance, taste or odor may indicate possible contamination.



After disinfecting the well, the water should be tested to determine whether all bacterial contamination has been removed. You should wait several days to test the water to be sure that all the chlorine has been flushed from the water system. Contact your local health department for more information about testing your well. Until testing shows that the water is free of contamination, you should continue to use bottled or disinfected water for drinking and food preparation as described in the Disinfecting Water section.


You may wish to consider retesting the well water again after several weeks. If flooding and groundwater contamination is extensive, your well may not be a suitable source of drinking water for some time. Severe flooding that damages the well casing, deposits debris around the well or submerges electrical controls will require a qualified professional for evaluation, servicing and disinfection.

Procedure for Disinfecting a Well

• Run water until clear, using an outdoor faucet closest to the well or pressure tank. 
• Mix two quarts household bleach containing about 5% chlorine in 10 gallons of water in a large bucket or pail in the area of the well casing. 
• Turn electrical power off to the well pump. Carefully remove the well cap and well seal if necessary. Set aside. 
• Place hose connected to outdoor faucet inside well casing. Turn electrical power back on to the well pump and turn water on to run the pump. 
• Carefully pour the water and bleach mixture from the bucket or pail down the open well casing. At the same time, continue to run the water from the hose placed inside the well casing. 
• At each indoor and outdoor faucet, run the water until a chlorine odor is present, then shut each faucet off. 
• Continue running water through the hose inside the well casing to recirculate the chlorine-treated water. Use the hose to also wash down the inside of the well casing. 
• After one hour of recirculating the water, shut all faucets off to stop the pump. Disconnect power supply to pump. Remove recirculator hose from well. 
• Mix two more quarts of bleach in 10 gallons of water and pour mixture down the well casing. Disinfect the well cap and seal by rinsing with a chlorine solution. Replace well seal and cap. Allow the well to stand idle for at least eight hours and preferably 12 to 24 hours. Avoid using the water during this time. 
• After the well has idled for the recommended period of time, turn the pump on and run the water using an outdoor faucet and garden hose in an area away from grass and shrubbery until the odor of chlorine disappears. Run all indoor and outdoor faucets until the odor and taste of chlorine disappears.

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Monday, July 22, 2013