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Private well flooding
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Private well flooding
If you suspect that your well has been affected by flood waters, Oregon Public Health recommends boiling water or obtaining water known to be safe from another source. Water should be boiled for one minute after it comes to a rolling boil. However, boiling water will not address all contamination. For example, boiling may actually concentrate nitrate levels. The best way to determine if the well has been contaminated is to have it tested for coliform bacteria, nitrate, and any other pollutants of concern by an accredited drinking water laboratory.
Signs of contamination
Cloudy or muddy water, flooded well houses or submerged well casing seals are signs that your well might have been contaminated by flood water.
If there is doubt about the safety of your water, it should not be used for drinking, brushing teeth, preparing food, making ice or mixing beverages. It can probably be safely used for all other household purposes.
Disinfecting well water
If the water from your well is clear you can disinfect the water taken from the well by adding 8 drops of chlorinated household bleach to each gallon of water and allowing it to stand for at least 30 minutes.
This is recommended for water that would be temporarily used for drinking, brushing teeth, washing dishes and for other food preparation activities.
Private well sanitation
If the well has an electrical pump, turn off all electricity and clear debris from the well. If electrical connections appear wet or damaged, get assistance from a well or pump contractor to avoid the risk of shock.
After the floodwater has subsided from the well vicinity, pump the well until the water runs clear. Use the outside faucet nearest the well to drain water from the well. If no pump is installed, bail water with a bucket until water is clear.
Disinfect the well with household bleach and then test it to be sure it is free of bacterial contamination and any other pollutants of concern. Steps for disinfecting your well are as follows:
Find and remove from the top of the well casing, the inspection plug. If there is not an inspection plug, you may be able to remove the air-vent line or you may be able to remove a plug or valve from the water line itself somewhere near the top of the seal.
Many wells have a foot valve that prevents addition of anything through the water line itself.
You may need to contact your pump supplier for advice about how to get bleach into the well.
If the casing of your well is not airtight before you remove the plug, it is very likely that the well will continue to be contaminated even without flooding. There should be no unplugged openings through the seal.
During storm events, water purification systems may not be functioning fully. Safe water for drinking, cooking, and personal hygiene includes bottled, boiled, or treated water. Your state, local, or tribal health department can make specific recommendations for boiling or treating water in your area. Here are some general rules concerning water for drinking, cooking, and personal hygiene.
Here are some general guidelines to keep you healthy and safe when water purification systems are not fully function. Keep these in mind when using water for drinking, cooking, and personal hygiene.
How to make your drinking water safe
Bring water to a rolling boil for 1 minute. This will kill harmful organisms. Boiling water is the preferred way to kill harmful bacteria and parasites.
If boiling water is not an option, use bottled water and make sure it came from a safe source. If you do not know that the water came from a safe source, you should boil or chemically treat it before you use it.
If you don’t have clean, safe, bottled water and if boiling is not possible, you often can make water safer to drink as a last resort by using a disinfectant, such as unscented household chlorine bleach, iodine, or chlorine dioxide tablets.
These can kill most harmful organisms.
Home treatment devices that do not boil or chemically disinfect the water with acceptable disinfectants are not considered reliable alternatives to boiling the water.
Use only bottled, boiled, or treated water until your supply is tested and found safe.