What is a Boil Water Advisory (BWA)?

Boil Water Advisories are often issued by water municipalities when damage occurs to a water line or parts of the main water distribution system. These alerts are also issued for a loss in water pressure, allowing bacteria to backwash into the water pipes.

Minerals and viruses like E. coli, cryptosporidium, and giardia may get into water when a pipe breaks or during a natural disaster, like flooding. Chemical spills that get into the water supply may also cause "Do Not Use" advisories. Water stored in coffee makers, ice machines or dispensers, and soda makers should not be used during a "Do Not Use" or boil water advisory. 

What contaminants might be in my water?

Major contaminants are rarely life threatening, but they make people, especially younger children, elderly people, or those with compromised immune systems very sick. Bacteria, Cryptosporidum, Giardia, E. Coli, and viruses are the most common contaminants during a boil water advisory. These organisms primarily affect the gastrointestinal system, causing diarrhea, abdominal cramps, nausea, and vomiting with or without a fever. Boiling or disinfecting will neutralize the bacteria in water, but installing a UV System  is the safest way to ensure that you never have to worry about contaminants in you water, not even during a BWA.


How long should I boil the water to ensure it is safe?

After a boil water advisory has been issued, bring the water to a full rolling boil for at least 1 minute to guarantee that the harmful bacteria and micro-organisms have been destroyed. 

How long should I boil the water to ensure it is safe?

Do I need to boil my tap water if it is filtered?

Yes, it's important to boil all tap water even if it is filtered. Most water filters (activated carbon, charcoal, pitcher filters, etc.) are not suitable for use on micro-biologically unsafe water and do NOT kill bacteria or viruses. If you run water through your filter during the Boil Water Advisory, it could be contaminated.

We recommend that you discard the filter and replace it with a new one once the boil advisory is lifted. Even if you have a fridge or ice filter, do not use ice form ice trays, dispensers, or ice makers. Make your own ice with boiled or bottled water.


What if I have a reverse osmosis system?

Although not designed for biological pathogen removal, RO, ultrafiltration, and other absolute rated sub-micron filters may reduce them. However, filters and membranes should be replaced and system and storage tank sanitized during a BWA. 

What if I have a reverse osmosis system?

What do I do if I don't have any power during a BWA?

For locations without power for boiling water, unscented household bleach may be used as a disinfectant. Add 8 drops (about 1/8 of a teaspoon) of undiluted bleach to a gallon of contaminated water. After stirring, allow the water to stand for 30 minutes. If the water is cloudy afterward, repeat the process. The water may smell like bleach, but it is safe for consumption. Always take safety precautions: use the bleach in a well-ventilated area and avoid skin contact.

What do I do if I don't have any power during a BWA?

How should I prepare food and wash dishes during a BWA?

Wash fruits, vegetables, dishes, and countertops with bottled or boiled water. Dishes may be hand washed in the contaminated tap water only after soaking them for at least one minute in a bleach solution rinse. To prepare a bleach solution rinse, combine 1 tablespoon of bleach in a gallon of water. Dishes should then be allowed to air dry completely before storage. 

If you use ready-to-use baby formula for your infant prepare powdered or concentrated baby formula with bottled water if possible. If you don't have access to bottled water, see the instructions above on how to use bleach to disinfect water. Make sure to sterilize all bottles and nipples before use. Please take every precaution to ensure that your baby doesn't ingest tap water during a BWA, as they're at the greatest risk for illness.

How should I prepare food and wash dishes during a BWA?

What should I do about bathing, brushing teeth, and washing clothes?

Swallowing water when bathing or showering during a BWA is not safe for you or your children. Give children a sponge bath to reduce the chance of them ingesting contaminated water. Consider using boiled water that's been cooled, disinfected water, or bottled water to bathe babies. Make sure your family is only using boiled, disinfected, or bottled water when brushing teeth.

What should I do about bathing, brushing teeth, and washing clothes?

Do I need to boil water for my pets?

Pets are susceptible to many of the same diseases as people. If you want to keep your pets healthy, give them boiled water that been cooled, disinfected water, or bottled water.

Do I need to boil water for my pets?

How do I flush my water system after the BWA is removed?

There are several steps to flushing water pipes and water systems at your home or business. Each of these steps must be followed carefully and in the right order.  

  1. Throw away all ice cubes, drinks, baby formula, and uncooked food (like soup) prepared with contaminated water during the day of the advisory. This includes soda makers and coffee makers that have water storage in the machine.  
  2. Begin with the tap at the highest level in your home or business (for example, the bathroom on the second floor). Flush all hot taps including baths and showers for at least 5 minutes. This will clear out the pipes, fixtures, and hot water tank.  
  3. Once hot taps have been flushed, flush all cold water taps, beginning with those at the highest level, for at least 5 minutes. This includes kitchens, bathrooms, wet bars, and utility sinks. Don't forget to flush the refrigerator's water dispensing system as well. 
  4. Flush all remaining faucets and appliances including hose bibs, external faucets, or fixtures not used for drinking water. Follow the manufacturer's instructions for cleaning and sterilizing CPAP machines, humidifiers, and other medical or health care devices that have had contact with water. Make sure to manually regenerate water softeners as well.
  5. Once the pipes and fixtures have been flushed, sediment filters for whole house filtration, reverse osmosis prefilters, refrigerator filters, and other point-of-use filters should also be changed.

If the boil advisory is only in effect for a few hours, your reverse osmosis membrane should be fine. However, if your reverse osmosis system has been sitting idle for a day or more, it may have bacteria growing in it. In such instances, the membrane should also be replaced.

Is my well water safe after a flood?

Well water requires a more detailed cleaning and sterilization method. For more information, see this informative PDF from the EPA.


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