What to Do During a Boil-Water Advisory
A boil-water notice can feel alarming, but the response is simple once you know it. Here is exactly what to do, what stays safe, and how to recover when it lifts.
A boil-water advisory is your utility telling you that the water may contain harmful microbes and should be boiled before use. They are usually issued after an event that could let pathogens in: a water main break, a pressure loss, equipment failure, flooding, or a positive bacteria test. The notice is a precaution, and following it correctly keeps you safe.
What an advisory means
It means the concern is microbial, the bacteria, viruses, and parasites covered in waterborne pathogens, not chemical. That distinction matters, because boiling solves microbial problems and is the right tool here. Take the notice seriously and assume the water is unsafe to drink untreated until the advisory is lifted.
How to boil correctly
Bring water to a rolling boil and hold it there for one minute (three minutes above 6,500 feet of elevation), then let it cool. Use boiled or bottled water for drinking, making ice, preparing food and infant formula, brushing teeth, and giving water to pets. More detail is in boiling water to make it safe.
What is safe and what is not
You can still use unboiled tap water for things that do not involve swallowing: washing hands with soap (then drying well), showering for most adults while avoiding swallowing water, laundry, and dishwashing if your machine has a hot sanitizing cycle. Avoid giving unboiled tap water to young children to bathe in if they tend to swallow it, and supervise handwashing for little ones.
If you cannot boil
If boiling is not possible, use bottled water. As a last resort when bottled water is unavailable, you can disinfect clear water with unscented household bleach, about eight drops (one-eighth teaspoon) per gallon, stirred and left for 30 minutes; this handles bacteria and viruses but not chemicals. Follow official guidance from your utility or local health department for the exact method.
When it is lifted
Once officials lift the advisory, flush your pipes by running cold-water taps for several minutes, run drinking fountains and appliances that use water, discard ice made during the advisory and make a fresh batch, run a cycle on water-using appliances, and replace any filter cartridges that were in use. Flushing clears any water that sat in your plumbing during the event and returns your system to normal.