Boil Water Advisory: What to Do During and After, According to CDC

During a boil water advisory, CDC says to use bottled water or tap water brought to a full rolling boil for 1 minute (3 minutes if you live above 6,500 feet), then cooled, for drinking, cooking, making formula and brushing teeth. Boil even if you have a filter. Showering is fine as long as you don’t swallow the water, and most laundry and handwashing can continue as normal unless local officials say otherwise. After the advisory lifts, you still need to flush your pipes, dump old ice, and replace filters before going back to normal.

Below is the detail, room by room, drawn from CDC guidance and state health department instructions.

First, check which kind of advisory you have

CDC describes three types of drinking water advisories, and they call for very different responses:

Boil water advisory. The water is, or might be, contaminated with germs. Boiling kills them.
Do not drink advisory. The concern is a chemical or toxin. Boiling does not make the water safe. Use bottled water for drinking and cooking.
Do not use advisory. Any contact with the water could be harmful, including on skin or in the lungs and eyes. Use bottled water for everything. CDC notes these are rare.

Everything below applies to a boil water advisory. If your notice says “do not drink” or “do not use,” follow that notice instead.

Advisories are issued by your water utility or a government agency. Check your utility’s website or local news for the official notice and any updates. If you’re on a private well, a utility advisory doesn’t cover your water, though a flood that triggered it might affect your well too (see our well water testing guide).

How to make water safe

Boiling. Bring clear water to a full rolling boil for 1 minute, or 3 minutes above 6,500 feet. Let it cool before using it, and store it in clean containers with covers.

If you can’t boil. CDC says unscented household bleach can disinfect water. Check the label: US bleach is typically 5% to 9% sodium hypochlorite. For that strength, add 8 drops per gallon of water, stir, and let it stand at least 30 minutes before drinking. If the water is cloudy, colored or very cold, double the amount. CDC notes bleach doesn’t work as well as boiling against parasites like Cryptosporidium and Giardia, so boil when you can.

Filters don’t replace boiling. CDC is explicit that you should boil tap water even if it has gone through a home filter or filter pitcher. Most household filters are not designed to remove bacteria and viruses.

What’s safe and what isn’t during the advisory

Drinking, cooking and food prep

Use bottled or boiled (cooled) water for drinking, cooking, washing fruits and vegetables, making coffee and tea, and preparing any food.

Baby formula and bottles

CDC says breastfeeding is the best option for infants. For formula, use ready-to-use formula if possible. A CDC fact sheet used by state health departments says to prepare powdered or concentrated formula with bottled water, or boiled water if bottled isn’t available. Sanitize all baby bottles. Our guide to tap water for baby formula covers formula safety in more depth.

Brushing teeth

Use boiled or bottled water. Don’t use unboiled tap water.

Ice

Don’t use ice or water from your refrigerator’s dispenser or any appliance connected to the water line. Throw out ice made with tap water and make new ice with bottled or boiled water.

Showers and baths

You can shower and bathe, but be careful not to swallow any water. For babies and young children, CDC suggests considering sponge baths to reduce the chance they swallow water.

Handwashing

CDC says that in many cases tap water and soap are fine for handwashing, but follow your local officials’ advice. Scrub for at least 20 seconds.

Dishes

Dishwasher: generally safe if it has a sanitizing cycle or the final rinse reaches at least 150°F (66°C). Check your manual.
By hand: wash and rinse in hot water as usual, then soak for at least one minute in warm water with 1 teaspoon of unscented bleach per gallon, and let the dishes air dry completely.
Disposable plates and cups are the simplest option if you have them.

Laundry, cleaning, pets and plants

Laundry: wash as usual.
Toys and surfaces: clean washable items with bottled, boiled or bleach-disinfected water.
Pets: give them bottled water or boiled water that has cooled. CDC notes pets can get sick from some of the same germs as people.
Houseplants and gardens: tap water is fine, including for edible plants.

After the advisory is lifted

An advisory is usually lifted once the utility has fixed the problem and follow-up tests come back clear. The Minnesota Department of Health, for example, explains that after a system is disinfected and flushed, the water is tested again for coliform bacteria, and the advisory is lifted if none are found.

That clean test applies to the utility’s pipes, not the water that has been sitting in yours. Minnesota’s health department gives a clear four-step routine for homes:

Flush household pipes and faucets. Run each cold-water faucet for five minutes, or until the water is noticeably colder.
Deal with ice. Throw away any existing ice. If you have an icemaker, flush its feed line and throw away the first new bin of ice.
Flush water heaters, water coolers and storage tanks. Run through at least one full tank volume.
Clean and replace. Clean water softeners and filters following the manufacturer’s instructions, and replace disposable filters.

A few extra notes:

Filters. A CDC fact sheet distributed by the Louisiana Department of Health says filters collect germs, so all water filters should be replaced after the advisory is lifted. That includes pitcher cartridges, refrigerator filters and under-sink cartridges. Wear gloves when changing them and wash your hands afterward.
Coffee makers and other appliances. Minnesota says beverage dispensers connected directly to the water supply shouldn’t be used until the advisory is lifted and their lines are flushed. Check the manufacturer’s instructions for cleaning.
Your utility’s notice comes first. Some utilities give longer flush times, especially for apartment buildings or long service lines. If their instructions differ, follow theirs.

How often does this happen?

Boil water advisories are usually short and local, but they are tied to the same issues that show up in a utility’s compliance record, such as bacteria detections. You can look up your water system to see its EPA compliance history over the last three years, including any health-based violations. For broader context on how safe US tap water is day to day, see is tap water safe to drink in 2026.

Quick checklist

During: - Boil 1 minute (3 above 6,500 ft) or use bottled water - Boiled or bottled water for drinking, cooking, formula, teeth and pets - No fridge ice or dispenser water - Shower but don’t swallow; sponge-bathe small children - Dishwasher only with sanitize cycle or 150°F final rinse

After: - Run each cold tap about 5 minutes - Dump ice; flush icemaker line; toss first new batch - Flush water heater with a full tank volume - Replace disposable filters; clean softeners per manufacturer