What Is a Boil Water Advisory?
A boil water advisory is a public notice from your local water utility or health department telling you that tap water may not be safe to drink unless it is boiled first.
This type of advisory is usually issued when there is a possible risk of harmful microorganisms in the water, such as bacteria, viruses, or parasites. It does not always mean contamination has been confirmed. Sometimes it means the water system has lost pressure, a water main has broken, flooding has affected the system, or a treatment issue has occurred.
In the United States, boil water advisories are most common after:
- Water main breaks
- Low water pressure
- Flooding
- Hurricanes or severe storms
- Power outages at treatment plants
- Equipment failures
- Possible bacterial contamination
- Repairs to local water lines
When a boil water advisory is issued, follow the instructions from your local water utility, city, county, or health department.
Boil Water Advisory vs. Do Not Drink Notice
Not all water warnings mean the same thing.
A boil water advisory usually means water may contain germs, and boiling can help make it safer for drinking.
A do not drink notice is different. It may be issued when water could contain chemicals, toxins, fuel, or other substances that boiling will not remove.
A do not use notice is even more serious. It may mean the water should not be used for drinking, cooking, bathing, washing, or cleaning until officials say it is safe.
This difference matters.
Boiling water can kill many disease-causing organisms, but it does not remove chemical contamination. If local officials say “do not drink” or “do not use,” do not assume boiling or filtering the water is enough.
How to Boil Water Safely
If your local advisory tells you to boil water, use this basic method:
- Fill a clean pot with tap water.
- Heat the water until it reaches a full rolling boil.
- Keep it boiling for 1 full minute.
- If you live above 6,500 feet elevation, boil for 3 minutes.
- Turn off the heat and let the water cool.
- Store the cooled boiled water in a clean, covered container.
Do not add ice to cool the water unless the ice was made from safe water.
If the water is cloudy, let it settle first if possible, then filter it through a clean cloth, paper towel, or coffee filter before boiling. Boiling is still needed afterward.
When Should You Use Boiled or Bottled Water?
During a boil water advisory, use boiled or bottled water for anything that could enter your mouth.
Use safe water for:
- Drinking
- Making coffee or tea
- Preparing baby formula
- Brushing teeth
- Washing fruits and vegetables
- Cooking food
- Making ice
- Mixing powdered drinks
- Preparing pet water
- Rinsing dishes by hand
- Taking medications
- Cleaning food-contact surfaces
When in doubt, use bottled water or properly boiled water.
Can You Brush Your Teeth with Tap Water?
No, not unless local officials say it is safe.
During a boil water advisory, you should brush your teeth with bottled water or boiled and cooled water. It is easy to swallow a small amount of water while brushing, so untreated tap water should be avoided.
This is especially important for children, older adults, pregnant people, and anyone with a weakened immune system.
Can You Wash Your Hands with Tap Water?
In many cases, you can wash your hands with tap water and soap during a boil water advisory, but you should follow local guidance.
Wash thoroughly with soap for at least 20 seconds, then dry your hands with a clean towel. If safe running water is not available, use an alcohol-based hand sanitizer that contains at least 60% alcohol.
When preparing food, baby formula, or bottles, use extra caution. If your hands may come into contact with food or feeding supplies, follow the safest guidance from your local health department.
Can You Shower or Bathe During a Boil Water Advisory?
Adults and older children can usually shower or bathe during a boil water advisory as long as they avoid swallowing the water.
Use caution with young children because they may accidentally swallow bathwater. For babies and toddlers, a sponge bath with safe water may be a better option until the advisory is lifted.
Do not use contaminated or unsafe water to clean open wounds. Use bottled, boiled, or otherwise safe water instead.
What About Babies and Formula?
For infants, the safest option during a boil water advisory is usually ready-to-use formula, if available.
If you must use powdered formula, prepare it only with bottled water or boiled and cooled water, unless your local health department gives different instructions.
Baby bottles, nipples, pacifiers, and feeding supplies should also be cleaned and sanitized carefully using safe water.
Families with infants should take boil water advisories seriously because babies are more vulnerable to illness from contaminated water.
Can Pets Drink Tap Water During a Boil Water Advisory?
Pets can also get sick from contaminated water.
During a boil water advisory, give pets bottled water or boiled and cooled water. This is especially important for dogs, cats, birds, reptiles, and small animals.
If you have aquariums, do not add untreated tap water directly to the tank during an advisory. Follow aquarium-safe water treatment guidance.
What Should You Do with Ice?
Throw away ice made during the advisory.
This includes ice from:
- Ice trays
- Refrigerator ice makers
- Ice machines
- Ice dispensers
Turn off automatic ice makers until the advisory is lifted and the water system has been flushed according to local guidance.
After the advisory ends, discard the first batch or two of ice after restarting the ice maker.
Can You Use a Dishwasher?
It depends on your dishwasher and local guidance.
Some dishwashers may be safe to use if they have a high-temperature sanitizing cycle or reach a proper final rinse temperature. However, not all dishwashers do.
If you are unsure, wash dishes with boiled or bottled water, or use disposable plates, cups, and utensils temporarily.
For handwashing dishes, use hot water and dish soap, then sanitize dishes if local officials recommend it. Let dishes air dry completely.
Can a Water Filter Replace Boiling?
No, not during a boil water advisory unless local officials specifically say the filter is approved for that situation.
Most home water filters are designed to improve normal tap water by reducing taste, odor, chlorine, sediment, particles, or certain contaminants depending on the filter design. They are not automatically designed to make microbiologically unsafe water safe during an emergency.
This is very important.
If your city issues a boil water advisory, do not rely on a standard countertop filter, refrigerator filter, pitcher filter, under-sink filter, or gravity filter as a substitute for boiling.
Use bottled water or boiled water until the advisory is lifted.
Where LCF Fits In
LCF water filtration systems are designed for everyday home water improvement. Depending on the model, they may help improve taste, reduce chlorine taste and odor, reduce sediment, and make daily tap water more enjoyable for drinking, cooking, coffee, and tea.
However, during an official boil water advisory, LCF filters should not be used as a replacement for boiling unless the local health authority says your water is safe to use again.
A practical approach is:
- During the advisory: use bottled water or boiled water
- After the advisory is lifted: flush your plumbing and filter system as recommended
- For everyday use afterward: return to your normal LCF filtration routine
This keeps safety first while still allowing your home filter to support better daily water quality after the emergency has passed.
What to Do When the Advisory Is Lifted
When local officials announce that the boil water advisory is lifted, your water system may still need a little attention before normal use.
Follow your local utility’s instructions first. In general, you may need to:
- Flush cold water faucets for several minutes
- Run each faucet before drinking from it
- Discard old ice
- Turn the ice maker back on after flushing
- Replace refrigerator filter cartridges if recommended
- Flush refrigerator water dispensers
- Clean and sanitize containers used during the advisory
- Flush water filters according to the product manual
- Replace filter cartridges if the manufacturer recommends it
If your water looks cloudy, smells unusual, or tastes strange after the advisory is lifted, contact your local water utility before drinking it.
Should You Replace Your Water Filter After a Boil Water Advisory?
It depends on the system, the advisory, and whether potentially contaminated water passed through the filter.
If water was used through a filter during the advisory, check the manufacturer’s instructions. Some filters may need to be flushed, sanitized, or replaced.
For LCF users, the safest approach is:
- Stop using the filter for drinking water during the advisory
- Use boiled or bottled water instead
- After the advisory is lifted, flush the system according to the manual
- Replace the cartridge if it may have been exposed to unsafe water or if water taste, odor, or flow changes
When in doubt, replace the filter cartridge. It is a simple step that helps restore confidence in your daily water routine.
What Supplies Should You Keep at Home?
Boil water advisories often happen suddenly, especially after storms, flooding, or pipe breaks. A small water emergency kit can make the situation much easier.
Consider keeping:
- Bottled water for emergencies
- Clean food-grade water containers
- A pot or kettle for boiling water
- A camping stove for outdoor use only
- Unscented household bleach for emergency disinfection, if recommended
- Disposable plates and utensils
- Hand sanitizer
- Paper towels
- Pet water supplies
- Replacement water filter cartridges
- A printed copy of local emergency contacts
Never use outdoor grills, camp stoves, or fuel-burning devices indoors. They can produce carbon monoxide, which can be deadly.
Who Should Be Extra Careful?
Some people are more vulnerable to illness from unsafe water.
Take extra precautions for:
- Babies and young children
- Pregnant people
- Older adults
- People with weakened immune systems
- People with serious chronic illness
- People recovering from surgery
- Anyone with open wounds
For these groups, use bottled water or properly boiled water for drinking, brushing teeth, food preparation, and personal care until officials say the water is safe.
Conclusion
A boil water advisory can be stressful, but the basic rule is simple: use bottled water or properly boiled water for anything that may enter your mouth.
Boiling water can help kill many harmful microorganisms, but it does not remove chemical contamination. Always follow the instructions from your local water utility or health department.
LCF filtration systems are helpful for everyday water taste, odor, sediment, and convenience, but they should not replace official boil water guidance during an emergency.
When the advisory is lifted, flush your plumbing, discard old ice, check your filter system, and return to your regular filtered water routine.
Safe water starts with the right response—and the right habits before, during, and after an emergency.