Why Water Advisories Can Be Confusing

When a water emergency happens, local officials may issue a public notice telling residents what to do with their tap water.

But the wording can be confusing.

You may hear terms like:

• Boil Water Advisory
• Boil Water Notice
• Do Not Drink Advisory
• Do Not Use Notice

These warnings do not all mean the same thing. The difference matters because the wrong response can put your family at risk.

A boil water advisory usually means water may contain harmful microorganisms, and boiling can help make it safer to drink. A do not drink advisory is different. It usually means water may contain chemicals, toxins, fuel, or other substances that boiling will not remove.

The safest rule is simple:

Always follow the exact instructions from your local water utility, city, county, or health department.

What Is a Boil Water Advisory?

A boil water advisory means your tap water may not be safe to drink unless it is boiled first.

This type of notice is often issued when there is a possible risk of bacteria, viruses, or parasites in the water system. It may happen after water pressure drops, a water main breaks, flooding affects the system, or treatment equipment fails.

Common reasons for a boil water advisory include:

• Water main breaks
• Low water pressure
• Flooding
• Hurricanes or severe storms
• Power outages at water treatment plants
• Equipment failures
• Possible bacterial contamination
• Repairs to water lines

A boil water advisory does not always mean contamination has been confirmed. Sometimes it is issued as a precaution because the water system may have been exposed to contamination.

What Should You Do During a Boil Water Advisory?

During a boil water advisory, use bottled water or properly boiled water for anything that could enter your mouth.

Use boiled or bottled water for:

• Drinking
• Making coffee or tea
• Cooking
• Brushing teeth
• Washing fruits and vegetables
• Making ice
• Mixing baby formula
• Giving water to pets
• Taking medication
• Preparing food
• Cleaning food-contact surfaces

To boil water safely, bring clear water to a full rolling boil for 1 minute. If you live at an elevation above 6,500 feet, boil it for 3 minutes. Then let the water cool and store it in a clean, covered container.

If the water is cloudy, let it settle first. You may also filter it through a clean cloth, paper towel, or coffee filter before boiling. Boiling is still needed afterward.

What Is a Do Not Drink Advisory?

A do not drink advisory means you should not drink the tap water, even if you boil it.

This warning is often issued when water may be contaminated with chemicals, toxins, fuel, industrial substances, or other pollutants that boiling does not remove.

In some cases, boiling can even increase the concentration of certain chemicals because water evaporates while the chemicals remain behind.

A do not drink advisory may happen after:

• Chemical spills
• Fuel contamination
• Wildfire damage to water systems
• Industrial contamination
• Harmful algal toxins
• Contamination with volatile organic compounds
• Water system damage involving plastic pipes or burned infrastructure
• Unknown contamination that may not be solved by boiling

During a do not drink advisory, use bottled water or another approved safe water source.

What Should You Do During a Do Not Drink Advisory?

During a do not drink advisory, do not use tap water for drinking or cooking unless local officials specifically say it is safe for that purpose.

Use bottled water for:

• Drinking
• Cooking
• Making coffee or tea
• Brushing teeth
• Washing fruits and vegetables
• Making ice
• Mixing baby formula
• Preparing pet water
• Taking medication

Depending on the type of contamination, local officials may also give instructions about bathing, showering, dishwashing, laundry, or cleaning.

Read the notice carefully. Some do not drink advisories allow limited uses of tap water, while others may restrict more household activities.

If the advisory involves chemicals, fuel, or toxins, do not assume that boiling, filtering, freezing, or letting water sit will make it safe.

Boil Water vs. Do Not Drink: The Key Difference

The difference comes down to the type of risk.

A boil water advisory is usually about germs.

A do not drink advisory is usually about chemicals or toxins.

Here is the simplest way to remember it:

Boil Water Advisory: Boiling may help because the concern is often bacteria, viruses, or parasites.
Do Not Drink Advisory: Boiling may not help because the concern may be chemicals, toxins, fuel, or other substances.

This is why the wording matters.

If officials tell you to boil water, boil it before using it for drinking or food preparation.

If officials tell you not to drink the water, do not drink it at all. Use bottled water or another approved source.

What Is a Do Not Use Notice?

A do not use notice is more serious than a do not drink advisory.

It may mean the water should not be used for drinking, cooking, bathing, washing, cleaning, or any household purpose until officials say it is safe.

This type of notice may be issued when water could be dangerous through skin contact, inhalation, or household use.

If your area receives a do not use notice, do not try to treat the water yourself. Follow local emergency instructions and use bottled water or another approved safe source.

Can a Water Filter Replace Boiling?

During an official advisory, do not rely on a standard home water filter unless local officials specifically say it is approved for that situation.

Most home water filters are designed for normal tap water conditions. They may help reduce chlorine taste, odor, sediment, particles, or certain contaminants depending on the filter design. But they are not automatically designed to make unsafe emergency water safe.

A filter that improves everyday tap water is not the same as an emergency treatment system.

During a boil water advisory, use bottled water or boiled water.

During a do not drink advisory, use bottled water or another approved safe source.

Can LCF Filters Be Used During a Water Advisory?

LCF filtration systems are designed for everyday tap water improvement. Depending on the model, they may help improve taste, reduce chlorine taste and odor, reduce sediment, and make water more enjoyable for daily drinking and cooking.

However, LCF filters should not be used as a replacement for official emergency instructions.

If your local water utility issues a boil water advisory, follow the boil water instructions.

If your local water utility issues a do not drink advisory, do not drink the water, even if it has passed through a filter.

After the advisory is lifted, you can return to your normal filtration routine after flushing your plumbing and filter system according to local guidance and your product manual.

What About Babies, Pets, and People with Health Risks?

Some people and animals are more vulnerable during water emergencies.

Take extra care with:

• Infants
• Young children
• Pregnant people
• Older adults
• People with weakened immune systems
• People with serious chronic illness
• Pets
• Aquarium fish and reptiles

For baby formula, ready-to-use formula is often the safest choice during a water advisory. If you must prepare powdered formula, use bottled water or another approved safe source according to local instructions.

Pets should also receive bottled, boiled, or otherwise approved safe water depending on the type of advisory.

What Should You Do When the Advisory Is Lifted?

When local officials say the advisory is over, do not immediately assume everything in your home is ready for normal use.

Follow your local utility’s instructions first.

You may need to:

• Flush cold water faucets
• Run taps for several minutes
• Flush refrigerator water lines
• Throw away old ice
• Restart and flush ice makers
• Clean and sanitize water containers
• Replace or flush filter cartridges
• Check whether your refrigerator filter should be replaced
• Run appliances according to manufacturer guidance

If the water still looks cloudy, smells unusual, or tastes strange, contact your local water utility before drinking it.

Quick Comparison: Boil Water Advisory vs. Do Not Drink Advisory

Conclusion

A boil water advisory and a do not drink advisory are not the same.

A boil water advisory usually means boiling can help make water safer because the concern is often germs. A do not drink advisory usually means boiling is not enough because the concern may be chemicals, toxins, fuel, or other substances.

During any water emergency, always follow the instructions from your local utility or health department.

LCF water filtration systems are helpful for everyday tap water taste, odor, sediment, and convenience, but they should not replace official emergency water safety guidance.

When water service returns to normal, flush your plumbing, check your filter system, and return to your regular filtered water routine with confidence.