What Is a Boil Water Advisory? The Three CDC Types

By SubcontractorHub Editorial Team·Published October 2026

Customers call a dealer when a city notice hits the phone. The notice is not a lab result from a private well, and it is not a filter quote. The file should say which of the three advisory types was issued, who issued it, and what the customer was told to do. SubcontractorHub holds that customer record. This page is the distinction.

Three Notices, Not One

The CDC overview of drinking water advisories says water utilities or government agencies issue an advisory if tap water is, or could be, contaminated with harmful germs, chemicals, toxins, or radioactive materials. The page names three types.

A boil water advisory tells you to boil tap water before using it. Boiling kills germs that could make you sick. A do-not-drink advisory tells you to use commercially bottled water for drinking and cooking, because swallowing chemicals or toxins could make you sick. A do-not-use advisory tells you to use commercially bottled water for all purposes, because contact with skin, lungs, or eyes could be dangerous. The CDC page says do-not-use advisories are rare.

During any of the three, the same page says not to drink or use water or ice from appliances connected to the water line. That includes the dispenser in a refrigerator or freezer. Write that line if the customer asks about ice that was already made.

What Is a Boil Water Advisory on the Boil Step

If bottled water is not available, the CDC page says to bring tap water to a full rolling boil for 1 minute. At elevations above 6,500 feet, boil for 3 minutes. Let it cool before use, so nobody is burned. The page also says to boil the water even if a home filter or a filtering pitcher already treated it.

Use bottled or boiled water for drinking and for preparing and cooking food. Brush teeth with boiled or bottled water, not with tap water that was not boiled. For pets, the page says commercially bottled water or boiled water that has cooled. For houseplants and gardens, including plants you eat, the page says tap water can be used. Those are different uses. Do not collapse them into one instruction.

Hands, Dishes, and Laundry

The CDC page says that in many cases people can wash hands with tap water and soap during a boil water advisory, and that they should follow local officials. Bathing and showering should avoid swallowing water. The page says to use caution with babies and young children, and to consider a sponge bath so they are less likely to swallow water.

Dishwashers are described as generally safe if they have a sanitizing cycle or reach a final rinse of at least 150°F (66°C). The page says to check the manual. For hand washing dishes, it gives four steps: wash and rinse as usual with hot water, then in a separate basin add 1 teaspoon of unscented household liquid bleach for each gallon of warm water, soak the rinsed dishes for at least one minute, and let them air dry. Laundry, on that page, is safe as usual.

Those steps are the CDC wording for a boil notice. They are not a do-not-use notice. If the paper on the door says do not use the water for any purpose, the bleach-soak paragraph is the wrong paragraph. Read the type before you repeat a step.

What the Three Types Hold

A Do-Not-Drink Notice Is Not a Boil

The CDC page says officials typically issue a do-not-drink advisory when tap water is, or could be, contaminated with harmful chemicals or toxins, and that boiling water which contains those chemicals or toxins will not make it safe. The bottled-water list on that section includes drinking and cooking, brushing teeth, washing fruits and vegetables, preparing food, mixing baby formula, making ice, and giving water to pets.

A dealer who tells that household to boil for one minute is repeating the germ instruction on a chemical notice. Write the type the utility printed. If the paper is missing, say the type is unknown. Do not guess a boil because the last city notice was a main break.

What the EPA Report Says a Utility Notice Is

EPA's report to Congress on boil water advisories, required by section 50115 of the Infrastructure Investment and Jobs Act, calls a boil water advisory a voluntary protective public health measure a public water system can take until contamination, or the potential for contamination, is corrected. The report says the majority of the advisories it studied were issued because of main breaks, distribution-system repairs, or loss of water pressure, and that most of those were a precaution while sampling checked for E. coli. It says the second highest category was unknown or unidentified reasons.

The same report says the majority were at community water systems, and that the majority occurred at systems using ground water. It describes a community system as one that serves at least 15 service connections used by year-round residents, or regularly serves at least 25 year-round residents. That definition sits next to what is a public water system. This article does not copy a national count of notices. The report's word was “majority,” and that is the word kept here.

What Is a Boil Water Advisory Next to a Private Well

A private well is not the community system in that report. A coliform hit on a single household jug is the subject of coliform bacteria in well water, not a utility advisory. Shocking that well, when a dealer is following a different procedure, is how to shock a well. Do not file a shock visit as if the city had issued a boil notice.

State rules for a private well, where they exist, are private well water regulations. A city customer who wants the detected bacteria line on the annual report should use how to read a consumer confidence report. The advisory is the short notice. The report is the year. They are not the same paper.

What to Write on the Customer File

Five lines keep the next visit from mixing a germ notice with a chemical notice, or a city notice with a private well.

1. The type: boil, do not drink, do not use, or unknown.
2. Who issued it, and the date on the notice.
3. The boil time only if the type is boil: 1 minute, or 3 minutes above 6,500 feet, as the CDC page states.
4. Whether the address is on a public system or a private well.
5. A note that this page did not set a filter percent or an installed price.

Where the Notice Sits for a Dealer

The customer will ask whether a softener, a carbon tank, or a pitcher replaces the boil. The CDC sentence fetched here says to boil even if a home filter was used, and it says boiling does not fix a chemical do-not-drink notice. Repeat the sentence that matches the type. Do not add a removal percent this page did not fetch.

A water treatment dealer who saves the type, the issuer, and the date can explain a later clear sample without pretending the notice was a private-well test. This article is not medical advice, and it does not tell a household to ignore the local paper. The local instruction wins when it is more specific than the CDC overview.

Frequently Asked Questions