I accidentally drank the water during a boil water advisory

First: the likelihood of becoming ill is low

If you drank a glass of tap water before you saw the notice, start here. New York State's health department, Michigan and Florida all say the same thing about it, in the same words: the likelihood of becoming ill is low.

That is the honest headline, and it is not a brush-off. The same New York guidance adds that illness is certainly possible, especially for people who have a chronic illness or may be immunocompromised. In practice it means watching for symptoms is the right response, and alarm is not.

Who is at higher risk

New York State and Michigan both describe waterborne illness of this kind as not usually serious or life threatening, except in the elderly, the very young, or those who are immune compromised. New York also names people living with a chronic illness.

If the person who drank the water is in one of those groups, both sets of guidance point the same way: seek medical attention, or contact their healthcare provider, rather than wait and see.

Symptoms to watch for

The symptoms named across New York State's, Michigan's and Florida's guidance are the same short list: diarrhea, nausea, vomiting and abdominal cramps, with or without fever.

None of them is specific to water. Michigan makes the point directly — symptoms associated with waterborne illness are also associated with foodborne illness, or even the common cold. So a symptom is a reason to pay attention, and to call a healthcare provider if it is severe or if the person affected is in a higher-risk group. It is not by itself evidence that the water caused it.

None of these health authorities publishes a time window for symptoms to appear, so this page does not invent one.

When to call a doctor

New York State's and Michigan's guidance both direct people with symptoms to seek medical attention and to contact their healthcare provider, and both single out the elderly, the very young and people who are immune compromised, for whom illness is more likely to be serious.

This page cannot diagnose anything and does not try to. If symptoms appear, if they are severe, or if the person affected is in one of those groups, a call to a healthcare provider is the next step.

What a boil water advisory is protecting you from

The organisms named in New York State's and Michigan's guidance are protozoa such as Giardia and Cryptosporidium, bacteria such as Shigella and E. coli, and viruses. Boiling is what kills them, which is why the notice asks for it.

It is worth knowing what boiling does not do, because it decides whether this page applies to you at all. EPA states that boiling or disinfection will not destroy other contaminants, such as heavy metals, salts, and most other chemicals. If the notice for your address is a do not drink advisory rather than a boil water advisory, it is a chemical event, and CDC's instruction there is commercially bottled water for drinking and cooking instead.

What to do from here

Stop using untreated tap water for anything you swallow: drinking, cooking, brushing teeth, ice and pets. CDC's replacement for all of those is commercially bottled water, or boiled water that has cooled.

To treat it yourself, bring the water to a full rolling boil for 1 minute — 3 minutes if you are above about 5,000 feet, which is EPA's trigger, while CDC sets the same three minutes above 6,500 feet — then let it cool. Follow your own utility's notice where it asks for longer.

Frequently asked questions

I drank tap water during a boil water advisory. Will I get sick?

Probably not. New York State's health department, Michigan and Florida all state that the likelihood of becoming ill is low. New York adds that illness is certainly possible, especially for people who have a chronic illness or may be immunocompromised, so the sensible response is to watch for symptoms rather than to assume either outcome.

What are the symptoms of drinking water under a boil water advisory?

New York State, Michigan and Florida all name the same short list: diarrhea, nausea, vomiting and abdominal cramps, with or without fever. Michigan adds the caveat that matters — symptoms associated with waterborne illness are also associated with foodborne illness, or even the common cold — so the symptoms do not tell you what caused them.

How soon would symptoms appear?

None of the health authorities behind this page publishes a time window, so we do not publish one either; a number invented here would read as medical fact and would not be one. What they do say is which symptoms to watch for — diarrhea, nausea, vomiting and abdominal cramps, with or without fever — and that anyone in a higher-risk group should seek medical attention rather than wait.

When should I see a doctor after drinking the water?

New York State's and Michigan's guidance is to seek medical attention and contact a healthcare provider if symptoms develop. Both describe this kind of illness as not usually serious or life threatening except in the elderly, the very young, or those who are immune compromised — and for those groups, contacting a provider rather than waiting is the advice.

What germs is a boil water advisory about?

New York State's and Michigan's guidance name protozoa such as Giardia and Cryptosporidium, bacteria such as Shigella and E. coli, and viruses. Boiling kills them, which is what the notice is asking you to do. It does not deal with chemicals: EPA states that boiling or disinfection will not destroy other contaminants, such as heavy metals, salts, and most other chemicals.

Sources

New York State Department of Health — Boil Water Notices: FAQ for Residents and Homeowners — retrieved 2026-08-22
City of Flint, Michigan — Boil Water Advisory FAQ — retrieved 2026-08-22
Florida Department of Health in Lee County — Boil Water Notice: Commonly Asked Questions — retrieved 2026-08-22
CDC — Drinking Water Advisories: An Overview — retrieved 2026-08-22
U.S. EPA — Emergency Disinfection of Drinking Water — retrieved 2026-08-22
Louisiana Department of Health — What to Do During a Boil Water Advisory — retrieved 2026-08-22

By TapWaterData Editorial