What triggers a boil water advisory?

Common triggers include a water main break that lets outside contamination into the pipes, a drop in system pressure, a treatment plant malfunction, positive bacteria (coliform/E. coli) test results, or flooding that overwhelms a treatment or distribution system.

How long should I boil water during an advisory?

The CDC recommends bringing water to a rolling boil for at least one minute (three minutes at elevations above 6,500 feet) to kill bacteria, viruses, and parasites. Let it cool before use.

Can I shower during a boil water advisory?

Short showers are generally fine for most advisories since the risk is from ingestion, not skin contact — but avoid swallowing water, and be more cautious with infants, young children, and anyone with open wounds or a compromised immune system. If the advisory specifically mentions chemical contamination rather than bacteria, follow the specific guidance issued, since chemical exposure through skin is a different risk than bacteria.

Is ice from my icemaker safe during a boil water advisory?

No. Discard ice made during or shortly before the advisory and stop using the icemaker until the advisory is lifted, since it uses unboiled tap water.

How long do boil water advisories usually last?

Most are resolved within 24-72 hours once the utility fixes the underlying issue and confirms clean follow-up test results, but advisories tied to major infrastructure damage or contamination events can last longer.

Boil Water Advisory: What It Means and Exactly What to Do

A boil water advisory (sometimes called a boil water notice or order) means your utility believes the water may contain disease-causing bacteria, viruses, or parasites, and that boiling is necessary before the water is safe to consume. Here's exactly what it covers — and what it doesn't.

What Causes an Advisory

Water main breaks — a drop in pipe pressure can let contaminated groundwater or soil bacteria seep in through the break
Treatment plant issues — a malfunction in disinfection or filtration equipment
Positive bacteria test results — routine monitoring detects coliform bacteria or E. coli
Flooding or natural disasters — can overwhelm treatment capacity or damage distribution infrastructure
Power outages — loss of pressure at pump stations can allow backflow contamination

What to Do — A Room-by-Room Checklist

Boil or Avoid

• Drinking water — boil 1 minute (3 minutes above 6,500 ft), then cool
• Water for cooking, and for washing fruits/vegetables eaten raw
• Water for making ice, coffee, tea, or baby formula
• Water for brushing teeth
• Pet water bowls

Usually Fine Without Boiling

• Handwashing with soap (avoid swallowing water)
• Short showers (avoid swallowing water; supervise young children closely)
• Laundry
• Dishwashing if your dishwasher has a hot/sanitize cycle (check manufacturer guidance); otherwise use boiled water or add a sanitizing step

During the Advisory

Discard ice made just before or during the advisory, and stop using automatic icemakers
Don't rely on a standard refrigerator filter — most are rated for taste/chlorine, not bacteria removal, unless specifically certified for that
Keep boiled water refrigerated in a clean, covered container for later use
Watch for symptoms like nausea, diarrhea, or cramps in household members, and contact a doctor if they occur

When It's Lifted

Utilities lift advisories only after follow-up bacteriological testing confirms the water is clean, typically 24-72 hours after the underlying issue is fixed. Once lifted, it's still good practice to run cold taps for a few minutes and flush ice makers and water filters before resuming normal use, since stagnant water sat in your home's pipes during the advisory.

Staying Informed

Advisories are typically announced through your utility's website, local news, reverse-911 calls or texts, and social media. You can check your system's compliance and violation history anytime on WaterQ's search, and set up an alert for your city or system to be notified of new violations.

Keep an Emergency Water Filter on Hand

A gravity-fed or bacteria/virus-rated emergency filter lets you skip boiling and have safe water ready during an advisory or outage.

Shop Emergency Water Filters →

*Disclaimer: WaterQ may earn a commission from qualifying purchases (see our affiliate disclosure). Not medical advice.

Quick Summary

• Boil for at least 1 minute (3 at high altitude) before drinking, cooking, or making ice/formula
• Short showers and handwashing are generally fine; just avoid swallowing water
• Discard ice and pause icemakers during the advisory
• Most advisories resolve in 24-72 hours once follow-up testing confirms the water is clean