Boil Water Advisory
A public health notice requiring residents to boil tap water before drinking or cooking, issued when water may be contaminated with disease-causing organisms.
How It Works
Boil water advisories are issued when: water pressure drops below a safe level (allowing contaminants to enter pipes through cracks), treatment systems fail, or pathogen testing detects bacteria like E. coli or total coliform. Boiling water for 1 minute (3 minutes above 6,500 feet elevation) kills virtually all bacteria, viruses, and parasites. During a boil advisory, water should be boiled for drinking, cooking, ice making, brushing teeth, and washing produce. Bathing is generally safe during a boil advisory. Advisories are lifted after water testing confirms the water is safe. In 2023, approximately 3,000 boil water advisories were issued across the United States.
Related Terms
- Health-Based Violation, The most serious type of drinking water violation, indicating that water quality has exceeded a maximum contaminant level or failed to meet a treatment requirement that directly protects health.
- Chlorination, The most common method of disinfecting drinking water, adding chlorine or chloramine to kill bacteria, viruses, and parasites before water reaches your tap.
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About This Definition
This definition is part of the IsWaterSafe Drinking Water Safety Glossary, 22 terms explaining water contaminants, treatment methods, and safety standards. Written for homeowners, renters, journalists, and public health professionals.