What is a Boil Alert?
A boil alert is a public advisory issued by health or water authorities when drinking water may be contaminated with harmful microorganisms such as bacteria, viruses, or parasites. These advisories are issued when water quality tests indicate unsafe conditions or when circumstances—such as a water main break, flooding, or equipment failure—suggest a high risk of contamination.
During a boil alert, residents are advised to boil tap water before consuming it, using it for cooking, or brushing their teeth. Boiling water effectively kills most pathogens, making it safe to drink. However, simply filtering water through a basic pitcher filter or drinking bottled water without verification may not be sufficient to protect against all contaminants.
Boil alerts are issued across the United States and worldwide to prevent outbreaks of waterborne illnesses, which can cause severe gastrointestinal symptoms and, in some cases, life-threatening infections.
What Can Cause a Boil Alert?
Boil alerts can be triggered by a variety of issues that compromise the safety of a community’s water supply. Some of the most common causes include:
1. Water Main Breaks
Aging infrastructure or extreme weather conditions can cause water pipes to crack or burst, allowing contaminants to enter the system. When a pipe breaks, water pressure drops, increasing the likelihood of bacteria infiltrating the supply.
2. Flooding
Heavy rains and flooding can overwhelm water treatment plants, carrying harmful bacteria and industrial waste into reservoirs, rivers, and groundwater. For example, in September 2017, Hurricane Harvey caused significant water contamination in Texas, leading to multiple boil water advisories.
3. Treatment Plant Failures
Malfunctions in a water treatment facility can result in insufficient disinfection of drinking water. In July 1993, a failure in Milwaukee’s water treatment system led to a Cryptosporidium outbreak, sickening over 400,000 people and causing at least 69 deaths.
4. Natural Disasters
Earthquakes, hurricanes, and other disasters can damage water infrastructure and introduce contaminants. In 2010, following the devastating earthquake in Haiti, a cholera outbreak linked to contaminated drinking water killed over 10,000 people and infected hundreds of thousands.
5. Sewage Contamination
Leaking sewage systems or cross-contamination between drinking water and wastewater lines can introduce dangerous bacteria like E. coli and Salmonella into the water supply. In Walkerton, Canada, in May 2000, an E. coli outbreak from contaminated drinking water resulted in seven deaths and over 2,300 illnesses.
Why Is It Important to Heed an Alert?
Ignoring a boil water alert can have serious health consequences. Contaminated drinking water can cause severe illnesses, particularly for children, the elderly, and individuals with weakened immune systems.
Health Risks of Contaminated Water
- Gastrointestinal Illnesses – Contaminants like E. coli, Salmonella, and Giardia can cause diarrhea, vomiting, stomach cramps, and fever.
- Hepatitis A – Drinking water contaminated with the hepatitis A virus can lead to liver infection, jaundice, and prolonged illness.
- Cholera and Dysentery – More common in developing regions, these bacterial infections cause severe diarrhea and dehydration, sometimes leading to death.
What Do I Do When There Is a Boil Alert?
When a boil alert is issued, it’s crucial to follow safety guidelines to avoid illness.
Steps to Take:
- Boil Your Water – Bring tap water to a rolling boil for at least one minute (or three minutes at higher elevations).
- Use Bottled Water – If boiling isn’t an option, use bottled water from a verified source.
- Avoid Ice and Water from Dispensers – Ice machines, refrigerator water dispensers, and soda fountains may still contain contaminated water.
- Sanitize Dishes – Wash dishes with boiled or bottled water, or use the dishwasher on a hot rinse cycle.
- Protect Pets – Boil water for pets, as they can also be affected by contaminated water.
- Be Cautious with Showers – Avoid swallowing water while bathing, and use boiled or bottled water to brush your teeth.
Will a Pitcher Filter Protect Me During a Boil Alert?
No, a basic pitcher filter is not sufficient to remove dangerous microorganisms. These filters are designed to reduce chlorine taste, sediment, and some heavy metals, but they do not kill bacteria, viruses, or parasites. If water is contaminated with E. coli, Cryptosporidium, or Giardia, drinking it—even if filtered—can still lead to illness. Always boil water or use an alternative purification method during a boil alert.
Will a Reverse Osmosis System Protect Me During a Boil Alert?
A reverse osmosis (RO) system can remove many contaminants, including bacteria and viruses. However, RO systems have limitations:
- Not Always Effective for All Microorganisms – Some bacteria and viruses are small enough to pass through the RO membrane.
- Pre-filters May Be Contaminated – If your RO system is connected to a contaminated water supply, bacteria may colonize the filters, making the system ineffective.
- Needs Proper Maintenance – Without frequent filter replacements, RO systems can lose their ability to purify water.
During a boil alert, it’s safest to boil water before using an RO system or switch to bottled water.
Will a Water Distiller Protect Me During a Boil Alert?
Yes, a water distiller is one of the most effective ways to purify water during a boil alert. Distillation involves:
- Boiling the Water – Converts water into steam, leaving behind bacteria, viruses, and heavy metals.
- Condensing the Steam – Turns purified vapor back into liquid form.
Distillation eliminates virtually all pathogens, making it safer than RO or pitcher filters.
Never Ignore a Boil Alert
A boil alert is a serious public health warning that should never be ignored. Whether caused by infrastructure failures, natural disasters, or contamination, these alerts help protect against dangerous waterborne diseases.
When faced with a boil alert:
- Boil tap water for at least one minute before drinking.
- Avoid relying on standard pitcher filters or RO systems alone.
- Consider using a water distiller for the safest purification.
- Stay informed and follow public health advisories.
Water contamination can have devastating effects, as seen in outbreaks like Milwaukee (1993), Walkerton (2000), and Haiti (2010). Taking the right precautions ensures you and your family stay safe during a boil alert.