Boiling water for drinking during a power outage

Nearly half of Texans remain under water-boil advisories today as a result of this week’s historic winter weather. Leaks caused by frozen pipes have devastated the state’s water supply, and authorities have advised millions of Texans to boil their water before using it for drinking, cooking, brushing their teeth and making ice. What’s more, thousands of Texans are still experiencing power outages, making it more difficult to boil their water on a stove like they normally would.

Virender K. Sharma, PhD, professor and director of the program on environmental and sustainability at Texas A&M University School of Public Health, says low water pressure and leaks in systems increase the potential for harmful organisms to be introduced to the water supply. As a chemist who researches inactivation of virus, bacteria, and toxins in water and air and removal of emerging contaminants such as antibiotics, estrogens and toxic metals in water, he provides the following tips for making tap water safer to consume during water-boil advisories.

How does boiling water make it safer to drink?

Boiling water kills many unsafe organisms. The most common of these is Escherichia coli (E. coli) bacteria, which can cause many types of infections including cholecystitis, bacteremia, cholangitis and urinary tract infection. Bringing water to a rolling boil for at least two minutes ruptures the membrane of the bacteria and kills the enzyme inside it. For better results, filter water after boiling it.

How long can boiled water be stored at room temperature?

Once you have killed bacteria in water by boiling it, it generally remains potable unless it is contaminated again. To prevent recontamination, store boiled water in a clean, disinfected container. Don’t store it in containers that were used to store chemicals or in milk or juice containers (unless they’re made of glass). Don’t reuse water that’s been used for washing.

How can I boil water if I don’t have electricity or a working stove?

If you are still without power and don’t have a gas stove, you can boil water over a wood fire in a fireplace, wood stove, barbecue pit or fire pit. That’s what people in developing countries do. In the village I grew up in in India, we collected wood every day so we could cook our food. Just be sure to follow wood-burning safety practices.

When using an alternate source of heat (generator, barbecue grill, etc.), keep in mind that carbon monoxide is produced by some of these sources. For example, generators and barbecue grills should be operated outdoors and at least 20 feet from any door or window. Follow guidelines from the Centers for Disease Control and Prevention on generator and furnace safety to prevent carbon monoxide poisoning,

What are signs that you’ve been infected by a water contaminant?

Diarrhea is the most common sign of infection caused by E. coli. Other symptoms include stomach cramping, pain or tenderness, nausea and vomiting. Contact your doctor if your symptoms persist, become severe or bloody.