Here are answers to your questions about the boil water notice in Houston after a major water main break

HOUSTON – A large part of Houston and surrounding areas are under a boil water notice after a massive water main break in east Houston flooded streets and surrounding neighborhoods Thursday afternoon.

Houston Mayor Sylvester Turner extended the boil water notice Friday afternoon until at least Saturday at 7 a.m. He said 43 samples have been collected and handed over to the Texas Commission on Environmental Quality to test for contamination. He expects to lift the ban early Saturday after the samples are cleared.

Understandably, people have questions about the boil water notice. Boiling kills harmful bacteria and other organisms in the water that may cause illness.

Here are some of the frequently asked questions and what city health officials say you should do:

What should I do if a boil water notice is issued?

“Do not drink the water without boiling it first. Bring all water to a rolling boil for at least two minutes, and let it cool before using, or use bottled water,” officials say. “Boiled or bottled water should be used for drinking, making ice, brushing teeth, washing dishes, food preparation, and water for pets.”

Officials also say you should throw away ice made during the time the notice was issued because freezing does not kill bacteria.

Is the water safe for washing dishes, laundry and bathing?

“The water is safe for washing dishes, but you should use hot, soapy water and rinse dishes in boiled water,” officials say. “There are no restrictions on doing laundry. The water is also safe for bathing.”

How do I prepare food and baby formula?

“Only use boiled or bottled water for cooking, making ice, washing fruits and vegetables, and making baby formula,” officials say. “If you must use water to make formula, use bottled water. If you don’t have bottled water, use water that has been rapidly boiled for at least three minutes.”

How long will the boil water notice continue?

“Customers should not stop boiling water until they receive notice from Houston Water. Typically the need to boil water lasts for 24 to 48 hours, but can be longer,” officials wrote. “How long will depend on the conditions that caused the need to boil, how quickly the conditions are corrected, and how long it takes for laboratory results to confirm it is safe to return to normal water use. Houston Water will provide updates on the progress of corrective actions and how long the event is expected to last.”

What do I need to do when the notice is lifted?

“Houston Water will notify you when it is no longer necessary to boil the water," officials wrote. "You should flush your water system by running all cold water faucets in your home for at least one minute, cleaning automatic ice makers by making and discarding three batches of ice, and running water softeners through a regeneration cycle.”

Why is the boil water notice important?

“Contaminated water may contain harmful bacteria, viruses, and parasites which can cause symptoms such as diarrhea, cramps, nausea, headaches, or other symptoms,” officials wrote. “They may pose a special health risk for infants, young children, some elderly and people with severely compromised immune systems.”

A map released by Houston Public Works shows the area under the boil water notice:

If you have more concerns or questions, you can call 311 or (713) 837-0311.