Why is it necessary to boil water for drinking and cooking when a city main breaks?

When a city's main water line breaks, it can contaminate the water supply with harmful bacteria and other microorganisms. Boiling water kills these contaminants, making it safe for drinking and cooking.

Here are some of the reasons why it is necessary to boil water after a main break:

* bacteria

E. coli, salmonella, and shigella are just a few of the bacteria that can contaminate water supplies after a main break. These bacteria can cause a variety of illnesses, including diarrhea, vomiting, and abdominal cramps. In severe cases, they can even lead to death.

* viruses

Viruses such as rotavirus and norovirus can also contaminate water supplies after a main break. These viruses can cause vomiting, diarrhea, and fever. They can also be spread from person to person, so it is important to take precautions to avoid contracting them.

* parasites

Parasites such as giardia and cryptosporidium can also contaminate water supplies after a main break. These parasites can cause diarrhea, vomiting, and abdominal pain. They can also be spread from person to person, so it is important to take precautions to avoid contracting them.

Here are some tips for boiling water safely:

* Fill a clean pot with water and bring it to a full boil.

*Let the water boil for at least 1 minute.

*If you are at high altitude, boil the water for 3 minutes.

*Let the water cool before drinking or using it to cook.

You should also avoid using water from public fountains or taps that have been contaminated by a main break. If you are unsure whether your water is safe to drink, contact your local health department.