During an event, such as a boil water advisory, boiling the water kills microorganisms such as bacteria, viruses, or protozoans that can cause disease. Boiling makes the tap water microbiologically safe.
Heat the water until bubbles come from the bottom of the pot to the top. Once the water reaches a rolling boil, let it boil for 1 minute. Turn off the heat source and let the water cool. Pour the water into a clean container with a cover for storage.