How Long to Boil Water to Purify

If your local health officials issue a boil water advisory, you should use bottled water or boil tap water. This is because a boil water advisory means your community’s water has, or could have, germs that can make you sick. How long do you have to boil water to purify it?

Boiling 1 min. will kill bacteria & viruses

  • If H2O is cloudy, filter through a paper towel or coffee filter
  • Bring H2O to a rolling boil 
  • At altitudes of 5,000 ft.+ boil H2O for 3 min.
  • Let H2O cool
  • Store it in a clean container     
  • Improve taste of H2O-add 1 pinch of salt to each liter of H2O

Boiling water is technically a pasteurization process.  According to the US Environmental Protection Agency (EPA), pasteurization is a process in which the organisms that could potentially cause harm to humans are killed off.

Boiling Tap Water for Drinking


The most likely reasons in which you would need to boil water would be in the case of a city or state-wide boil-water order.  These occur as a result of biological water contamination.  Under these circumstances, tap water that is normally safe is too contaminated to drink.  The most likely events that lead to the biological water contamination include:

  • Loss of H2O pressure in municipal or well water distribution systems
  • Loss of disinfection in the municipal or well water system
  • Extreme contamination of water prior to disinfection
  • Waterline breaks
  • Purification system breaks
  • Severe weather events
  • Power outages

Under a Boil Water Advisory if you don’t it is possible you can suffer a serious illness caused by bacteria that will reproduce in water that is not boiled to temperatures that are sufficient to kill them. Water needs not just to be boiled but in order to work, the water needs to be boiled and then left for at least a full minute under a full boil to kill off these bacteria. Then the water should be cooled down before being consumed.  Advisories may include information about preparing food, drinks, or ice; dishwashing; and hygiene, such as brushing teeth and bathing.

After an emergency or disaster such as a water main break, hurricane, or flood, your tap water may not be available or safe to use. In these situations, it’s important to know how to prevent illness from unsafe water. Boiling water is the easiest method for purifying drinking water to kill off biological contamination such as bacteria that carry diseases and viruses. Boiling water will not reduce chemical contamination. In fact, some chemical contaminants may get more concentrated after the loss of water in vapor in the boiling process.

  • If you know or suspect your water is unsafe, don’t use that water to drink, wash dishes, brush your teeth, wash and prepare food, wash your hands, make ice, or make baby formula.
  • Use bottled, boiled, or treated water for drinking, cooking, and personal hygiene.
  • Follow recommendations from your state, local, or tribal health department for boiling or treating water in your area.
  • Never use water from radiators or boilers that are part of your home heating system. Learn about places inside and outside of your home where you might find other sources of water that are safe to use.

How to Boil Water


According to the Centers for Disease Control;  If you don’t have safe bottled water that is stored away, you need to boil your water to make it safe to drink. Boiling is the easiest surest method to kill disease-causing germs, including viruses, bacteria, and parasites that may contaminate your source of drinking water. After you boil the water the taste will become flat you can improve the taste by:

  • pouring it from one container to another and then allowing it to stand for a few hours
  • adding a pinch of salt for each quart or liter of boiled water.



What is the Best Way to Filter Well Water? 

Use a Whole House Water Filtration system that contains:

  • Pre-Filter Sediment Removal
  • Water Softener
  • Carbon Filter (kills Bacteria)
  • Pre-micro-sediment
  • Reverse Osmosis-(Dissolved Contaminants to .01 microns in size)
  • Polishing-Coconut Fiber-UV treatment (kills Virus & Cyst)
  • Minerals-added that were stripped ………………………………………………………………………………………….. Read more


If the water is cloudy, first filter it through a clean cloth, paper towel, or coffee filter, or try and settle it out. Then, draw off the clear water and follow the steps below.

  1. Bring the clear water to a rolling boil for at least 1 minute (at elevations above 6,500 feet, boil for 3 minutes).
  2. Let the boiled water cool.
  3. Store the boiled water in clean sanitized containers with tight covers


Most people know that water boils at 212º F  or 100 º C  but only at sea level. At higher altitudes, the boiling point of water decreases and at lower it decreases. So just check your location and altitude.

What Is My Elevation Tool: Find your current elevation based on your device’s location. For best results, click the Use device location button above the map. The panel above the map will show your elevation, and a red marker will show your location on Whats My Elevation Google Maps.


What are the Best RV Water Filters and Water Filter Systems?

According to EPA, look for a reputable filter with a pore size of 0.2 microns or less. This size removes microbes & bacteria that are larger.
Filters are broken into 2 classifications:
Absolute 1- remove microns that are Giardia & Cryptosporidium microbes.
Absolute 2 type removes part of the microbe ..……………………………………………………………………………………………………… Read more

How Long to Boil Water to Kill Bacteria


Every species of bacteria and microorganism has a range of temperatures that it can live and will die. Most bacteria can be killed off by boiling in 10 minutes or less.  Slow small bubbles when boiling water are not enough to kill off microbes.

A rolling boil continually falling over the top of each other will ensure the proper killing of bacteria like Chyrptosporidian, Giardia, virus, and bacteria allow it to cool, put it in a clean container then refrigerate it.

The bacteria, protozoans, and viruses are usually sensitive to inactivation at temperatures ranging below 100 degrees. The examination of thermal inactivation in water reveals that bacteria are sensitive to heat, and they die at temperatures above 56 degrees Celsius.


See the source image


According to FDA, Bottled H2O’s are safe to drink for at least 2 years if:

  • Kept in the dated heavy Protective Package
  • Store in a cool, dark place
  • Away from products with strong chemical odors
  • Void of exposure to the sun
  • Never stored on the ground
  • Has an NSF/IBWA Logo on a bottle
  • Rotated by date on a regular basis ..………………………………………………………………………… Read more


JimGalloway Author/Editor



CDC-Making Water Safe in an Emergency

EPA- Drinking Water in Your Home 


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