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Methane in Well Water

Frequently Asked Questions 

May 2016

This fact sheet answers questions about methane gas in private drinking water wells, and lists 

actions people can take to protect their health. 

What is methane? 

• Methane is a colorless, odorless gas that can dissolve in water. 

• Methane in water escapes quickly to the air as a gas. 

• Methane gas can build up in poorly ventilated areas, such as 

bathrooms, laundry rooms, and in the well itself. If too much of the gas 

builds up, it can cause a fire or explosion. 

• Methane can also change the chemistry of your well water, making 

your water unpalatable and releasing iron and manganese that can 

adversely affect taste and stain plumbing fixtures. 

How do I know if methane is in my water? 

• If your water has bubbles similar to carbonated soda or if it looks white 

or milky, methane might be in the water. 

What can I do if methane is in my water?

• Put a gas detector in your home to warn you if methane in the air in 

your home is near or at an unsafe level. Carefully read the directions 

that come with the detector. Make sure you know how to use the 

detector. 

• Ventilate your home to lower the amount of methane gas in the air, 

especially in small or enclosed rooms where you use the most water, 

such as the bathroom, laundry room, and kitchen. 

• Have a vent installed on your wellhead. 

• Keep sparks or open flames away from the wellhead and out of 

enclosed areas of your home, such as the bathroom and laundry room. 

• Install a water treatment system to remove dissolved methane from 

your well water before it enters your home.

Where can I get a gas leak detector and how do 

I use it? 

• You can buy a gas leak detector that will alert you with light or sound 

at most home improvement or hardware stores. Look for one that will 

detect methane. It might be called a gas leak detector, a combustible 

gas detector, or an explosive gas detector.

• Follow the directions included with the detector to find the best place 

to install it. Generally, good places to install detectors inside the home 

are those where the most groundwater use occurs. This include the 

bathroom, laundry room, utility room, and kitchen.

Agency for Toxic Substances and Disease Registry

Division of Community Health Investigations (DCHI)
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What should I do if the gas leak detector alarms? 

• A gas detector warns you when levels of some gases in the air might be dangerous. 

• If you hear the alarm, open the windows in your home and put out any open flames, such as cigarettes or 

candles. 

• To be safe, you should get your family out of the house. 

• Call 911 at a place away from your house. 

• Do not go back into your house until the fire department checks your house and says it is safe. 

How do I ventilate my home? 

• In small or enclosed areas where you use a lot of water, such as the bathroom, laundry room, or kitchen, make 

sure you turn on a fan or open a window when water is running for more than a few minutes. 

How can I vent my water well for methane? 

• You can put a vent on your wellhead that will let the methane gas escape before it enters your home. 

• Check with your state environmental and health or local public health agencies for a list of certified water 

well drillers and pump installers than can install a well cap for you. County extension agents may also be able 

to give you advice about your private well quality – to find your county extension visit https://nifa.usda.gov/

partners-and-extension-map?state=All&type=Extension.

For more information call 1-800-CDC-INFO (232-4636) or visit https://www.cdc.gov/info.

The Agency for Toxic Substances and Disease Registry is a federal public health agency of the U.S. Department of 

Health and Human Services. ATSDR promotes healthy and safe environments that prevent harmful exposures to toxic 

substances. To learn more about ATSDR, visit www.atsdr.cdc.gov.