Water and flame of burning methane coming out of a drilled well/© Adobe Stock
Methane (CH4) is a colorless, tasteless, and odorless gas that can dissolve in water. It occurs naturally in some water wells due to geological processes, but it can also enter wells through human activities such as coal mining, gas well drilling, pipeline leaks, and landfills. Methane gas alone is not a known health hazard if consumed, but at high concentrations, it can escape quickly from water and become an explosive hazard.
Methane can build up in poorly ventilated spaces, including bathrooms, laundry rooms, and within the well itself. If too much methane accumulates, it can cause a fire or explosion. Methane can change the chemistry of water. It helps release iron and manganese, altering the taste of water.
When should I test for methane in my well water?
If you notice the signs of methane, such as milky water, pulsations at the faucets, or flammable conditions, in your well water, you should have it tested. To ensure you are protecting your family’s health, we have developed a set of recommendations for testing that are provided in our article, "What do I need to know about sampling my well water?".. When testing your well water you will very rarely be testing for only one thing — like iron — and instead testing for a suite of constituents that are important to identify if in your drinking water.
What treatment should I use if there is methane in my well water?
How do I remove methane from my water?
The safe level of methane in well water depends on the concentration. Wells with methane concentrations below 10 mg/L are generally considered safe for use. Homeowners with wells containing methane concentrations above 28 mg/L should take immediate action to reduce this concentration. Those with concentrations between 10 and 28 mg/L should monitor their wells to prevent dangerous increases.
Once you test and have decided to treat your water to remove methane, the Minnesota Department of Health has developed a Home Water Treatment Guide that covers treatment for any common constituent in well water. The most important advice we can provide you is if you are going to add treatment to your home water system, be sure the treatment device has been certified to remove iron by an independent third-party certification organization.
Where can I get local help and information about methane in my well water?
Contact your local health department – They can help you interpret your sample results and may have information on the best treatment options for your situation. If they personally aren’t able to answer your questions, they will know who to contact who will be able to help you, likely at your state health department.
Contact a water treatment professional – We would recommend contacting a water treatment professional who has been certified through the Water Quality Association’s Professional Certification Program.
State or Federal Geologic or Water Resource Agency – They may have completed field studies of your area or collected samples from water wells to map and understand the water quality in your state. In addition, they may house water well logs, including yours, or be able to provide additional information about the aquifer your well is getting water from.
Consult your well driller or drilling contractor – The contractor that drilled your well, and other local contractors, may be aware of the water quality issues nearby including high methane levels, and might have worked with other well owners in your area to solve this issue.
Research online – You should be inquisitive; it will help you significantly because there can be great information available online. Use search terms like “my state (CA, ME, IL, etc.) water well logs,” “my state groundwater quality,” or “my state well water quality.”
Contact us directly – If these other local sources don’t work out for you, we may be able to help. We may be able to provide direct assistance, and/or direct you to a technical assistance provider in your area who can help answer your questions (This is a free service funded by USEPA).
Additional Resources
Methane in Well Water, May 2016, Center for Diseases Control and Prevention.
Methane in Well Water, June 2011, Minnesota Department of Health.
Keech, D. K. and M. S. Gaber. "Methane in Water Wells", Well Journal, February 1982, pp. 33-36, National Ground Water Association.
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