Water Q&As: Why does my water smell like rotten eggs?

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Learn about the causes of bad-smelling water and what you can do about it.

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Why does my water smell like rotten eggs?

Water Questions and Answers

You would know it if you had this problem! A frequent cause of musty, earthy odors in water is naturally occurring organic compounds derived from the decay of plant material in lakes and reservoirs. In some parts of the country, drinking water can contain the chemical hydrogen sulfide gas, which smells just like rotten eggs. This can occur when water comes into contact with organic matter or with some minerals, such as pyrite. The situation mostly occurs as groundwater filters through organic material or rocks.

Water containing hydrogen sulfide can have an odor that is objectionable (and the water may taste really bad), but generally the water is not harmful to health. However, odors can be caused by other constituents as well, so you may want to call your local Health Department and mention the odor to them. The best way to find out what is in your water is to have the water tested by a state certified laboratory. A list of these labs is available from the U.S. Environmental Protection Agency State Certification Program. Your local county Extension office may also offer water testing.