Why Your Well Water Smells Like Rotten Eggs

What does it mean if your well water smells like sulfur or rotten eggs? What is that a telltale sign of? Do you know what to do about it? 

Water experts report that nearly every time, foul-smelling water results from bacteria in the well. Sulfur bacteria actually use this mineral as an energy source. The bacteria then produces hydrogen sulfide gas which is what you are noticing when your water has a “rotten egg” smell. 

Hydrogen sulfide gas can also come from natural sources. This gas can enter wells as a result of the decay of organic matter or due to chemical reactions within soil and rocks around the well. 

Bacteria in Your Hot Water System

When your hot water is affected, it could be because of microorganisms growing in your hot water tank. You may notice this offensive smell when you first turn on your hot water. This can happen when your hot water temperature is on a low setting or if these sulfur bacteria exist in your water supply. These bacteria are more likely to flourish in your heated water than in your cool water supply.  

Alternatively, corrosion inside your water heater can change naturally occurring sulfates into the odorous hydrogen sulfide gas. 

The Solution for Smelly Water

If you have a private well and experience odorous water, you will first need to test your well for bacteria. Be sure to get a test kit from a reputable lab that will test for a wide spectrum of bacteria, not just the most common forms such as E. Coli and coliform. There are thousands of other bacteria that could be lurking in your well water. A comprehensive test will show which are present. A reputable firm can also recommend what you can do about them. A full scan of all factors in your water that could affect your health will help you determine precisely what the problem is.

How Often Should You Test Your Water?

You should test your well water at least every two years and if you are experiencing a foul smell or something that smells like rotten eggs, test it right away. 

Once you’ve identified the bacteria, you should disinfect your well using recommended disinfecting products. Do not flush your system with bleach. This can be toxic to humans and may remain in various parts of your system for many weeks or even longer. Bleach is heavier than water and it has a tendency to gather in some tricky places where it may not come out. 

There are better, more effective, less toxic products to clean out your system. A reputable water testing lab will recommend what to use and how much of it is needed to disinfect your well. Afterwards, you should have the well water tested again to be sure it is now free of the bacteria that were living in it before.

To find out more about the right way to fully test your well water, please contact ETR Labs at (800) 344-9977 or visit our water test kit page here.