If you’ve ever experienced water that smells like rotten eggs, you’re not alone! Many homeowners deal with smelly water, and while it’s often not a major health risk, it can be a sign of something that needs attention. You can restore the quality of your water and get rid of well water odors by determining the cause and finding the best solution with a little detective work.

What Causes Water That Smells Like Rotten Eggs?

There are several reasons your well water might have a strange smell, and they range from harmless to more serious concerns.

One of the most common and often seasonal culprits behind that “rotten egg” smell is hydrogen sulfide gas. H₂S is produced when sulfur-reducing bacteria in the water break down sulfur compounds, typically in oxygen-poor environments like deep wells. While hydrogen sulfide itself isn’t harmful in low concentrations, it can be damaging to your plumbing, cause staining, and leave behind that unmistakable odor.

Another smelly well water issue could be coming from an iron bacteria problem, which produces a musty or swampy odor. These bacteria feed on iron and manganese in the water and can leave slimy, rust-colored deposits in pipes and fixtures. In some cases, decaying organic material like leaves or algae near your well can introduce earthy or fishy smells, especially in shallow wells.