Sulfur water (or sulphur water) is a condition where the running water contains a high amount of hydrogen sulfide gas that escapes into the air when the plumbing line is opened, giving a distinct "rotten egg" smell.
The condition indicates a high level of sulfate-reducing bacteria in the water supply. This may be due to the use of well water, poorly treated city water, or water heater contamination.
Various methods exist to treat sulfur in water. These methods include
Studies from The Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) suggest that drinking high level sulfate waters can cause diarrhea, particularly for infants.