Rotten egg smell in water
A rotten egg smell in water is usually hydrogen sulfide gas or sulfur bacteria — not dangerous at low levels, but you should test before masking it with a filter.
The smell often shows up in hot water first. It can come from the well, the water heater, or drains — note where you smell it before you call a lab.
What to test
- General chemistry panel on a private well if the smell is constant at the cold tap.
- Bacteria if the smell started after a flood or service disruption.
NGWA well help: 855-420-9355. Find a certified lab: EPA certified laboratory contacts.