That sulfur smell is almost always hydrogen sulfide, a gas that forms when organic matter (like old leaves or tiny bacteria) breaks down in your water supply. Think of it as nature’s way of saying, “Yep, there’s some decomposing stuff in here.” It’s the same smell you get near a hot spring or a marsh—except now it’s in your sink.
Your city’s treatment plant works hard to remove this, but sometimes a little sneaks through the pipes. It’s not dangerous in small amounts, but it can make you wonder if you’ve accidentally moved into a swamp.
