Stinky water to one sink

hey all I'm having a problem with a bad sulfur type smell but it's only coming from one faucet????,it's the one in the main floor bathroom, we are on a well and there's no smell from any others including the shower in the same bathroom, what's with that??????????

odor

Pour some Liquid Plummer down the sink's overflow opening to "burn out" the accumulation inside it. That should cure the problem.

You can also replace the supplies for the faucet under the sink.