Garbage disposal in sink smells... What can I do?

Our downstairs bathroom sink smells like sulfer to me... my husband says it smells like bleach. :confused: It seems to have the more of an odor in the morning. This is the only sink that smells this way. We are on county water. I just want to brush my teeth with clean smelling water.:D ...

I have cleaned the trap and used trap cleaning liquid. This helps for a short time and then the odor returns.

The water that comes out of our two sinks in our master bathroom smells like sewage! Our house was just built this past year so I'm not sure what is causing this problem.

My kitchen sink, installed 6 months ago, has a musty smell. I believe it comes from the $500. Grohe faucet. The hole in the granite where the faucet comes up through seems to smell, and sometimes I think that when I turn on the water, a musty smell comes along with it. The water doesn't taste...