Taste comes from the dissolved minerals and compounds in the water. The two most common reasons for weird tasting or smelling water are:
1. Chlorine smell or taste is usually from the chlorine used to disinfect the water supply to keep it safe. If the smell is particularly bothersome, let the water stand in an open container for a few minutes. The chlorine will dissipate and the container can be covered for later use.
2. Bad smells at kitchen sinks can be from the garbage disposal or drain. Try running the garbage disposal with the faucet on to flush any debris out of the drain.
3. If a bathroom or sink is not used often, the p-trap could be dry and odors are coming back up the drain from the sewer. Runs some water down the drain to refill the p-trap.
4. A rotten-egg smell in is caused by a harmless amount of hydrogen sulfide dissolved in the water. It usually comes from the hot water faucet. Slightly raise the temperature in your hot water heater or let the water flush for a few seconds and the smell will disappear.