From time to time, most people notice nasty odors coming from one of their drains. This can be quite annoying. Nobody wants to smell sewage or mold while they brush their teeth or wash their hands! You may wonder what is causing the sewage odor, and here's the short answer: it could be a number of things. For the longer answer and a look at each of the possibilities, keep reading.
A Dry Drain Trap
Each drain should be equipped with a trap. The trap is a piece of pipe that bends down in a "u" shape. If you accidentally drop anything down the drain, like a ring for example, it gets caught in the trap. The "u" shape of the trap means that when the drain is used regularly, water collects in there. This is really a good thing, as that water keeps any little food particles or other stuff that gets caught in the trap from smelling too much. But if you don't use the sink for a long time, the trap can dry out and the remaining material in the trap can start rotting, which gives off a nasty odor.
If you suspect this is the problem, there's an easy fix. Dump a bunch of baking soda down the drain, let it sit for a few hours, and then rinse it away. The baking soda will neutralize any odors in the trap, and running water will flush it out.
A Clogged Drain
If the offending odor is accompanied by a slow drain, then you probably have a clog. The debris that causes clogs, which is often human hair, soap scum, and grease, can start molding and rotting, giving off some pretty serious odors. A clog directly in the drainpipe is often pretty easy to clear with a plunger. If that does not work, give your plumbing contractor a call. They can use a high-pressure water device, called a hydrojet, to blast out the drain. This also works for clogs further down the line.
Plugged Sewer Vents
Your home's sewer lines are set up with vents which allow gases to escape from the roof. If these vents get clogged, however, the gas will have nowhere else to go but out the drains, and the gas is definitely smelly. If your drains are also a little slow and are making gurgling noises, then you almost certainly have a problem with the vents. Your plumbing contractor can easily come to clear them out.
Stinky odors coming from a drain are not something to ignore. Try dumping some baking soda down the drain, and if that does not help, use the plunger, then call a plumbing contractor.