Yes, sewage smells can originate from a floor drain. If the P-Trap in the floor drain dries out or if there's a clog or other issue in the plumbing system, sewer gasses can escape through the drain, causing nasty odors. Regularly pouring water into the drain helps maintain the water seal and prevent those smells, but if the smell persists, you should have a plumbing professional inspect the drain for potential problems.

If you’re not using a septic system, problems with your home’s plumbing won’t cause this—it’s a city problem. A large blockage in the municipal sewage lines may cause those lines to back up into your home. This is extremely unpleasant and can be a serious health risk due to bacteria and other contaminants. If this occurs, call a pro (or your city) immediately.

A professional drain cleaner is a plumber or specialized drain cleaner with the necessary tools to unclog drains and tiles to keep waste water flowing out to the septic tank or city sewer for processing. Keeping wastewater from backing up into your home helps keep you and your family safe from potential contamination and sickness. These pros can help resolve nearly any drain situation in a safe and efficient manner.

Never pour used motor oil down the drain. Doing so can have serious environmental consequences, including contaminating groundwater, endangering animals, and killing vegetation. It can also clog your pipes, causing backups in your plumbing or the wastewater treatment plant. In most places, pouring motor oil down the drain is illegal, whether you do it in your home or a storm drain.