Sewage odors not only offend your nose, making being in your laundry room difficult, but they can also threaten your health. As soon as you detect a sewage smell coming into a room, you need to either determine the source and take action to remedy the problem, or contact a plumber for professional help.
Dangers of Sewer Gases
Sewer gases can be toxic to humans, especially if you breathe the gasses in for long enough of a period of time. Sewer gases can contain toxic components such as ammonia and hydrogen sulfide, although the levels vary depending on the composition of the sewer contents, according to the Wisconsin Department of Health Services. Sewer gases may also contain methane, which will combust when exposed to sparks or flames in your house.
Every drain in your house, including your washing machine's drain pipe, has a trap designed to help keep sewer gasses from reaching the drain opening. If you look under a sink in your house, you will notice the curving section of pipe called the trap. The trap will stay full of water at any given time, unless a leak in the pipe occurs. Not using your washing machine for a long period of time will result in the water in the trap not being replenished and evaporating over time. Once the trap is dry enough, sewer gases will pass through and come into the laundry room through the washing machine's drain pipe.
Your house's drain system needs to be vented properly, or sewer gasses may escape into your house. The vent pipes connect to the main drain pipes in the house, allowing the sewer gasses to escape up the vent pipes and into the open air above the house's roof. The vent pipes' openings allow fresh air to travel into the drain pipes as needed, replacing any air that washes down the pipes and into the sewer. From the rooftop, shine a flashlight down the vent pipes to look for clogs. A plumber can analyze your house's plumbing and determine if the vent pipe setup is sufficient or is causing the problem.
Drain Line Clog
Clogs in your washing machine's drain line will produce offensive odors that may resemble sewer gas. The washing machine's drain line may have a partial clog without you realizing it, since a partial clog will allow the water to continue flowing down the drain pipe. Bacteria will form on organic clog materials such as hair and soap, causing the sewer-like smell every time water washes down the drain pipe. A drain snake will help clear out partial clogs, and pouring bleach down the drain pipe will kill the bacteria living in the pipe.