Can Sewer Gas Leak Into a Home and Cause Health Issues?

Sewer gas is a blend of gases produced by decomposing waste in your plumbing system. The main components are hydrogen sulfide, methane, ammonia, and carbon dioxide. Each has a distinct odor, but the rotten egg smell of hydrogen sulfide is often the first clue that gas is leaking into your living space.

Even small leaks can create a noticeable smell. The gas can seep through cracks in pipes, loose joints, or a dry floor drain. In humid climates, freeze and thaw cycles can shift soil and stress underground pipes, making small gaps more likely over time.

Sewer gas can enter through cracks in your main drain line, loose toilet seals, or a dry floor drain. The vent stack that runs through your roof can also become blocked by debris or ice, causing pressure to build and push gas back into the home. Sump pumps and aging pipe joints are other frequent culprits.

Check the areas around toilets, sinks, and floor drains for a noticeable sulfur smell. If you have a basement, inspect the walls and floor for damp spots or stains, which can indicate hidden pipe damage. A smoke test by a professional can pinpoint the exact entry point.

Regular maintenance can prevent sewer gas issues. Run water in every drain, including floor drains, at least once a week to keep the water seal intact. Have your plumbing vents inspected periodically for blockages, especially after heavy storms or freezing weather.