The Causes of Sewage Odor in a Basement

If you notice a sewage odor in your basement, you may have "sewer gas" or a sewage spill. Since sewer gas and raw sewage represent health dangers, investigate sewage odors immediately.

Causes

Sewer gas refers to a mixture of gases created by decaying waste. Exposure to sewer gas can cause dizziness, headache, nausea and nervousness. Exposure to high levels of sewer gas causes death. Sewer gas is also highly flammable.

Prevention/Solution

Prevent or remedy sewer gas by flushing basement floor drains with water. In addition, check the roof plumbing vent to make sure snow, ice, leaves or bird nests are not blocking the vent. Do not smoke or use open flames in areas contaminated by sewer gas.

Considerations

Raw sewage sometimes comes up through basement floor drains when sewer lines become blocked. If there is raw sewage in your basement, call your city sewer helpline to check whether the blockage has occurred in the city's sewers or in yours. Keep children and pets away from raw sewage, which often carries dangerous bacteria and viruses.

Treatment

Contact a plumber to remove the sewer blockage. Clean raw sewage from your basement with hot water and detergent, then rinse surfaces with diluted bleach. Wear boots, rubber gloves and goggles. Discard porous objects contaminated with raw sewage, such as cardboard. Use fans to improve circulation and prevent mildew.

References

• City of Minneapolis: Sewer Problems in the Home
• Washington State Department of Health: Cleaning Up a Sewage Spill
• Wisconsin Department of Health Services: Sewer Gas