The short answer
What Causes Lingering Sewage Smells
Sewage odor can stick around even after a thorough cleanup because the smell comes from bacteria and organic matter that seep into porous surfaces like drywall, wood, and carpet padding. If any of those materials were soaked, they can hold the odor for weeks or months unless removed.
Moisture is another culprit. Sewage water can wick up walls or pool under flooring, and damp areas keep bacteria active. Even a small hidden puddle can keep the smell alive. Check baseboards, corners, and any spot that feels cool or damp to the touch.
- Porous materials like drywall and wood absorb sewage odor
- Hidden moisture behind walls or under floors keeps bacteria active
- Cracks in pipes or seals can let new sewage seep in
- Ventilation systems can recirculate trapped odors
- Old stains on concrete or tile can still release smell
How to Find the Source of the Smell
Start by sniffing around the area to see if the odor is strongest near a floor drain, toilet base, or sink. A persistent smell may indicate a leaky pipe or a failed wax ring on a toilet, which can allow small amounts of sewage to escape without being obvious.
If you live in Mesa, keep your shutoff valve location written down so you can stop water quickly if a leak worsens. Also, check crawl spaces for damp spots. If you can't locate the source, a professional with moisture meters and borescopes can find it.
Steps You Can Take Right Now
Open windows and use fans to increase airflow, which helps dry out surfaces and disperse odors. Remove any wet or stained materials you can safely handle, such as rugs, cardboard, or furniture that was soaked. Place them outside in a dry, airy spot.
Clean hard surfaces with a disinfectant and a solution of water and mild detergent. Do not mix bleach with other cleaners, as that can create dangerous fumes. After cleaning, dry the area thoroughly with towels and fans. See a doctor if you feel unwell from the smell or fumes.
- Open windows and run fans to dry the area
- Remove soaked rugs, furniture, and porous items
- Wipe hard surfaces with disinfectant and dry completely
- Check for new leaks around toilets, drains, and pipes
- Use a dehumidifier to lower indoor humidity
When to Bring in the Pros
If the smell persists after several days of airing out and cleaning, the problem may be deeper than surface odors. Local water damage pros have equipment to detect hidden moisture and can remove and replace affected building materials like drywall and insulation.
They also use professional-grade deodorizers and antimicrobial treatments that are stronger than household products. In cases where sewage backed up from a main line, the cleanup may involve more extensive work, such as disinfecting the entire area and checking for contamination in walls and subflooring.
How to Prevent Sewage Smells from Returning
Prevention starts with fixing any plumbing issues quickly. A slow-draining toilet or a gurgling sink can signal a blockage in the sewer line. Have a plumber inspect and clear blockages before they cause a backup. Also, keep floor drains filled with water to prevent sewer gases from rising into your home.
After any sewage incident, replace porous materials that cannot be fully cleaned. Consider using water-resistant materials in areas prone to moisture, such as tile or sealed concrete. Regularly check under sinks and around toilets for leaks, and address them immediately to avoid hidden damage and odors.
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Call Now (480) 898-4279Frequently asked questions
How long does sewage smell last after cleanup?
It depends on the extent of the contamination and how well the area was cleaned and dried. Surface odors may fade in a few days with ventilation, but if porous materials or hidden moisture remain, the smell can persist for weeks or longer.
Can I use bleach to get rid of sewage smell?
Bleach can disinfect hard surfaces, but it doesn't always remove odors from porous materials, and mixing it with other cleaners can release toxic gases. Use a disinfectant designed for sewage cleanup and follow the label instructions. For stubborn smells, professional deodorizing may be needed.
Is it safe to stay in a home with a sewage smell?
Sewage odors indicate the presence of bacteria and potentially harmful gases. If the smell is strong or you feel dizzy, nauseous, or have trouble breathing, leave the area and get fresh air. See a doctor if you feel unwell. For minor lingering smells, ventilate well and address the source.