What to Do If Sewage Backs up in the Basement?
Last updated October 25, 2026
The short answer
Stop Water Use Right Away
The first step is to stop all water use in your home. Do not flush toilets, run sinks, or use the washing machine. Any water sent down the drains can add to the backup and make the mess worse. This is the most important action you can take to limit damage.
If you know where the main water shutoff valve is, turn it off if it is safe to do so. This stops the flow of water into the house. If you are unsure, leave it on and avoid using water. Write down the location of the valve now so you can find it quickly in an emergency.
Keep People and Pets Away
Sewage contains bacteria, viruses, and other harmful pathogens. Do not let children or pets walk through the flooded area. Do not try to clean it up yourself. Even a small amount of sewage can cause serious illness if you come into contact with it.
Open windows to let fresh air in, but do not run fans that blow air around the room. That can spread contaminants. Wear gloves, boots, and a mask if you must enter the area for any reason. After any brief contact, wash your hands thoroughly with soap and clean water.
- Turn off the water main if you can reach it safely
- Do not flush toilets or run any water in the house
- Keep children and pets out of the flooded area
- Open windows for ventilation, but avoid fans
- Wear protective gear if you must enter the space
- Call local water damage pros for sewage cleanup
Call the Pros for Sewage Cleanup
Sewage backup cleanup is not a do-it-yourself job. The pros have the right equipment to remove contaminated water safely and dispose of it properly. They also use sanitizing agents that kill bacteria and viruses on surfaces. Attempting to clean it yourself can spread contamination and put your family at risk.
The pros who handle sewage backup cleanup will assess the extent of the damage. They will remove standing water, clean and disinfect all affected surfaces, and dry the area thoroughly. They can also identify the source of the backup, which might be a clogged main line or a problem with your home's plumbing.
Policies vary, and your insurer decides what is covered. Check your home insurance policy to see if sewage backup is included. Some policies cover this type of damage, but many do not. Contact your insurance company to ask about your coverage and what steps you need to take.
Document the Damage for Your Records
Before any cleanup begins, take photos and videos of the affected area. Capture the water level, any damaged items, and the overall condition of the basement. This documentation can be helpful if you file an insurance claim. Keep a list of items that were damaged and their approximate value.
Do not throw away damaged items until you have documented them. If possible, move undamaged items to a dry area. The pros may need to remove flooring, drywall, and insulation that came into contact with sewage. These materials are porous and cannot be fully cleaned, so they will likely need to be replaced.
Prevent Future Sewage Backups
Once the cleanup is complete, think about what caused the backup. A clogged main sewer line or a blocked vent pipe are common causes. Tree roots can also invade sewer lines over time. If your home has a backwater valve, make sure it is working properly. If not, consider having one installed by a plumber.
Regular maintenance can help prevent future problems. Avoid flushing anything other than toilet paper, and do not pour grease down the drain. If you live in Caldwell, keep the location of your shutoff valve written down. A plumber can inspect your sewer line and recommend any necessary repairs.
The pros can also help with structural drying and dehumidification after the cleanup. This ensures that all moisture is removed from walls and floors, reducing the risk of mold growth. Mold can develop within 24 to 48 hours in damp conditions, so thorough drying is essential.
Water damage does not wait
Water keeps spreading into floors and walls, so it is worth acting early. Calls are answered 24/7.
Call Now (208) 729-2441Frequently asked questions
Is sewage backup covered by home insurance?
Coverage depends on your specific policy. Many standard policies exclude sewage backup, but you may be able to add it as an endorsement. Check your policy documents or contact your insurance company to ask. If you have coverage, document the damage and file a claim promptly.
Can I clean up sewage myself?
It is not recommended. Sewage contains harmful bacteria and viruses that can cause illness. Professional cleaning is safer and more effective. The pros have the right equipment and sanitizing agents to properly disinfect the area. If you must handle any cleanup, wear protective gear and wash thoroughly afterward.
How long does sewage cleanup take?
The time depends on the extent of the damage. A small backup might be cleaned in a few hours, while a larger one could take days. The pros will need to remove water, clean and disinfect, and dry the area. They can give you a better idea after assessing the situation.