Do not open a cleanout cap during a backup, and do not use chemical drain openers. Keep children and pets out of affected rooms.
Right now
- Stop running water, flushing toilets, and running the dishwasher or washing machine
- Keep everyone out of the affected area
- If sewage is near outlets or appliances, stay out of it
- Open windows for ventilation if you can do so without walking through it
Is it your line or the city’s?
If neighbors are having the same problem, the blockage may be in the public sewer, and the city or sewer district should be called. If only your house is affected, the blockage is most likely in your own line.
Cleanup
Sewage contamination needs protective gear and proper disinfection. Porous items that were soaked, such as carpet and drywall, usually have to be removed. Photograph everything for insurance before cleanup starts.
What comes next
Once the line is cleared, a camera inspection shows why it happened — roots, a collapsed section or buildup — so it can be fixed rather than cleared again next time.