Skip to content

Sewage backup: what to do and how to clean up safely

Sewage coming up through a drain, toilet, or floor is a health hazard. This page helps you stop it from getting worse, keep people safe, and decide what you can clean and what needs a professional.

Do this now

  1. Stop using water in the home. Do not flush toilets, run taps, or use the washing machine or dishwasher, since this sends more water into the blocked line.
  2. Keep children, pets, and anyone who is unwell away from the affected area.
  3. Do not touch the sewage with bare skin. Do not walk through it in bare feet.
  4. If you can do it without stepping in the water, switch off electricity to the wet area at the breaker.
  5. Call a plumber. If neighbors are affected too, or the problem seems to come from the street, call your water or sewer utility.

Why sewage is dangerous

Sewage can carry bacteria, viruses, and parasites that cause stomach illness and infections. Contact with the skin, eyes, or mouth, and even touching your face with dirty hands, can spread them. Fumes and mold add to the problem in closed rooms.

Children, older adults, pregnant people, and anyone with a weak immune system are at higher risk. Let others do the cleanup if you are in one of these groups.

... danger "Never enter standing sewage near electricity" Water near outlets, cords, appliances, or a breaker panel can shock you. If the panel is wet or you would have to step through water to reach it, stay away and call an electrician or your utility.

Find the cause

A backup can come from a blocked line in your home, from a blocked or broken sewer line between your house and the street, or from the public sewer. Heavy rain and flooding can overload sewers and push water back into homes.

  • If only one drain is affected, the blockage may be in that drain's branch.
  • If several drains back up, or the lowest drains in the house gurgle, the main line may be blocked.
  • If neighbors have the same problem, tell your utility.

Do not pour chemical drain cleaners into a line that is backing up. They can burn skin, react with other chemicals, and splash back.

Protective gear

For any cleanup you do yourself, wear:

  • Waterproof rubber gloves, with an outer pair of heavy work gloves if you can
  • Rubber boots
  • Goggles that cover the eyes
  • A mask, such as an N95 respirator, if there is spray, dust, or heavy mold
  • Old clothes or waterproof coveralls that you can wash or throw away

Cover cuts and scrapes with waterproof bandages. Do not eat, drink, or smoke while you work, and do not touch your face.

Cleaning up

Small spills from one fixture, such as a toilet overflow with clean contents, are different from a full backup. If the water is dark, smelly, or covers a large area, call a professional cleanup company.

For a small area:

  1. Open windows to let air in, and keep children and pets out.
  2. Remove standing sewage with a bucket, and avoid splashing.
  3. Throw away items that soaked up sewage and cannot be cleaned, such as carpet, padding, mattresses, and stuffed toys.
  4. Wash hard surfaces with soap and water, and then disinfect them. A common mix from US health agencies is 1 cup of household bleach in 5 gallons (about 4 liters in 19 liters) of water.
  5. Never mix bleach with ammonia or other cleaners. Open windows while you use it.
  6. Dry the area quickly with fans and a dehumidifier.

... warning "Wash well afterward" Wash your hands with soap and clean water after cleanup, after touching anything that touched sewage, and before you eat. Wash work clothes separately in hot water with detergent. Disinfect boots, gloves, and tools you want to keep.

Food and water

Throw away food that touched sewage or sat in the affected area, including items in packages that cannot be washed and disinfected. If your drinking water may be affected, use bottled water until your utility or health department says it is safe.

When to call for professionals

  • A plumber, for blockages and broken lines
  • Your water or sewer utility, if the problem may be in the public system
  • A professional cleanup company, for a large backup or one that has soaked into walls or floors
  • An electrician, if water reached outlets or the panel
  • A doctor, if anyone has vomiting, diarrhea, fever, or a wound that becomes red or swollen after contact

Contact your insurer and ask whether sewer backup is covered, since many policies need a separate add on. Photograph the damage before cleaning up, and keep receipts.