Sewage backup at home: stay safe first, then decide what you can clean

Treat any sewage backup as a health hazard. Keep children, pets, and anyone pregnant, with breathing problems or with a weakened immune system out of the area. Stop running water in the house, and if the backup may be in the public sewer line, call your sewer utility first. A small spill on a hard, sealed floor can be cleaned with rubber gloves, boots, goggles, detergent and a disinfectant. A backup that soaked carpet or drywall, or spread across rooms, is a job for professionals, and porous materials it soaked usually have to be thrown away. Standard homeowners policies typically exclude sewer backup unless you added a backup endorsement.

Safety first

• Call 911 for a gas smell, sparking, a sagging ceiling or an injury.
• Electricity: CDC advises turning off power at the main breaker if circuits or equipment are wet or near water. Only do this if you can reach the panel from dry ground; if you can’t, leave and call for help.
• Don’t touch sewage with bare skin. CDC advises rubber boots, rubber gloves and goggles whenever sewage is involved.
• Who should stay out: EPA says people with asthma or other breathing problems, or with weakened immune systems, should stay away from cleanup. It also says children and pregnant people should not take part.
• Cuts: if an open cut or sore touched floodwater or sewage, CDC says to wash it with soap and water and apply antibiotic ointment. Talk to a doctor if you’re worried about an exposure.
• Stop adding water. Every flush, shower, dishwasher or laundry cycle sends more water into a blocked line.

Why sewage is different from a clean-water leak

Restorers classify sewage as Category 3, the grossly contaminated end of the IICRC S500 scale. It can carry bacteria, viruses and other harmful agents. Water that backs up from the drain side of a fixture, such as a floor drain, tub or toilet backing up from the sewer, counts as Category 3 even when it looks clear. EPA notes that floodwater can bring bacteria, chemicals and other hazards into the home. That’s why the rules for what can be saved are much stricter than for a burst supply line.

First question: your line or the utility’s?

The pipe that carries wastewater from your house to the public sewer is the lateral. SacSewer, which serves Elk Grove and much of Sacramento County, explains that the customer owns the upper lateral and the utility owns the lower lateral. Access pipes called cleanouts usually sit near that dividing point: a building cleanout close to the house, and a utility cleanout in an easement or the public right-of-way.

• Clues that the main line is blocked: several drains back up at once, the lowest fixture fills when you flush or run the washer, or sewage comes out of a cleanout in the yard.
• Clue that it’s a branch clog: only one fixture is affected.
• Elk Grove and SacSewer areas: SacSewer asks customers to call it first for a backup, slow drains or sewer odors. SacSewer can check whether the problem is in the utility’s part of the system. A SacSewer cleanout typically includes a relief valve that lets sewage escape at the cleanout, outside, when the backup is in the utility’s pipes. That helps keep it out of the house.
• Stockton, Lodi, Manteca, Lathrop and Galt: check your sewer bill or city website for the utility’s number before you call a plumber.

The Insurance Information Institute’s sewer backup guide notes that most homeowners are responsible for maintaining and repairing their own lateral. Common causes of backups include tree roots entering cracks and joints, and aging pipes. SacSewer’s maintenance tips also warn against pouring grease down drains and flushing wipes. A backwater (backflow) prevention valve, installed by a plumber on the building sewer, lets wastewater out and closes to keep it from flowing back in.

What usually gets thrown away

CDC advises throwing away anything you can’t clean or dry quickly. Its list includes mattresses, carpeting, carpet padding, rugs, upholstered furniture, cosmetics, stuffed animals, baby toys, pillows, foam-rubber items, books, wall coverings and paper products. It also advises discarding drywall and insulation contaminated with sewage or floodwater. EPA’s guidance is similar: throw away materials that soak up a lot of water and can’t be cleaned and dried.

Hard, non-porous items such as metal, glass, glazed tile, sealed stone and hard plastic can usually be cleaned and disinfected. Solid wood framing and concrete are usually cleaned, treated and dried rather than removed, but a professional should make that call on site.

Before anything goes to the curb, photograph it and write it down. Your adjuster may want a record of what was discarded.

Cleaning a small spill yourself

EPA’s mold-cleanup guidance says that when water damage was caused by sewage or other contaminated water, you should call in a professional. If the spill is truly small, meaning a little water on a hard, sealed floor from one fixture, with no carpet, drywall or cabinets touched and no one at higher risk in the home, these steps follow CDC’s disaster-cleanup guidance:

1. Gear up: rubber boots, rubber gloves and goggles.
2. Remove the mess with disposable towels and bag it.
3. Clean every affected surface with hot water and laundry or dish detergent.
4. Disinfect with a household disinfectant, following its label. Never mix bleach with ammonia or any other cleaner, and don’t use bleach in a closed space; open windows and doors first.
5. Dry the area quickly. CDC’s target is within 24 to 48 hours.
6. Wash up with soap and water. Wash the clothes you wore in hot water and detergent, separately from other laundry.
7. Keep children and pets away until cleanup is complete.

If you smell sewage after cleaning, or the floor keeps getting wet, the problem isn’t solved. Water may have reached under the flooring or into the wall.

When to call professionals

Call in a professional if sewage:

• reached carpet, drywall, baseboards, cabinets or anything under the flooring
• spread beyond one small area, or the backup is still rising
• came into a home where someone is at higher risk

Also call one if your heating and cooling system may be affected. EPA says not to run an HVAC system you suspect is contaminated. Professional Category 3 cleanup typically involves containment, protective equipment, removal of contaminated porous materials, cleaning and disinfection, and drying verified with moisture readings.

Insurance: check for a backup endorsement

The Insurance Information Institute says sewer backups are not covered under a typical homeowners policy or by flood insurance. Backup coverage has to be bought separately, usually as an endorsement added to the homeowners policy. Look on your declarations page for a “water backup” or “sewer/drain backup” endorsement and its limit. Whether a particular backup qualifies is up to your policy and your insurer. Report the loss promptly and document everything before cleanup.

This guide is general safety information. For medical questions, talk to your doctor; for sewer ownership in your neighborhood, ask your sewer utility.