What a sewage backup looks and smells like
The clearest sign is dirty water coming up out of the lowest drain in the house, usually a basement floor drain, a ground-floor shower, or a tub, when water is used somewhere else.
- Toilets that gurgle or bubble when a sink or washing machine drains
- Water rising in a tub or shower when a toilet is flushed
- Several fixtures draining slowly at the same time
- Dark water with solids and a strong sewer odor at a floor drain
- Sewage at the cleanout cap in the yard
- Wet, foul-smelling carpet near a bathroom or laundry
A single slow sink is a local clog. Multiple fixtures acting up together means the main drain line is blocked and a backup is coming if you keep using water.
What causes sewer and septic backups
Tree roots. Roots find the joints in older clay and cast iron sewer laterals and grow into the pipe until paper and solids catch on them.
Grease and wipes. Cooking grease hardens inside the line. Wipes, even those sold as flushable, don't break down the way toilet paper does.
Collapsed or bellied pipe. Old laterals crack, shift, or sag, creating a low spot where solids settle.
Overloaded public sewers. During very heavy rain, stormwater leaks into the sanitary system and can push sewage back toward low-lying connections.
Septic problems. A full tank, a failed pump, or a drain field saturated by rain will back up into the house the same way.
Why sewage is handled differently from other water damage
Sewage is Category 3 water, the most contaminated classification used in restoration. It carries bacteria, viruses, and parasites that cause illness through skin contact, through hand-to-mouth contact, and through contaminated dust once things dry out. That changes the rules.
With clean water, the goal is to dry materials in place. With sewage, anything porous that got wet is removed, because it can't be reliably cleaned. Drying a sewage-soaked carpet just produces a dry contaminated carpet.
What sewage backup cleanup involves
Containment
The affected area is isolated with plastic sheeting, and a path out of the house is protected so contamination isn't tracked through clean rooms. HVAC vents in the area are sealed.
Removal of sewage and solids
Liquid is extracted and solids are collected for proper disposal. Crew members work in protective suits, gloves, boots, and respirators.
Removal of contaminated materials
Carpet, pad, wet drywall and insulation, baseboards, and soaked contents are bagged and removed. Drywall is cut above the highest point the water reached or wicked.
Cleaning and disinfection
Remaining hard surfaces, such as concrete, framing, tile, and subfloor, are washed to remove residue, then treated with a disinfectant. Cleaning has to come first. Disinfectant doesn't work through a layer of soil.
Drying
Once clean, the structure is dried with air movers and dehumidifiers, as described under structural drying.
Final check
Moisture readings confirm the structure is dry, and the area is inspected for remaining residue and odor before containment comes down.
The blockage itself must be cleared by a plumber, ideally before or during cleanup so the line doesn't back up again onto cleaned surfaces. A camera inspection of the line afterward tells you if the cause was a one-time clog or a damaged pipe.
Why older Winston-Salem neighborhoods see more sewer backups
Many houses in the older parts of Winston-Salem, including much of Ardmore and West End, were built in the early 1900s and still drain through their original clay or cast iron laterals. Those same streets are lined with large, mature hardwoods. Jointed clay pipe and decades-old tree roots are a predictable combination: roots enter at the joints, and the line backs up every year or two until it's repaired or replaced.
Heavy summer storms add to it by loading the sewer system with rainwater. If you own a house of that age here and have had one backup, a camera inspection of the lateral is worth the money, and so is asking your insurance agent about a water backup endorsement.
What affects the cost of sewage cleanup
Sewage cleanup costs more than a clean-water loss of the same size because of the protective equipment, containment, disposal, and disinfection involved. Within that, the area affected and the finishes in it are the main variables.
- Area and depth. One bathroom floor versus an entire finished basement.
- Finishes. Bare concrete is cleaned and disinfected. Carpet, drywall, cabinets, and wood flooring have to be removed and hauled away.
- How far it wicked. The longer sewage sits, the higher it climbs in drywall and the more has to be cut out.
- Contents. Sorting, cleaning, or disposing of furniture and stored items.
- HVAC involvement. Floor ducts or a furnace that took in sewage need separate cleaning or replacement.
- Crawl space contamination. A broken drain line under the house means removing contaminated soil cover and vapor barrier in tight quarters. See crawl space water removal.
Plumbing repair and any sewer line replacement are separate costs from the cleanup.
Why every indoor sewage backup is urgent
Unlike most water problems, there's no version of sewage on the floor that should wait a few days. Contamination spreads on shoes and through the air handler, porous materials absorb more by the hour, and the odor moves into the rest of the house. Call the same day. Call immediately if sewage is still rising, if it has reached carpet or finished walls, if it's near floor vents or the furnace, or if anyone in the home is very young, elderly, pregnant, or immune-compromised.
After cleanup: What to watch and what to do next
You'll have a clean, dry, stripped area ready for new flooring and drywall. There should be no sewer odor. If one returns, call, because it means either a missed pocket of contamination or a drain issue such as a dry trap or a line that is backing up again.
Have the lateral inspected by camera if that hasn't been done. Consider a backwater valve if your plumber finds that the public main was the source. And avoid sending grease and wipes down the drains.
Sewage cleanup is one of the services we provide as a water damage restoration company serving Winston-Salem. If the backup left lingering dampness or was discovered late, mold remediation may also be needed.
Related services for contaminated water losses
- Basement and crawl space water removal
- Structural drying and dehumidification
- Storm water damage, including outdoor floodwater, which is treated as contaminated
Sewage backup cleanup questions
Can I clean up a sewage backup myself?
A small overflow from a toilet bowl onto a tile floor, caught immediately, can be cleaned with gloves, disposable towels, and disinfectant. A backup from the drain line that reached carpet, drywall, wood floors, or a finished basement should be handled professionally because porous materials absorb the contamination and can't be disinfected by surface cleaning.
Does carpet have to be thrown out after a sewage backup?
Yes. Carpet and pad that contacted sewage are removed and disposed of. The same goes for wet drywall, insulation, particleboard, and most upholstered items that were soaked.
Who is responsible for the sewer line, me or the city?
Generally the property owner is responsible for the lateral that runs from the house to the public main, and the utility is responsible for the main. If you suspect the blockage is in the public main, for example several neighbors are backing up at once, report it to Winston-Salem/Forsyth County Utilities.
Is sewage backup covered by homeowners insurance?
Often not under the base policy. Water backup through sewers and drains is commonly excluded unless you purchased a specific endorsement for it. Check your declarations page or ask your agent.
How long does sewage cleanup take?
Removal and disinfection of a typical single-area backup are usually done in a day. Drying the structure afterward takes several more days. Larger basement losses take longer.
Is it safe to stay in the house?
If the backup is confined to one area that can be sealed off, and you have a working bathroom elsewhere, most households stay. If sewage reached the main living areas, the only bathroom, or the HVAC system, staying elsewhere until cleaning is finished is the safer choice, particularly with young children, older adults, or anyone with a weakened immune system.