Sewer backup: who to call first, and what to do while you wait
Sewage in the house is a two-part problem — a blocked line that keeps pushing, and contaminated water that has to be removed. They are fixed by different people, in that order.
Here is the call order that actually stops it, what to keep away from, and what your insurance will and won't touch — in the order you need it.
Black water is a two-pro problem: plumber first, restoration crew second. We line up vetted local pros who handle both — you pay nothing for the match.
Step 1 — stop adding water
No flushing, no showers, no dishwasher, no washing machine, no running taps. If the backup is happening while water is in use, that use is feeding it. Shut off the water supply to appliances you can reach without entering the contaminated area.
Step 2 — get people away from it
- Children, pets, and anyone pregnant, elderly or immunocompromised stay out of the affected rooms entirely.
- Do not wade in. Sewage carries bacteria, viruses and parasites. A cut on your foot is an infection risk.
- Watch the electrical side. If water is near outlets, a sump pump, a washer, a furnace or the electrical panel, do not enter. Call an electrician or your utility. Water plus live circuits is the fast way to turn a cleanup into a tragedy.
- Do not run fans or a shop vac across sewage. It aerosolizes contamination and spreads it through the house.
Step 3 — call in the right order
- Your city sewer authority or a drain-cleaning plumber. The blockage is the cause. Many municipalities clear blockages in the public main for free; ask before you pay someone to rod a line the city owns. If the blockage is on your side of the connection, a drain plumber clears it.
- Your landlord, in writing, if you rent. A text or email with photos creates a record and usually starts a repair obligation.
- Your insurer. Ask two things: does the policy have a water/sewer backup endorsement, and what is the sublimit? Note the claim reference.
- A restoration or cleanup firm for extraction, disinfection, contaminated-material removal and drying — after the flow is stopped. Compare written scopes; the sewage cleanup cost guide explains what drives the price.
Step 4 — document before anything moves
Wide shots of each affected room, close-ups of the waterline and of any damaged belongings, and a written timeline (time noticed, time water was shut off, who you called). Keep receipts for anything you buy — gloves, containers, a hotel night. The claim documentation checklist gives the sequence, and it is free to print.
Why this is not a normal water cleanup
| Factor | Clean-water leak | Sewage backup |
|---|---|---|
| Water category | Category 1 (clean supply water) | Category 3 (black water — grossly contaminated) |
| Porous materials | Often dryable and salvageable | Carpet, padding, drywall below the line, upholstery usually removed |
| PPE and containment | Basic | Suits, respirators, air scrubbers, containment |
| Disposal | Limited | Contaminated debris requires proper disposal |
| Typical price effect | Baseline | Same square footage commonly runs higher — see cost ranges |
A crew that offers to "save" black-water carpet is selling you mold and odor risk. Removal is the standard, not the upsell.
Insurance: the endorsement question
Standard homeowners forms commonly exclude water that backs up through sewers or drains, and add coverage only through a water-backup endorsement with its own sublimit. Endorsements, sublimits and state rules vary. Look for "water backup," "sewer backup" or "sump overflow" on your declarations page, then confirm the dollar limit with your insurer. Our insurance guide covers where sudden damage and gradual seepage get treated differently.
Preventing the next one
- Know your responsibility line. Ask the city where your lateral connects; blockages on your side are yours.
- Do not pour grease, wipes or "flushable" products. They are the most common cause of residential backups.
- Consider a backwater valve if your basement has fixtures below the street level, and ask a plumber whether local code allows or requires it.
- Have the line inspected if backups repeat — tree roots and collapsed clay pipe do not fix themselves.
Frequently asked questions
Who do I call for a sewer backup?
Start with the cause, not the cleanup. If sewage is backing up from a floor drain or tub when you use water, the line is likely blocked and a drain-cleaning plumber or your municipal sewer authority is the first call — in many cities the utility handles blockages in the public main at no cost to you. Once the flow is stopped, a restoration or cleanup firm handles contaminated water, materials and drying. If the backup is inside a rental, notify the landlord in writing immediately.
Is a sewer backup an emergency?
Treat it as urgent. Sewage is Category 3 black water: it carries bacteria, viruses and parasites, and porous materials it touches usually cannot be saved. Do not wade in barefoot, do not run fans across it, and keep children and pets out. Electrical equipment near standing sewage is a shock hazard. The cleanup itself can often wait for business hours, but the exposure risk starts immediately.
Does homeowners insurance cover a sewer backup?
Usually not under a standard policy unless a sewer or drain backup endorsement is attached, and even then sublimits and exclusions apply. Standard homeowners forms commonly exclude water that backs up through sewers or drains; an endorsement adds a limited amount of coverage. Check your declarations page for "water backup" or "sewer backup" and ask your insurer what the sublimit is before you assume anything.
What should I do first when sewage backs up into the basement?
Stop using water in the house so you do not add to the backup. Keep people and pets out of the affected area, and do not touch sewage with bare hands. If water is near outlets, the panel or appliances, do not enter — call an electrician or the utility. Photograph from a safe position, notify your landlord or insurer, and arrange professional extraction and disinfection. Porous items that contacted sewage are generally a disposal decision, not a cleaning project.
How long does sewer backup cleanup take?
Extraction and disinfection of a single room is often a day of work; drying the structure after contaminated materials are removed typically runs several days with monitoring. Full basement cleanouts with contents disposal and rebuild take longer. Timelines depend on how much material is removed and how quickly drying starts — see our restoration timeline guide.
Can I clean up a sewage backup myself?
Small, contained backups still involve Category 3 contamination, and professional crews use PPE, antimicrobials, air scrubbers and legal disposal routes. Homeowners sometimes handle a tiny spill at their own risk, but the material handling and health exposure are the reasons this is usually hired out. Never mix bleach with other cleaners, and never dry-sweep or vacuum sewage-contaminated debris with a household vacuum.
Black water needs pros today, not Monday
ZIP + one sentence gets you 2–3 vetted 24/7 restoration and plumbing pros — plumber first, cleanup crew second. You pay nothing for the match.
Don't see pros for your ZIP? Find a verified one yourself — 3 steps
- Search the IICRC pro directory — iicrc.org/find-a-pro lists water/fire restoration firms with active certification. Enter your ZIP; pick one with a 24/7 phone line.
- Check your state license — every legit restoration/plumbing firm is searchable in its state contractor registry (Texas: TDLR license lookup; most states: search "[your state] contractor license lookup"). License number in the footer or on the truck = ask for it and verify. 60 seconds, prevents the worst hires.
- Ask your insurer's adjuster — carriers keep preferred-vendor lists (state farm, allstate, progressive all have them) and a same-day direct repair line. If your loss is a claim, that line often responds faster than any public search.
Still stuck? Email [email protected] with your ZIP — we're expanding coverage metro by metro, and if we can't match you we'll point you to the best free directory for your county.
Last reviewed: November 2026.