Q.When sewage backs up, is it our problem or the utility's?

A.Sewer backup responsibility splits at the pipe: in WSSC territory you maintain the sewer service from the property line to the house, and the utility handles its main and the connection to it.

So the first bill is almost always yours. Even when the clog turns out to be on the utility's side, WSSC Water says homeowners must still pay the plumber's bill for the visit that found it. What changes is who clears the blockage and whether a claim is worth filing.

Montgomery and Prince George's are WSSC Water territory, while Baltimore City and Rockville run their own programs.

Who is responsible for which part of the sewer?

WSSC's rule is plain: upkeep of the sewer service, from where it crosses the property line up to the house, falls on the owner. If your service ties into a WSSC main that runs through a right-of-way on your own lot, WSSC maintains only the actual connection to its main line.

Everything inside the house is yours too. The WSSC code adds that the owner must hire, at the owner's own expense, a WSSC-licensed Master Plumber or Sewer and Drain Cleaner to clear a stoppage between the building and the main (2024 WSSC code).

How do we report a sewer backup to WSSC Water?

WSSC accepts blockage reports only from registered plumbers, and plumbers and sewer drain cleaners must be WSSC-registered to work in the two counties. You're allowed to snake the line yourself. If the plumber finds the stoppage in WSSC's portion, WSSC clears it at no charge. For a backup in progress, WSSC's 24-hour emergency line is listed on its sewer backups page.

When sewage backs up in a WSSC home

1. Hold off on flushing, showers and laundry.
2. Keep everyone out of the wet area until you know the power is off.
3. Photograph the damage and keep every receipt.
4. Call a WSSC-registered plumber or drain cleaner to find the stoppage.
5. If it's in WSSC's portion, have the plumber report it so WSSC clears it.
6. If WSSC roots or a broken WSSC pipe caused it, contact the WSSC Claims Office.
7. Call your insurance company the same week.

Can we get the utility to pay for the damage?

Sometimes. If roots or a broken WSSC pipe caused the backup, WSSC says to contact its Claims Office for possible reimbursement, and its Claims page takes property damage claims online. Nothing is automatic.

Rockville runs its own sewers. Its claims policy can pay up to $2,500 toward documented remediation costs or your insurance deductible after a city sewer backup or water main break, and the city asks residents to call its 24-hour Public Works hotline before calling a plumber.

Montgomery County says it has no financial assistance program like Rockville's. For Prince George's, Howard, Anne Arundel, Frederick and Baltimore counties, we found no county program. Our roundup of help paying for flood fixes lists everything we did find.

What does Baltimore City offer?

Baltimore City has two City programs, and you can use one or the other for a given backup, not both. Report the backup to 311 either way.

The Expedited Reimbursement Program pays up to $5,000 per dwelling unit, per event, for documented cleanup, disinfection and disposal after a capacity-related wet-weather backup; that page counts at least half an inch of rain in 24 hours as wet weather. Applications must arrive within 90 days. If you're insured, you need your insurer's final determination first, and property damage claims go to the City Law Department instead.

The SOS Cleanup Program offers free cleanup, and since October 2026 its pilot reaches some backups in dry weather, if the blockage is on the City-owned part of the lateral. SOS has its own rainfall rule, so let 311 confirm whether you qualify. Both are City of Baltimore programs and don't extend to Baltimore County homes.

Doesn't homeowners insurance cover this?

Often not, unless you added coverage. The Maryland Insurance Administration says a policy may pay for sewage that comes up through drains when you've added a water/sewer back-up endorsement. Maryland requires insurers to offer it, but most endorsements won't pay to repair or replace the pipe itself. Check your declarations page for that endorsement, and read what a backup endorsement pays for.

The bottom line

Your side is the house and the pipe out to the property line; the utility's side is its main and the connection to it. You'll pay the plumber either way, but a WSSC claim, Rockville's policy or a Baltimore City program may cover some of the rest. The cleanup itself is in our sewage cleanup guide, and a backwater valve is the usual way to prevent a repeat.

Readers also ask

Can we report a clog to WSSC ourselves?

WSSC takes blockage reports only from registered plumbers. For sewage actively backing up, its 24-hour emergency line is on its sewer backups page.

Does WSSC pay the plumber if the clog was on its side?

No. WSSC says homeowners pay the plumber's bill even when the blockage is in the WSSC-maintained portion. If WSSC roots or a broken WSSC pipe caused it, ask its Claims Office about reimbursement.

Do Baltimore City's programs cover Baltimore County?

No. The Expedited Reimbursement and SOS Cleanup programs are City of Baltimore programs. We found no Baltimore County equivalent.

Will flood insurance pay for a sewer backup?

Sometimes. FloodSmart says a flood policy covers a sewer backup during a heavy rainstorm but not one caused by clogged pipes, and an NFIP policy typically has a 30-day waiting period.

How long do we have to apply in Baltimore City?

Ninety days from the backup. If you're insured, get your insurer's final determination first, since the City requires it.