Sewer Line Repair Seattle: $100 to $170 a Foot + City Rules

Seattle rows come from Seattle Public Utilities and Angi; national rows are labeled.

Do this now: signs of a broken side sewer

1. Stop using water in the house if drains are backing up.
2. Call a plumber first, SPU says, and call SPU at (206) 386-1800 if the plumber suspects the City main.
3. Before any clearing, call Puget Sound Energy at 1-888-225-5773 to rule out a cross-bored gas line (SPU).
4. Photograph sewage damage and call your insurer. The Insurance Information Institute says to save receipts.
5. Call 811 before anyone digs, so buried utilities are marked.

Who owns the side sewer in Seattle?

You do, all the way out to the main. "If you own your home or building, you own your side sewer up until the public sewer pipe under a street near your home," Seattle Public Utilities says. A side sewer may be shared with a neighbor, so a backup can start on the other property. SPU keeps side sewer permit records, called side sewer cards, that show where the line runs; ask the plumber to pull yours before digging. We found no City repair program or cost share for side sewers.

Is it urgent? When a Seattle sewer line cannot wait

Sewage in the house is urgent. Slow drains, gurgling and odors can wait for a scheduled camera inspection, which SPU prices at $230 to $845. Seattle's rain stresses old lines: Sea-Tac averages 93.4 days a year with measurable rain, NOAA's 1991 to 2020 normals show. If a City sewer problem caused the backup, SPU says you can file a claim with the City for reimbursement. For a backup tonight, see emergency plumber in Seattle; for cleanup, sewage cleanup.

Street work needs a Seattle licensed and bonded contractor

Because the side sewer runs under the sidewalk or street, part of most repairs is in the City right-of-way, and SPU says any repair there must be done by a contractor licensed and bonded to work in Seattle. Ask for that license, plus the company's Washington L&I registration, which the Verify tool shows with any bond lawsuits and safety citations.

Trenchless or dig in Seattle

SPU puts trenchless repair at $100 to $170 a foot. This Old House's 2026 national figures put trenchless lining and bursting at $60 to $250 a foot and traditional excavation at $50 to $200 a foot plus digging. Seattle's median home was built in 1976, and 22.8% of units date to 1939 or earlier, Census counts show, so older clay lines with root intrusion are common candidates for lining. SPU recommends an inspection every 2 to 3 years when large trees are near the line.

Side sewer facts for Seattle, from the official city, county, state, utility, Census and NOAA pages listed under Sources.

Questions to ask a Seattle sewer contractor

1. Are you licensed and bonded to work in the Seattle right-of-way?
2. Can I watch the camera inspection and keep the video?
3. Is the break on my side sewer, a shared line or the City main?
4. Is the pipe a candidate for lining, and what is the price per foot?
5. What is your L&I registration number, and can I see proof of insurance?

More Seattle plumbing guides

Clogs first: drain cleaning in Seattle. All plumbing: plumber in Seattle. Other cities: sewer line repair in Portland and sewer line repair in Sacramento. National prices: sewer line repair. Calls go to an independent company that serves your area and takes this kind of job (how calls work).