Side sewer repair options in Seattle: trenchless vs traditional

Seattle Public Utilities' side sewer repair methods page describes four general types of structural repair, and notes that two or more may be combined on one job:

Different contractors may recommend different methods for the same pipe, often based on their own equipment and experience. That is normal, which is why SPU suggests collecting several bids and asking each contractor to explain why their method fits your defects.

Start from the camera video. A single defect usually points to a spot repair. Several defects along the run, or a pipe that has collapsed, usually means replacement, either by open cut or by bursting. Questions to put to each bidder:

• Which defects, at what footage, does this repair fix, and which does it leave?
• Does the work extend into the street or alley? Work in the public right of way adds cost and permits.
• For lining: how are the connection at the main and any branch lines reopened, and is there a warranty in writing?
• For bursting or open cut: where will the pits go, and how will the yard, driveway or sidewalk be restored?
• Will you provide video after the work is done?

Permits are always required for side sewer repair work, on private property and in the right of way, according to SPU; they are not required for root removal or unclogging. As of October 1, 2025, SPU issues side sewer permits instead of the Seattle Department of Construction and Inspections, through the Seattle Services Portal (how to apply). The repair application asks you to say whether there will be work in the right of way and whether pipe lining is planned on private property or in the right of way. Lining alone does not count as right-of-way work on the form.

SPU's side sewer permits page lists the costs and timelines:

• Sanitary repair permit on private property: generally $280, including one to two inspections
• Drainage repair permit on private property: generally $375, including one to two inspections
• Repair permits are processed by the end of the next business day after the application is received
• A permit is valid for 18 months unless renewed
• Any work in the public right of way, such as excavation or equipment staging, also needs a separate permit from the Seattle Department of Transportation

The contractor schedules a city inspection before the pipe is covered, and a final inspection follows when the work is complete. If the repair cannot meet code, for example a pipe with less than a two percent slope or a backflow preventer valve in the side sewer, SPU's documents page says a recorded Side Sewer Release and Indemnification Agreement is required.

SPU's Troubleshooting Your Sewer Problem guide says a repair that does not require digging could range from $60 to $200 per foot, and that a repair requiring digging in the public right of way would cost even more. Angi's national 2026 sewer line replacement guide gives an average replacement cost of $3,319 with a typical range of $225 to $10,000, $60 to $250 per linear foot for both traditional and trenchless replacement, and $600 to $1,050 for a cracked pipe spot repair. These are national figures, so compare them with local written bids. Add the SPU permit fee and, if needed, the SDOT permit and street restoration.

The Seattle Office of Housing's Side Sewer Assistance Program offers interest-free loans to income-eligible homeowners to repair a broken or collapsed side sewer. You must live in Seattle and own and occupy the home; renters are not eligible, and income must be at or below the city's Home Repair Income Guidelines. After approval, a Property Rehabilitation Specialist schedules an assessment and helps with bids. No work can begin until the loan documents are signed and recorded, so apply before you hire.

SPU's side sewer page says that where your pipe joins a neighbor's before reaching the main, you share maintenance and repair responsibility from that point to the main. SPU encourages neighbors to agree on the scope of repairs and the contractor, and recommends at least three bids before any work starts.

SPU distinguishes rooter companies, which unclog lines, side sewer contractors, which repair and replace side sewers, and plumbers, who work on fixtures and piping inside the building. For a structural repair you want a side sewer contractor. Check the company in the L&I Verify tool and get written bids that state the method, the footage covered, the permits included and the restoration. Our sewer line repair page, inspection guide and hiring guide go further.

We are an independent guide, not a contractor, and we do not perform plumbing work. To reach a plumber, call one of the licensed contractors listed on this page or see all listed contractors. If you prefer, email us your neighborhood or ZIP code, the problem and a few photos. We reply by email with next steps. Run the checks on this page on anyone you hire, including the contractors listed on this page.