Seattle Side Sewer Permits: What Homeowners Need to Know
By Magnolia Plumbing & Sewer · · Sources linked in each section
If you own a house in Seattle, you own the sewer pipe that connects it to the City’s main, including the part under the sidewalk and street. When that pipe needs work, several City offices may be involved. This guide pulls together what Seattle Public Utilities, SDOT and the city code say, as of October 2026.
1. You own the side sewer, all the way to the main
SPU: "The entire side sewer (all the way to the connection to the public main) is owned and maintained by the property owner." Technically it includes all piping outside the building footprint (except foundation drains) up to, but not including, the tee, wye or connection to the main. Piping inside the building is plumbing, regulated by Public Health – Seattle & King County (SPU permits).
If your side sewer joins a neighbor's before reaching the main, you share responsibility from the junction onward. There may be a recorded easement setting out the terms (SPU).
2. When a permit is required, and when it isn’t
- Required: connecting to the public sewer; repairing, altering, adding to, abandoning, removing or capping a side sewer. Repair permits include replacing an exterior cleanout or yard drain, and lining.
- Not required: root removal and unclogging.
- Extra permit: any work in the public right-of-way (equipment staging, excavation, restoration) also needs an SDOT Side Sewer permit.
Sources: SPU: Side sewer permits; SPU: Side sewer repair methods; SDOT: Right-of-way side sewer FAQs.
3. Who issues it, how fast, and what it costs
Since October 1, 2025, SPU has issued side sewer permits instead of SDCI, through the Seattle Services Portal. SPU says it processes repair and addition/alteration permits by the end of the next business day. A permit is valid for 18 months (SPU how to apply; SPU).
| Permit | Fee |
|---|---|
| Sanitary repair, private property | $280 |
| Drainage repair, private property | $375 |
| Addition / alteration | $375 |
| Right-of-way work | Separate SDOT fees |
These are City permit fees, not contractor prices. Extra inspections are billed hourly. Source: SPU: Side sewer permits.
4. Who can do the work
Seattle code allows side sewer work in a public place only by a registered side sewer contractor (RSSC), with direct onsite supervision. Permits for public-place work are issued only to RSSCs. For work entirely on private property, a permit can be issued to the owner, occupant or their agent (SMC 21.16.055, 21.16.080). In 2025 the City moved RSSC registration to SPU.
Plumbing contract work in Washington must be done by a licensed plumbing contractor; check licenses with L&I Verify.
5. What the City inspects
- A City inspector inspects the pipe before it is covered, and again at final.
- New sewer pipe over 10 feet must pass a water or air pressure test, running when the inspector arrives.
- No 90° bends or tees; use 45° or 22½° fittings.
- Minimum pipe size: 4 inches on private property for one unit; 6 inches in the right-of-way or for two or more units.
- Street and sidewalk damage must be restored to SDOT standards.
Sources: SPU: Side sewer repair methods; SPU: Side sewer permits; SPU: Side sewer defects and issues.
6. Before you get bids
- Pull your side sewer card from the City viewer.
- Get a camera inspection after any blockage is cleared, and keep a copy of the video.
- Have the contractor write down the footage to each defect and mark it on the ground.
- Get at least three written bids, as SPU recommends.
- Call 811 two business days before digging, and hire a private locator for lines you own.
- Ask about SPU’s interest-free loans for qualifying low- and fixed-income customers, or Seattle Office of Housing home repair loans.
Sources: SPU: Side sewer repair methods; Seattle Public Utilities: Your side sewer; SPU: Side sewer permits.
Frequently asked questions
Is the City responsible for my sewer pipe under the sidewalk?
No. SPU says the property owner owns and maintains the entire side sewer to the connection with the public main, including the portion in the right-of-way.
Can a homeowner pull their own side sewer permit?
For work entirely on private property, Seattle code allows a permit to be issued to the owner, occupant or agent. Work in a public place requires a registered side sewer contractor.
Related pages
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