Who answers for your side sewer?

In Tacoma and in Pierce County's sewer area, the property owner maintains the side sewer from building to public main while the utility maintains the main; other utilities word this differently or have no confirmed statement.

Revised November 4, 2026

What a side sewer is

It is the private pipe that carries wastewater from your building to the public main, and it may not stop at the curb. Pierce County's code text treats the side sewer stub, from the main to the property line or easement edge, as part of the building sewer the owner maintains. Tacoma also runs its owner's stretch to the city's main. So you can be responsible for pipe under a street you don't own.

If you aren't sure you have a sewer at all, begin with how to tell sewer from septic.

What Tacoma's rule adds

Tacoma's is the fullest published rule here, and it applies in Tacoma only. Its 2021 manual, according to a search summary, also makes the owner responsible for repairing curb, gutter, sidewalk and street damaged during a side sewer repair.

Tacoma's undated Side Sewers 101 flyer says repairs or replacements can average $5,000 to $10,000; treat that as a dated figure from one city. Since December 1, 2010, real estate professionals there have had to hand over that kind of flyer to both parties before closing.

Who may do the work

The answer depends on where the pipe lies and whose sewer it reaches.

• Tacoma, private ground. The city says you can work on your own side sewer with a permit from Planning and Development Services, (253) 591-5030.
• Tacoma, right-of-way. Even on part of your private line, repairs there are for a contractor who is licensed and bonded for Tacoma.
• Pierce County sewer. A Pierce County Registered Sewer Contractor must do building sewer work, according to the county's customer guide.
• Ruston. Replacing the line from main to home takes a building permit with a site plan drawn to scale, and digging close to the right-of-way may add a street excavation permit.

Permits by place covers other offices, and how to check a plumber or contractor covers the state lookup.

Finding the line

Tacoma suggests checking house plans, asking the previous owner, searching permit records or the DART map, or calling 811 or (800) 424-5555. It says its records are more detailed for homes built after 1950. Don't count on the locate to mark your private pipe: state law leaves an end user responsible for finding the lines they own on their own property, as explained in the dig law and 811.

Tacoma's flyer also warns about clay and concrete lines, covered under old lines.

When it fails, and what helps pay

A cracked line that still works need not be fixed at once, says Tacoma's flyer, but sewage that won't flow and backs up is a Sanitary Sewer Overflow. Missing the city's deadline can mean fines or water shut-off by the health department.

Tacoma says to call Sewer Transmission immediately at (253) 591-5585 if sewage backs up inside while you aren't using water, and to call a private service for slow drainage.

Tacoma offers low-interest Sewer Conservation Loans to qualified homeowners, at (253) 502-2255. Pierce County has a Residential Side Sewer Conservation Loan covering only the private line. The South Tacoma sheet and the Puyallup sheet list local numbers.

Where a permit or your contractor calls for a cleanout on the private line, the fittings are sold as cleanouts and plugs. PlumbingSupplyAndMore is run by the same team as this site.

If sewage backs up, stop using the drains, and keep people and pets out of the area until someone qualified has looked at it. Trenches can collapse, so leave deep digging and any work in a street to the licensed or registered contractors each city requires, and call 811 before any digging. If unsure, call a licensed plumber.