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Your Property’s Side Sewer

What is a side sewer?

A side sewer is the privately owned and maintained sewer pipe which connects the plumbing system of a building or house to the public sewer pipes, also known as the City sewer main.

side sewer

In Seattle, the property owner owns and is responsible for side sewer connection to the City’s sewer main, even under street right-of-way. (Seattle Municipal Code 21.16.190). A side sewer can travel a variety of paths before reaching the City sewer main, including crossing other private property and connecting with a neighbor’s side sewer.

The Department of Planning and Development may have information about the specific path of your side sewer.

If you are having issues with your side sewer, one of the best ways to diagnose the problem is to have a sewer scope, or sewer video, taken of your side sewer by a private side sewer inspector or those specialized in plumbing.

Side Sewer Problems

If you notice slow drainage or suspect a blockage, the problem is likely in your private side sewer line. You can contact a private service company to have your private side sewer inspected for problems.

For more tips on side sewer investigation and repair, see Troubleshooting Your Sewer Problem (pdf).

When should I call the City?

  • Call Seattle Public Utilities (SPU) at (206) 386-1800 immediately if sewage is coming up inside your home when you are not using water. A crew will check the city’s sewer and notify you of the results of their investigation as soon as possible. City crews are responsible for maintaining the main sewer lines.
  • If the plumber tells you the problem is beyond your side sewer, call Seattle Public Utilities at (206) 386-1800.

What steps should I take to get my side sewer repaired?

  • Use a search engine to look up plumbing, drains, and sewer cleaning, or look online under sewer inspection.
  • If you want to make repairs to your side sewer, you will need a side sewer permit from the City of Seattle to complete this work.

What resources are available for repairing side sewers?

The Seattle Office of Housing offers Home Repair Loans for owner-occupied, single family homes with low- to moderate-income families.

How do I clean up after sewage backs up into my home?

Thorough cleaning of indoor sewage spills is necessary to protect people -- especially small children -- from harmful bacteria and viruses. Clean-up should begin as soon as possible to reduce the risk of exposure to sewage.