Side Sewers: Before You Buy or Sell Property

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Get to know what’s underground
Side sewer repairs or replacement can be expensive – averaging $5,000 to $15,000 – and can often come as a surprise to property owners when sewage starts coming out of sinks, toilets, bathtubs and other building drains!  Property owners should plan for side sewer maintenance and repair just as they do for replacement of roofs, furnaces and other major working systems of the building or residence.

Side sewers are the pipe that connects a building’s plumbing to the City-maintained sanitary sewer main. The sewer main carries wastewater from your side sewer to the City’s treatment facilities.

To protect the value of your investment and avoid the surprise of costly repairs, the City of Tacoma recommends inspecting a building’s side sewer if it is more than 25 years old and/or does not have plastic PVC pipe running from the building to the City sewer main.

Why does this matter to me?

  • In Tacoma, property owners are responsible for repair and maintenance of their private side sewer.
  • Buildings constructed prior to 1980 are likely to have side sewers made of clay or concrete pipes. These can crack, shift out of place, and/or be subject to intrusion by roots, causing leakage or blockage in the pipe.
  • When your side sewer is blocked, sewage from your home can back-up in your pipes and surface through your sinks, toilets, bathtubs and other building drains, causing a health issue as well as a potentially expensive mess. Side sewer blockages are typically caused by failures in the pipe. Potential failures can be easily detected by a simple inspection before they cause a serious problem.
  • Rainwater and groundwater that gets into the sanitary sewer system from leaky side sewers, and roof and foundation drains can cause overflows of untreated or partially treated wastewater (sewage) into streets, homes, businesses and local waterways. This rainwater and groundwater should be directed to the local surface water system.
  • Just as groundwater can leak into a side sewer, sewage can leak out of a side sewer and become a public health hazard.
  • If you know the condition of your property’s side sewer, you can better prepare for repair or replacement instead of finding out about a problem when the sewer backs up.

How do I find out the condition and age of a side sewer and what it’s made of?
How do I know if there are sources of rainwater or Groundwater getting into the side sewer?

  1. Ask the current property owner if there have been any issues with slow-draining plumbing fixtures, sewage backups, or if there have been any inspections or repairs on the side sewer.
  2. The City has permit records for some of the properties in Tacoma. To research City of Tacoma permit records, visit and click on Permit / Site History or call Site Development at 253-591-5760.
  3. Hire a side sewer contractor or a drain cleaner to perform a video inspection of the side sewer and to inspect the building for sump pumps, drains, or other sources that may be allowing rainwater or groundwater to enter the side sewer.

Need help paying for sewer repairs or replacement?
If your side sewer needs repair or replacement, you may be eligible for a low-interest loan through the City’s Sewer Conservation Loan Program. For more information, go to or call (253) 591-5760.

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