Side Sewers 101

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What is a private side sewer?
A side sewer, also known as a lateral sewer or private connection, carries wastewater from a home or business’s toilets and drains to the City’s main sewer line, where it continues to a wastewater treatment plant.

Who is responsible for the maintenance of the side sewers?
Maintenance of side sewers, from the building to the City main, is the responsibility of the private property owner. The City’s responsibility is the maintenance of the sewer main, including the tees, wyes and risers at the main.

What are common problems associated with side sewers?
Side sewer pipe made of clay or concrete can crack, shift out of place, and/or be subjected to intrusion by roots, resulting in leakage and blockage. In addition, some side sewers lack the right kind of cleanouts, which provides access for clearing blockages. A cleanout is a pipe that extends vertically from a side sewer to ground level or close to the ground surface; it is used for access to clean and inspect a side sewer.

Should I have my side sewer inspected?
When your side sewer pipe fails and causes a blockage, 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. Potential failures can be easily detected by a simple inspection before they cause a serious problem.
The City recommends that property owners investigate the location and condition of their existing side sewer – especially if the sewer is more than 25 years old or does not have plastic PVC pipe running from the building to the City sewer main.

Are side sewer repairs or replacement expensive?
Yes. Side sewer repairs or replacements can average $5,000 to $10,000. Costs will be greatly impacted by the number of surface improvements, such as street or driveway pavements, sidewalks, retaining walls or extensive landscaping that need to be rebuilt and also by the depth of the side sewer.

Does the City have any information about my side sewer?
The City has permit records for some, but not all, of the properties in Tacoma. To research City of Tacoma permit records, refer to Searching for Permit Records tip sheet. For recent permit history call Site Development at 253-591-5760 or email at . You may also search the City’s online records for permit information and verify that a permit was issued through our Online Permitting system, at The City has more information about homes built after 1950, and has records only of work done with permits.

How do I know where my side sewer is located?
To find the location of a home or business’s side sewer, check building plans, ask the previous owner, or look for cleanouts in the yard or landscaping. You can also contact the City to see if there are any permit records for your property that show the location of the side sewer.

How do I find the cleanout?
Not every property has a cleanout. Most cleanouts are located within 2 feet of the building where the side sewer comes out or approximately where the side sewer crosses from private property into the right-of-way. In some older homes, cleanouts may also be found in basements or within crawl spaces underneath homes. Cleanouts are typically covered with a plastic or metal lid or are just a 4- to 6-inch pipe extending out of the ground with a screw-on cap. You can also contact the City to see if there are any permit records for your property that show the location of a cleanout.

How do I know what kind of side sewer I have?
Most homes in Tacoma were built before 1950 and few have had their side sewers replaced. Clay and concrete sewer pipe was used extensively up through the 1970s. Since then, most side sewers have been constructed with more modern and tighter sealing materials such as PVC. You can contact the City to see if there are any permit records for your property that show the pipe material used to construct your side sewer.

What if my side sewer has cracks/debris/holes/roots, but the sewer line still works? Do I have to fix it?
You are not required to make immediate repairs, but are encouraged to plan for repair or replacement as appropriate. A side sewer with cracks or breaks can more easily become blocked by dirt, rocks or roots. A blocked side sewer line can back sewage up into a building and potentially cause property damage. Being aware of the condition of your side sewer means you can be proactive with planned repair and maintenance rather than being surprised with a big mess and a hefty repair bill. To read about the City of Tacoma’s recommendations regarding specific side sewer problems, please refer to the Side Sewer Condition Assessment & Repair Manual. For a copy, go to or call Site Development at 253-591-5760.

At what point am I required to repair or replace my side sewer?
If a property’s side sewer problem gets to the point where sewage won’t flow at all and backs up into a building, yard or elsewhere outside the plumbing system, it is considered a Sanitary Sewer Overflow, which is illegal and a health hazard. If this happens, the City notifies the property owner and gives a fixed amount of time to make repairs. In the event that repairs aren’t made in the time provided, the property owner may face fines or water shut-off by the health department.

What if I have a sump pump/roof drain/floor drain connected to my side sewer?
Property owners are encouraged to make sure surface water from roofs, floor drains, sump pumps, etc., either soaks in on site or is directed to the surface water system. During heavy rains, rain that gets into the wastewater system causes “peak flows” that can be as much as seven times the normal flow in the system. This can overwhelm the wastewater sewers and treatment facilities, resulting in untreated or partially treated wastewater overflowing into basements, streets or Commencement Bay. Keeping rain out of the surface water system also helps keep wastewater rates lower by not having to spend money to treat clean surface water.

What’s the difference between the surface water system and the wastewater system?
The City of Tacoma has a separated sewer system.

  • The wastewater system collects water that leaves homes and businesses through sinks, showers and toilets. It flows through your side sewer, the City’s sewer main and pump stations to the wastewater treatment plant where it is treated. The treated water is released into Commencement Bay.
  • The surface water system collects water that runs off our streets, roofs, yards and driveways. It flows through drains, storm sewer pipes, pump stations and/or stormwater holding ponds directly into streams, rivers, Commencement Bay and Puget Sound.
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