Seattle Public Utilities (SPU) is set to begin sewer inspections using a method called "smoke testing" in West Seattle’s Arbor Heights Neighborhood, with work scheduled from late July through the end of August 2025. This initiative is part of SPU's ongoing efforts to safeguard public health and the environment by maintaining essential sewer and drainage systems.
The project aims to identify sewer leaks and pipe connection problems within the public right-of-way. SPU has contracted Pro-Vac to conduct these inspections. The process involves blowing a colorless water vapor, often referred to as “smoke,” into sewer pipes through maintenance holes. This "smoke" is non-toxic and non-staining, although it may carry a distinctive odor. It is capable of traveling up to 1,500 feet within the sewer pipe.
What Residents Should Expect:
• Advance Notice: Residents in affected areas will receive a door hanger notice 24 to 48 hours before the inspection takes place.
• Normal Services: Homes and businesses will continue to receive normal sewer services throughout the inspection period.
• Preparing Your Home: To prevent the "smoke" from entering your building, residents are advised to run water for 30 seconds in all sinks, baths, and showers, and pour water into exposed floor drains prior to the testing. This ensures that "p-traps" – the U-shaped pipes under each drain – are filled with water, which acts as a seal.
• Normal Observations: It is normal to see or smell the "smoke" coming from maintenance holes in the street or right-of-way, sewer vents from roofs, or emerging from the ground. In such cases, no action is required.
• If Smoke Enters Your Building: If you detect or smell “smoke” inside your house or building, open doors or windows immediately to increase ventilation. The vapor should clear within a few minutes.
• Persistent Smoke Inside: If smoke continues to remain in your building for more than five minutes, you should speak with the on-site field representatives or workers conducting the inspections. Alternatively, you can contact SPU’s emergency Operations Response Center (ORC) at (206) 386-1800.
• Plumbing Issues: Smoke may enter a building if there are issues with the building's sewer pipe vents or p-traps. If smoke entered your building and did not stop after you added water to a drain, SPU recommends considering contacting a plumber to investigate potential plumbing problems.
For more information about the project, residents can contact Kenny Moffat at Seattle Public Utilities by calling (206) 615-1013 or emailing kenny.moffat@seattle.gov. Interpretation services are available by calling the same number
