Sanitary Sewer Utility

Sewer Utility crews are responsible for maintaining the public sewer system to ensure a constant and efficient flow of wastewater. Crews utilize special equipment including high-pressure jetting, special cameras to inspect lines for breaks or blockages due to fats, oil and grease (FOG) or tree roots. This includes the maintenance of: 

• Over 105 miles of sanitary sewer lines and approximately 2,400 manholes
• Maintaining lift stations
• Responding to system emergencies
• Implementing the City's Fats-Oil-Grease Program

What the City Does 

Wastewater generated from bathrooms and kitchens is collected and pumped through a series of pump stations and low-pressure mains that convey flows around the perimeter of the island through the City’s Lakeline sewer system and then to a King County Department of Natural Resources treatment facility in Renton.  

Fats, Oil and Grease (FOG)

FOG can clog pipes and can create public health problems. FOG comes primarily from cooking, where fats, oil and grease from rinsing dishes can go down the drain. As the FOG cools in the wastewater system, it builds up along the inner walls of the pipe causing backups. Never pour grease or put food waste down the drain or toilet.​ Food service establishments must also follow special regulations to minimize FOG. Learn more about FOG.