Repair on a wastewater maintenance hole

The Wastewater Division of Public Works operates, maintains, and repairs 123 miles of wastewater (sewer) mains, over 3,600 maintenance holes, and six wastewater pump stations. The pump stations convey wastewater to King County's Wastewater Treatment Plants.

The Wastewater Division maintains the City's wastewater mains by performing cleaning, ensuring root removal, and conducting video inspections of the sewer main lines. They also maintain the wastewater maintenance holes through cleaning and infiltration and structural repairs. The photo above is a structural repair done by maintenance crews during the summer of 2019. They are also responsible for keeping Kirkland's six wastewater pump stations operating continuously.

Wastewater is the used water that enters the wastewater system via sinks, toilets, showers, washing machines, drains, and other fixtures. It is mostly water but also contains phosphorous, nitrogen, fats, oils, grease, pathogens, and solids. Kirkland’s wastewater system is separate from the stormwater system, which captures water through storm drains and the natural environment. Stormwater does not go to a treatment plant like wastewater; it travels into our streams, rivers, and finally into Lake Washington.

There are two sewer districts within the city limits of Kirkland. The Northshore Utility District provides wastewater service to the northern, more recently annexed part of the City while Kirkland Public Works provides service to the southern portion. The Northshore Utility District can be reached at 425-398-4400. This map shows the approximate boundaries of the different water and sewer districts(PDF, 10MB) that serve Kirkland.

There are 11,202 private side sewer connections to the City's main. If you would like the City to check for an as-built for a particular property within Kirkland's sewer area, use the Our Kirkland service portal or call 425-587-3800.

Keep your drains fat-free!

Fats, oils, grease (FOG) comes mostly from pre-rinsing dishes or washing pots and pans in the kitchen. When cooking fat, oil, or grease is allowed to go down the drain, it eventually cools in the wastewater (sewer) system and sticks to pipes creating FOG buildup, also known as a fatberg.  The buildup causes clogs and backups into homes and businesses, wastewater overflows and spills onto private property, streets, and into local waters.  FOG buildup increases the cost of maintaining Kirkland's wastewater treatment systems and can create serious public health problems.  FOG can wreak havoc on wastewater drains and pipes. Fortunately it is also a valuable resource.  You can recycle your used cooking oil by bringing it to a collection tank at the North Kirkland Community Center

Don't flush trash

King County: Wipes, paper towels, and other "unflushables" can create a sewer backup in your home. Flush only toilet paper and protect your home, the sewer system, and the environment.

 Only flush toilet paper - everything else in the trash even if labeled as flushable

Only flush toilet paper - everything else in the trash even if labeled as flushable

Sewer rates

Current City of Kirkland sewer rates can be found on this page Water, Sewer, and Garbage Rates

Septic systems

Public Health — Seattle & King County's On-site Sewer System (OSS) Program provides educational, advisory, and permitting services for owners of septic systems.

King County Regional Wastewater Services Plan

Since 1958, King County has protected water quality in the Puget Sound region by providing wastewater treatment services to King, Pierce, and Snohomish counties. Visit the King County Regional Wastewater Services Plan page to learn more. 



Industrial waste

All dischargers that generate and dispose of industrial wastewater to the sewer system must get approval from the King County Industrial Waste Program prior to discharging.