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Natural Resources and Parks

King County, Washington

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Feb. 23, 2011

Clean-water investments bolster economic growth, support regional environmental goals

Sewer improvement projects top King County priority list in 2011

Investments in clean-water projects to support economic growth, protect Puget Sound and sustain the region’s enviable quality of life will be a top priority in 2011 for King County Executive Dow Constantine.

“Clean water and adequate wastewater treatment capacity are crucial for economic growth and job creation,” said Executive Constantine. “Our wastewater treatment system keeps tons of pollutants out of our regional waterways each year and protects the natural resources that make our area such an attractive place to live, work and play.”

Over the coming year, King County’s Wastewater Treatment Division will invest $232 million in dozens of sewer improvement projects to upgrade aging facilities, build new capacity to accommodate population growth, and improve water quality by reducing combined sewer overflows near some of Seattle’s most popular recreation areas. Other projects include addressing historically contaminated sediments in the Lower Duwamish Waterway and Elliott Bay.

“In King County, economic prosperity and environmental health are intertwined. The investments we’re making this year will put people to work in the short term while providing infrastructure to support long-term economic growth and responsible development,” said Constantine.

Here is a list of some of the major projects King County will undertake in 2011.

North King County/South Snohomish County

Brightwater: Construction is winding down on the largest expansion of the regional wastewater treatment system since the 1960s. Component testing has already begun at the Brightwater Treatment Plant, which is nearly completed and on schedule to begin operating in August. The plant’s adjacent community and education center, along with more than 70 acres of restored habitat and public space, will be open to the community in September.

Contractors are scheduled to complete mining on the remaining 1.5 miles of tunnel in September. King County has budgeted $121 million on Brightwater in 2011.

North Creek Pipeline: In 2011, King County will budget $2.4 million to begin initial design on a project to replace a 14,275-foot segment of sewer line that carries wastewater from a large portion of south Snohomish County to King County’s regional system for treatment.

East King County

Kirkland Pump Station: King County is budgeting $5.5 million in 2011 to continue construction upgrades to this aging facility that serves City of Kirkland sewer customers. The project will entail increasing pumping capacity, replacing aging equipment, and installing new, larger diameter pipes.

Bellevue Influent Trunk: King County is budgeting $4.1 million in 2011 to replace and enlarge a segment of sewer line originally constructed in 1966. Construction is scheduled to begin in June.


Puget Sound Beach CSO Control: King County will move forward on four projects to control combined sewer overflows, or CSOs, that occur during heavy rains near popular recreation beaches in West Seattle, North Beach and Magnolia. The county has budgeted $5.2 million on environmental review, permitting and design in 2011.

Ballard Siphon: King County has budgeted $12.5 million to begin construction on a project to replace a 75-year-old wood stave pipe that extends across the Lake Washington Ship Canal. The new pipe will replace a 36-inch-diameter sewer pipe that was installed in 1935 and currently conveys up to 60 million gallons a day of wastewater across the canal.

Fremont Siphon: King County has budgeted $1.9 million to begin preliminary design on a project to replace the Fremont Siphon, which has been in service for more than 100 years.

Interbay Pump Station: Construction will get under way in 2011 on a project to replace pumping equipment and aging electrical systems at this critical pump station near the West Point Treatment Plant in Magnolia. The county has budgeted $5.7 million for the project this year.

Barton Street Pump Station upgrade: In 2011, King County has budgeted $1.9 million to continue final design for upgrading this pump station to meet current design and safety standards. Improvements will include a new emergency generator system, larger pumps, and an upgraded electrical system.

West Point Waste-to-Energy: In 2011, King County has budgeted $9 million for construction on a new cogeneration a facility that will convert digester gas into a source of heat and electrical power for the treatment plant. An $8.2 million grant awarded by EPA in 2009 will cover about 44 percent of the project’s total cost.

Sediment Management Program: This program enables King County to address sediment contamination near CSO locations in Puget Sound. The county has budgeted $1.5 million in 2011 to continue its efforts to remove historic CSO contamination and restore habitat at locations in Elliott Bay and the Duwamish Waterway.

South King County

South Treatment Plant improvements: In 2011, King County has budgeted $10 million for a number of projects at the South Treatment Plant in Renton to improve system reliability, increase efficiency and ensure continued compliance with permits. Projects include replacing outmoded control system software, replacing pumps and relining pipes and tanks.


Lower Duwamish Waterway Superfund : King County will maintain its involvement in the Lower Duwamish Waterway Group, which is currently working with EPA and the state Department of Ecology to identify a Superfund cleanup strategy to address historically contaminated sediments in the waterway. The county has budgeted $2.7 million to work on Superfund activities in 2011.

Regional Infiltration and Inflow Control Program: In 2011, King County will invest $5.8 million to partner with the Skyway Water and Sewer District on a project to repair leaky pipes in their system to keep stormwater and groundwater out of regional treatment facilities, which takes up capacity and costs money to treat.


People enjoy clean water and a healthy environment because of King County's wastewater treatment program. The county’s Wastewater Treatment Division protects public health and water quality by serving 17 cities, 17 local sewer districts and more than 1.5 million residents in King, Snohomish and Pierce counties. Formerly called Metro, the regional clean-water agency now operated by King County has been preventing water pollution for nearly 50 years.

Note to editors and reporters: Visit the WTD Newsroom, a portal to information for the news media about the Wastewater Treatment Division, King County Department of Natural Resources and Parks:

Related information

Projects under construction and in planning

King County Wastewater Treatment