Wastewater infrastructure investments a major priority in 2007

Continuing its forward-thinking program to ensure the regional sewer system functions reliably and keeps pace with growth, King County’s Wastewater Treatment Division will invest $230 million this year in nearly a dozen major capital improvement projects and numerous smaller ones that will protect public health and water quality over the next several years.

Projects include upgrading and replacing aging facilities, expanding existing ones and building new facilities such as the Brightwater treatment system to provide enough capacity for the region’s growing population. Planned projects will also include controlling combined sewer overflows, cleaning up contaminated sediment in the Duwamish River and Elliot Bay, and continuing construction on a pipeline and facilities to distribute reclaimed water in the Sammamish Valley.

Major construction and design projects scheduled for 2007 throughout the system include:

East King County Carnation Wastewater Treatment Facility:Construction is now under way on a wastewater treatment facility to replace failing septic systems in the City of Carnation. In addition to the treatment plant, the county will also begin construction on the companion Chinook Bend Wetlands Enhancement project, which will use the highly treated reclaimed water produced at the new plant to enhance and improve habitat in the Chinook Bend Natural Area. The Chinook Bend Natural Area will serve as the primary discharge point for the plant, which is scheduled to begin operating in 2008. Expenditures this year are expected to be $13.5 million.

Juanita Bay Pump Station Replacement Project: The county plans to spend about $11 million to continue work on a new 30.6 million-gallon-a-day pump station in north Kirkland, which will provide additional capacity to serve growth in this portion of the system. The pump station will be 70 feet deep and will include three underground levels to house pumping and electrical equipment.

Bellevue Pump Station Upgrade: The county expects to solicit bids and select a contractor to upgrade an aging pump station in west Bellevue and build a new 5,500-foot-long, 24-inch-diameter force main for carrying wastewater for treatment at South Plant in Renton. The county has budgeted $9.8 million for project-related expenditures in 2007.

North King County/South Snohomish County

Brightwater: Construction is under way on Brightwater, the county’s largest clean-water project in 40 years. King County has budgeted about $153 million in 2007 for construction on the conveyance system, which includes a pump station in Bothell and a 14-mile-long wastewater pipeline that will run 40 to 450 feet below ground from the Brightwater Treatment Plant north of Woodinville to Point Wells in Shoreline.

In 2007, the county will spend about $50 million as construction on the treatment plant facilities begins as early as this summer. County staff will continue working with Snohomish County to secure building permits. Construction on the Brightwater North Mitigation Area, located at the north portion of the 114-acre treatment plant site, will conclude in 2007. This project includes 40 acres of open space, habitat enhancement, trails and a field house for community use. Investment in this project from 2006 to 2007 will reach about $8 million.

Brightwater Reclaimed Water Backbone: Construction continues this year on a pipeline system to bring reclaimed water produced at the Brightwater Treatment Plant to irrigators and industrial customers in north King and south Snohomish counties. The project includes converting an existing force main into a reclaimed water pipeline that will run from the North Creek Pump Station in Bothell to the York Pump Station in Redmond, and installing reclaimed water pipes in the tunnel being built for the Brightwater conveyance system. Expenditures are estimated at $1.6 million in 2007.

Hidden Lake Pump Station and Sewer Improvement Project: This project in Shoreline will replace King County’s 40-year-old Hidden Lake Pump Station and 12,000 feet of the Boeing Creek trunk sewer. The project also includes a 500,000-gallon underground wastewater storage pipe to prevent overflows to Puget Sound. Additionally, the county is working with Seattle Public Utilities to replace 5,000 feet of water mains. The county plans to spend about $15.2 million in 2007 during construction on the new pipelines, the storage facility, and 6.8-million-gallon-a-day pump station.

Seattle

Combined Sewer Overflow Control: The county will continue its program to reduce combined sewer overflows, or CSOs, that occur in older parts of the system during heavy rains, degrading water quality and posing public health risks. In 2007, King County will spend about $1.7 million to begin predesign on the Puget Sound Beaches Project to upgrade pump station facilities and/or increase storage at the North Beach, Murray and Barton pump stations, and South Magnolia outfall. The projects will include a siting process that will enable interested community members to get involved in some aspects of project planning.

Sediment Management Program: This program enables King County to proactively address sediment contamination near combined sewer overflow, or CSO, locations in Puget Sound. Among planned projects for 2007, the county will work with permitting and regulatory agencies as planning gets under way on a project to remove an estimated 17,000 cubic yards of contaminated sediment at the old Denny Way outfall near Myrtle Edwards Park. Expenditures for the program are expected to be $2.7 million.

Densmore Drain: The county will install a stilling vault and ventilation pipe to better control stormwater and prevent overflows into the Lake Washington Ship Canal and Lake Union. The project will also include replacing the existing 36-inch-diameter drainpipe with one that’s more stable and reliable. Construction on this $1.6 million project should be completed this spring.

Lower Duwamish Waterway Cleanup: The county will continue its commitment to cleaning up contaminated sediments, implementing source control actions, and complying with agreements with regulators and local governments. In 2007, the Wastewater Treatment Division will continue to work with the City of Seattle on the cleanup of Slip 4, an identified early action area in the Lower Duwamish Waterway. The $1.6 million investment in 2007 will also include continued collaboration with the City of Seattle, the Port of Seattle and The Boeing Company on the Lower Duwamish Waterway Superfund site, which is part of a long-term cleanup effort.

53rd Avenue Pump Station: Improvements to this Alki Avenue pump station will increase system reliability and help make the facility a better neighbor. Planned construction, scheduled to begin in September, includes installing new odor control equipment, upgrading the facility’s electrical and mechanical systems, and doubling the size of the below-ground pump station. The county is now finalizing design and securing permits needed to begin the project in September. Expenditures this year are expected to be $3.2 million.

Ballard Siphon: To protect water quality in the Lake Washington Ship Canal, King County is investing $16.4 million in the Ballard Siphon Project, which will replace a 70-year-old wooden sewer pipe that extends across the floor of Salmon Bay near the Hiram M. Chittenden Locks. In 2007, the county will focus on completing design, securing permits, and soliciting bids for construction.

King Street Odor Control: In 2007, the county will begin a project to build a new one-story odor control facility just south of King Street Station near the Weller Street Bridge. The project will help improve air quality in south Pioneer Square by reducing or eliminating odors from the Elliot Bay Interceptor, a large sewer pipe that carries wastewater from south Seattle through the downtown area to West Point Treatment Plant. Expenditures this year are expected to be $1.1 million.

Murray Avenue Pump Station: This year, King County will spend $1.2 million upgrading the electrical system in this West Seattle pump station. The county will also finalize design on a structure for new odor control and emergency generator equipment, which will incorporate the design guidelines established with the help of local community members.

South King County

Fairwood Interceptor: King County will soon complete a project that began in 2000 to re-route and replace an aging pipeline in an area prone to erosion and landslides, and to improve water quality and slope stability around Madsen Creek. The project also included upsizing pipes to increase system capacity in the area. The county expects to invest $900,000 this year to complete construction of the project and to restore roads, sidewalks and public rights-of-way that were disturbed by the earlier construction work

Kent/Auburn Conveyance System Improvement Project: This project will expand capacity in the rapidly growing south portion of King County’s service area by adding approximately five miles of 18-to 54-inch-diameter pipes in Kent, Auburn, Algona and Pacific. Construction is scheduled to start in 2008 and conclude in 2010. The county plans to spend about $3 million on design work in 2007.

Black Diamond Wastewater Storage Facility: In 2007, the county will begin design on an underground wastewater storage facility in the City of Black Diamond that will extend the life of existing equipment and defer the need to build additional new pumping facilities for several years. The county plans to spend about $1 million of the project’s overall $5 million budget this year.

Regionwide

Regional Infiltration and Inflow (I/I) Control Program Implementation: The county is working cooperatively with local sewer agencies to implement the Regional I/I Control Program, which was approved by the King County Council in 2006. I/I is clean water that gets into the sewer system from leaky pipes or manholes on private property or local sewer systems during rainy weather, taking up capacity needed for wastewater conveyance and treatment. In 2007, the county will begin work on at least two projects to reduce the volume of I/I that gets into the sewer system. By investing $25 million in these projects over two years, the county hopes to find cost-effective ways to reduce I/I and save ratepayers money over time by not having to build new facilities to accommodate these flows.

For more information

Other information about wastewater construction projects and programs is available on the Web site for the Wastewater Treatment Division:

The wastewater treatment system operated by King County now includes 348 miles of sewer lines, 47 wastewater pump stations, three stormwater treatment plants, a treatment plant on Vashon Island, two regional treatment plants in Renton and Seattle, and two new treatment plants under construction in south Snohomish County and the City of Carnation. The system now serves 1.4 million people across a 420-square-mile area in the central Puget Sound region including parts of Snohomish and Pierce counties.

Formerly called Metro, the regional public utility has been preventing water pollution for more than 40 years.