The American Council of Engineering Companies (ACEC) Washington recently recognized two GeoEngineers projects with local Engineering Excellence Awards, the Fishtrap Creek Suspension Bridge and Go East Landfill Closure. The Go East Landfill Closure and Redevelopment won a Silver Best-in-State Award for Complexity, and the Fishtrap Creek Suspension Bridge received a Gold Best-in-State Award for Original or Innovative Application of New and Existing Techniques. GeoEngineers is proud to have contributed to these award-winning projects alongside talented partners—and congratulations to the owners, the City of Lynden and Century Communities!
Fishtrap Creek Suspension Bridge
Gold Best-in-State, Washington
Located in Lynden, Washington, the new Fishtrap Creek Suspension Bridge spans Fishtrap Creek, connecting Depot Street to North 8th Street as part of the Jim Kaemingk Trail extension. The 120-foot-long multi-modal (pedestrian and bikes) suspension bridge features pin pile supported cast-in-place concrete abutments, “dead man” anchor beams for cable support, weathering steel towers, and a timber superstructure.
A GeoEngineers team led by Sean Cool played a pivotal role in the geotechnical design, ensuring the 8-inch diameter pipe piles and 5-foot-tall by 16-foot-long buried concrete anchor beam would provide suitable support for the bridge. The bridge connects to a new section of at-grade paved trail and 225 feet of elevated boardwalk through wetland areas, supported on diamond pier foundations to minimize impacts. GeoEngineers (Fiona McNair) also provided environmental permitting services and habitat mitigation design for the bridge and trail project.
The Fishtrap Creek Suspension Bridge is not only a vital public asset but also a landmark in Lynden, reflecting the city’s commitment to sustainable growth and environmental stewardship. This ACEC award underscores the project’s success in integrating engineering excellence with community needs and environmental responsibility. The project’s construction was completed with significant volunteer labor.
Go East Landfill Closure and Alpine Estates Subdivision Redevelopment
Silver Best-in-State, Washington
GeoEngineers partnered with private investors, Century Communities, and PACE Engineers to safely close and redevelop the abandoned Go East Landfill in southeast Everett, Washington. Decades of inaction left the site contaminated, unsafe, and unutilized. Through careful environmental planning and geotechnical engineering design, GeoEngineers helped transform this brownfield into a community park surrounded by Alpine Estates, a 96-unit residential development.
putting DDC into action at the Go
East site in April, 2021.
GeoEngineers’ project team was led by Bob Metcalfe and Colton McInelly (geotechnical engineering and landfill cap design), and Terry McPhetridge and Garrett Leque (environmental expertise). The project required support from design through construction from a large team of GeoEngineers staff over the past five years. The landfill closure successfully consolidated 60,000 cubic yards of landfill debris from a 9.6-acre footprint to a 6-acre footprint and capped the landfill with a LLDPE geomembrane and geocomposite drainage system, and two feet of soil cover to isolate contaminated material.
To address potential long-term settlement concerns beneath the stormwater detention pond, GeoEngineers designed and implemented Deep Dynamic Compaction (DDC) to compact the landfill material below the pond footprint before the geomembrane system was installed. DDC reduced settlement risks to the detention pond and geomembrane cap system while reducing project costs, time, and risks associated with traditional over-excavation and replacement methods.
GeoEngineers also provided full-time environmental oversight to manage the excavation and disposal of hazardous materials, including 250 tons of asbestos-containing debris. The project mitigated health risks for residents while minimizing environmental disruption by preserving less-impacted areas of the site, such as the northeast slope. GeoEngineers also provided full-time monitoring and testing during construction of the landfill cap system including the geomembrane installation and seam welding, geocomposite drainage layer installation, anchor trench construction, as well as realignment of the west creek.
Once the landfill was successfully capped and closed, a real-estate deal with Century Communities completed the transformation and ultimately funded the landfill closure. Instead of hazardous and abandoned land, the property has been transformed into a community park constructed over the consolidated landfill and surrounded by a new 96-unit residential subdivision.
