The Washington State American Public Works Association (Washington APWA) gave a Project of the Year Award to GeoEngineers’ Oak Harbor Clean Water Facility project. The new facility, along with the adjacent Windjammer Park and other waterfront features, are landmark projects for the Oak Harbor community on Whidbey Island, Washington.
GeoEngineers provided geotechnical services as a subconsultant for this complex project for almost a decade—and guided it through every phase of development.
“It felt like we did a little bit of everything on this project,” said GeoEngineers Project Manager Sean Cool. “The extent of our involvement, from early site selection to design and construction observation, was unique.”
Senior Principal Geotechnical Engineer J. Gordon collaborated with the city and design team during the site selection process in 2010, when Oak Harbor began planning for a renovated waterfront area blending public park land, natural wetland areas and overhauled water treatment facilities. Along the way, GeoEngineers also provided geotechnical services for a new outfall and renovations of the neighboring Windjammer Park.
Soil conditions on the site proved challenging. The nearshore site contained liquefiable beach deposits, organic material and shallow groundwater. The geotechnical team recommended sheetpile and tieback shoring (that also acted as a groundwater a cutoff wall for up to 25-foot deep excavation) and a combination of ground improvements including stone columns and micropiles to give adequate foundation support and uplift resistance.
The new complex replaces an aging water facility once located on part of this waterfront site and at a nearby lagoon. As the system aged it could no longer be used as designed, leaving Oak Harbor with a patchwork water treatment system in need of replacement to meet current and future demands. Now, all the city’s wastewater will be treated at the new facility using sustainable membrane bioreactor (MBR) technology, drastically improving the quality of outfall water entering Oak Harbor Bay.
GeoEngineers’ Bellingham geotechnical team spearheaded our work on this project, but staff from across the company contributed expertise around specific shoring and groundwater issues. As the project ramped up, Cool also had to call on more engineers and field staff to help with monitoring during construction.
“It’s one of the things I love most about our company,” Cool says. “Our ability to call on specialized people for these big projects is valuable. And we couldn’t have done it without the numerous field staff that came up and helped out during construction.”