Quick action was required to prevent an imminent release of refuse to the marine environment from a landfill perched atop a rapidly eroding high coastal bluff above the Straits of Juan de Fuca. We met the challenges posed by the site’s complex geometry with design elements including: aggressively steep cut and fill slopes (2.5H:1V) in refuse and a 110-foot-high mechanically reinforced earth buttress to stabilize the seismically unstable slope, a new cover system with a bentonite-amended low-permeability soil layer below a synthetic turf cap, and shoreline stabilization seawalls and revetments. Successfully accelerated, the project was completed in about half the time typical of similar projects.
Washington Boulevard, located along a steep coastal bluff, has exhibited landslide movement several times in the past decade. Aspect performed multi-phase geologic and geotechnical assessments of earth movement with focused deep-subsurface explorations. Results of the exploration and slope-stability analysis were verified with slope inclinometers and groundwater level monitoring. Based on our targeted remediation concepts and cost estimates, Kitsap County decided to add drainage improvements to enhance stormwater handling. In addition, Kitsap County implemented a groundwater and landslide monitoring program, which Aspect is effecting.