Port Angeles Landfill Accelerated Geotechnical Investigation and Design

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.