Location: St. Helens, Oregon
Client: Confidential Pulp and Paper Manufacturer
Contract Value: $1,088,967

AEC was selected to perform closure activities at a former mill site which involved constructing a six-acre cover over the existing disposal area of the mill’s clarifier solids landfill.

Along with initial clearing and grubbing, AEC crews graded a substantial amount of material in place on the westerly side of the landfill to achieve minimum slopes and provide smooth contours. We then filled localized areas of stabilized slopes with waste from the westerly side of the landfill, and placed on-site soil or imported fill material as needed to achieve minimum slopes and provide smooth contours. We removed excess rock from the top of the corner berm extensions and placed it in the west side of the landfill to help shape the final contours for positive surface drainage. Next, we exposed the bottom clay layer along the perimeter of the edge where the final cover tie-in occurred.

In total, we installed 270,000 square feet of geomembrane liner, 62,000 square feet of geocomposite drainage layer, 10,000 tons of imported sand layer, 16,000 cubic yards soil cover layer, and 4,290 lineal feet of gas collection trench with pipe, The project required us to procure, manage, and perform strict quality control on large quantities of import materials such as rip rap, sand, geotextile, and pipe.

After all heavy excavation activities were complete, we installed a passive gas venting system and vegatative layer, constructed stormwater management facilities, and stabilized the site with appropriate eriosion control measures.