OwnerRappahannock Regional Solid Waste Management Board
489 Eskimo Hill Road
Stafford, VA 22555
Project TypeLandfill Cap - 18 acres
EngineerDraper Aden Associates
8090 Villa Park Drive
Richmond, VA 23228
Start / FinishJuly 2016 - November 2016
Description / Significance
Sargent Corporation completed a project to cap Cells B, C, and D of the Rappahannock Regional Solid Waste Management Board (R-Board) Regional Landfill in Stafford, Virginia.
After crews stripped the topsoil and completed site preparation on the area to be capped, they ensured that a 12″ layer of intermediate cover soil was in place to provide a cushion for the liner system on top of the existing waste.
The project required crews to place 25,500 cubic yards of intermediate cover soil below the liner system and 48,000 cubic yards of protective cover soil on top of the liner system. All of the soil fill came from two on-site borrow areas.
Crews also brought in 11,000 cubic yards of fill to construct 8,900 linear feet of stromwater diversion berms on the side slopes of the landfill.
After construction of the stormwater diversion berms, crews installed a 4″ sockpipe – a perforated pipe covered by a sock – like fabric that filters the water and prevents fine-material from getting into the pipe – buried about 12″ deep in the toe of the berms.
Crews also extended existing landfill gas wells to meet the new cap grades, installed 3,800 square yards of Flexamat in the side slope water downchutes in lieu of rip rap, and installed 500 cubic yards of rip rap toe drain around the perimeter of the cap.
Several challenges were met due to the majority of work being completed on steep slopes while installing liner around and over the side slope berms.