(Certified Best Practice by BMPCOE)
Department of Energy, Oak Ridge Operations - Oak Ridge, TN
Due to the requirements of the Resource Conservation and Recovery Act (RCRA), certain landfill and hazardous waste areas at the DOE-Oak Ridge Facilities had to be contained. Leaching was occurring from the buried wastes into the groundwater system through the numerous faulted rock layers, and therefore the means of preventing the surface water from penetrating the filled areas needed to be developed.
The Oak Ridge
Facilities personnel applied their extensive expertise in RCRA permits,
containment, closure plans, and dealing with all of the regulatory
Areas as large as 90 acres had to be capped, and the
solution that was developed was to contour the top surface into a berm shape.
Two feet of clay was highly compacted to a permeability of 1x10-7 cm/sec. The
clay was then covered with 30 mil poly vinylchloride (PVC) welded into one
piece. A drain net with a filter on top was then placed on top of the PVC to
allow the water to drain as much as possible before reaching the PVC in lieu
of the normal one foot of sand. Two feet of earth was placed on top to provide
for green cover growth (Figure 4-2).
This method has proven effective at stopping the leaching and could have wide application to many industrial and municipal landfill operations. Over 600 wells are in use at Oak Ridge for monitoring the leaching.