Opal Group Inc.

Stapleton Voluntary Closure

City and County of Denver Department of Aviation

Denver, CO

The City and County of Denver agreed to perform a Voluntary Corrective Action to close a former waste disposal area. The site is located on property near the former Stapleton International Airport in Denver, Colorado. The purpose of the corrective action was to contain a former unauthorized six-acre drum disposal landfill area. The closure was made particularly difficult due its close proximity to the Sand Creek stream channel and adjacent Sierra Club wetlands area. The key elements of the corrective action, implemented by Opal Group, L.L.C. personnel, included the following:

Construction of a 1,850 linear foot bentonite slurry containment wall surrounding the landfill area. The slurry wall averaged 25 feet in depth and was keyed two feet into a regional shale layer.
Installation of a 6-acre composite cap over the landfill area.
Restoration of approximately 600 linear feet of tributary embankment.
Excavation and placement of 67,000 cubic yards of soil for composite landfill cap.

Type of Work: Multi-Media Cap, Slurry Wall, Stream Bank Modifications

Size: 6 acre cap, 67,000 cyds Excavation, 1,850 ft slurry wall

Services: Environmental Remediation