As part of its decades-long support of environmental remediation efforts at the former Langley Air Force Base, now part of Joint Base Langley-Eustis, HGL designed a joint remedy to address contaminated soil and sediment at three neighboring sites. These sites included a former landfill, a pesticide storage area, and a shoreline area adjacent to the landfill known as the LTA Cove. The remedy included dewatering the cove by installing sheetpile cofferdams, excavating/disposing of 17,000 cubic yards of PAH- and lead contaminated soil and sediment on site, constructing a landfill cap, and restoring 5 acres of wetlands.
Approximately 700 linear feet of new shoreline revetment was installed along the landfill slope adjacent to the Back River to protect the soil cover from hurricanes that create high tides and water levels. The revetment, constructed in 2009, has subsequently withstood numerous hurricane and big storm events without failure. For the restored wetlands, vegetated buffers and stormwater controls were created adjacent to them to protect the vegetation from erosion, an increasing threat owing to climate change and rising sea levels.