TN&A has performed landfill investigation and design for multiple agencies. TN&A’s staff, con­sisting of civil engineers, environmental engineers, geologists, and hydrogeologists, have a broad base of experience in conducting landfill projects. TN&A’s staff have performed detailed evaluations for selected landfill sites, cover system design, liner installation and documentation, liner design, gas collection design, gas alarm systems, gas migration prevention systems, flare station design, trash placement grading plans, stormwater collec­tion, leachate collection and treatment, hazardous waste separation, and waste characterization.

TN&A has completed design and construction for the complete rehabilitation of an abandoned landfill at Lake City Army Ammunition Plant in Independence, Missouri. This project included construction of a leachate and seep collection system that conveyed contaminated liquid into two 10,000-gallon covered concrete basins. Additionally, a new cover was constructed over the landfill to meet state requirements, promote surface drainage and reduce surface water infiltration. The cover consisted of 24 inches of compacted clay, 12 inches of lightly compacted topsoil, and established vegetation. TN&A met the challenges of high water table conditions at the site by designing and installing pre-cast concrete basins rather than cast-in-place, thus drastically reducing the time required for dewatering, and the cost of handling potentially contaminated groundwater.