The Tampa Electric Company desired to close and cap this former surface impoundment. The disposal site covered 16 acres and was up to 50 feet thick.
SCS Engineers was retained to prepare closure plans for the site, which contained coal combustion residuals (CCR) and dredged sediments. The work included a geotechnical investigation for characterizing the CCR and the dredged material, and preparation of estimates of landfill consolidation. The characterization investigation was designed to support our stability analysis for the landfill mass.
The presence of significant quantities of saturated dredge sediment and CCR inside and on top of the landfill complicated the geotechnical analyses and design solution. The final cover was comprised of multiple geosynthetic product layers to provide a low-permeability cap and to promote cover stability. The drying and compacting of 100,000 tons of CCR and dredged material, along with the installation of the geomembrane liner, were projects we completed within 60 days.
Included in this project was full construction quality assurance (CQA) of the cover system, in accordance with state requirements and preparation of the certification of construction completion report for the Florida Department of Environmental Protection.
Services performed by SCS Engineers included: