In 1996, Waupaca Foundry, Inc. (WFI), needed to expand their existing landfill to accommodate continued growth of their foundry facility. WFI asked TRC to provide permitting assistance and help them through the regulatory approval and construction process. To reduce construction costs, foundry byproduct materials would need to be used in the construction of the cap and liner system as a substitute for clay soils, which are scarce in the area.
TRC has provided a full range of consulting services over the years for multiple phases of WFI’s landfill expansion, including design, permitting and final construction. Key services include:
- Prepared initial site development and feasibility reports for the Wisconsin DNR.
- Developed a plan of operation and design that worked with the existing topography, including access/haul roads, screening from an adjacent highway, storm water controls and a leachate management system (included piping, lift stations, loadout facility and two 20,000-gallon underground storage tanks).
- Developed an alternative design and permit modification request for the beneficial reuse of foundry byproducts, which was approved by the regulatory agency. Because of a lack of clay soils in the area, the alternative design included the beneficial reuse of select foundry byproduct to be used as a compacted layer in combination with a geomembrane layer for the final cover system. TRC also prepared a plan modification to allow select foundry byproduct materials to be used in conjunction with a geosynthetic membrane for future phases of the landfill liner system.
- Developed engineering plans and specifications for the construction of liner and leachate collection systems and final cover systems, and provided contractor bidding assistance. TRC’s on-site engineer performed construction quality assurance, including construction observation and documentation.
Successful expansion efforts have given TKW an additional 15 years of capacity for its landfill. Additional cost-saving benefits include:
- The landfill expansion design maximized property use, available on-site soil, and airspace capacity.
- The use of select foundry byproduct materials, combined with a geomembrane, to replace clay soils that would need to be imported, reduced construction costs.
- The beneficial reuse of foundry byproduct in the cover minimized waste disposal, providing additional valuable airspace in the landfill.