Ames crews closed two Flue Gas Desulfurization (FGD) ponds used in power plant operations at Naughton Power Plant in Wyoming. The ponds spanned 85 acres, with pond material considered environmentally hazardous. Dewatering operations moved contaminated water from FGD ponds 1 and 2 to a different pond on the property for storage. The material was moved through both a new and an existing pipe network to stabilize the pond materials.
After dewatering, cut-to-fill material from an on-site borrow source was used to fill the ponds and each one was covered with GCL liner. Due to the sensitive nature of the materials in the ponds, the capping work was staged to accommodate settlement while not compromising geotechnical stability or the integrity of the liner and capping systems. The liner was then covered with additional borrow material and seeded.