Case Study: AECOM Process Technologies provided turnkey delivery of the hybrid-closure of a 32-acre coal ash pond, effectively reducing the size of the closed impoundment by more than half.
AECOM provided design through construction along with permitting support for the closure of a coal ash pond at a Midwest power plant. The project involved both Closure in Place (CiP) and Closure by Removal (CbR) to reduce the footprint of the closed CCR impoundment.
Material excavated from the CbR section was consolidated in the designated CiP footprint prior to the installation of a cover system in accordance with the CCR Rule. A buffer area was constructed using structural fill in place of excavated CCR material to act as a buttress to hold CiP materials in place. A stormwater pond was constructed where the CCR materials were excavated to manage stormwater from the nearby coal storage area.
Dewatering and stabilizing the material to be compacted on the CiP area was achieved via excavated ditches and sumps in conjunction with pumping. Well points facilitated dewatering of the deepest areas, with lime used for material stabilization.
The pond closure was executed in accordance with EPA and state requirements and completed within budget prior to the mandated compliance date.