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Location
Lexington, Kentucky
Start Date
6-5-2026 8:00 AM
End Date
6-5-2026 8:30 AM
Description
Closure by removal (CbR) of CCR impoundments presents complex challenges, particularly when unique hydrogeologic conditions exist. This presentation highlights the advance planning and ongoing closure of a Midwestern utility’s East Ash Pond (EAP), a relatively small facility with highly atypical characteristics. To comply with the CCR Rule, sluicing to the EAP ceased while the generating unit remained operational. Fly ash handling was converted to a dry system for beneficial reuse; however, wet sluicing of bottom ash continued. To avoid constructing a new regulated CCR impoundment, an innovative geotextile tube containment area (GTCA) was designed and implemented to capture bottom ash solids, enabling EAP closure to proceed without additionally permitting a new regulated CCR impoundment. A comprehensive alternatives analysis guided the EAP’s closure approach, supported by the development of a dynamic cost estimating tool and an environmental visualization system (EVS) model to evaluate potential beneficial use of mixed CCRs. The EAP’s location in a historic streambed, with ash deposits approximately 30 feet below groundwater and the adjacent river elevation, required an extensive dewatering program employing multiple methods. Excavation was further complicated by steep inboard slopes, necessitating buttressing for stability concurrent with ash removal. CCR removal confirmation posed additional challenges and was resolved through collaboration with state regulators. The adopted methodology combines a 2-step approach of using visual identification of native soils in the field followed by laboratory analysis using polarized light microscopy (PLM) and a comparison to pre-established background levels. Over-excavation was also conducted in some cases. This case study demonstrates how innovative design, rigorous planning, and adaptive execution can overcome significant technical and regulatory hurdles to achieve safe and efficient CCR compliance.
Document Type
Presentation
Archival?
Archival
Included in
Energy Systems Commons, Environmental Indicators and Impact Assessment Commons, Environmental Monitoring Commons, Mining Engineering Commons, Oil, Gas, and Energy Commons, Structural Materials Commons, Sustainability Commons
Adaptive Design and Execution in CCR Pond Closure: A Case Study of Technical and Regulatory Innovation
Lexington, Kentucky
Closure by removal (CbR) of CCR impoundments presents complex challenges, particularly when unique hydrogeologic conditions exist. This presentation highlights the advance planning and ongoing closure of a Midwestern utility’s East Ash Pond (EAP), a relatively small facility with highly atypical characteristics. To comply with the CCR Rule, sluicing to the EAP ceased while the generating unit remained operational. Fly ash handling was converted to a dry system for beneficial reuse; however, wet sluicing of bottom ash continued. To avoid constructing a new regulated CCR impoundment, an innovative geotextile tube containment area (GTCA) was designed and implemented to capture bottom ash solids, enabling EAP closure to proceed without additionally permitting a new regulated CCR impoundment. A comprehensive alternatives analysis guided the EAP’s closure approach, supported by the development of a dynamic cost estimating tool and an environmental visualization system (EVS) model to evaluate potential beneficial use of mixed CCRs. The EAP’s location in a historic streambed, with ash deposits approximately 30 feet below groundwater and the adjacent river elevation, required an extensive dewatering program employing multiple methods. Excavation was further complicated by steep inboard slopes, necessitating buttressing for stability concurrent with ash removal. CCR removal confirmation posed additional challenges and was resolved through collaboration with state regulators. The adopted methodology combines a 2-step approach of using visual identification of native soils in the field followed by laboratory analysis using polarized light microscopy (PLM) and a comparison to pre-established background levels. Over-excavation was also conducted in some cases. This case study demonstrates how innovative design, rigorous planning, and adaptive execution can overcome significant technical and regulatory hurdles to achieve safe and efficient CCR compliance.
