Fly Ash Impoundment Closure and Dam Modification
For this 300-acre wet fly ash impoundment closure, ENTACT conducted a multiyear phased approach with a crew of more than 70 people. Closure construction started with the draining of surface water via pumping or by digging temporary drainage channels in the deposited ash to direct water to an area immediately behind the main dam. As we managed the surface water, we also excavated the exposed fly ash and relocated and/or regraded the surface to meet subgrade elevations across the site.
Work progressed from the highest to lowest elevations across the impoundment to protect and manage stormwater during construction. With close coordination of on-site activities, ENTACT completed the project safely and within the client’s timeline. At project completion, over 5 million cubic yards of ash and soils were managed and 300 acres were capped.