A CASE STUDY
Capping semi-liquid solids with geosynthetic layers
A U.S.-based polyethylene and polyester resin/polymer producer recently closed a manufacturing facility in Wilmington, N.C. . The company hired an engineering firm to manage the demolition and removal of the expansive
structures and infrastructure. Part of the environmental responsibilities was to also find a viable solution for closing a 12-acre sludge basin. But first, the engineers needed to determine sludge volume and understand which dewatering methods would be the most effective.
Solution: The engineering firm determined the best approach was to cap the solids in place. The depth of the sludge ranged from 7ft to 9ft across the basin, so developing a safe, effective, and economical solution was a priority. A plan was needed to enable a crew
Result: Closing the basin full of solids proved to be successful and cost-effective. Costs normally associated with dewatering and hauling solids were avoided by using the layered grid and membrane methods. The project stayed within budget and was completed on time without any safety violations. This new method to capping solids could possibly be utilized for other industrial closures such as coal ash, mining operations, or any site that contains a non-solidified sludge.