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Safe Basin Closure


Duke Energy engineers look over plans at a coal ash site.

Safely managing coal ash in a changing climate

The scientific studies of coal ash and our basins, dam safety inspections, emergency planning, ongoing environmental monitoring efforts and more – performed by the company and outside experts – are how we protect the environment and the communities we serve.

This information shapes operational procedures, site-specific ash basin closure plans, and projects to enhance climate resiliency. Our approach addresses the operational, environmental, strategic and financial risks associated with effectively managing coal ash today and for decades after basin closure.

All closure plans are engineered to improve groundwater and ensure the long-term safety of ash storage. 

Independent experts

Independent experts, including a national advisory board comprised of the foremost national experts on coal ash, engineers, scientists and dedicated teams at Duke Energy, have spent thousands of hours studying data, building enhanced groundwater and surface water protection programs and engineering closure solutions that protect people and the environment in a cost-effective manner.

The National Ash Management Advisory Board (NAMAB) is led by Dr. John Daniels, P.E., a former program director at the U.S. National Science Foundation and current professor and chair of the Department of Civil and Environmental Engineering at the University of North Carolina at Charlotte.

Working with Duke Energy engineers and scientists, NAMAB developed a set of guiding principles for safe basin closure. These principles provide a sustainable framework for promoting recycling, protecting groundwater and minimizing impacts to local communities and the environment, while safely anticipating major storms, flooding and even seismic events.


Guiding Principles for Ash Basin Closure

Each basin is unique, and that's why each closure plan is customized to the site to ensure it is most effective. State and federal laws outline two main options to close ash basins: capping in place or excavation. In either scenario, water is safely removed from each basin in a way that protects water quality in the nearby lake or river, conducted with the oversight of state regulators. Both options provide benefits to groundwater, though excavation may be appropriate for site-specific reasons. In January 2020, Duke Energy announced a major agreement with North Carolina regulators and community groups to permanently close the company's remaining nine coal ash basins in the state, primarily by excavation with ash moved to lined landfills.

Duke Energy Ash Metrics Fleetwide