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Mayo Power Station Coal Ash Closure Determination

The Coal Ash Management Act (CAMA) provides three principal closure pathways:

  • Option A: closure in a manner allowed for a high-risk site, such as excavation and disposal in a lined landfill
  • Option B: closure with a cap-in-place system similar to the requirements for a municipal solid waste landfill
    • for this option, there is a further requirement that upon full implementation of the closure plan, the groundwater must be in compliance with the 2L standard at the compliance boundary of the impoundment.
  • Option C: closure in accordance with the federal CCR rule adopted by the EPA. 

After conducting a rigorous scientific review of Duke Energy’s proposals for Mayo, and conducting public listening sessions in impacted communities, DEQ has determined Option A is the only closure option that meets the requirements of Coal Ash Management Act to best protect public health and the environment. Coal ash must be excavated and moved to a lined landfill.

DEQ's Coal Ash Impoundment Closure Determination (April 1, 2019)

Preliminary Groundwater Flow and Transport Modeling (Fate Transport)

Community Impact Analysis (NEBA)

Comprehensive Site Assessment -- Report, Figures, Tables, and Appendices

Public Comments – January 2019

Saturated Ash Considerations

Facility Permit Information 

Next Steps

By August 1, 2019, Duke Energy will submit a closure plan aligned with the department's findings and recommendations. From there DEQ will review the plans and provide them for public comment before finalizing or approving a plan.