Mayo Steam Station Coal Ash Closure Plan

Under a settlement agreement with community and environmental groups and Duke Energy that ends the appeal litigation, Duke Energy will move forward with excavation plans at the Mayo Steam Station and dispose of ash in a lined onsite landfill.

Duke submitted a closure plan by the December 31, 2019 deadline, as required by the Coal Ash Management Act (CAMA) of 2016 and in accordance with the agreement. On April 29, 2020, DEQ issued its approval for the closure plan. 

Next Steps

DEQ is reviewing the corrective action plans submitted by Duke Energy and will review permit applications for closure activities as they are submitted.  

Facility Permit Information 

Public Meetings

Closure-Related Permitting Actions

Closure-Related Permitting Actions

Division of Air Quality

Final Permit - May 2021

Final Hearing Officer's Report

Public Hearing Recording

Draft Environmental Justice Report

Draft Permit

Draft Permit Review

Public Notice

Division of Waste Management

Permit 7307-INDUS-2021, Mayo Ash Basin Landfill


Division of Water Resources

Closure Plan Decision Closure Plan submitted 12/31/2019

Closure Plan submitted 12/31/2019

Mayo Closure by Excavation Plan and Appendices

Corrective Action Plan submitted 12/31/2019

Corrective Action Plan submitted 12/31/2019

Mayo Corrective Action Plan

Closure Determination April 1, 2019

Closure Determination April 1, 2019

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