Why Did EPA Select the Duke Energy Ponds for Inspection?
The ash pond integrity at Duke Energy’s North Carolina facilities is regulated by the North Carolina Division of Dam Safety in the Department of Environment and Natural Protection (NCDENR).
The NCENR rated almost all of Duke Energy’s ash ponds as “high hazard potential” based on the North Carolina Dam Safety Regulations rating system. The high hazard potential ratings under this system were assigned due to the potential environmental damage that could result from an ash release in the event of a pond failure. The high hazard potential rating is not an indication of the structural integrity of the ash ponds, nor does it mean that failure of an ash pond with such a rating will probably cause loss of human life. The EPA selected Duke Energy’s North Carolina ash ponds for inspection based on the NCDENR high hazard potential ratings.
The ash pond integrity at Duke Energy’s Ohio facilities is regulated by the Ohio Department of Natural Resources (ODNR). These ash ponds have been assigned moderate II ratings by the ODNR. The USEPA translated this ODNR rating, along with Duke Energy answers to an Information Collection Request for these ponds, into a significant hazard potential rating. The ODNR rating is not related to the stability of those ponds but to the potential for environmental or economic harm should the impoundment fail.