Buck Coal Pile Assessment Comments 1-11-19

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Director
Paul Draovitch
Senior Vice President
Environmental, Health & Safety
Duke Energy
526 South Church Street
Mail Code EC3XP
Charlotte, North Carolina 28202
NORTH CAROLINA
Environmental QuaUty
January 11, 2019
Subject: Former Coal Pile Assessment Work Plan Comments — Buck Combined Cycle
Station
Dear Mr. Draovitch:
On December 11, 2018, the North Carolina Department of Environmental Quality Division of
Water Resources (Division) received the proposed Former Coal Pile Assessment Work Plan for
the Buck Combined Cycle Station. The Division has reviewed and hereby approves the proposed
assessment activities under the condition that the following items are addressed as part of the plan
implementation and the results reported in the facilities updated Corrective Action Plan (CAP).
• Since well cluster GWA-9S/D/BRA is being relocated, the Division recommends either
adding a bedrock well at GWA-19S/D cluster or drilling a new well cluster
(shallow/deep/bedrock) upgradient of the former coal pile (see attached map for potential
drilling location).
• Add a well cluster (shallow/deep/bedrock) downgradient of the former coal pile (see
attached map for recommended drilling location).
• Please update Table 2 to reflect the additional wells requested.
• Ensure that laboratory detection limits are below the applicable preliminary soil
remediation goals.
• Add hexavalent chromium to the parameter list for groundwater sampling.
If applicable, the results should also be incorporated into the updated CAP's revised geochemical
and groundwater fate and transport models. If the results of the modeling show current or future
impacts to groundwater and/or surface water from this area, then appropriate remedial strategies
shall be proposed in the CAP.
North Carolina Department of Environmental Quality I Division of Water Resources
Q F0 512 North Salisbury Street 1 1636 Mail Service Center I Raleigh, North Carolina 27699-1636
'=�-` 919.707.9000

If you have any questions, please contact Joanna Harbison (Mooresville Regional Office) at (704)
663-1699 or Steve Lanter (Central Office) at [phone].
Sincerely,
/onRisg , Chief
Animal Feeding Operations and Groundwater Section
Attachment: Map
cc: MRO WQROS Regional Office
WQROS Central File Copy