7305_DukeMayo_Approval_GWAssessmentWorkplan_DIN27539_20170322

March 22, 2017

Sent via email – [e-mail]

Kimberlee Witt, P.E.
Duke Energy Progress, LLC
Environmental Services
3195 Pine Hall Road
Belews Creek, North Carolina 27009

RE: Approval of Groundwater Assessment Work Plan
Duke Energy Progress - Mayo Steam Station
CCR Landfill
7305-INDUS-2012
Person County
DIN 27539

Dear Ms. Witt,

The Solid Waste Section (Section) has reviewed the Work Plan for Assessment of Groundwater
at Mayo Plant Landfill (DIN 27462) submitted on your behalf by SynTerra on February 23, 2016.
The Work Plan includes assessing three separate areas around the landfill: 1) Area 1
downgradient of the truck wash station, 2) Area 2 downgradient of the leachate transfer vault
and 3) Area 3 downgradient of the leachate pump station east of the landfill. The Work Plan
proposes to install well clusters in the three areas which includes wells screened in the surficial
(S), transition zone (D) and upper bedrock (BR) flow zones. The Section understands not every
well cluster location will have sufficient saturation to install all three well depths. The Work
Plan proposes the following well clusters: Area 1 LMW-6, LMW-7, LMW-8 and LMW-9; Area 2
LMW-10, LMW-11 and LMW-12; and Area 3 LMW-13.

The Section approves this Work Plan.

Please contact me at [phone] or via email [e-mail] if you have any
questions or concerns regarding this letter.

Sincerely,

Elizabeth S. Werner
Permitting Hydrogeologist
Solid Waste Section

Cc: Ed Sullivan, P.E. – Duke Energy Progress
Ellen Lorscheider – Section Chief, SWS
Ed Mussler, P.E. – Permitting Branch Head, SWS
Shannon Aufman – Permitting Engineer, SWS
Shawn McKee – Environmental Senior Specialist, SWS
Jason Watkins – Field Operations Branch Head, SWS