09-05-17 Jay Zimmerman Soil and Groundwater Background Concentrations

t� REnKGY.
Paul nraovircf,
Serriur Vika Pre�,ideriL
Environmental, Health & Safety
526 Sourfi Church Sheet
EC3xv
Charlotte. NC ?8202
980.373.0408
September 5, 2017
Mr. S. Jay Zimmerman, P.G.
Directur, Division of Water Resources
North Carulina Department of Environmental Quality
1611 Mail Service Center
Raleigh, NC 27699-1611
RE: Soil and Gruundwdter Background Concentrations - Remaining I en Duke Energy Fatalities
Response to DEQ Letter of July 7, 2017
Dear Mr. Zimmerman:
Duke Energy is in receipt of your July 7, 2017 letter regarding "Duke Energy Submittal — Background Soil
and Groundwater Statistical Methodology fur 14 Duke Energy Facilities e-mails Submitted May 26,
2017" which included comments on the Buil and groundwater data sets Duke Energy submitted to DEQ
on May 26, 2017. Enclosed are I echnical Memoranda providing revised background soil and
groundwater data sets as well as calculated background threshold values (BTVs) for inorganic
constituents in soil and groundwater for the Allen, Asheville, Buck, Cape Fear, Cliffside (Rogers), Dan
River, RF Cee, Marshall, Sutton and Weatherspoon facilities. Submittals for the Belews Creek, Mayo,
Riverbend and Roxboro facilities were submitted under cover letter dated August 4, 2017. Duke Energy
would appreciate DEQ's review and approval of these B rvs before the end of the month to tacilitate
timely preparation of the CSAs for the subject sites.
I he methods fur developing BTVs described in the memoranda were approved by DEQ and are based on
the US Environmental Protection Agency (USEPA) "Unified Guidance", USEPA's Guidance for Comparing
Background and Chemical Concentrations in Soil for CERCEA Sites, and the ProUCL Technical Guide.
I hese B1 -Vs demonstrate that many of the constituents analyzed as part of the CSAs occur naturally in
background IUcatiuns in concentrations above the 15A NCAC ZE groundwater standards.
At the direction of DEQ, additional soil samples have been, or soon will Be, collected at each of these ten
sites. Duke Energy plans to update these Technical Memoranda fur soil in the near future so that they
can be reviewed and approved by DEQ in sufficient time to be incurporated into the updated CSAs for
the subject sites.
If you have any questions or need any clarification regarding the information provided, please contact
Ed Sullivan at [e-mail] or at 980-373-3719 at your convenience.
Respect Ily submitted,
Pa Draovitch
Senior Vice President
Environmentdl, Realth & Safety

Mr. Jay Zimmerman Letter
5ep:ember 5, 2017
cc: Mr. Ed Sullivan — Duke Energy
Ms. Kathy Webb — SynTerra
Enclosures:
Technical Memoranda — "Background Threshold values for Soil' — Allen, Asheville, truck, Cape Fear,
Cliffside (Rogers), Dan River, HF Cee, Marshall, Sutton and Weatherspoon Facilities
Technical Memoranda — "Background i hreshold values for Groundwater" — Allen, Asheville, Buck, Cape
Fear, Cliffside (Rogers), Dan River, HF Lee, Marshall, Sutton and Weatherspoon Facilities
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