Duke Letter August 2017 Soil and GW BC, Mayo, Riverbend & Roxboro

f(� DUKE
ENERGY
August 4, 2017
Mr. S. Jay Zimmerman, P.G.
Director, Division of Water Resources
North Carolina Department of Environmental Quality
1611 Mail Service Center
Raleigh, NC 27699-1611
RE: Soil and Groundwater Background Concentrations
Belews Creek, Mayo, Riverbend and Roxboro Facilities
Response to DEQ Letter of July 7, 2017
Dear Mr. Zimmerman:
Paul Draovitch
Senior Vice Presideni
Environmental, Health & Safety
526 S. Church Street
Mail Code: EC3XF
Charlotte, NC 28202
[phone]
Duke Energy is in receipt of your July 7, 2017 letter regarding "Duke Energy Submittal — Background Soil
and Groundwater Statistical Methodology for 14 Duke Energy Facilities e-mails Submitted May 26,
2017" which included comments on the soil and groundwater data sets Duke Energy submitted to DEQ
on May 26, 2017. Enclosed are Technical 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 Belews Creek, Mayo, Riverbend and Roxboro facilities.
Duke Energy would appreciate DEQ's review and approval of these BTVs before the end of the month to
facilitate timely preparation of the CSAs for the subject sites.
The methods for 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 CERCLA Sites, and the ProUCL Technical Guide.
These BTVs demonstrate that many of the constituents analyzed as part of the CSAs occur naturally in
background locations in concentrations above the 15A NCAC 2L groundwater standards.
At the direction of DEQ, additional soil samples were recently collected for each of the four sites. Duke
Energy plans to update these Technical Memoranda for soil in the near future so that they can be
reviewed and approved by DEQ in sufficient time to be incorporated 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.
ectfully submitted,
Paul Draovitch
Senior Vice President
Environmental, Health &Safety

Mr. Jay Zimmerman Letter
August 4, 2017
cc: Mr. Ed Sullivan — Duke Energy
Ms. Kathy Webb — SynTerra
Enclosures:
Technical Memoranda — "Background Threshold Values for Soil" — Belews Creek, Mayo, Riverbend and
Roxboro Facilities
Technical Memoranda — "Background Threshold Values for Groundwater" — Belews Creek, Mayo,
Riverbend and Roxboro Facilities
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