NC0001422_Appdx A - Regulatory Correspndence_20200814

Corrective Action Plan Update August 2020
L.V. Sutton Energy Complex SynTerra
APPENDIX A
REGULATORY CORRESPONDENCE
Notice of Regulatory Requirements (NORR)
NCDEQ direction for site assessment and corrective action.
Background Soil and Groundwater Statistical Methodology for 14 Duke
Energy Facilities
Duke Energy Submittal - Background Soil and Groundwater Statistical
Methodology for 14 Duke Energy Facilities e-mails submitted May 26,
2017
Summary of the revised background groundwater dataset and the
statistically determined background values
Approval of Provisional Background Threshold Values for Allen Steam
Station... L. V. Sutton Energy Complex, and W. H. Weatherspoon Power
Plant
Corrective Action Plan Content for Duke Energy Coal Ash Facilities
Approval of Revised Background Threshold Values L. V. Sutton Energy
Complex
NCDEQ reviewed the CSA Update, letter to Duke Energy
Completion of Permanent Alternate Water Supply Requirements Under
General Statute 130A-309.21 1 (cl)
Duke Energy Interpretation of Corrective Action Plan Content Guidance
Re: Optimized Interim Monitoring Plans (IMP) for 14 Duke Energy Facilities -
Modification Request Annual Reports - Modification Request

Corrective Action Plan Update August 2020
L.V. Sutton Energy Complex SynTerra
APPENDIX A (CONTINUED)
REGULATORY CORRESPONDENCE
Response to the Optimized Interim Monitoring Plans (IMP) for 14 Duke
Energy Facilities - Modification Request Annual Reports - Modification
Request
Final Comprehensive Site Assessment and Corrective Action Plan Approvals
for Duke Energy Coal Ash Facilities
Duke Energy Interpretation of Corrective Action Plan Content Guidance
(January 23, 2019) - NCDEQ Response and Conditional Approval
Approach to Managing Constituents of Interests for Purposes of Corrective
Action Plans
Issues Related to Implementation of Closure Plans and Groundwater
Corrective Action Plants (CAPs)
NCDEQ approval of revised CAP submittal date of August 3, 2020
RE: North Carolina Department of Environmental Quality Letter Dated
January 31, 2020, Issues Related to Implementation of Closure Plans
and Groundwater Corrective Action Plan (CAPs)
NCDEQ agreed with Duke Energy's statistical approach in an email
NCDEQ approval of surface water evaluation
Updated Corrective Action Plan and Comprehensive Site Assessment Content
Duke Energy Coal Ash Facilities
RE: Sutton Plant 1984 Ash Pond Dam - NEWHA-005

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NCDENR
North Carolina Department of Environment and Natural Resources
Pat McCrory John E. Skvarla, III
Governor Secretary
August 13, 2014
CERTIFIED MAIL 7004 2510 0000 3651 1168
RETURN RECEIPT REQUESTED
Paul Newton
Duke Energy
526 South Church Street
Charlotte, NC 28202
Subject: Notice of Regulatory Requirements
Title 15A North Carolina Administrative Code (NCAC) 02L .0106
14 Coal Ash Facilities in North Carolina
Dear Mr. Newton:
Chapter 143, North Carolina General Statutes, authorizes and directs the Environmental
Management Commission of the Department of Environment and Natural Resources to protect
and preserve the water and air resources of the State. The Division of Water Resources (DWR)
has the delegated authority to enforce adopted pollution control rules.
Rule 15A NCAC 02L .0103(d) states that no person shall conduct or cause to be conducted any
activity which causes the concentration of any substance to exceed that specified in 15A NCAC
02L .0202. As of the date of this letter, exceedances of the groundwater quality standards at 15A
NCAC 02L .0200 Classifications and Water Quality Standards Applicable to the Groundwaters
of North Carolina have been reported at each of the subject coal ash facilities owned and
operated by Duke Energy (herein referred to as Duke).
Groundwater Assessment Plans
No later than September, 26 2014 Duke Energy shall submit to the Division of Water Resources
plans establishing proposed site assessment activities and schedules for the implementation,
completion, and submission of a comprehensive site assessment (CSA) report for each of the
following facilities in accordance with 15A NCAC 02L .0106(g):
Asheville Steam Electric Generating Plant
Belews Creek Steam Station
Buck Steam Station
Cape Fear Steam Electric Generating Plant
Cliffside Steam Station
1636 Mail Service Center, Raleigh, North Carolina 27699-1636
Phone: [phone] Internet: www.ncdenr.gov
An Equal Opportunity 1 Affirmative Action Employer— Made in part by recycled paper

Mr. Paul Newton
August 12, 2014
Page 2 of 3
Dan River Combined Cycle Station
H.F. Lee Steam Electric Plant
Marshall Steam Station
Mayo Steam Electric Generating Plant
Plant Allen Steam Station
Riverbend Steam Station
Roxboro Steam Electric Generating Plant
L.V. Sutton Electric Plant
Weatherspoon Steam Electric Plant
The site assessment plans shall include a description of the activities proposed to be completed
by Duke that are necessary to meet the requirements of 15A NCAC 02L .0106(g) and to provide
information concerning the following:
(1) the source and cause of contamination;
(2) any imminent hazards to public health and safety and actions taken to mitigate
them in accordance to 15A NCAC 02L .0106(f);
(3) all receptors, and significant exposure pathways;
(4) the horizontal and vertical extent of soil and groundwater contamination and all
significant factors affecting contaminant transport; and
(5) geological and hydrogeological features influencing the movement,. chemical, and
physical character of the contaminants.
For your convenience, we have attached guidelines detailing the information necessary for the
preparation of a CSA report. The DWR will review the plans and provide Duke with review
comments, either approving the plans or noting any deficiencies to be corrected, and a date by
which a corrected plan is to be submitted for further review and comment or approval. For those
facilities for which Duke has already submitted groundwater assessment plans, please update
your submittals to ensure they meet the requirements stated in this letter and referenced
attachments and submit them with the others.
Receptor Survey
No later than October 14t', 2104 as authorized pursuant to 15A NCAC 02L .0106(g), the DWR is
requesting that Duke perform a receptor survey at each of the subject facilities and submitted to
the DWR. The receptor survey is required by 15A NCAC 02L .0106(g) and shall include
identification of all receptors within a radius of 2,640 feet (one-half mile) from the established
compliance boundary identified in the respective National Pollutant Discharge Elimination
System (NPDES) permits. Receptors shall include, but shall not be limited to, public and private
water supply wells (including irrigation wells and unused or abandoned wells) and surface water
features within one-half mile of the facility compliance boundary. For those facilities for which
Duke has already submitted a receptor survey, please update your submittals to ensure they meet
the requirements stated in this letter and referenced attachments and submit them with the others.
If they do not meet these requirements, you must modify and resubmit the plans.

Mr. Paul Newton
August 12, 2014
Page 3 of 3
The results of the receptor survey shall be presented on a sufficiently scaled map. The map shall
show the coal ash facility location, the facility property boundary, the waste and compliance
boundaries, and all monitoring wells listed in the respective NPDES permits. Any identified
water supply wells shall be located on the map and shall have the well owner's name and
location address listed on a separate table that can be matched to its location on the map.
Failure to comply with the State's rules in the manner and time specified may result in the
assessment of civil penalties and/or the use of other enforcement mechanisms available to the
State.
We appreciate your attention and prompt response in this matter. If you have any questions,
please feel free to contact S. Jay Zimmerman, Water Quality Regional Operations Section Chief,
at [phone].
2hn
ierely,
E. Skvarla, III
Attachment enclosed
cc: Thomas A. Reeder, Director, Division of Water Resources
Regional Offices — WQROS
File Copy

August 12, 2014
GUIDELINES FOR COMPREHENSIVE SITE ASSESSMENT
This document provides guidelines for those involved in the investigation of
contaminated soil and/or groundwater, where the source of contamination is from:
■ Incidents caused by activities subject to permitting under G.S. 143-215.1
■ Incidents caused by activities subject to permitting under G.S. 87-88
■ Incidents arising from agricultural operations, including application of
agricultural chemicals, but not including unlawful discharges, spills or
disposal of such chemicals
Comprehensive Site Assessment (CSA)
NOTE: Regional Offices may request additional information in support of the CSA to aid
in their review and will not approve the CSA if any of the elements specified below have
not been included or have not been sufficiently addressed
Minimum Elements of the Comprehensive Site Assessment Report:
A. Title Page
• Site name, location and Groundwater Incident number (if
assigned) and Permit Number;
• Date of report;
• Responsible Party and/or permiee, including address and
phone number;
• Current property owner including address and phone
number;
• Consultant/contractor information including address and
phone number;
• Latitude and longitude of the facility; and
• Seal and signature of certifying P.E. or P.G., as appropriate.
B. Executive Summary
The Executive Summary should provide a brief overview of the pertinent
site information (i.e., provide sufficient information to acquaint the reader
with the who, what, when, where, why and how for site activities to date).
1. Source information:
Type of contaminants
2. Initial abatement/emergency response information.
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August 12, 2014
3. Receptor information:
•
Water supply wells;
•
Public water supplies (wells, surface water intakes);
•
Surface water bodies;
•
Wellhead protection areas;
•
Deep aquifers in the Coastal Plain physiographic region;
•
Subsurface structures; and
•
Land use.
4. Sampling/investigation results:
•
Nature and extent of contamination;
•
Maximum contaminant concentrations;
•
Site hydrogeology.
5. Conclusions
and recommendations.
C. Table of Contents
• First page number for each section listed.
• List of figures (all referenced by number and placed in a
single section following contents text).
• List of tables (all referenced by number and placed in a single
section following contents text).
• List of appendices.
D. Site History and Source Characterization
• Provide a history of property ownership and use. Indicate
dates of ownership, uses of the site, and potential sources of
contaminants.
• Discuss the source(s) of contamination, including primary
and secondary sources.
• For permitted activities, describe nature of activity, permitted
waste, application of all instances of
over-application/irrigation of wastes or water
• Summarize assessment activities and corrective actions
performed to date including emergency response, initial
abatement, primary and secondary source removal.
• Discuss geographical setting and present/future surrounding
land uses.
E. Receptor Information
Provide a site map showing labeled well locations within a

August 12, 2014
minimum of 1500 feet of the known extent of contamination.
Key to the table and maps described.
NOTE: As the known extent of contamination changes, the
receptor survey must be updated to reflect the change. This
applies throughout the Receptor Information section.
• In table format, list all water supply wells, public or private,
including irrigation wells and unused wells, (omit those that
have been properly abandoned in accordance with 15A
NCAC 2C .0100) within a minimum of 1500 feet of the known
extent of contamination. Note whether well users are also
served by a municipal water supply.
• For each well, include well number, well owner and user
names, addresses and telephone numbers, use of the well,
well depth, well casing depth, well screen interval, and
distance from source of contamination;
NOTE: It will often be necessary to conduct any or all of the
following in order to ensure reliability in a water supply well
survey.
o Call the city/county water department to inquire about
city water connections,
o Visit door-to-door (make sure that you introduce
yourself and state your purpose to residents prior to
examining their property) to obtain accurate
description of water usage, and if some residents are
not at home, ask surrounding neighbors who are
home about the water usage at those residences.
Even if a public water line is available, some
residents still use their well water and are not
connected to the public water system; and
o Search for water meters and well houses.
• Site map showing location of subsurface structures (e.g.,
sewers, utility lines, conduits, basements, septic tanks,
drain fields, etc.) within a minimum of 1,500 feet of the known
extent of contamination;
• Table of surrounding property owner addresses;
• Discuss the availability of public water supplies within a
minimum of 1,500 feet of the source area, including the
distance and location to the nearest public water lines and
the source(s) of the public water supply;
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August 12, 2014
• Identify all surface water bodies (e.g., ditch, pond, stream,
lake, river) within a minimum of 1,500 feet of the source of
contamination;
• Determine the location of any designated wellhead protection
areas as defined in 42 USC 300h-7(e) within a minimum of
1,500 feet of the source of contamination. Identify and
discuss the location of the water supply well(s) for which the
area was designated a wellhead protection area, and the
extent of the protected area. Include information about the
well owner, well -construction specifications (especially at
screened intervals), pumping rate and pumping schedule.
Information regarding designated wellhead. protection areas
may be obtained by contacting the Public Water Supply
Section at [phone];
• Discuss the uses and activities (involving possible human
exposure to contamination) that could occur at the site and
adjacent properties. Examples of such activities and uses
include but are not limited to use of a property for an office,
manufacturing operation, residence, store, school, gardening
or farming activities, recreational activities, or undeveloped
land;
• Determine whether the contaminated area is located in an
area where there is recharge to an unconfined or
semi -confined deeper aquifer that is being used or may be
used as a source of drinking water. Based on a review of
scientific literature on the regional hydrogeology and well
construction records and lithological logs for deeper wells in
the area, identify and describe the deep aquifers underlying
the source of contamination. Include information on the depth
of the deep aquifer in relation to the surficial saturated zone,
the lithology and hydraulic conductivity of the strata between
the surficial aquifer and the deeper aquifer, and the
difference in groundwater head between the surficial aquifer
and the deeper aquifer. Discuss the local and regional usage
of the deep aquifer and the draw down from major pumping
influences. Also, specify the distance from the source of
contamination to major discharge areas such as streams and
rivers. Cite all sources and references used for this
discussion.
NOTE: This requirement (last bullet) only pertains to
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August 12, 2014
contamination sources in the Coastal Plain physiographic region
as designated on a map entitled "Geology of !North Carolina"
published by the Department in 1985. However,
recharge/discharge, hydraulic conductivity, lithology, head
difference, etc. is also important information at mountains
and piedmont sites.
F. Regional Geology and Hydrogeology
Provide a brief description of the regional geology and hydrogeology. Cite
all references.
G. Site Geology and Hydrogeology
• Describe the soil and geology encountered at the site. Use
the information obtained during assessment activities (e.g.,
lithological descriptions made during drilling, probe surveys,
etc.). This information should correspond to the geologic
cross sections required in N. below; and
• Based on the results of the groundwater investigation,
describe the site hydrogeology, including a discussion of
groundwater flow direction, hydraulic gradient, hydraulic
conductivity and groundwater velocity. Discuss the effects of
the geologic and hydrogeological characteristics on the
migration, retardation, and attenuation of contaminants.
H . Soil Sampling Results
Using figures and tables to the extent possible, describe all soil sampling
performed to date and provide the rationale for sample locations, number
of samples collected, etc. Include the following information:
• Location of soil samples;
• Date of sampling;
• Type of soil samples (from excavation, borehole, Geoprobe,
etc.);
• Soil sample collection procedures (split spoon, grab, hand
auger, etc.)
• Depth of soil samples below land surface;
• Soil sample identification
• Soil sample analyses;
• Soil sample analytical results (list any contaminant detected
above the method detection limit); and
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August 12, 2014
• Identify any sample analytical results that exceed the
applicable cleanup levels.
NOTE: Information related to H. above should correspond to the
sampling location and sampling results maps required in N. below.
I . Groundwater Sampling Results
Using figures and tables to the extent possible describe the groundwater
sampling performed to date and provide the rationale for sample locations
(based on source and contaminant type), number of samples collected,
etc. Include the following information:
• Location of groundwater samples and monitoring wells;
• Date of sampling;
• Groundwater sample collection procedures (bailer, pump,
etc.);
• Groundwater sample identification and whether samples
were collected during initial abatement, CSA, etc.;
• Groundwater sample analyses;
• Groundwater sample analytical results (list any contaminant
detected above the method detection limit; and
• Identify all sample analytical results that exceed 15A NCAC
2L or interim standards.
NOTE: Information related to 1. above should correspond to the
sampling location and sampling results maps required in N. below.
J. Hydrogeological Investigation
Describe the hydrogeological investigation performed including all
methods, procedures and calculations used to characterize site
hydrogeological conditions. The following information should be discussed
and should correspond to the maps and figures required below:
• Groundwater flow direction;
• Hydraulic gradient (horizontal and vertical);
• Hydraulic conductivity;
• Groundwater velocity;
• Contaminant velocity;
• Slug test results; *
• Aquifer test results;
• Plume's physical and chemical characterization; and
• Fracture trace study if groundwater in bedrock is impacted.
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August 12, 2014
* Check with the Regional Office prior to performing these tests
and study to see if necessary for the site.
K. Groundwater Modeling Results
Groundwater modeling or predictive calculations may be necessary at
some sites (source area proximate to surface water, source area located
within wellhead protection area or source area overlying semi -confined or
unconfined deeper Coastal Plain aquifer) to verify, based on site specific
hydrogeological conditions, whether groundwater contamination poses a
risk to receptors. For contamination shown to pose a risk to receptors,
groundwater modeling may be necessary to determine an appropriate
cleanup level for contaminated groundwater. Modeling should illustrate the
input data used to complete the model and will generally be required for
natural attenuation proposals (see Groundwater Modeling Policy at
http://portal. ncdenr.org/web/wq/aps/a-wr)ro/policy).
NOTE: Input data for models should be derived from site specific
information with limited assumptions or estimates. All assumptions and
estimated values including biodegradation rates must be conservative
(predict reasonable worst -case scenarios) and must be well documented.
L. Discussion
• Nature and extent of contamination, including primary and
secondary source areas, and impacted groundwater and
surface water resources;
• Maximum contaminant concentrations;
• Contaminant migration and potentially affected receptors
M. Conclusions and Recommendations
If corrective action will be necessary, provide a preliminary evaluation of
remediation alternatives appropriate for the site. Discuss the remediation
alternatives likely to be selected. Note that for impacts to groundwater
associated with permitted activities, corrective action pursuant to 15A
NCAC 2L .0106(k), (1) and (m) is not applicable, unless provided for
pursuant to 15A NCAC 2L .0106(c) and (e) or through a variance from the
Environmental Management Commission (EMC).
N. Figures
9 71/2 minute USGS topographic quadrangle map showing an area

August 12, 2014
within a minimum of a 1,500-foot radius of the source of
contamination and depicting the site location, all water supply wells,
public water supplies, surface water intakes, surface water bodies,
designated well head protection areas, and areas of recharge to
deeper aquifers in the Coastal Plain that are or may be used as a
source for drinking water;
Site map locating source areas, site boundaries, buildings, all water
supply wells within a minimum of 1,500 feet, named
roads/easements/right-of-ways, subsurface utilities, product or
chemical storage areas, basements and adjacent properties, scale
and north arrow;
At least two geologic cross sections through the saturated and
unsaturated zones intersecting at or near right angles through the
contaminated area using a reasonable vertical exaggeration.
Indicate monitoring well/sample boring/sample locations and
analytical results for soil samples. Identify the depth to the water
table. Provide a site plan showing the locations of the cross
sections;
■ Site map(s) showing the results of all soil sampling conducted.
Indicate sampling identifications, sampling depths, locations and
analytical results;
■ Site map(s) showing the results of all groundwater sampling
conducted. Indicate sampling locations, monitoring well
identifications, sample identifications, and analytical results;
Separate groundwater contaminant iso-concentration contour maps
showing total volatile organic compound concentrations, total
semi -volatile organic compound concentrations and concentrations
for the most extensive contaminant. Maps should depict the
horizontal and vertical extent. Contour line for applicable 2L
standard should be shown in bold;
■ Site map(s) showing the elevation of groundwater in the monitoring
wells and the direction of groundwater flow. Contour the
groundwater elevations. Identify and locate the datum (arbitrary
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August 12, 2014
1000, USGS, NGVD) or benchmark. Indicate the dates that water
level measurements were made. There should be one map for each
series of water level measurements obtained;
■ Groundwater contaminant iso-concentration contour cross-section;
and
■ Site map(s) showing the monitoring wells.
NDTE: If possible, use a single base map to prepare site maps using a
map scale of 9 inch = 40 feet (or a smaller scale for large sites, if
necessary). Maps and figures should include conventional symbols,
notations, labeling, legends, scales, and north arrows and should
conform to generally accepted practices of map presentation such as
those enumerated in the US Geological Survey pamphlet, "Topographic
Maps".
O. Tables
List all water supply wells, public or private, including irrigation wells
and unused wells, (omit those that have been properly abandoned
in accordance with 15A NCAC 2C .0100) within a minimum of 1500
feet of the known extent of contamination For each well, include the
well number (may use the tax map number), well owner and user
names, addresses and telephone numbers, use of the well, well
depth, well casing depth, well screen interval and distance from the
source of contamination;
List the names and addresses of property owners and occupants
within or contiguous to the area containing contamination and all
property owners and occupants within or contiguous to the area
where the contamination is expected to migrate;
■ List the results for groundwater samples collected including sample
location; date of sampling; sample collection procedures (bailer,
pump, etc.); sample identifications; sample analyses; and sample
analytical results (list any contaminant detected above the method
detection limit in bold); and
List for each monitoring well, the monitoring well identification
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August 12, 2014
numbers, date water levels were obtained, elevations of the water
levels, the land surface, top of the well casing, screened interval
and bottom of the well.
P Appendices
• Boring logs and lithological descriptions;
• Well construction records;
• Standard procedures used at site for sampling, field equipment
decontamination, field screening, etc.;
• Laboratory reports and chain -of -custody documents;
• Copies of any permits or certificates obtained, permit number,
permitting agency, and
• Modeling data and results;
• Slug/pumping test data; and
• Certification form for CSA
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August 12, 2014
DIVISION OF WATER RESOURCES
Certification for the Submittal of a Comprehensive Site Assessment
Responsible Party and/or Permittee:
Contact Person:
Address:
City: State: Zip Code:
Site Name:
Address:
City: State: Zip Code:
Groundwater Incident Number (applicable):
I, , a Professional Engineer/Professional Geologist
(circle one) for (firm or
company of employment) do hereby certify that the information indicated below is
enclosed as part of the required Comprehensive Site Assessment (CSA) and that
to the best of my knowledge the data, assessments, conclusions,
recommendations and other associated materials are correct, complete and
accurate.
(Each item must be initialed by the certifying licensed professional)
1. The source of the contamination has been identified. A list of all
potential
sources of the contamination are attached.
2. Imminent hazards to public health and safety have been identified.
3. Potential receptors and significant exposure pathways have been
identified.
4. Geological and hydrogeological features influencing the movement
of groundwater have been identified. The chemical and physical character of the
contaminants have been identified.
5. The CSA sufficiently characterizes the cause, significance and
extent of groundwater and soil contamination such that a Corrective Action Plan
can be developed. If any of the above statements have been altered or items not
initialed, provide a detailed explanation. Failure to initial any item or to provide
written justification for the lack thereof will result in immediate return of the CSA to
the responsible party.
(Please Affix Seal and Signature)
11

%DUKE
ENERGY,
October 9, 2015
Mr. Tom Reeder
Assistant Secretary for the Environment
North Carolina Department of Environmental Quality
1601 Mail Service Center
Raleigh, North Carolina 27699-1601
Subject: 90 Day Extension for Corrective Action Plans
Dear Assistant Secretary Reeder:
Harry K. Sideris
Senior Vice -President
Environmental, Health & Safety
526 South Church Street:
Mail Code ECUP
Charlotte, North Carolina 28202
704-382-4303
Duke Energy is requesting a 90 day extension for submittal of the final Groundwater Corrective Action
Plans per Section 130A-309.209(b)(1) of the Coal Ash Management Act of 2014. This extension request
was discussed with NCDEQ technical staff on September 23 and with NCDEQ management on October
2. It is Duke Energy's understanding based on these discussions that NCDEQ would like to divide the
CAP scope into two parts with the first part submitted on the original due dates and the second part
submitted 90 days later. The following due dates are our understanding based on these discussions:
Plant Name
CAP Part I Due Date
CAP Part 2 Due Date
Weatherspoon Power Plant
November 3, 2015
February 1, 2016
HF Lee Energy Complex
November 3, 2015
February 1, 2016
L.V. Sutton Energy Complex
November 3, 2015
February 1, 2016
Dan River Steam Station
November 12, 2015
February 10, 2016
Rogers Energy Complex
Riverbend Steam Station
November 16, 2015
February 14, 2016
February 14, 2016
February 19, 2016
February 19, 2016
February 19, 2016
November 16, 2015
November 21, 2015
November 21, 2015
Allen Steam Station
Buck Steam Station
Asheville Steam Electric Plant
Cape Fear Plant
Mayo Steam Electric Power _
Plant
November 21, 2015
December 1, 2015
February 29, 2016
December 1, 2015
December 1, 2015
February 29, 2016
Roxboro Steam Electric Plant
February 29, 2016
Marshall Steam Station —
December 7, 2015
March 6, 2016
Belews Creek Steam Stati=—December
8, 2015
March 7, 2016

Duke Energy proposes that the Part 1 CAP reports (submitted 90 days after the Groundwater Assessment
Reports were submitted) include: background information, a brief summary of the CSA findings, a brief
description of site geology and hydrogeology, a summary of the previously completed receptor survey, a
description of 2L and 2B exceedances, proposed site -specific groundwater background concentrations, a
detailed description of the site conceptual model, and groundwater flow and transport modeling. Part 2
would contain the remainder of the CAP including the risk assessment, alternative methods for achieving
restoration, conceptual plans for recommended corrective actions, implementation schedule, and a plan
for future monitoring and reporting.
If you have comments and/or questions, please direct them to me at 704-382-4303.
Sincerely,
Harry K. Sideris
Senior Vice -President
Environmental, Health & Safety

N ;r
;--1 0.
Water Resources
Environmental Quality
April 28, 2017
Paul Draovitch
Senior Vice President
Environmental, Health & Safety
Duke Energy Energy
526 South Church Street
Mail Code EC3XP
Charlotte, North Carolina 28202
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. JAY ZIMMERMAN
Director
Subject: Request for Additional Information regarding Statistical Methods for Developing
Reference Background Concentrations for Groundwater and Soil at Coal Ash
Facilities (HDR Engineering, Inc. and Synterra Corporation, January 2017)
Dear Mr. Draovitch:
The North Carolina Department of Environmental Quality (DEQ) received the technical
memorandum (TM) titled Statistical Methods for Developing Reference Background
Concentrations for Groundwater and Soil at Coal Ash Facilities (HDR Engineering, Inc. and
Synterra Corporation, January 2017) on January 20, 2017. DEQ grants conditional approval of
the document; however, outstanding technical issues must be resolved to proceed with the site
assessments and corrective action. To address outstanding issues, Duke Energy shall provide the
following information in the form of dataset transmittals and a revised TM.
Datasets
• Provide up-to-date digital spreadsheets of raw background groundwater data for each
facility by May 26, 2017, and include, within the raw background data s readsheet as
"strike-throughs" e in ividual monitoring data results that Duke Energy believes hould
be omitted from t e ba-c-rg-rouna clatasetau e o a t pHigh turbidity, c auto -
correlation (see comment below), (d) outlier designation, (e) non -detect values that are
above 2L/IMAC, or (f) other reasons.
Provide up-to-date digital spreadsheets of raw background soil data for each facility by
May 26, 2017. Any soil data collected since submittal of the Comprehensive Site
Assessments should be included in the table and existing soil data should be reviewed to
identify any quality control issues (i.e., sampling intervals, corresponding boring sample
ID, etc.) along with identification of outliers and revised accordingly.
Once DEQ reviews and approves the raw background datasets, background groundwater and soil
determinations should be completed and provided within 30 days.
State of North Carolina I Environmental Quality I Division of Water Resources
Water Quality Regional Operations Section
1636 Mail Service Center I Raleigh, North Carolina 27699-1636
919-707-9129

Revised Draft of Statistical Methods for Developing Reference Background Concentrations
for Groundwater and Soil at Coal Ash Facilities (HDR, January 2017)
Groundwater Background Comments
• Introduction. Page 1. The memorandum states that "For the purpose of establishing
background threshold values at this time, the value which represents the upper threshold
value from the upper tail of the data distribution for a given constituent will be
considered the value representative of a naturally occurring concentration, or the
proposed provisional background threshold valuue." The words "the upper tail of
should be removed. As stated in EPA/600/R-07/041, ProUCL Technical Guide, 2013,
page 17, "The objective is to compute background statistics based upon the majority of
the dataset representing the main dominant background population, and not to
accommodate a few low probability high outliers (e.g. coming from extreme tails of the
data distribution) that may also be present in the background dataset." The memorandum
should reference the ProUCL page 17 language and be updated accordingly.
• Part II, Page 7. Autocorrelation. Duke Energy states that autocorreiation will be
evaluated using a "sample autocorrelation function". The Division position is to use a
minimum 60-day interval between sample events. Duke may, at any time, submit for
consideration evidence that data from additional sample events spaced closer together in
time are not autocorrelated, but for purposes of the raw background dataset and
background determinations required at this time, the minimum 60-day interval should be
used. The memorandum should be updated accordingly.
• Part IV, Page 14. Step 3. The memorandum states that "If data are normally and
lognormally distributed, but not gamma distributed, preference should be given to upper
tolerance levels (UTLs) produced assuming data are lognormally distributed provided
the logged data have a standard deviation less than or equal to one". The Division does
not concur. Assuming data follow the corresponding UTL distribution type, the
following UTL computation preference should be used: normal UTL, then gamma UTL,
then lognormal UTL, then nonparametric UTL. However, as stated in ProUCL, because
lognormal distributions can result in unrealistically high UTL computations, lognormal
UTL should be avoided when skewness is high (e.g. standard deviation of logged data is
> 1 or 1.5) and sample size is small (e.g., < 20 --- 30). In this case, nonparametric UTL
should be preferred over lognormal UTL. The memorandum should be updated
accordingly.
• Part IV, Page 14. Step S. The memorandum states that "A minimum of eight valid
background groundwater samples should be obtained prior to producing background
Page 2 of 4

threshold values (BTVs) for each constituent in each flow layer". Eight samples should
be changed to ten samples. The memorandum also states that "In addition, a minimum of
eight additional samples should be obtained prior to evaluating ifnew background data
should be combined with previous data to produce revised BTVs. " In practice, time
frames needed to collect ten additional background samples may not be available given
CAMA and other deadlines. In these cases, DEQ will determine what data are
appropriate for inclusion in a comprehensive background dataset based on all relevant
considerations. The memorandum should be updated accordingly.
Part IV, Page 14. Step 5. The memorandum states that "If it is deemed necessary to
produce BTVs prior to obtaining eight valid samples, NCDEQ will be consulted and the
maximum observation may need to be used as a BTV". BTVs are expected to be
produced for all constituents and flow systems whether ten valid samples are available.
If less than ten valid samples are available for this detennination, no formal UTL
statistics should be run and the provisional background threshold value (PBTV) for a
constituent and flow system should be computed to be either: a) the highest value, or b) if
the highest value is above an order of magnitude greater than the geometric mean of all
values, then the highest value should be considered an outlier and removed from further
use and the PBTV is computed to be the 2nd highest value. The memorandum should be
updated accordingly.
Comments on Duke Energy's January 20, 20/17 "Responses to DEQ's November 22, 2016
informal comments"
Duke Energy Response #3. Duke Energy's response does not address the exclusion of
autocorrelated samples that have been collected too close in time. DEQ's protocol
included a criterion that samples not be collected too close in time and selected 60 days
as a reasonable frequency at which autocorrelation would not be expected. Duke Energy
should acknowledge and address this issue.
Duke Energy Response #11. The summary spreadsheets to which Duke Energy refers
do not, in many cases, include an indication of outliers or autocorrelated data. These
values should be clearly indicated within the summary spreadsheets.
• Non -detect values above the 2LAMAC standards should be deleted from use in the raw
background dataset.
Soil Background Comments
Part I, Page 4. The memorandum states that "Duke Energy and NCDEQ have agreed
that soil samples can be pooled from multiple depth intervals. A statistical evaluation of
the soil data sets will be performed to confirm the approach is appropriate". The
memorandum references USEPA's Guidance for Comparing Background and Chemical
Page 3 of 4

Concentrations in Soil for CERCL 4 Sites (USEPA 2002) but does not specify the
statistical evaluations that are proposed to evaluate the applicability of pooling soil data.
The memorandum should be updated with methodology to:
confirm that pooling multiple depth intervals at a site is appropriate.
confirm that pooling soil data from different geologic formations at a site is
appropriate.
statistically evaluate soil results that are below a detection limit when that detection
limit is above the protection of groundwater threshold.
If you have any questions regarding any information provided, please feel free to contact Ted
Campbell (Asheville Regional Office) at 828-296-4683 or Steve Lanter (Central Office) at 919-
807-6444.
Sincerely,
S4Ja erman, P.G., Director
Division of Water Resources
cc: WQROS Regional Office Supervisors
WQROS Central File Copy
HDR (Attn: Mark Filardi) 440 South Church Street, Suite 1000, Charlotte, NC 28202
SynTerra (Attn: Kathy Webb) 148 River Street, Suite 220, Greenville, SC 29601
Page 4 of 4

Paul DrauvitO
(' DUKE
ENERGY
May 2b, 2U17
Mr. S. Jay Zimmerman, P.v.
Director, Division of water Resources
North Carolina Department of Envirojtmental Quality
1b11 Mail Service Center
Raleigh, NC 27699-1611
S, �nwr Vise President
Environmental. Health 9 Satety
52b Svutn Unurirt Street
t=C3XP
9 0.373.U4Ub
RE: Response to DEQ Letter Dated April 28, 2U1/
Request for Additional Intormation Regarding Statistical Methods for Developing Reference
Background Concentrations for Groundwater and Soil at Coal Ash Facilities (HDR Eng;tteet;ttg,
Inc. and SynTerra Corporation, January 2017)
Dear Mr. Zimmerman:
DuRe Energy is in receipt of the above-reterencCd letter trom the North Cat olina Depaffinem: of
Environmental Duality (DEQ) which included comments on the Technical Memorandum (TM) titled,
"Statistical Methods for Developing Heference Background Concentrations for Groundwater and Soil at
Coal Ash Fac;l;r;es (Background Methodology)", prepared by HDR Engineering, Inc. and SynTerra
Corporation, dated January 2u17. Although Conditional Approval was granted to the January TM, DEQ
requested a revised TM along with updated data sets for bacRground groundwater concentrations and
soil concentrations.
DuRe Energy encloses herein the revised TM whichi incorporated DEQ comment along with updated data
sets for bacRground groundwater concentrations and bacRground soil concentrations for each of the 14
present and former coal-fired facilities in North Carolina. Below are DEQ's comments fro... the April 28,
2U17 letter and DuRe Energy's response in italics.
Datasets
"Provide up-to-date digital spreadsheets of raw background groundwater data for each facility by May
2b, 2017, and include, within the raw bacRground data spreadsheet as'striRe-throug5s', the individual
monitoring data results that Duke Energy believes should be omitted trom the background databet doe
to (a) High pH, (b) high turbidity, (c) auto- correlation (see comment below), (d) outlier designation, (e)
non -detect values that are above 2L/IMAC, or (t) other reasons.'
Enclosed are Excel® spreadsheets for each of the 14 Duke Energy facilities which provide the updated
background groundwater dara for each facility. "Srrike-rhroughs" were used to identify which analytical
results would be excluded from the initial background data set for statistical evaluurion due rro e1rher of
the following criteria pH greater than 8-5, turbidity greater than 1U NTv, less than a bu-day interval
between viable sample events, method derecrion limits (MDLs) greater than the 2L/IMAC for non -detect
samples, or other documented rationale_ i he enclosed site -specific Technical Memorandums mote whet e
additional sampling results are required to add to the existing data sets to provide a sufficient pool of
darn to begin zruri.5 cal attulya;a.

Pir. Jay Zimmtl rmcin Cotter
May 26, 2017
"Provide up-to-date digital spreadsheets of raw background soil data for each tacility By May 26, 2017.
Any soil data collected since submittal of the Comprehensive Site Assessments should be included in the
taBle and existing soil data should Be reviewed to identify any quality control issues (i.e., sampling
intervals, corresponding Boring sample ID, etc.) along with identiticaiion of outliers and revised
accordingly."
Enclosed are EAcel m spreadsheers for each of rhr 14 fac;l;r;es which provide rhr updated background soil
data for each facility. 'strike-rhroughs" were used to idenrify which analytical results would be
excludedrrom the initial background data set for statistical evaluation. The enclosed site -specific
Technical Memorandums ►cote where oddit;onal soil sampling results ate necessary to add to the eAi�r;,iy
data sets to provide a sufficient pool of data to begin statistical analysis.
Introduction. Page 1. "Thememorandum states that 'For the purpose otestaBiishing Background
threshold values atthistime, the value which reps esentsthe upper threshold value trom tfie upper
tail of the data distributionfor a given constituent will be considered the value representative of a
naturally occurring concentration, or the proposed provisional Background threshold value.' The
wuida the--uppertail of -,huuid be re, ,iuved. A»tated in EPA/600/R-07/041, P,uUCLTecfinical
uuide, LuIs, page 17, The objective is to compute background statistics based upon the majority of
the dataset representing the main dominant background population, and not to accommodate a few
low proBaBility high outliers (e.g. coming tram eATrume tails otthe data dish iBotion) that may also be
present inthe background dataset.' i he memorandum should reference the Prouc.L page 17
language and be updated accordingly."
The text within the revised draft of the TM has been modified accordingly to reflect the suggested
removal of "rhe upper rail of". Addirionally, the rear has been modified to include reference to the
ProUCL Technical Guide.
Part II, Page 7. Autocorrelation. "Duke Energy states that autocorrelation will be evaluated using a
'sample autocorrelation tunction'. The Division position is to use a minimum bu-day interval Between
sample events. Dake may, at any time, submit for consideration evidence that data trom additional
sample events spaced closer together in time are not autocorrelated, but for purposes of the raw
Background dataset and Background determinations required at this time, the minimum bu-day interval
should Be used. The memorandum should Be updated accordingly."
The text within the revised draft of the TM has been updated in response to this comment. I he following
text was added in Part Il:
"For purposes of the initial r aw backgr ound dataset and development of PPBTvs, a m;n;rnurn 60-day
interval between sample events will be used. In the event samples are collected at intervals shorter than
60 days (e.g., for catchup sampling at problematic locations, site conditions, etc.), autocorrelation
evaluations will be performed and may be provided to the Division of Water Resources as lines of
evidence to confirm the samples are ,at autoco,related and cart be;ncluded ;rr the background data
ser.5."
Part IV, Page 14. Step 3. "The memorandum states that 'if data are normally and lognormally
d;srr;bured, bur ,or gamma d;srr;bured preference should be g;ven To upper Tolerance levels (UTLs)

Mr. Jay zimme, man Cettci
May 26, 2017
produced assuming data are lognormally distributed provided the logged data have a standard
deviation less than or equal to one'. The Divibluii duca nut concur. Assuming data tollow the
corresponding U I L distribution type, the following u 11 computation preference should be used: not mal
UTL, then gamma UTL, then lognormal UTL, then nonparametric UTL. However, as stated in ProULL,
because lognormal distributions can result in unrealistically high UTL computations, lognormal UTL
Should be avoided when skewness is high (e.g. standard deviation of logged data is - 1 or 1.5) and
sample bite ib small (e.g., < 20 - 30). In this case, nonparametric UTL should be preterred over lognormal
u 11. 1 he memorandum should be updated accordingly."
The text within the revised draft of the TM has been updored as follows:
"When Elora sets used for producing UTLs can be fitted to multiple distribution models, a specific
hierarchy preference is applied. calculation of a specific u►L will follow the distribution hierarchy
preference below, with the noted exceptions:
1. normal,
2. gamma,
3. lognormal, and
4. nonparametric.
The exception to the hierarchy is based on situations where the darn ber eAhibira skewness rhar is
mode, ate arrd hiyher (e. y...5raridard deviation of logged data is greater than 1) and sample size is small
(e.g., n < 30). In these situations, the nonparametric UTL is preferred over lognormal UTL."
Part Iv, Page 14. Step 5. "The memorandum states that 'A minimum vt eight valid Background
groundwater samples should Be obtained prior to producing background threshold values (BTVs) for
each cumiitaem in each tlow layei . Eight samples should Be changed to ten samples. The
memorandum also states that 'In addition, a minimum of eight additional bampleb bhould be obtained
prior to evaluating it new Background data should be combined with previous data to produce revised
BTVz,.' In practice, time trames needed to collect ten additional Background samples may not Be
available given LAMA and other deadlines. In these cases, DEQ will determinu what data are
appropriate for inclusion in a comprehensive background dataset based on all relevant considerations.
The memorandum should Be updated accordingly."
The text within the revised draft of the TM has been updated as follows to reflect a minimum of ten
samples will be obtained prior to development of backyrourid threshold vulue�:
"In addition, the allocated time fr ame rierebsary ro collecr an additional ten samples for further
evaluation of background may not be available given the assessment deadlines and autocorrelation
restrictions. In evaluating the need for inclusion of additional background data to produce revised BTVs,
DEQ will determine what data are appropriate for inclusion it, a rornpreherisive buckground dara set
based on relevant considerations."
Part IV, Page 14. Step 5. "The memorandum states that 'If it is deemed necessary to produce 131 vs
prior to obtaining eight valid sampleb, NCDEQ will be consulted and the maximum observation may
need to Be used as a BTV. BTVs are expected to be produced for all constituents and flow bybtCms
whether ten valid samples are available. It less than ten valid samples are available for this
3

Mr. jay Zimmerman letter
May 26, 2017
determination, no tormal UTL statistics should be run and the provisional background threshold value
(PBTV) for a constituent and flow system should be computed to be either:a)the highest value, or
b) if the highest value is above an order of magnitude greater than the geometric mean of all values,
then the highest value should 6C cun�idered a. � outlier and , emoved trui,, turther use and the PBTV
is computed to be the znd highest value. The memorandum should be updated accordingly."
The rexr w;rh;„ the , evi.5ed dr aft of the TM hay been updated ry clur;fy haw aurrrples will be handled ;f
less than 10 valid samples I he text states the following-
A minimum of ten valid background groundwater samples should be obtained prior to producing BTVs
for each const;tuent;n each flow layer. if it is deemed necessary to produce BTVs prior to obta;n;,ig ten
valid samples, UTLs will not be calculated and the PPBTV for a constituent within a flow layer will be
estimated to be either:
r. the highest value, or
• if the highesr value ;s an order of magnitude greater than the geometric mean of all
values, then the highest value will be considered an outlier and the second highest value
Will be utilized as the PPBTV.
In situations where there are non -detects and less than ten valid samples, the geometric mean, which is
the product of all values (including the censored values) taken to the root of n, may not be representative
of the central tendency of thar sample. The median may be a better reference value from which to
deter rrr;rre;f the highest value is an acceptable estimate for the PPBTV, and rrray be ut;IiLed ;f deterrrr;rred
appropriate. "
Cu, ,mCnta on Doke Energy's January 20, 2017 "Responses to DEQ'b November 22, 2016 informal
comments"
"Duke Energy Rebpuiue #3. Duke Eneigy'brcbponbc dvcz, "m addre» the EAclubiun of
autocorrelated samples that have been collected too close in time. DELt's protocol included a
criterion that samples not be collected too close in time and selected bU days as a reasonable
treuuency at which aatoco,relation wuuld not be expected. Duke Energy should ack,owledge and
address this issue."
The rexr within the , ev;�ed d, aft of the TM hug beer, updated ;n Parr 11, Secr;on b ro address rh;s
comment. The text states:
"For purposes or the initial raw background dataset and development of PPB I Vs, a minimum 60-day
inrerval berween v;able sample events will be used. In the evenr samples are collected or intervals
shorter than bu days (e.g., for catchup sampling at problematic locations site conditions, etc_),
outocorrelation evaluations will be performed and provided as lines of evidence to confirm the samples
are nor ourocor, elured and uan be ;nrluded it, the barky, ound darn sers."
"Duke Energy Response #11. The summary spreadsheets to which Duke Energy reters do not, in
many cases, include an indication of outliers or autocorrelated data. These values bhould be clearly
indicated within the summary spreadsheets."
The enclosed EncelO spreadsheets for each of the 14 fac;l;t;es have beer, updated to show nutl;e,3 ;f they
are present prior to performing the preliminary data analysis as described in the revised draft TIVI. Note
4

Mr. Jay cimmurr„ar, iEttcr
May 2b. 2017
that autocorrelated data (i.e., less than bU days between sample events) and data excludedror being
uar„de the pH a„d rurb;diry ra„gczi, a,e Oenrified using 'Srr;ke-rh,ough�"if, the updared spreadsheers as
described above and in the revised draft 11P1.
"Non -detect values above the 2L/IMAC standards should be deleted from use in the raw Background
dataset."
The enclosed Excel' spreadsheets for each of the 14 facilities have been updated accordingly. The text in
Part 1 of the revised draft TM has been revised to reflect the comment above as well_
"PaFT I, Pagc 4. The me,, orandUrn btaicb thai'Duke Encrgy and NCDEQ have agreed that soil
samples can be pooled from multiple depth intervals. A statistical evaluation of the soil data sets
will Be pertormed to contirm the approach is appropriate'. The memorandum references USEPA's
Guidance for Comparing Background and Chemical Concenrrar;ons inSoil for CERCLA Sires (USEPA
2uu2) but does not specify the statistical evaluations that are proposed to evaluate the appliLaBility
of pooling soil data. The memorandum should be updated with methodology to:
confirm that pooling multiple depth intervals at a site is appropriate.
cuntirm that pooling coil data truni ditterent geulugic turmation�, at a aiie
appropriate.
statistically evaluate soil results that are below a detection limit when that
detection limit is above the protection of groundwater threshold."
The rexr ;„ Parr 1 of the , ev;-Ned d, aft TM hu.) been mud;f;ed ro reflecr the commenr above. The rexr
states:
'...Only constituent concentrations from samples collected above the water table will be utilized for
producing BTVs. To allow fD, rompariann of ,eaulra frron, soil samples collecred from differenr deprh
intervals and locations across the site to the BTVs, background soil samples will be pooled from multiple
depth intervals and non -impacted locations. Non -detect sample results with a method detection limit
above the Nvrrh Carvl;nu Prorecr;o„ of G, um,dwurer Preliminary Soil Remediarion Goal (PSRG) will be
excluded from the background soil dataset.
Soil dara are suscepr;ble ro eAh;bir sparial variarion (by aeprh and geology), and as such preliminary data
analysis methods will be used to evaluate the soil data set. To aid in identifying outliers, visual
assessments will be performed using box -and -whisker plots and quantitative assessments will be used to
re.5r for differences in mean or median concenrrar;on across deprh inrervals or geologic formations.
Results from the statistical analysis of soil data sets will allow for decisions to be made if pooling of soil
data across multiple depth intervals or geologic formations is appropriate."
DuRe Energy, along with our consultants, and DEQ statt discussed the above -referenced letter during a
meeting ai the Winbtun-Salmi Rcgiunal Office ui, May 18, 2017. li was Duke Energy's understanding
from that meeting that DEQ will review the enclosed data sets within two weeks. Duke Energy will then
have 30 days to complete the statistical analysis for background soil and groundwater determinations
for each site.
5

Mr. Jay Zimmerman Ceiier
May Z6, ZUl/
If you have any questions or need any clarification regarding the information provided, NlCabe t,Cpntact
Ed Sullivan at ed.sullivanCuduke-energy.com or at 98U-373-3719 at your convenience.
Respe tfully submitte
Pa I Draoviich
SVP — Environmental, Realth & Safety
cc: Mr. Ed Sullivan — Duke Energy
IDIr. Lhad Hearn — HDR
Ms. Kathy We66 — Syn I erra
Enclosures:
Rcvlscd Draft ICchni,al PIcm.randum, dated Play 26, 2017 — "Statistical Methods for Developing Reterence Background
Concentrations for Groundwater and Soil at Coal Asfi Facilities"
Updated site Soil and Groundwater 1 echnical Memorandums
Updated Site Soil and bruundwater Excel® Spreadsheet Data Sets
0

Water Resources
Environmental Quality
July 7, 2017
Paul Draovitch
Senior Vice President
Environmental, Health & Safety
Duke Energy
526 South Church Street
Mail Code EC3XP
Charlotte, North Carolina 28202
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. JAY ZIMMERMAN
Director
Subject: Duke Energy Submittal - Background Soil and Groundwater Statistical Methodology for
14 Duke Energy Facilities a -mails submitted May 26, 2017
Dear Mr. Draovitch:
The North Carolina Department of Environmental Quality (DEQ) has received and reviewed the May 26,
2017 a -mails from Duke Energy providing background soil and groundwater datasets. These site -specific
data were compiled following direction provided in an April 28, 2017 letter from DEQ to address technical
concerns related to site assessment and corrective action along with revisions to the Statistical Methods for
Developing Reference Background Concentrations for Groundwater and Soil at Coal Ash Facilities (HDR
Engineering, Inc. and Synterra Corporation, January 2017) technical memorandum (TM).
Attached are reviews of the soil and groundwater datasets for each Duke Energy coal ash facility. These
reviews identify data that are appropriate for inclusion in the statistical analysis to determine background
threshold values for both media following the methodology outlined in the TM. Additional requirements
related to soil and groundwater background determinations are specified for each facility. With approval
of these background datasets, preliminary background determinations for each media are expected to be
completed and provided within 30 days of receipt of this letter for those facilities that will submit
Comprehensive Site Assessments (CSAs) by October 31, 2017. For all other facilities that will submit
CSAs later, preliminary background determinations for each media are due within 60 days of receipt of this
letter.
If you have any questions, please feel free to contact Steve Lanter at [phone].
Sincerely,
S. Jayinlerman, P.G., Director
Division of Water Resources
Attachments: DEQ Background Dataset Reviews for the 14 coal ash facilities
cc: WQROS Regional Offices
WQROS Central File Copy
State of North Carolina I Environmental Quality I Division of Water Resources
Water Quality Regional Operations Section
1636 Mail Service Center I Raleigh, North Carolina 27699-1636
919-707-9129

Allen Steam Station
Groundwater
• The following background wells are appropriate for use:
o BG-lS, BG-2S/D, BG-4S/DBR, GWA-19S, GWA-21SBR, GWA-23S, and
GWA-26S/D
• The following background wells are NOT appropriate for use:
o BG-lD — Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
o BG-2BR — Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included. (Note: while there does
appear to be a topographic divide additional evaluation is needed to determine if
this is just a shallow divide or if it is indeed a divide for all flow layers.)
o AB-4S/DBR — Groundwater elevations below the nearest pond elevation has been
observed in several sampling events since installation of AB-4S/D. Due to the
potential for groundwater flow from the basin toward/through the well cluster this
location should NOT be considered a background location. AB-4BR should also
NOT be considered a background location (potential vertical migration from the
unconsolidated zone). (Note: Duke will evaluate further regarding pond elevation
utilized for assessment.)
o GWA-21D —Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
• All identified sample event dates are appropriate for use.
• The dataset for the shallow flow layer meets the minimum requirement of 10 samples after
excluding samples.
• The dataset for the deep flow layer does NOT meet the minimum requirement of 10
samples after excluding samples. Additional samples are require .
• The dataset for the bedrock flow layer does NOT meet the minimum requirement of 10
samples after excluding samples. Only 4 valid samples, but when additional evaluation
regarding nearest pond elevation used for the AB-4S/DBR locations is provided additional
samples may be available for inclusion.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
• The following background samples are appropriate for use:
o BG-lD (1.0-2.0), BG-lD (9.0-10.5), BG-1D (19.0-20.5), BG-lD (45-50), BG-2D
(1.0-2.5), BG-2D (8.5-10.0), BG-2D (18.0-20.0), BG-3D (1-2.5), BG-3D (13.5-
15), BG-3D (18.5-20), GWA-14D (10.0-12.0), GWA-8D (38.5-40), and GWA-8D
(48.5-50)
• The following background samples are NOT appropriate for use:
o GWA-15D —Sample is at or immediately adjacent to the waste boundary west of
the ash storage area and was also collected in fill material (according to boring log).
Allen Steam Station Pagel of 2

o GWA-5D —Sample is at or immediately adjacent to the waste boundary east of the
ash basin (immediately downgradient) and was also collected in fill material
(according to the boring log).
• The dataset meets minimum requirement of 10 samples after excluding samples.
• The reporting limits for Antimony and Thallium were above the IHSB PSRG Protection of
Groundwater values. Therefore, the number of useable values in the background dataset
is severely limited for these constituents. Additional samples analyzed at a lower detection
limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Allen Steam Station Page 2 of 2

Asheville Steam Electric Plant
Groundwater
• All identified background wells are appropriate for use.
o MW-101 CB-01, CB-09, CB-09SL, NM-24S, CB-011), AMW-03B, and CB-09BR
o Duke Energy recommended adding wells GW-I, GW-1D, and GW-1BR to the
background dataset. Based on a review of the information provided, these wells
may be added to the background dataset. If these wells are added, the new raw
background dataset should be re -submitted to DWR.
• The datasets for each flow layer meets the minimum requirement of at least 10 samples.
• All identified sample event dates are appropriate for use.
• All identified outliers are acceptable and should be removed from the background dataset.
o If GW-1, GW-ID, and GW-1BR are added to the background dataset then re -test
the new dataset for outliers and re -submit to the DWR, including strikethroughs of
outliers and other unusable data (e.g high pH, high turbidity, autocorrelated data.
Soil
• The following background samples are appropriate for use:
o CB-01 SB (7-8), CB-01 SB (30-31), CB-09 SB (1-2), CB-09 SB (25-27), GW-01
SB (1-2), MW-11SB (1.5-2), MW-12 SB (1.5-2), MW-13SB (1.5-2), MW-13SB
(14.5-15), MW-14SB (1.5-2), MW-22 (1-2), MW-23BR (2-3), and NM-24SB (1-
2)
• The following background samples are NOT appropriate for use:
o MW-08 and MW-09 — Samples are at or immediately adjacent to the waste
boundary and should not be used as background locations, even though the samples
were collected above the seasonal high water table.
o CB-08, MW-03, MW-05, and MW-07 — Downgradient of site contamination.
o MW-13SB (22-22.5) — Sample was collected 3-feet below the water table and
should not be used.
• The dataset meets the minimum requirement of at least 10 samples after excluding samples.
• The reporting limits for Antimony, Thallium, and Selenium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the
background dataset is severely limited for these constituents. Additional samples analyzed
at a lower detection limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Asheville Steam Electric Plant Page 1 of 1

Belews Creek Steam Station
Groundwater
• All identified background wells are appropriate for use:
o BG-2S, BG-3S, MW-202S, MW-3, BG-1D, BG-2D, BG-3D, BG-202D, BG-2BR-
A, and MW-202BR
• The datasets for the shallow and deep flow layers meet the minimum requirement of 10
samples.
• The dataset for the bedrock flow layer does NOT meet the minimum requirement of 10
samples. Additional samples are required.
• All identified sample event dates are appropriate for use.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
• All identified background samples are appropriate for use:
o BG-1D (1-2), BG-1D (11), BG-1D (21), BG-lD (31), BG-2D (1-2), BG-2D (10-
12), BG-2D (20-22), BG-2D (30-32), BG-3S (1-2), BG-3S (10-12), BG-3S (20-
22), GWA-3D (34-35.5), GWA 4S (45-47), GWA-12D (10-12), GWA-12D (15-
17), GWA-12D (20-22), and GWA-12D (25-27)
• The dataset meets the minimum requirement of 10 samples.
• The reporting limits for Antimony, Thallium, and Selenium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the
background dataset is severely limited for these constituents. Additional samples analyzed
at a lower detection limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Belews Creek Steam Station Page 1 of 1

Buck Combined Cycle Station
Groundwater
• The following background wells are appropriate for use.
o BG-18, BG-2S/D, BG-3SBRU, NM-6S/D, GWA-lS, MW-613R, and MW-8S/D
• The following background wells are NOT appropriate for use:
o BG-1D/BR— Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
o BG-2BR — Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
o MW-8BR — Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
• All identified sample event dates are appropriate for use.
• The datasets for each flow layer meets the minimum requirement of 10 samples after excluding
samples.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
The following background samples are appropriate for use:
o BG-lD (1-2), BG-1D (9.8-11.2), BG-1D (16.4-17.9), BG-2D (2), BG-2D (10-11.5),
BG-2D (13.5-15), BG-3BRU (1-2), BG-3BRU (10-10.5), BG-3BRU (20-20.5), GWA-
lOD (3.0), and GWA-11D (19-20.5)
The following background samples are NOT appropriate for use:
o GWA-11) — Sample was collected from 0.3-0.6 ft. bgs. Per IHSB Guidance, these
samples were taken too shallow.
o GWA-6BRU — Sample is located downgradient of the Cells 2 and 3 and within 1 foot
of the water table.
o GWA-7D — Sample is located downgradient of the Cells 2 and 3 and within 1 foot of
the water table.
o GWA-91) — Sample is located downgradient of Cell 1, both sample intervals were
collected in fill material (according to boring log) and one sample interval was
collected within 1 foot of the water table.
o GWA-12S —Sample is located downgradient of the ash basin.
o GWA-22D — Sample is located downgradient of Cell 1 and sample interval was
collected in fill material (according to boring log).
• The dataset meets minimum requirement of 10 samples after excluding samples.
• The reporting limits for Antimony, Thallium, and Selenium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the background
dataset is severely limited for these constituents. Additional samples analyzed at a lower
detection limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing fill
should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Buck Combined Cycle Station Page 1 of 1

Cane Fear Steam Electric Plant
Groundwater
• All identified background wells are appropriate for use:
o MW-15SU, MW-15SL, MW-16S, MW-09, MW-9BR, MW-15BR, and MW-16BR
• The datasets for all flow layers meet the minimum requirement of 10 samples.
• The following sample event dates are NOT appropriate for use:
o MW-15BR
■ 3/2/16 — Less than 60 days from previous sample.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
• The following background samples are appropriate for use:
o BG-01(Geosyntec)(2.0-2.5), BG-02(Geosyntec)(2.0-2.5), BG-03(Geosyntec)(2.0-
2.5), MW-09 SB(2-3), MW-09 SB (6-7), and MW-22 SB (3-4)
• The following background samples are NOT appropriate for use:
o MW-05BR SB(0-2), MW-09 SB(0-2), MW-l0BR SB(0-2), MW-12BR SB(0-2),
MW-15 SB(0-2), MW-20 SB(0-2), MW-22 SB(0-2), and MW-23 SB(0-2) — Per
IHSB Guidance, these samples were taken too shallow.
o BG-04(Geosyntec)(2.0-2.5) and BG-05(Geosyntec)(2.0-2.5) — Samples taken
down -gradient of 1985 Ash Pond.
• The dataset does NOT meet the minimum requirement of 10 samples. Additional samples
are required.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Cape Fear Steam Electric Plant Page 1 of I

James E. Rogers Energy Complex
Groundwater
• All identified background wells are appropriate for use.
o BG-1S, CCPMW-1S, MW-305, MW-325, GWA-245, GWA-255, GWA-30S, BG-
1D, MW-24D, MW-32D, GWA-24D, MW-32BR, CCPMW-ID, MW-24DR,
GWA-24BR, GWA-30BR, MW-22BR, and MW-22DR
• The datasets for all flow layers meet the minimum requirement of 10 samples.
• All identified sample event dates are appropriate for use.
• The following outliers are NOT appropriate for use and should be removed from the
background dataset:
Soil
o Total Dissolved Solids — 10,700,000 ug/L (saprolite)
o Total Dissolved Solids — 4,410,000 ug/L (saprolite)
o Total Dissolved Solids—407,000 ug/L (transition zone)
o Total Dissolved Solids—116,000 ug/L (transition zone)
o Iron — 31200 ug/L (transition zone)
o Vanadium — 3 ug/L (transition zone)
The following background samples are appropriate for use:
o BG-ID (3.5-5), BG-ID (8.5-10), BG-2D (3.5-5), BG-2D (8.5-10), BG-2D (18.5-
20), BG-2D (28.5-30), MW-30D (3.5-5.5), MW-30D (8.5-10), MW-30D (18.5-20),
MW-30D (28.5-30), MW-32D (3.5-5), MW-32D (8.5-10), MW-32D (18.5-20),
MW-32S (22.5-24), MW-42D (28.5-30), and GWA-25D (8.5-10)
The following background samples are NOT appropriate for use:
o BG-lS (3.5-5), BG-IS (8.5-10), MW-30S (4-5), MW-30S (9-10), MW-30S (19-
20), and MW-30S (28-29), — Only analyzed for TOC.
o GWA-1 OD — Located at or immediately adjacent to the waste boundary at Units 1-
4 basin.
o GWA-31D (7), GWA-31D (8.7), and GWA-31BR — Located at or immediately
adjacent to and downgradient of the waste boundary at Unit 5 basin and are adjacent
to a road and parking lot.
o MW-38D (33.5-35) — This location is downgradient of the Unit 5 Inactive Ash
Basin and adjacent to the Broad River.
o GWA-3D (48.5-50) — Location is downgradient of the Unit 5 Inactive Ash Basin.
o GWA-12BRU (20-23.5) — Location is immediately downgradient of Units 1-4
Inactive Ash Basin. May be close to water table and is near the Broad River.
o GWA-21BRU (5) — This sample may be immediately above the water table and
more importantly, the location is potentially downgradient of a basin and is situated
adjacent to the Broad River where there a potentially significant fluctuations of
water levels by a discharge point.
o GWA-22S (3-5) — Location is side gradient of the Active Ash Basin and adjacent
to the Broad River. The sample was collected within the screen interval of the well.
James E. Rogers Energy Complex Page 1 of 2

o GWA-27D (13.5-15) and GWA-27D (24.9) — Location is adjacent to and
downgradient of the impoundment. The sample was collected within the screened
interval of the well.
o NM-40BRU (3.5-5) — Location is adjacent to and downgradient of the Unit 5
Inactive Ash Basin and near the Broad River, and the sample was collected from
within the screened interval.
o GWA-61) (28.5-30) — Location is immediately downgradient of Unit 5 Inactive Ash
Basin and may be close to water table and is near the Broad River.
• The dataset meets the minimum requirement of 10 samples after excluding samples.
• The reporting limits for Antimony, Thallium, and Selenium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the
background dataset is severely limited for these constituents. Additional samples for these
three parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• The following outlier is NOT appropriate for use and should be removed from the
background dataset:
o MW-32S (22.5-24)
■ Arsenic — 7.9 mg/kg
James E. Rogers Energy Complex Page 2 of 2

Dan River Combined Cycle Station
Groundwater
• The following background wells are appropriate for use:
o GWA-9S, BG-11), GWA-9D, MW-231), MW-23BR, BG-5S, BG-51), BG-IOS,
BG-101), and BG-10BR
o GWA-9S/D and BG-IOS/D/BR appear to be appropriate for use; however, further
evaluation will be needed to determine whether these wells are truly located up -
gradient of the ash storages.
• The following background wells are NOT appropriate for use:
o GWA-12S/D —It appears that coal ash constituent boron, have been detected in soil
samples taken from this well.
o MW-20S/D — This well could be impacted by groundwater flowing from the
storage 1 area.
• The datasets for the shallow and deep flow layers meet the minimum requirement of 10
samples after excluding samples.
• The dataset for the bedrock flow layer does NOT meet the minimum requirement of 10
samples. Additional samples are required.
• All identified sample event dates are appropriate for use.
o Provisional background threshold value for hexavalent chromium (shallow flow
layer), vanadium (shallow flow layer), and radionuclides (shallow flow layer) are
based on a limited dataset. Additional samples are required.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
The following background samples are appropriate for use:
o BG-513(1-2), GWA-2D(19-20), GWA-9D(20-21.5), GWA-1O1)(9-10), SB-1(1-2),
SB-1(10-11.5), SB-1(15-16.5), SB-1(20-21.5), SB-1(25-26.5), SB-2(1-2), SB-
2(10-11.5), SB-2(20-21.5), SB-2(30-31.25), SB-2(35-36), SB-2(65-65.3), SB-3(1-
2), SB-3(10-11), SB-3(20-21.5), and SB-3(35-36.5)
The following background samples are NOT appropriate for use:
o BG-1D(0-2) — Per IHSB Guidance, this sample was taken too shallow.
o GWA-3D(5-6.5) — Sample taken in close proximity to Ash Storage 1.
o GWA-6S(9-11) — Sample taken down -gradient of Ash Basin Primary Cell
o GWA-10D(19-20) and GWA-10D(25) — Samples taken down -gradient of Ash
Storage 2.
o GWA-1113(10-11.5) — Sample taken down -gradient of Ash Storage 1.
Th dataset meets minimum requirement of 10 samples after excluding samples.
The reporting limits for Antimony, Thallium, and Selenium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the
background dataset is severely limited for these constituents. Additional samples analyzed
at a lower detection limit for these parameters are necessary.
Dan River Combined Cycle Station Page 1 of 2

• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Dan River Combined Cycle Station Page 2 of 2

H. F. Lee Enerev Complex
Groundwater
• The following background wells are appropriate for use:
o AMW-11S, AMW-12S, AMW-13S, AMW-17S, IMW-01S, IMW-03S, AMW-
11BC, AMW-12BC, AMW-13BC, AMW-16BC, IMW-01BC, IMW-02BC, and
IMW-03BC.
o AMW-016BC —The location maybe near the contact with the Black Creek. Please
confirm.
The datasets for the surficial and Cape Fear flow layers meets the minimum requirement
of 10 samples.
The dataset for the Black Creek flow layer does NOT meet the requirement of 10 samples.
Additional samples are required.
The following sample event dates are NOT appropriate for use.
o AMW-12S
■ 3/1/16 — Less than 60 days from previous sample.
o AMW-13S
■ 3/1/16
—Less than 60 days from previous sample.
o AMW-12BC
■ 3/1/16
— Less than 60 days from previous sample.
o AMW-13BC
■ 3/1/16
— Less than 60 days from previous sample.
o IMW-0lBC
■ 3/4/16
— Less than 60 days from previous sample.
o IMW-02BC
• 3/3116 — Less than 60 days from previous sample.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
The following background samples are NOT appropriate for use:
o AMW-12 SB (5-6) — Sample may have been taken within 1 foot of the seasonal
high water table.
o IMW-05 SB (0-2.5) and IMW-05 SB (4-6). This location is in very close proximity
to the southeast corner of Inactive Basin 3 and possibly influenced by the presence
of the ash basin. Per IHSB Guidance, these samples were taken too shallow.
o AMW-18 SB (0-2.5) and AMW-18 SB (3-5). Samples were collected from the
core of the plume migrating from the Active Basin.
o AMW-04 SB (1-2) and AMW-04 SB (4-5). Samples are located at the western end
of the Active Basin, adjacent to the Neuse River.
o AMW-16BC (19-21).
o AMW-11 (0-2), AMW-12 SB (0-2), AMW-13 SB (0-2), and AMW-16BC (0-2) -
Per IHSB Guidance, these samples were taken too shallow.
H. F. Lee Energy Complex Pagel of 2

• The dataset does NOT meet the requirement of 10 samples. Additional samples are
required.
• The reporting limits for Antimony and Thallium were above the IHSB PSRG Protection of
Groundwater values. Therefore, the number of useable values in the background dataset
is severely limited for these constituents. Additional samples analyzed at a lower detection
limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
H. F. Lee Energy Complex Page 2 of 2

Marshall Steam Station
Groundwater
• The following background wells are appropriate for use.
o GWA-4S/D, GWA-5S/D, GWA-6S/D, GWA-8S/D, GWA-12SBR, BG-3BR, MS-
10, MW-4, and MW-4D
• The following background wells are NOT appropriate for use:
o BG-lBR — Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
o GWA-12D — Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
• The datasets for each flow layer meets the minimum requirement of 10 samples after
excluding samples.
• All identified sample event dates are appropriate for use.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
• The following background samples are appropriate for use:
o BG-3D(1-2), BG-313(10-12), GWA-2DA(3-5), GWA-2DA(8-10), GWA-4D(52-
53), GWA-5D(27.5-29.0), GWA-14S(3-5), and GWA-14S(8-10)
• The following background samples are NOT appropriate for use:
o GWA-1BR — Sample is within the waste boundary downgradient of the ash basin
and coal pile.
o MW-14BR — Sample is located downgradient of the ash basin and Phase I Landfill
(unlined).
• The dataset does NOT meet minimum requirement of 10 samples. Additional background
samples are required.
• The reporting limits for Antimony and Thallium were above the IHSB PSRG Protection of
Groundwater values. Additional samples analyzed at a lower detection limit for these
parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Marshall Steam Station Page 1 of 1

Mayo Steam Electric Plant
Groundwater
• The following background wells are appropriate for use:
o MW-125, BG-02, MW-12D, BG-Ol, MW-13BR, and MW-14BR
• The following background wells are NOT appropriate for use:
o MW-IOBR
• The dataset for the surficial flow layer does NOT meet the minimum requirement of 10
samples. Additional samples are needed.
• The datasets for the transition zone and bedrock flow layers meets the minimum
requirement of 10 samples.
o Provisional background threshold values for radionuclides in the transition zone
flow layer are based on a limited dataset. Additional samples are required.
• The following sample event dates are NOT appropriate for use:
o BG-01
Soil
■ 11/3/2015 —Less than 60 days from previous sample.
■ 1/8/2016 — Less than 60 days from previous sample.
• 9/8/2016 — Less than 60 days from previous sample.
■ 3/28/17 — Less than 60 days from previous sample.
o MW-10BR
■ 1M16 —Less than 60 days from previous sample.
■ 9/7/16 —Less than 60 days from previous sample.
o MW-13BR
■ 1/7/2016 — Less than 60 days from previous sample.
• 9/6/2016 — Less than 60 days from previous sample.
All identified outliers are acceptable and should be removed from the background dataset.
The following background samples are appropriate for use:
o MW-08BR (0.75-1.25), MW-08BR (25.5-26), MW-IOBR (0.75-1.0), MW-12D (1-
2), MW-12D (25-26), SB-01 (1-2), and SB-01 (13.5-14.5)
The following background samples are NOT appropriate for use:
o MW-03BR (0.8-1.25) and MW-15BR (0.5-1) — Samples taken down -gradient of
Ash Basin.
o MW-11BR (0-2) and MW-13BR (0-2) —Per IHSB Guidance, these samples were
taken too shallow.
o SB-02 (0.5-2) and SB-02 (11.0-12.5) — Boring log indicates the presence of coal
ash.
o SB-03 (5-6) and SB-03 (17-18.5) — Boring log indicates the presence of coal ash.
o SB-05 and SB-06. Sample locations were adjacent to the 1981 landfill.
The dataset does NOT meet the minimum requirement of 10 samples. Additional samples
required.
Mayo Steam Electric Plant Page 1 of 2

• The reporting limits for Antimony and Thallium were above the IHSB PSRG Protection of
Groundwater values. Therefore, the number of useable values in the background dataset
is severely limited for these constituents. Additional samples analyzed at a lower detection
limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Mayo Steam Electric Plant Page 2 of 2

Riverbend Steam Station
Groundwater
• The following background wells are appropriate for use:
o BG-lS, MW-7SR, MW-7D, BG-4S, GWA-14S, BG-41), BG-5D, and BG-5BR
o MW-71) was listed under the shallow flow laver. Please re-evaluate.
• The following background wells are NOT appropriate for use:
o GWA-5S — Groundwater water elevations were similar and sometime lower than the
historical water elevation of ash basin. Also, the wells are within compliance boundary
and not far from the waste boundary.
• The datasets for shallow meets the minimum requirement of 10 samples after excluding
samples.
• The datasets for the deep and bedrock flow layers does NOT meet the minimum requirement
of 10 samples. Additional samples are required.
• All identified sample event dates are appropriate for use.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
• The following background samples are appropriate for use:
o BG-lD (5-6), BG-1D (14-15), BG-lD (24-25), BG-2D (3.5-5), BG-2D (48-49), BG-
3D (3-5), BG-31) (18.5-20), BG-3D (23-24), GWA-51) (58.5-60), GWA-6D-1(43.5-
45), GWA-6D-2(48.5-50), GWA-21D(3.5-5), GWA-211)(8.5-10), GWA-21D(18.5-
20), GWA-21D(48.5-50), MW-7BR(43.5-45), and OB-2(38.5-40.0)
• The following background samples are NOT appropriate for use:
o GWA-3D(18.5-19) — Sample taken down -gradient of Ash and Cinder Storage Areas.
o GWA-7S(7.0-8.0) — Sample taken down -gradient of Ash Basins.
o GWA-8D(8.5-10) — Sample taken down -gradient of Ash Basins.
o GWA-9D (1), GWA-10S (8-9), and NM-15D (3.5-5) — Downgradient location and
maybe within the High Seasonal Water Table.
o GWA-20D(40-41.5) — Sample taken in close proximity to Ash Storage Area.
o GWA-22D(38.5-40.0) — Sample taken in close proximity to Ash Storage Area.
o GWA-23D(33.5-35) — Sample taken within the waste boundary of the Ash Storage
Area.
o OB-1(33.5-35.0) — Sample taken inclose proximity to Ash Basin.
• The dataset meets the minimum requirement of 10 samples after excluding samples.
• The reporting limits for Antimony, Thallium, and Selenium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the background
dataset is severely limited for these constituents. Additional samples analyzed at a lower
detection limit for these parameters are necessary
• Please state whether any background sample included fill material. Samples containing fill
should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Riverbend Steam Station Page 1 of 1

Roxboro Steam Electric Plant
Groundwater
• The following background wells are appropriate for use:
o BG-1, MW-15D, MW-18D, BG-01BR MW-IOBR, MW-14BR, MW-15BR, MW-
18BR, and MW-19BRL
• The following background wells are NOT appropriate for use:
o MW-13BR, MW-16BR, and MW-17BR
• The datasets for all flow layers meet the minimum requirement of 10 samples after
excluding samples.
• The following sample event dates are NOT appropriate for use:
o BG-01
■ 9/8/2016 — Less than 60 days from previous sample.
■ 11/16/16 —Less than 60 days from previous sample.
o BG-01BR
■ 7/9/15 — Less than 60 days from previous sample.
o MW-17BR
• 11/10/16 —Less than 60 days from previous sample.
All identified outliers are acceptable and should be removed from the background dataset.
Soil
• The following background samples are appropriate for use:
o MW-08 (14-16), MW-08 (21-23), MW-13BR (22-24), MW-14BR (1-1.25), MW-
14BR (31-31.5), MW-14BR (37.5-38), MW-17 (29-31), MW-18 (31-33), and MW-
18 (37-38)
• The following background samples are NOT appropriate for use:
o MW-07 (0-2), MW-08 (0-2), MW-IOBR (0-2), MW-13BR (0-2), MW-15 (0-2),
MW-16 (0-2), and MW-18 (0-2) — Per IHSB Guidance, these samples were taken
too shallow.
• The dataset does NOT meet the minimum requirement of 10 samples. Additional samples
are required.
• The reporting limits for Antimony and Thallium were above the IHSB PSRG Protection of
Groundwater values. Samples for these two parameters need to be reported below these
values.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Roxboro Steam Electric Plant Page 1 of 1

�n

L. V. Sutton Energy Complex
Groundwater
• All identified background wells are appropriate for use:
o MW-05A, MW-0513, MW-3713, MW-0413, MW-05C, MW-08, MW-37C, MW-05CD,
MW-05D, MW-37D, MW-05E, and MW-37E
o Lower Surficial Aquifer — An adequate dataset has been provided for all constituents,
with the exception chromium (VI). Additional samples are planned for collection to
bring the total number of valid chromium (VI) samples to ten by second quarter 2017.
• The datasets for the upper and lower surficial flow layer meet the minimum requirement of 10
samples.
• The dataset for the Upper Peedee flow layer does NOT meet the minimum requirement of 10
samples. Additional samples are planned for collection to bring the total number of valid
samples to ten (second quarter 2017 at the earliest). It was agreed upon to use a pH of less than
or equal to 9.7 S.U. as the upper threshold for these zones in the Peedee aquifer.
• The dataset for the Lower Peedee flow layer does NOT meet the minimum requirement of 10
samples. New and replacement wells have been added to the groundwater monitoring network
(MW-5R-E, MW-8E, MW-41E). Additional samples are planned for collection to bring the
total number of valid samples to 10 (second quarter 2017 at the earliest). It was agreed upon
to use a pH of less than or equal to 9.7 S.U. as the upper threshold for these zones in the Peedee
aquifer.
• All identified sample event dates are appropriate for use.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
• The following background samples are appropriate for use:
o AW-02C (10-11) and MW-37C (4-6)
• The following background sample are NOT appropriate for use:
o AW-01C (0-2), AW-02C (0-2), AW-03C (0-2), AW-04C (0-2), AW-06D (0-2), AW-
07D (0-2), MW-37C (0-2), SMW-01C (0-2), SMW-02C (0-2), SMW-03C (0-2),
SMW-04C (0-2), SMW-05C (0-2), and SMW-06D (0-2) — Per IHSB Guidance, these
samples were taken too shallow.
o AW-05C (4-6) and AW-05C (9-11) —Samples are down -gradient of the ash pond.
• The dataset does NOT meet the minimum requirement of 10 samples. Additional samples are
require .
• The reporting limits for Antimony, Cobalt, and Thallium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the background
dataset is severely limited for these constituents. Additional samples analyzed at a lower
detection limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing fill
should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
L. V. Sutton Energy Complex Page 1 of 1

W.H. Weatherspoon Power Plant
Groundwater
• All identified background wells are appropriate for use.
o BW-02S, BW-03S, CCR-101-13G, MW-01, BW-03I, and BW-03D
• The dataset for the surficial flow layer meets the minimum requirement of 10 samples
• The dataset for the Lower Yorktown does NOT meet the minimum requirement of 10
samples. Additional samples are required.
• The dataset for the PeeDee does NOT meet the minimum requirement of 10 samples.
Additional samples are required.
• The following sample event dates are NOT appropriate for use.
o BW-03S
■ 3n116 — Less than 60 days from previous sample.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
No soil background data was provided. Please coordinate the collection of background
soil data with the DWR Fayetteville Regional Office.
W. H. Weatherspoon Power Plant Page 1 of I

t� RERKGY.
Paul nraovird,
Serrivr Vies PreSiderrt
Environmental, Health & Safety
526 Sourfi Church SneCt
EC3xv
Charlotte, NC ?6202
9803710408
September 5, 2017
Mr. S. Jay Zimmerman, P.G.
Director, Division of Water Resources
North Carolina Department of Environmental Quality
1b11 Mail Service Center
Raleigh, NC 27b99-1b11
RE: Soil and Groundwater Background Concentrations - Remaining l en Duke Energy Facilities
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 a -mails Submitted May 26,
2017" which included comments on the suit 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 Lee, 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 CERCCA 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 locations in concentrations above the 15A INCAC 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 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.
Respect Ily submitted,
Pa Draovitch
Senior Vice President
Environmental, Realth & Safety

Mr. Jay Zimmerman Letter
September 5, 2017
cc: Mr. Ed Sullivan — Duke Energy
Ms. Kathy Webb — SynTerra
Enclosures:
Technical Memoranda — "Background Threshold values for Soil' — Allen, Asheville, t3uck, Cape Fear,
Cliffside (Rogers), Dan River, Fli- lee, 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
2

K`
Water Resources
Environmental Quality
October 11, 2017
Paul Draovitch
Senior Vice President
Environmental, Health & Safety
Duke Energy
526 South Church Street
Mail Code EC3XP
Charlotte, North Carolina 28202
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. JAY ZIMMERMAN
Director
Subject: Approval of Provisional Background Threshold Values for Allen Steam Station,
Asheville Steam Electric Plant, Buck Combined Cycle Station, Cape Fear Steam
Electric Plant, James E. Rogers Energy Complex, Dan River Combined Cycle
Station, H. F. Lee Energy Complex, Marshall Steam Station, L. V. Sutton Energy
Complex, and W. H. Weatherspoon Power Plant
Dear Mr. Draovitch:
The North Carolina Department of Environmental Quality's Division of Water Resources (DWR)
has reviewed Duke Energy's calculated provisional background threshold values (PBTVs) for soil
and groundwater for the subject facilities. DWR calculated PBTVs based on the vetted
background data in the letter to Duke Energy dated July 7, 2017, using the Revised Statistical
Methods for Developing Reference Background Concentrations for Groundwater and Soil at Coal
Ash Facilities dated May 26, 2017 and any subsequent information provided.
Per 15A NCAC 02L .0202(b)(3), where naturally occurring substances exceed the established
standard, the standard shall be the naturally occurring concentration as determined by the Director.
Therefore, PBTVs that are calculated to be above the 15A NCAC 02L .0202 groundwater
standards or Interim Maximum Allowable Concentrations (IMACs) and accepted by DWR shall
become the enforceable groundwater standard. Otherwise, the enforceable groundwater standards
shall be those listed under 15A NCAC 02L .0202(h) including any effective IMACs.
The attachments document DWR's concurrence/non-concurrence with Duke Energy's calculated
PBTVs for groundwater and soil. For all Duke Energy's calculated PBTVs that DWR finds
acceptable, DWR hereby approves those values. If DWR does not find the Duke Energy's
calculated PBTVs acceptable, justification is provided on the attachments. Duke Energy will be
responsible to provide revised values for DWR to review and approve.
Please note that the approved PBTVs are based on the current data available. DWR recognizes
that, as new data is gathered going forward, the approved PBTVs may be refined. Thus, there will
be need for a periodic review of the data and recalculation of the PBTVs. The timeframes for the
State of North Carolina I Environmental Quality I Division of Water Resources
Water Quality Regional operations Section
1636 Mail Service Center I Raleigh, North Carolina 27699-1636
919-707-9129

periodic review will established by DWR at a later date and any revised PBTVs will be subject to
approval by the DWR's Director.
Along with the specific comments provided on the attachments, DWR offers the following general
comments with regards to the PBTVs
In cases where the PBTVs calculated by Duke Energy use groundwater and soil samples
that have less than 10 samples, the calculated values are acceptable per the guidance
provided in the Revised Statistical Methods for Developing Reference Background
Concentrations for Groundwater and Soil at Coal Ash Facilities dated May 26, 2017.
However, these calculated values may be open to revision by DEQ once additional valid
samples are collected.
Outliers are identified with three statistical lines of evidence: Box Plots, Q-Q Plots, and
95% Significance Levels. Based on these lines of evidence, if Duke Energy chooses not
to exclude an outlier, then additional rationale or justification shall be provided for DWR
review.
The PSRG for Chromium that will be applied shall be the more conservative value for
Chromium (VI) which is 3.8 mg/kg.
If you have any questions, please contact Debra Watts at [phone].
Sincerely,
�-elcc
JSIZiennanP.G., Director
Division of Water Resources
Attachments
cc: WQROS Regional Office Supervisors
WQROS Central File Copy

Allen Steam Station - Groundwater Provisional Background
Threshold Values
Parameter
Reporting
Units
Duke Ener t Calculated PBTVs
15A NCAC 02L
Standard or
IMAC
DWR Concurrence (Acceptable/Not Acceptable)
Comments
Flo% Unit
Flow Unit
Shallow
Deep I
Bedrock
Shallow
Deep
Bedrock
pH
S.U.
5.2 -7.5
6.7.8.4
7.5 - 7.8
6.5-8.5
Acceptable
Acceptable
Acceptable
Deep and bedrock data set is insufficient and must be updated with additional data.
Alkalinity
mg/L
188.773
74
83.4
NE
Acceptable
Acceptable
Acceptable
Aluminum
µg L
427
540
301
NE
Acceptable
Acceptable
Acceptable
Antimony
0.876
0.69
0.5
1
Acceptable
Acceptable
Acceptable
Arsenic
0.42
1.4
_
0.4
10
Acceptable
Acceptable
Acceptable
Barium
pg/L
78
52.4
21
700
Not Acceptable
Acceptable
Acceptable
Duke revised shallow value - 125.4 ug/L. Please revise table accordingly.
Deep and bedrock data set is insufficient and must be updated with additional data.
Beryllium
g/L
0.127
0.2
0.1
4
Acceptable
Acceptable
Acce table
Deep and bedrock data set is insufficient and must be updated with additional data.
Bicarbonate
mg/L
I88.',73
74 1
83.4
NE
Acceptable
Acceptable
Acceptable
Boron
WL
50
50
50
700
Acceptable
Acceptable
Acceptable
Cadmium
0.08
U.08
11.08
2
Acceptable
Acceptable
Acceptable
Calcium
mg/L
20
14.2
20.4
NE
Acceptable
Acceptable
Acceptable
Carbonate
mg/L
5
5
5
NE
Acceptable
Acceptable
Acceptable
Chloride
mg/L
10.9
6
Lb
250
Acceptable
Acceptable
Acceptable
Chromium (VI)
µg/L
7J42
1.2
0.2.3
NA
Acceptable
Acceptable
Acceptable
Duke should verify that only Chromium (VI) data was evaluated to establish value.
Deep and bedrock data set is insufficient and must be updated with additional data.
Chromium
@/L
1 6.927
6.8
5.6
10
Acceptable
Acceptable
Acceptable
Deep and bedrock data set is insufficient and must be updated with additional data.
Cobalt
4.338
0.5
0.27
1
Acceptable
Acceptable
Acceptable
Copper
2.265
1.7
1.2
1000
Acceptable
Acceptable
Acceptable
Iron
834.8
555
294
300
Acceptable
Acceptable
Acceptable
Lead
kmg/L
0. tt__
5.61
0.1
0.1
15
Acceptable
Acceptable
Acceptable
Magnesium
I 4.58
4.75
NE
Acceptable
Acce table
Acceptable
Manganese
577.9
60A
39.1
50
Acceptable
Acceptable
Acceptable
Memu
D.2
2.4
" 0.2
1
Acceptable
Acceptable
Acceptable
Methane
WL
11.4
.3 .9
10
NE
Acceptable
Acceptable
Acceptable
Page 1 of 2

Allen Steam Station - Groundwater Provisional Background Threshold Values
Parameter
Reporting Units
Duke Energl Calculated PBTVs
Flow Unit
15A NCAC 02L
Standard or
]MAC
DWR Concurrence(Acceptable/Not Acceptable)
Comments
Flow Unit
Shallow
Dee
Bedrock
Shallow
Dee
Bedrock
Molybdenum
y
µ91L
+
30._
4.4
NE
Acceptable
Not Acceptable
Acceptable
Duke should verify deep value with geometric mean and revise if needed.
D and bedrock data set is insufficient and must be updated with additional data.
Nickel
4.024
4.024
R.I
3.4
100
Acceptable
Acceptable
Acceptable
Deep and bedrock data set is insufficient and must be updated with additional data.
Nitrate + Nitrite
mg-N/L
1.8
0.94
0.41
11•
Acceptable
Acceptable
Acceptable
Potassium
mg/L
5.24
_
9.89
6.06
NE
Acceptable
Acceptable
Acceptable
Selenium
g/L.
0.5
0.5
0.5
20
1 Acceptable
Acceptable
Acceptable
Sodium
Strontium
mg/L
15.2.19
286
28.3
200
7.71
106
NE
NE
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acce table
Sulfate
mg/L
31,41
1 16.2
2.9
250
Acceptable
Acceptable
Acceptable
Sulfide
mg/L
0.1
_
0.12
0.1
NE
Acceptable
Acceptable
Acceptable
TDS
mg/L
180.957
12ti
147
500
Acceptable
Acceptable
Acceptable
Thallium
µg/L
0.1
0.1
0.1
0.2
Acceptable
Acceptable
Acceptable
TOC
mg/L
18.022
11
5.6
NE
Acceptable
Not Acceptable
Acceptable
Duke should verify deep value with geometric mean and revise if needed.
Deep and bedrock data set is insufficient and must be updated with additional data.
Vanadium
L
5.33
9.6
10.8
1 0.3
1 Acceptable
Acceptable
I Acceptable
Deep and bedrock data set is insufficient and must be updated with additional data.
Zinc
pg/L
R0.02
17J
15 t
1000
Acceptable
Not Acceptable
Not Acceptable
Duke should verify deep and bedrock value with geometric mean and revise if needed.
Deep and bedrock data set is insufficient and must be updated with additional data.
Radium (Total)
Umnium(Total)
pci/
p mL
1 iR6
0.001037
0.613
0.0005
1.103
0.00039
NE
NE
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Deep and bedrock data set is insufficient and must be updated with additional data.
NA - Not Applicable
NO - Not Detected
NE - Not Established
mglL - milligrams per liter
pCi/L - picocuries per liter
Radium (Total) - Radium-226 and Radium-228 combined
* lie 15A NCAC 02L Standard is 10 mg/L for Nitrate and I mg/L for Nitrite (added for a anal of I I mg/L)
S.U. -Standard Unit "Duke plans to update the shallow and deep data set in the near future. PBNs will be revised accordingly. Bedrock flow
layer data set will remain insufficient until additional sampling events are completed.`•
TOC - Total Organic Carbon
TDS - Total Dissolved Solids
pg/mL - micrograms per milliliter
pg/L - micrograms per liter
Uranium (Total) - Uranium-233. Uranium-234. Umnium-236. and Uranium-238 combined
Page 2 of 2

Allen Steam Station - Soil Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Fuergy
Calculated
PBI,vs
PSRG Protection
of Groundwater
DWR Concurrence
(Acceptable/Not
Acceptable)
Comments
H
S.U.
3.3_- 6.8
NE
Acceptable
Aluminum
mg/kg
_ _
26991
NE
Acceptable
Antimony
mg/kg
N A
0.9
Not Acceptable
Use PSRG of 0.9. To be revised when valid data set is available.
Arsenic
mgfkg
3.7
5.8
Acceptable
Only 5 valid samples in data set.
Barium
mglkg
233
580
Acceptable
Beryllium
mg/kgmg/kg
1.304
63
Not Acceptable
Normal UTL - 1.78 mg/kg.
Boron
mg/kg
23.4
45
Acceptable
Only 9 valid samples in data set.
Cadmium
mg/kgmg/kg
0.368
3
Acceptable
Calcium
mg/kgmg/kg
1192
NE
Not Acceptable
Normal UTL - 859.9 mg/kg.
Chloride
mg/kgmg/kg
ND
NE
Acceptable
Chromium
mg/kgmg/kg
93.57
3.8
Not Acceptable
Normal UTL - 20.42 m
Cobalt
mg/kgmg/kg
48.6
0.9
Acceptable
Copper
mgIkg
78 15
700
Acceptable
Iron
mg/kgmg/kg
69316
150
Acceptable
Lead
mg/kgmg/kg
12.31
270
Acceptable
Magnesium
m
15100
NE
Acceptable
Manganese
mg/kg
_ _
1786
65
Acceptable
Mercury
mglkg
0.0233
1
Acceptable
Molybdenum
mgkg
4.6
NE
Acceptable
Nickel
mg/kgmg/kg
9.079
130
Not Acceptable
Log UTL - 10.91 m
Nitrate as N)
mg/kgmg/kg
ND
NE
Acceptable
Potassium
mg/kg
_ 13742 _
NE
Not Acceptable
Normal UTL - 14,097 mg/kg.
Selenium
mg/kg
NA
2.1
Not Acceptable
Use PSRG of 2.1. To be revised when valid data set is available.
Sodium
mg/kgmg/kg
_
461
NE
Acceptable
Strontium
me/kg
24.91
NE
Not Acceptable
Normal UTL - 14.41 mg/kg.
Sulfate
m kg
♦n
NE
Acceptable
Thallium
mg/kg
N A
0.28
Not Acceptable
Use PSRG of 0.28. To be revised when valid data set is available.
Vanadium
mg/kg
_
I.t2.2
6
Acceptable
Zinc
mg/kg
112.1
1200
Acceptable
NA - Not applicable (dataset contains zero valid samples)
ND - Non -Detect
NE - Not Established
mg/kg - milligrams per kilogram
S.U. - Standard Unit

Asheville Steam Electric Plant- Groundwater Background Threshold Values
Parameter
Reporting Units
Uuke Enerq Calculated PRIVs
15A NCAC 02L
Standard or
IMAC
DWR Concurrence (Acce table/Not Acceptable)
Comments
Flow I:nit
Flow Unit
Alluvium ShallowF14.75
Bedrock
Alluvium
Shallow
Dee
Bedrock
H
S.U.
4.6-5.1 43.$.8
4.1-8.1
6.5-8.5
Acceptable
Acceptable
Acceptable
Acceptable
Alkalinity
m L
10.9 t4.2
70A
NE
Acceptable
Acceptable
Acceptable
Acceptable
Aluminum
L
73 602.2
199.3
NE
Accetable
Acce table
Acce table
A table
Antimon
µg/L
I �1
I
I.
Ac table
Acce table
Acc table
Acc table
Arsenic
I t I
1
10
Acceptable
Acceptable
Acceptable
Acceptable
Barium
µg/L
50 14a
41.16
700
Ac table
Acce table
Acc table
Acc table
B Ilium
µg/L
t1
1
4
A table
Acce table
Acce table
Acc table
Bicarbonate
Boron
mg/L
119fl,
10.9 1i
50 so -�
50
70A
50
NE
700
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Cadmium
_
1 __ _ "1_
2.6� _ Inn 1913
5 5 5
2
Acceptable
Acceptable
Acceptable
Acceptable
Calcium
mg/L
_ 24_I';_
5
NE
Acceptable
Acceptable
Acceptable
Acceptable
Carbonate
m
NE
Acceptable
Acceptable
Acceptable
Acceptable
Chloride
m
_
IS
_
l4
6.7
_
6.5
250
Acceptable
Acceptable
Acceptable
Acceptable
Chromium (VI)
1191
OAI
1313
0.261
0.423
NA
Acceptable
Ac table
Acceptable
Acceptable
Chromium
5
5
1 z2
_
1.1
10
Acceptable
Acceptable
Acceptable
Acceptable
Cobalt
AWL
429
S.ti.52
4.661, 1
1
Acceptable
Not Acceptable
Acceptable
Acceptable
Shallow: non -parametric distribution; 95% UTL (bootstrap and BCA bootstrap avenge) with 95% coverage = 6.9.
copper
5
5
i.Ox f- 1
1000
Acceptable
Acceptable
Acceptable
Acceptable
Iron
µg'L
598
_1050 1785- 1246
_ I _ _1 1
_R= T 3 371 t 330
725 380 104.7
03 0.2 0.05
300
Acceptable
Not Acceptable
Not Acceptable
Acceptable
Shallow: gamma distribution; 95% UTL (WE and HW avenge) with 95% coverage = 941.
Deep: notmaldistribution; 95%UTLwith95%coven a=779.
Lead
1191L
I
15
NE
50
Acceptable
Acceptable
Acceptable
Acceptable
A table
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Not Acceptable
Bedrock: non-pammetric distribution; 95% UTL (bootstrap and BCA bootstrap average) with 95% coverage = 93.
Magnesium
Manganese
mg/L
119/1.
3,86
363
Mercury
L
0.1
1
Acceptable
Acceptable
Acceptable
Acceptable
Methane
µg1-
230
10
10
Ill
NE
Not Acceptable
Acceptable
Acceptable
Acceptable
Alluvium: 230 is an outlier and Should be removed from dataset; normal distribution, 95% UTL with 95% coverage =
128.
Molybdenum
µPL
1
_ _ 1 I _ 3.7
t-- _ 10 u,82c 1.77
_ 2,4 0 RT__ _ _0.422
Lot 1.871 _ 4.785
1.88 I _t _ 1
_�._-
4.D6 _ 11 �; 9.013
93.98 _.i ➢'. Gi 88
50 _5_46' S.n
_ 6.1 _ 0.1 - _01 _
IU4p ! I II c
_. .r
0.2 _ 11.2 __ U.2
0.70R 0 599 _ LI02
0.625 0.41 OA32
NE
Acceptable
Acceptable
Acceptable
Acceptable
Nickel
g'L
5
100
le
Acceptable
Acceptable
Acceptable
Nitrate + Nitrite
m -N/L
0.113
11°
le
Acceptable
Acceptable
Acceptable
Potassium
mg/L
MR5
NE
20
le
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Selenium
f
Sodium
m
6.18
NE
le
Acceptable
Acceptable
Acceptable
Strontium
µ
20
NE
le
Acce table
Acce table
Acce table
Sulfate
m L
4,6
11.1
56
0,2
250
le
Acceptable
Acceptable
Acceptable
Sulfide
mg/L
NE
Acceptable
Acceptable
Acceptable
Acceptable
TDS
mg/L
500
Acceptable
Acceptable
Acceptable
Acceptable
Thallium
0.2
Acceptable
Acceptable
Acceptable
Acceptable
TOC
m L
0.72
NE
Acceptable
Acceptable
Acceptable
Acceptable
Vanadium
'L
03
0.3
Acceptable
Acceptable
Acceptable
Acceptable
Zinc
µg�L
22 45.4 27.57
5
1000
Acceptable
Acceptable
Acceptable
Acceptable
Radium (Total)
Ci/L
4.17 6.832 6.61
6554
NE
Acceptable
Acceptable
Acce table
Not Acce table
Bedrock: normal distribution; 95%UTL with 95%coven a=5.8.
Unnium(TmaT)
µ mL
O.OIro35 O.D0035 0.1100402
6.09045396
NE
A table
Acce table
Acce table
Acce table
NA -Not Applicable
ND -Not Detected
NE . Not Established
mg/L - milligrams per liter
pCi/L - picocuries per liter
Radium (Total)- Radium-226 and Radium-228 combined
-The 15A NCAC 02L Standard is 10 mg/L for Nitrate and l mg/L for Nitrite (added for a total of 11 mg/L)
S.U. - Standard Unit
TUC - Total Organic Carbon
TDS - Total Dissolved Solids
µg/mL. micrograms per milliliter
µg(L - micrograms per liter
Uranium (Total)- Umnium-233, Uranium-234, Uranium-236, and Umnium-238 combined

Asheville Steam Electric Plant - Soil Background Threshold Values
Parameter
Reporting
Units
Duke Fnergv
Calculated PB'1'l's
PSRG Protection
of Groundwater
DWR Concurrence
(Acceptable/Not Acceptable)
Comments
H
S.U.
3.4 - 8.9
NE
Acceptable
Aluminum
mg/kg
33951
NE
Acceptable
Antimony
mg/kg
NA
0.9
Not Acceptable
Use PSRG of 0.9. To be revised when valid data set is available.
Arsenic
mg/kg
5.06
5.8
Acceptable
Barium
mg/kg
219.9
580
Acceptable
Beryllium
mg/kg
1.959
63
Acceptable
Boron
mg/kg
36.6
45
Acceptable
Cadmium
mg/kg
ti D
3
Not Acceptable
Use PSRG of 3. To be revised when valid data set is available.
Calcium
mg/kg
1295
NE
Acceptable
Chloride
mg/kg
NI)
NE
Acceptable
Chromium
mg/kg
64.89
3.8
Acceptable
Cobalt
mg/kg
49.6_2
0.9
Acceptable
Copper
mg/kg
_
76.6
700
Acceptable
Iron
mg/kg
53379
150
Acceptable
Lead
mg/kg
71.04
270
Acceptable
Magnesium
mg/kg
9673
NE
Acceptable
Manganese
mg/kg
1228
65
Acceptable
Mercury
mg/kg
0.070'
1
Acceptable
Molybdenum
mg/kg
ND
NE
Acceptable
Nickel
mg/kg
2758
130
Acceptable
Nitrate (as N)
mg/kg
NI)
NE
Acceptable
Potassium
mg/kg
4754)
NE
Acceptable
Selenium
mg/kg
7
2.1
Acceptable
Sodium
mg/kg
NI)
NE
Acceptable
Strontium
mg/kg
7.756
NE
Acceptable
Sulfate
mg/kg
N1)
NE
Acceptable
Thallium
mg/kg
NA
0.28
Not Acceptable
Use PSRG of 0.28. To be revised when valid data set is available.
Vanadium
mg/kg
_
82.78
6
Acceptable
Zinc
mg/kg
218.5
1200
Acceptable
NA - Not applicable (dataset contains zero valid samples)
ND - Non -Detect
NE - Not Established
mg/kg - milligrams per kilogram
S.U. - Standard Unit

Buck Combined Cycle Station - Groundwater Provisional Background Threshold Values
Parameter
Reporting
Units
_Duke Energy Calculated PBTVs
—
I7ow Enit
15A NCAC 02L
Standard or
MAC
DWR Concurrence (Acceptable/Not Acceptable)
Comments
Flow Unit
—
Shallow
Dec
Bedrock
Shallow
Deep
Bedrock
pH
S.U.
4.5 - 6.4
5.9 - SA 1
5.8 - 7.8
6.5-8.5
Acceptable
Acceptable
Acceptable
Alkalinity
mg2
67.3
70.4
72
NE
Not Acceptable
Not Acceptable
Acceptable
Duke revised shallow - Gamma 117.2 ug/L and deep - Gamma 80.2 ug/L.
Please revise table accordingly.
Aluminum
µg/L
_
272.8
404
240
NE
Acceptable
Acceptable
Acceptable
Antimony
µg/L
I
1
1
1
Acceptable
Acceptable
Acceptable
Arsenic
µg/L
I
1
1
10
Acceptable
Acceptable
Not Acceptable
Duke revised bedrock - Gamma 3.3 ug/L. Please revise table accordingly.
Barium
µg/L
43.5
19
90.8
700
Not Acceptable
Acceptable
Acceptable
Duke agreed Shallow Nomal UTL - 50.6 ug/L.
Beryllium
µg L
0.139
1
0.2
4
Not Acceptable
Acceptable
Acceptable
Duke utilized Gamma UTL for shallow - 0.81 ug/L. Please revise table
accordin I .
Bicarbonate
mg/L
92.261
84.371
72
NE
Acceptable
Acceptable
Acce table
Boron
L
50
50
50
700
Acceptable
Acceptable
Acce [able
Cadmium
L
1
1
1
2
Acceptable
Acceptable
Acceptable
Calcium
mg/L
13.1
14
13.3
NE
Acceptable
Acceptable
Acceptable
Carbonate
mg/L
5
5
5
NE
Acceptable
Acceptable
Acceptable
Chloride
mg/L
7.559
_
4.454
4.818
250
Acceptable
Acceptable
Acceptable
Chromium (VI)
g/L
2.428
0.5
1.20
NA
Acceptable
Acceptable
Acceptable
Chromium
g/L
5.04
5
3.603
10
Acceptable
Acceptable
Acceptable
Cobalt
L
8.345
0.297
0.289
1
Acceptable
Acceptable
Acceptable
Copper
L
4.431
5
5.164
1000
Acceptable
Acceptable
Iron
L
64fiA
499.9
1 146.6
300
Acce table
Acceptable
Lead
µg/L
1
1
I
15
Acceptable
Acce table
n
Ma esium
m L
8.68
5.859
7.59
NE
Acc table
Acce table
Manganese
g/L
197.9
7
7
50
Acce table
Acce table
Page 1 of 2

Buck Combined Cycle Station - Groundwater Provisional Background Threshold Values
Parameter
Reporting
Units
fluke Energv Calculated PBTVs
Flow Unit
15A NCAC 02L
Standard or
IMAC
DWR Concurrence (Acceptable/Not Acceptable)
Comments
Flow Unit
Shallow
Deep
Bedrock
Shallow
Deep
Bedrock
Mercury
g/L
0.05
0.05
0.05
1
Not Acce table
Not Acceptable
Not Acceptable
Shallow, deep, and bedrock Non -Par. UTL - 0.2 u L.
Methane
µg/L
10
10
10
NE
Acceptable
Acceptable
Acceptable
Molybdenum
1
2
5.9
NE
Acceptable
Acceptable
Acceptable
Nickel
L
7.2
5
5
100
Acceptable
Acceptable
Acceptable
Nitrate + Nitrite
m -N/L
0.4
2
0.8712
ll*
Acceptable
Acceptable
Acceptable
Potassium
m
5
6.89
6.613
NE
Acceptable
Acceptable
Acceptable
Selenium
µg/L
1
1
1
20
Acceptable
Acceptable
Acceptable
Sodium
mg/L
8.22
13
9.8
NE
Acceptable
Acceptable
Acceptable
Strontium
µg/L
108
129
98.5
NE
Acceptable
Acceptable
Acceptable
Sulfate
m
3.3
6.7
2.4
250
Acceptable
Acceptable
Acceptable
Sulfide
m
0.1
0.1
0.1
NE
Acceptable
Acceptable
Acceptable
TDS
mg/L
212.02
130
145.049
500
Acceptable
Acceptable
Acceptable
Thallium
µg/L
0.2
0.2
1 0.2
0.2
Acceptable
Acceptable
Acceptable
TOC
mg/L
1100
1
1600
NE
Not Acceptable
Acceptable
Not Acceptable
Shallow background value should be 1.1 ug/L. Please revise accordingly.
Duke should verify bedrock value with geometric mean and revise if needed.
Vanadium
g/L
7.69
8.418
14.12
0.3
Acceptable
I Acceptable
Acceptable
Zinc
µg/L
26.39
10
17.4
1000
Acceptable
Acceptable
Acceptable
Radium (Total)
Ci/L
1.608
0.6
1.6
NE
Acceptable
Acceptable
Acceptable
Uranium Total
mL
0.0005
0.0005
0.0005
1 NE
Acceptable
Acceptable
Acceptable
NA - Not Applicable
ND - Not Detected
NE - Not Established
mg/L - milligrams per liter
pCi/L - picocuries per liter
Radium (Total) - Radium-226 and Radium-228 combined
*The 15A NCAC 02L Standard is 10 mg/L for Nitrate and I mg/L for Nitrite (added for a total of 11 mg/L)
S.U. - Standard Unit
TOC - Total Organic Carbon
TDS - Total Dissolved Solids
µg/mL - micrograms per milliliter
µg/L - micrograms per liter
Uranium (Total) - Uranium-233, Uranium-234, Uranium-236, and Uranium-238 combined
Page 2 of 2

Buck Combined Cycle Station - Soil Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energy
Calculated
PB'CN s
PSRG Protection
PSRG
of Groundwater
Concurrence
(Acceptable/Not
Acceptable)
Comments
H
S.U.
4.1 - 6.7
NE
Acceptable
Aluminum
M&g
25978
NE
Acceptable
Antimony
m
NA
0.9
Not Acceptable
Use PSRG of 0.9. To be revised when valid data set is available.
Arsenic
mg/kg
1.7
5.8
Acceptable
Only3 valid samples in data set.
Barium
m
_
U2.9
580
Acceptable
Beryllium
mg/kg
2.8
63
Not Acceptable
Gamma UTL - 4.52 mg/kg.
Boron
mg/kg
_
56.3
45
Acceptable
Cadmium
mg/kg
ND
3
Acceptable
Calcium
m
718
NE
Not Acceptable
Normal UTL - 999.1 mg/kg.
Chloride
mg/kg
ND
NE
Acceptable
Chromium
mg/kg
24,64
3.8
Acceptable
Cobalt
m
46.5
0.9
Acceptable
Copper
mg/kg
88.76
700
Acceptable
Iron
mg/kg
78988
150
Acceptable
Lead
mg/kg
15.36
270
Acceptable
Magnesium
m
33058
NE
Not Acceptable
Normal UTL - 14,554 mg/kg.
Manganese
mg/kg
1748
65
Acceptable
Mercury
mg/kg
0.0778
1
Acceptable
Molybdenum
mg/kg
ND
NE
Acceptable
Nickel
mg/kg
15.85
130
Acceptable
Nitrate as N)
mg/kg
ND
NE
Acceptable
Potassium
mg/kg
21444
NE
Not Acceptable
Normal UTL - 21,063.5 mg/kg.
Selenium
mglkg
N:%
2.1
Not Acceptable
Use PSRG of 2.1. To be revised when valid data set is available.
Sodium
ND
NE
Acceptable
Strontium
9.869
NE
Acceptable
Sulfate
ND
NE
Acceptable
Thallium
:iMjg/1Cg
N.4
0.28
Not Acce table
Use PSRG of 0.28. To be revised when valid data set is available.
Vanadium
202.6
6
Acc tableZinc
105.4
1200
Acceptable
NA - Not applicable (dataset contains zero valid samples)
ND - Non -Detect
NE - Not Established
mg/kg - milligrams per kilogram
S.U. - Standard Unit

Cape Fear Steam Electric Plant - Groundwater Provisional Background Threshold Values
Re
Rep MIS
Uuke b nugr (alauldcd PBI l's
15A NCAC 02L
Standard or
IMAC
DWR Concurrence (Acceptable/Not Acceptable)
Comments
host I nit
Flow Unit
._
SurFicial Bedrock
Surlieial
Bedrock
pH
S.U.
5.8 - 6.4 _5.5 - %.2
6.5-8.5
Acceptable
Acceptable
Alkalinity
mg/L
206 _ 237 Y _
323._3 _ _ _ 11%
I I _
3 6
NE
Acceptable
Acceptable
Aluminum
µg/L
NE
Acceptable
Acceptable
Antimony
Arsenic
L
l
10
Acceptable
Acceptable
Acceptable
Acceptable
Barium
_
183 _ 471
1 1
20M1 235
700
Acceptable
Acceptable
Beryllium
µg/L
4
Acceptable
Acceptable
Bicarbonate
m
NE
Acceptable
Acceptable
Boron
a
_ _ _
177 _ so
700
Acceptable
Acceptable
Cadmium
L
_ _ _
1 1_
2
NE
Acceptable
Acceptable
Acceptable
Acceptable
Calcium
mg/L
__ _
82.6
Carbonate
mgfL
5
_ _6.2b
5
NE
Acceptable
Acceptable
Chloride
mg/L
250
22o
250
Acceptable
Acceptable
Chromium (VI)
11911,
0.12
0!�3
NA
Acceptable
Acceptable
Chromium
pgfL
1
_ _
I
10
Acceptable
Acceptable
Cobalt
L
89
1.15
1
Acceptable
Acceptable
Copper
L
4
1
1000
Acceptable
I Acceptable
Iron
µg/L
375W
_ _
910
300
Acceptable
Not Acceptable
RRO calculated value of 750 ug/L for bedrock. Removed 4230, 2290, 1800, and 1220 as outliers. Duke Energy
notified ofdiscrepancy by email on 9-15-17
Lead
L
1
1
15
Acceptable
Acceptable
Magnesium
mg/L
32 c
30.8
NE
Acceptable
Acceptable
Manganese
g/L
9170
991
50
Acceptable
Acceptable
Mercury
L
0.05
0.05
1
Acceptable
Acceptable
Methane
L
1 10
25
NE
Acceptable
Acceptable
Molybdenum
L
1
11.5
NE
Acce table
Acceptable
Nickel
µg/L
78.11
2
100
Not Acceptable
Acceptable
RRO calculated value of48 ug/L. for surficial. Removed 150 as outlier. Duke Energy notified ofdiscrepacy by
email on 9-15-17
Nitrate -Nitrite
m -N/L
1.61
2.49
Il*
Acceptable
Acceptable
Potassium
mg/L
1
2.49
NE
Acceptable
Acceptable
Selenium
g/L
1
1."
20
Acceptable
Acceptable
Sodium
m
190
725
NE
Acceptable
Acceptable
Strontium
+L
994
a06
NE
Acceptable
Acceptable
Sulfate
I m 'L
510
1 %
250
Acceptable
Acceptable
Sulfide
mg/L
0.1
0.1
NE
Acceptable
Acceptable
TDS
m L
1200
675
500
Acceptable
Acceptable
Thallium
0.2
_
0.2
0.2
Acce table
Acceptable
TOC
m9fL
6.3 _
13
NE
Acceptable
Acceptable
Vanadium
L
1.268
2.37
0.3
Acceptable
Acceptable
Zinc
L
62
5
1000
Acceptable
Acceptable
Radium (Total)
pCi/L
3.459
NE
Acceptable
Acceptable
Uranium (Total)
g'mL
__1.03 _
O.01b"
0.00196
NE
Acceptable
Acceptable
NA. Not Appkeable
ND - Not Detected
NE - Not Established
mg/L- milligrams per liter
pCJL-picocuries per liter
Radimn (Total) . Radimn.226 and Radium-228 coinbeed
*The 1 SA NCAC 02L Standard is 10 mall, for Nitrate and I mg/L for Nitrite (added for a total of I I mg/L)
S.N. - Staudard Brut
TOC - Total Organic Cuban
TDS - Total Dissolved Solids
µghn]. - microgrmms per milliliter
pall. - micrograms per liter
❑mnimn (Total) - Uranium-233, Umnimn-234, Uranimn-236, and Uranium-238 combined

Cape Fear Steam Electric Plant - Soil Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energy
Calcualated
PB'iVs
of PSRG Protection
of Groundwater
DWR Concurrence
(Acceptable/Not
Acceptable)
Comments
pH
S.U.
5.2-6.7
NE
Acceptable
The PBTV was based on either the highest value or if the highest value is above an order of magnitude greater than
the geometric mean of all values, then the highest value should be considered an outlier and removed from further
use and the PBTV is computed to be the second highest value.
Aluminum
mg/kg
44400
NE
Acceptable
Antimony
mg/kg
0.177
0.9
Acceptable
Arsenic
mg/kg
8.1
5.8
Acceptable
Barium
mg/kg
224
580
Acceptable
Beryllium
mg/kg
1.2
63
Acceptable
Boron
mg/kg
14.4
45
Acceptable
Cadmium
mg/kg
0.69
3
Acceptable
Calcium
mg/kg
2750
NE
Acceptable
Chloride
mg/kg
301
NE
Acceptable
Chromium
mg/kg
40.4
360000
Acceptable
Cobalt
mg/kg
31.9
0.9
700
Acceptable
Acceptable
Copper
mg/kg
17.4
Iron
mg/kg
2%0
150
Acceptable
Lead
mg/kg
26.1
270
Acceptable
Magnesium
mg/kg
3420
NE
Acceptable
Manganese
mg/kg
370
65
Acceptable
Mercury
marJka
0.113
1
Acceptable
Molybdenum
mg/kg
3.3
NE
Acceptable
Nickel
mg/kg
9.2
130
Acceptable
Nitrate (as N)
mg/kg
30.1
NE
Acceptable
Potassium
mg/kg
427
NE
Acceptable
Selenium
mg/kg
4.4
2.1
Acceptable
Sodium
mg/kg
338
NE
Acceptable
Strontium
I mg/kg
35.8
NE
Acceptable
Sulfate
mg/kg
301
250
Acceptable
Thallium
mg/kg
0.349
0.28
Acceptable
Vanadium
mg/kg
I
42
6
Acceptable
Zinc
mg/kg
154
1200
Acceptable
NA - Not applicable (dataset contains zero valid samples)
ND - Non -Detect
NE - Not Established
mg/kg - milligrams per kilogram
S.U. - Standard Unit

James E. Rogers Energy Complex- Groundwater Provisional ackground Threshold Values
Parameter
Reporting
Units
Duke Energy Calculated PBM
Flo% Unit
15A NCAC 02L
Standard or
IMAC
DWR Concurrence (Acceptable/Not Acceptable)
Comments
Flow Unit
Shalon,
Ikeep
Bedrock
Shallow
Deep
Bedrock
pH
S.U.
4.4-6.1
41.E-6.1
5.4-7A
6.5-8.5
Acceptable
Acceptable
Acceptable
Alkalinity
m
13.67
19.74
53
NE
Acceptable
Acceptable
Acceptable
Aluminum
WL
253
290
208.2
NE
Acceptable
Acceptable
Acceptable
Antimony
µg/L
1
I
1
1
Acceptable
Acceptable
Acceptable
Arsenic
WIL
I
1.303
1
10
Acceptable
Acceptable
Acceptable
Barium
µglL
73.03
23
A933
700
Acceptable
Acceptable
Acceptable
Beryllium
L
0.188
0.2
1
4
Acceptable
Acceptable
Acceptable
nate
mg(L
14.42
18.13
68.92
NE
Acceptable
Acceptable
Acceptable
50
50
50
700
Acceptable
Acceptable
Acceptable
m
1
I
1
2
Acceptable
Acceptable
Acceptable
mg/L
3.221
I1
16
NE
Acce table
Acce table
Acceptable
te
m
5
5
5
NE
Acc table
Acc table
Ac fable
m
7.7
5.1 RAM
6.16 0.12
250
Acceptable
Acceptable
Ac table
m (vq
0.4.42
NA
Acceptable
Acc table
Acceptable
m
µg(L
3.96R 1'91 r567
_10.65 _ 9 041 _ 1 497
6.5ao n4-r '- 5
7653 ! 5.96220
1 _ I_ �1
2.4-4 _ 1.6 2.328
16X.6 _ _'8 zl 80.4
0.2 U2 f 0.2
10
Acce table
Acc table
Acceptable
1
Acceptable
Not Acceptable
Acceptable
Deep: non -parametric distribution; 95% UTL (bootstrapand BCA bootstrapaverage) with 95% -coverage = 5.1.
Copper
1000
Acceptable
Acceptable
Ac mble
Iron
Lead
µg/L
300
Not Acceptable
Not Acceptable
Acceptable
Shallow: log normal distribution; 95% UTL with 95% coverage = 684.
Deep: no -parametric distribution; 95% UTL(bootstrap and BCA bootstrap averse with 95%coverage =515.
IS
Acceptable
Acceptable
Acceptable
Magnesium
mg1L
NE
Acceptable
Acceptable
Acceptable
Manganese
ltS1L
50
Acceptable
Acceptable
Acceptable
Mercury
1
NE
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Methane
Molybdenum
µg/L
_
10 I! I51 _ In
1 _ I _ I 716
6.LS6 _
8.837_I^_2.R
NE
Acceptable
Acceptable
Acceptable
Nickel
Nitrate +Nitrite
IL91L
m-N/L
100
Acceptable
Acceptable
Acceptable
It-
Acceptable
Acceptable
Acceptable
Potassium
mg/L
5
g
_U.u�
s
NE
Acceptable
Acceptable
Acceptable
Selenium
9911.
1
1
1
20
Acceptable
Acceptable
Acceptable
Sodium
mg/L
6.139
4.41
7.42
NE
NE
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Strontium
36.71
56.14
107.1
Sulfate
mg/L
1.169
10
15.1
250
Acceptable
Acceptable
Acceptable
Sulfide
mg/L
0.1
0A
0.1
NE
Acceptable
Acceptable
Acceptable
TDS
mg/L
75A7
70.98
120
500
Acceptable
Acceptable
Acceptable
Thallium
0.117
0.063
0.2
0.2
Acceptable
Acceptable
Acceptable
TOC
mg/L
I
I
I
NE
Acceptable
Acceptable
Acceptable
Vanadium
µg/L
1.059
1.095
037
0.3
Not Acceptable
Acceptable
Acceptable
Shallow: normal distribution; 95% UTL with 95% coverage = 0.8.
All vanadium values reported as ", I ugtU'should be omitted from the background dataset because the detection
limit is above the IMAC.
D : vanadium = 3 u L(deep) is identified as an outlier and should be omitted from the damsel.
Zinc
µgfL
15
15.a3
10
1000
Acceptable
Acceptable
Acce table
Radium (Total)
Cill,
2.58
I51
d.l
NE
Acceptable
Acceptable
Acceptable
Uranium (Total
mL
0.0005
Q01g5
0.ODU5
NE
Acce mble
Acceptable
Acceptable
NA - Not Applicable
S.U. - Standard Unit
NO - Not Detected
TOC - Total Organic Carbon
NE - Not Established
TDS - Tom] Dissolved Solids
mg/L - milligrams per liter
µg/mL - microgams per milliliter
pCi/L - picocuries per liter
µg/L - micrograms per liter
Radium (Total) - Radium-226 and Radium-228 combined
Uranium (Total) - Uranium-233, Umnium-234, Umnium-236, and Umnium-238 combined
-The 15A NCAC 02L Standard is 10 mg/L for Nitrate and I mg/L for Nitrite (added for a total of 11 mg/L)

James E. Rogers Energy Complex - Soil Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energy
Calculated
PR r�•s
PSRG Protection
of Groundwater
DWR Concurrence
(Acceptable/Not Acceptable)
Comments
H
S.U.
4.7 - 6.7
NE
Acceptable
Aluminum
mgfkg
36464
NE
Acceptable
Antimony
mgfkg
NA
0.9
Not Acceptable
Use PSRG of 0.9. To be revised when valid data set is available.
Arsenic
mgfkg
4.88
5.8
Acceptable
Barium
m
233
580
Acceptable
Beryllium
m
_ _ 38.9
63
Acceptable
Boron
mg/kg
1.92
45
Acceptable
Cadmium
mgfkg
ND
3
Not Acceptable
Use PSRG of 3. To be revised when valid data set is available.
Calcium
m
_ 304
NE
Acceptable
Chloride
m
ND
NE
Acceptable
Chromium
mg/kg
_ 109 _
3.8
Acceptable
Cobalt
m
_ 59.5
0.9
Not Acceptable
Normal distribution at 5% significance level; 95% UTL with 95% coverage = 43.
Copper
mg/kg
34.7
700
Acceptable
Iron
m
75162
150
Acceptable
Lead
mvJkQ
38.1
270
Acceptable
Magnesium
mgfkg
2.1562
NE
Acceptable
Manganese
m
1518
65
Not Acceptable
Gamma distribution at 5% significance level; 95% UTL WH and H W averse with 95% coverage = 1421.
Mercury
mg/kg
0.016
1 -
Acceptable
Molybdenum
mgfkg
U.97
NE
Acceptable
Nickel
m
66.2
130
Acceptable
Nitrate (as N)
m&g
ND
NE
Acceptable
Potassium
m
18460
NE
Acceptable
Selenium
mgfkg
_ 12 _
2.1
Not Acceptable
N < 10 so use maximum = 8.3
Sodium
mg/kg
194
NE
Acceptable
Strontium
mg/kg
14.1
NE
Acceptable
Sulfate
mg/kg
ND
250
Acceptable
Thallium
m
_ _ N n _
0.28
Not Acceptable
Use PSRG of 0.28. To be revised when valid data set is available.
Vanadium
m
142
6
Acceptable
Zinc
m
214
1200
Acceptable
NA - Not applicable (dataset contains zero valid samples)
ND - Non -Detect
NE - Not Established
mg/kg - milligrams per kilogram
S.U. - Standard Unit

Dan River Combinded Cycle Station- Groundwater Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energy Calculated PBTVs
Flow Unit
15A NCAC 02L
Standard or
IMAC
DWR Concurrence (Acceptable/Not Acceptable)
Comments
Flow Unit
Shallow
Deep
Bedrock
Shallow
Deep
Bedrock
H
S.U.
4.0-7.1
5.3-6.8
6.7-8.4
6.5-8.5
Acceptable
Acceptable
Acceptable
Alkalinity
mg/L
77.7
168
236
NE
Acceptable
Acceptable
Acceptable
Aluminum
118
113
100
NE
Acce table
Acceptable
Acceptable
Antimony
g/L
0.5
0.5
0.5
1
Acceptable
Acceptable
Acceptable
Arsenic
g/L
0.5
1.62
0.833
10
Acceptable
Acceptable
Acceptable
Barium
L
19
80.4
128
700
Acceptable
Acceptable
Acceptable
Beryllium
µg/L
0.429
0.0772
0.0625
4
Acceptable
Acceptable
Acceptable
Bicarbonate
mg/L
77.7
168
233
NE
Acceptable
Acceptable
Acceptable
Boron
50
50
50.9
700
Acceptable
Acceptable
Acceptable
Cadmium
L
0.08
0.08
0.08
2
Acceptable
Acceptable
Acceptable
Calcium
mg/L
19A
59
59.1
NE
Acceptable
Acceptable
Acceptable
Carbonate
mg/L
5
5
5
NE
Acceptable
Acceptable
Acceptable
Chloride
mg/L
7.3
6.8
7.1
250
Acceptable
Acceptable
Acceptable
Chromium I)
L
0.58
1.24
0.15
NA
Ace table
Acceptable
Acceptable
Chromium
µg/L
1.26
3.42
8.31
10
Acce table
Acceptable
Acceptable
-
Cobalt
µ L
2A
0.85
1
1
Ace table
Acceptable
Acceptable
Copper
I ggfL
2.67
2.29
13
1000
Acceptable
Acceptable
Acceptable
Iron
µg/L
152
2130
1400
300
Acceptable
Not Acceptable
Acceptable
Please explain why two distinguished subgroups of population exist and whether they should be
grouped together should also be evaluated.
Lead
AWL
0.1
0.13
1.4
15
Ace table
Acceptable
Acceptable
Magnesium
mgIL
12.2
15.9
20.7
NE
Acceptable
Acceptable
Acceptable
Manganese
81.2
552
38.9
50
Ace table
Acceptable
Acceptable
Mercury
AWL
0.2
0.2
0.2
1
Acceptable
Acceptable
Acceptable
Methane
pg/L
10
10
233
NE
Acceptable
Acceptable
Acceptable
Molybdenum
0.5
0.927
1.4
NE
Acceptable
Acceptable
Acceptable
Nickel
2.88
3.65
19.2
100
Acceptable
Acceptable
Acceptable
Nitrate + Nitrite
to -N/L
0.53
0.349
0.074
11•
Acceptable
Acce table
Acceptable
Potassium
mg/L
5
5
5
NE
Accept le
Acceptable
Acceptable
Selenium
0.5
0.5
1 0.5
20
Acceptable
Acceptable
Acceptable
Sodium
mg/L
17.3
17.8
19.2
NE
Acceptable
Acceptable
Acceptable
Strontium
P&I
211
481
2120
NE
Acceptable
Acceptable
Acceptable
Sulfate
mg/L
36.7
36.7
11.3
250
Acceptable
Acceptable
Acceptable
Sulfide
mg/L
0.1
0.1
0.1
NE
Acceptable
Acceptable
Acceptable
TDS
m L
187
244
284
500
Ace table
Acceptable
Acceptable
Thallium
µg/L
0.1
0.1
0.1
0.2
Ace table
Acceptable
Acc table
TOC
mg/L
1
1
1
NE
Ac table
Acceptable
Acce table
Vanadium
L
0.413
0.645
2.52
0.3
Ace table
Acceptable
Acceptable
Zinc
pg/L
46.3
10
16
1000
Acce table
Acce table
Acceptable
Radium (Total)
pCi/L
1.45
1.38
1.63
NE
Acceptable
Acceptable
Acceptable
Uranium Total
mL
0.005
0.00106
1 0.002
NE
Ace table
Acce [able
-Acce table
NA - Not Applicable
S.U. - Standard Unit
ND - Not Detected
TOC- Total Organic Carbon
NE - Not Established
TDS - Total Dissolved Solids
mg/L -milligrams per liter
µg/mL - micrograms per milliliter
pCi/L- picocuries per liter
pg/L- micrograms per liter
Radium (Total) - Radium-226 and Radium-228 combined
Uranium (Total) - Uranium-233, Uranium-234, Uranium-236, and Uranium-238 combined
*The 15A NCAC 02L Standard is 10 mg/L for Nitrate and 1 mg/L for Nitrite (added for a total of 11 mg/L)

Dan River Combined Cycle Station - Soil Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energy
Calculated
PBTVs
PSRG Protection
of Groundwater
DWR Concurrence
(Acceptable/Not
Acceptable)
Comments
pH
S.U.
2.3 - 9.4
NE
Acceptable
Aluminum
mg/kg
34500
NE
Acceptable
Antimony
mg/kg
NA
0.9
Not Acceptable
Use PSRG of 0.9. To be revised when valid data set is available.
Arsenic
mg/kg
12.37
5.8
Acceptable
Barium
mg/kg
132.9
580
Acceptable
Beryllium
m
3.313
63
Acceptable
Boron
mg/kg
ND
45
Acceptable
Cadmium
mg/kg
ND
3
Acceptable
Calcium
mg/kg
2276
NE
Acceptable
Chloride
mg/kg
ND
NE
Acceptable
Chromium
mg/kg
44.54
3.8
Acceptable
Cobalt
mg/kg
29.23
0.9
Acceptable
Copper
mg/kg
87.34
700
Acceptable
Iron
mg/kg
68009
150
Acceptable
Lead
mg/kg
30.94
270
Acceptable
Magnesium
mg/kg
12119
NE
Acceptable
Manganese
mg/kg
802
65
Acceptable
Mercury
mg/kg
0.04
1
Acceptable
Molybdenum
mg/kg
ND
NE
Acceptable
Nickel
mg/kg
45.58
130
Acceptable
Nitrate (as N)
mg/kg
ND
NE
Acceptable
Potassium
mg/kg
3160
NE
Acceptable
Selenium
mg/kg
NA
2.1
Not Acceptable
Use PSRG of 2.1. To be revised when valid data set is available.
Sodium
mg/kg
ND
NE
Acceptable
Strontium
mg/kg
84.96
NE
Acceptable
Sulfate
mg/kg
ND
250
Acceptable
Thallium
mg/kg
NA
0.28
Not Acceptable
Use PSRG of 0.28. To be revised when valid data set is available.
Vanadium
mg/kg
58.73
6
Acc table
Zinc
m
191.8
1200
Acceptable
NA - Not applicable (dataset contains Zero valid samples)
ND - Non -Detect
NE - Not Established
mg/kg - milligrams per kilogram
S.U. - Standard Unit

H. F. Lee Energy Complex - Groundwater Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energy Calculated PB"1"%'s
Flow Unit
15A NCAC 02L
Standard or
IMAC
DWR Concurrence (Acceptable/Not
Comments
Flow Unit
S6allosa. (alleFesur
Shallow
Cape Fear
H
S.U.
3.4-6.8 5.3-8.3
73 _ 219
6.5-8.5
Acceptable
Acceptable
Alkalinity
L
NE
Acceptable
Acceptable
Aluminum
1059 �- _ 264
NE
Acceptable
Acceptable
Antimony
µg/L
I I_ 1
I
Acceptable
Acceptable
Arsenic
1 _ _'� _ _ 1
o41 _"_ 342
1 1
10
Acceptable
Acceptable
Barium
700
Acceptable
Acceptable
Beryllium
4
Acceptable
Acceptable
Bicarbonate
mg/L
73.9
219
NE
Acceptable
Acceptable
Boron
50
700
Acceptable
Acceptable
Cadmium
µg/L
1
_256
1
2
Acceptable
Acceptable
Calcium
L
11.2 "
30.8
NE
Acceptable
Acceptable
Carbonate
m
5
5
NE
Acceptable
Acceptable
Chloride
M91L
19
72
250
Acceptable
Acceptable
Chromiurn(VI)
µg/L
0.354
0.15
NA
Acceptable
Acceptable
Chromium
I
1
10
Acceptable
Acceptable
Cobalt
13.7
8.07
1
Acceptable
Not Acce table
Cape Fear Aquifer PBTV -1 (99%ile)
Copper
4.39
1
1000
Acceptable
Acceptable
Iron
µg/L
6320
11600
300
Not Acceptable
Acceptable
SurficialAquifer PBTV-413.8(99%ile)
Lead
Z.61
/
15
Acceptable
Acceptable
Magnesium
m
6.55
6.94
NE
Acceptable
Acceptable
Manganese
µ
1140
111"
50
Not Acceptable
Acceptable
SurficialAquifer PBTV - 838 (99%ile)
Mercury
µg/L
0.05
0.05
1
Acceptable
Acceptable
Methane
16.7
7701
NE
Acceptable
Acceptable
Molybdenum
1
10.9
NE
Acceptable
Acceptable
Nickel
pg/L
9.81
15.3
100
Acceptable
Acceptable
Nitrate + Nitrite
m -N/L
II
0.953_
If*
Acceptable
Acceptable
Potassium
mg/L
4,95
5.2
NE
Acceptable
Acceptable
Selenium
1
1
20
Acceptable
Acceptable
Sodiwn
mg/L
11.5
102
NE
Acceptable
Acceptable
Strontium
119
13.1
NE
Acceptable
Acceptable
Sulfate
mg/L
54.7
23
250
Acceptable
Acceptable
Sulfide
mg/L
0.1 _
0.1
NE
Acceptable
Acceptable
TDS
L
163
385
500
Acceptable
Acceptable
Thallium
µg/L
0.2 �_ 0.2
0.2
NE
Acceptable
Acceptable
Acceptable
Acceptable
MOLL L
_
15 - - 1.7
n.411 2.18_
20+ _ R
2? a _ 3.01
n.002 iii 0.00114
Vanadium
0.3
Acce table
Not Acceptable
Cape Fear Aquifer PBTV - 0.3 (99%ile)
Zinc
L
1000
Acceptable
Acceptable
Radium (Totall
pCVL
NE
Acceptable
Acceptable
Uranium (Total)
mL
NE
Acceptable
Acceptable
NA - Not Applicable
ND - Not Detected
NE - Not Established
mg/L - milligrams per liter
pCYL - pic.enas per liter
Radium (Total) - Radium-226 and Radian-228 combined
'The 15A NCAC 02L Standard is 10 mg/L for Nitrate and 1 mail, for Nitrite (added for a total of I I my L)
S.U. - Standard Unit
TOC - Total Ortgnic Carbon
TDS - Total Dissolved Solids
µg/ml. - micrograms per milliliter
µg/L - micrograms per liter
Uranium (Total) - Uranium-233, Uranium-234, Umnium-236, and Ummum-238 combined

H. F. Lee Energy Com lex - Soil Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energy
Calculated
PB'f 4 s
PSRG Protection
of Groundwater
DWR Concurrence
(Acceptable/Not
Acce table
Comments
H
S.U.
NE
Duke Energy/Synterra collected one soil sample that fit the criteria for background sampling prior to this submission.
Per Ryan Czop additional soil analyses and PBTV will be forthcoming in early October. To be revised when valid data set is
available.
Aluminum
mg/kg
NE
Antimony
m
0.9
Arsenic
mg/kg
5.8
Barium
m
580
Beryllium
mg/kg
63
Boron
m k
45
Cadmium
mg/kg
3
Calcium
mg/kg
NE
Chloride
mg/kg
NE
Chromium
mg/kg
3.8
Cobalt
mg/kg
0.9
Copper
m
700
Iron
mg/kg
150
Lead
mg/kg
270
Magnesium
mg/kg
NE
Manganese
mglkg
65
Mercury
mg/kg
I
Molybdenum
mg/kg
NE
Nickel
mg/kg
130
Nitrate as N)
m
NE
Potassium
mg/kg
NE
Selenium
mg/kg
2.1
Sodium
mg/kg
NE
Strontium
mg/kg
NE
Sulfate
mg/kg
250
Thallium
mg/kg
0.28
Vanadium
m
6
Zinc
m g
1200
NA - Not applicable (dataset contains zero valid samples)
ND - Non -Detect
NE - Not Established
mgtkg - milligrams per kilogram
S.U. - Standard Unit

Marshall
Steam Station - Groundwater Provisional Back round Threshold Values
Parameter
Reporting
Units
Duke Energy Calculated PBTVs
Flow [;nit
15A NCAC 02L
Standard or
IMAC
DWR Concurrence (Acceptable/Not Acceptable)
Comments
Flow Unit
Shallow
Deep
Bedrock
Shallow
Deep
Bedrock
H
S.U.
4.8 - 6.1
5.8 - 7.9
5.9 - 7.1
6.5-8.5
Acceptable
Acceptable
Acceptable
Alkalinity
m
29.7
237.502
108
NE
Acceptable
Acceptable
Acceptable
Aluminum
925.6
190.1
463
NE
Not Acceptable
Acceptable
Acceptable
Shallow - Removed 1,200 u L Gamma UTL - 612.4 u . Please revise accordingly.
Antimony
1
11.5
1
1
Acceptable
Acceptable
Acceptable
Arsenic
11.219
1.5
1
10
Acceptable
Acceptable
Acceptable
Barium
148
45.53
66.9
700
1 Acceptable
Acceptable
Acceptable
Beryllium
PgL
0.374
0.0759
t
4
Acceptable
Acceptable
Acceptable
Bicarbonate
mg/L
30.8
237.502
108
NE
Not Acceptable
Acceptable
Acceptable
Shallow - Removed 186 ug/L Normal UTL - 36.93 mg/L. Duke should verify value removed to ensure value
was in proper units revise if needed.
Boron
L
50
50
50
700
Acceptable
Acceptable
Acceptable
Cadmium
0.08
1
2
Acceptable
Acceptable
Acceptable
Calcium
m L
6.115
_0.08
88.033
13.7
NE
Acceptable
Acceptable
Acceptable
Carbonate
m
5
5
5
NE
Acceptable
Acceptable
Acceptable
Chloride
mgIL
4.3
5.186
2.7
250
Acceptable
Acceptable
Acceptable
Chromium(VI)
µg/L
1.742
1.48
4.818
NA
Not Acceptable
Not Acceptable
Not Accetpable
Duke should verify values established for Chromium (VI) were done so using Chromium (VI) data and not
total Chromium.
Chromium
µg/L
4.822
2.545
5
IO
Not Acceptable
Not Acceptable
Not Accetpable
Duke should verify values established for Chromium were done so using Chromium data and not total
Chromium (VI).
Cobalt
3.7
2.4
3.802
1
Acceptable
Acceptable
Acceptable
Copper
1191L
3.131
3.7M
5
1000
Acceptable
Acceptable
Acceptable
Iron
AWL
817.5
336.6
675.8
300
Acceptable
Acceptable
Acceptable
Lead
0.738
0.348
1
15
Acceptable
Acceptable
Acce table
Magnesium
m
1.517
8.723
13.6
NE
Acceptable
Acceptable
Acc table
Man anew
82
187.1
310
50
Acceptable
Acceptable
Acceptable
Page 1 of 2

Marshall Steam Station - Groundwater Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energy Calculated PBTVs
Flow Unit
15A NCAC 02L
Standard or
IMAC
DWR Concurrence (Acceptable/Not Acceptable)
Comments
Flow Unit
Shallow
Deer
Bedrock
Shallow
Deep
Bedrock
Mercury
0.05
0.2
0.05
1
Not Acceptable
Acceptable
Not Acceptable
Shallow, deep, and bedrock Non -Par. UTL - 0.2 u
Methane
to
10
16.4
NE
Acceptable
Acceptable
Acceptable
Molybdenum
AgIL
0.684
9
4.262
NE.
Acceptable
Acceptable
Acceptable
Nickel
ggfL
5.944
7.325
5
100
Acceptable
Acceptable
Acceptable
Nitrate + Nitrite
m -N/L
1.6
0.8946
0.38118
ll*
Acceptable
Acceptable
Acceptable
Potassium
m
5
4.453
8.19
NE
Acceptable
Acceptable
Acceptable
Selenium
0.5
0.5
1
20
Acceptable
Acceptable
Acceptable
Sodium
mg/L
9.753
39.917
14
NE
Acceptable
Not Acceptable
Acceptable
Deep - Removed 7,550 ug/L Gamma UTL - 42.61 mg/L. Duke should verify value removed to ensure value
was in proper units revise if needed.
Strontium
197.1
548.2
195
NE
Acceptable
Acceptable
Acceptable
Sulfate
m
1.9
50.259
14.4
250
Acceptable
Acceptable
Acceptable
Sulfide
m
0.1
0.1
0.1
NE
Acceptable
Acceptable
Acceptable
TDS
mg/L
79.833
257.046
177
500
Acceptable
Not Acceptable
Acceptable
Deep Normal UTL - 221.1 ug/L. Please revise accordingly.
Thallium
0.2
0.1
0.2
0.2
Acceptable
Acceptable
Acceptable
TOC
mg/L
1 1
4
1
NE
Acceptable
Acceptable
Acceptable
Vanadium
99fL
6.884
4.373
22,93
0.3
Acceptable
Acceptable
Acceptable
Zinc
t5.93
31.05
10
1000
Acc table
Acce table
Acc table
Radium (Total)
Ci/L
U.47
NA
1.884
NE
Acc table
Acc table
Acc table
Uranium Total)
mL
0.0005
ti N
0.0005
NE
Acceptable
Acceptable
Acceptable
NA - Not Applicable
ND - Not Detected
NE - Not Established
S.U. - Standard Unit
TOC - Total Organic Carbon
TDS - Total Dissolved Solids
mg/L - milligrams per liter µg/mL - micrograms per milliliter
pCi/L - picocuries per liter µg/L - micrograms per liter
Radium (Total) - Radium-226 and Radium-228 combined Uranium (Total) - Uranium-233, Uranium-234, Umnium-236, and Uranium-238 combined
*The 15A NCAC 02L Standard is 10 mg/L for Nitrate and 1 mg/L for Nitrite (added for a total of I 1 mg(L)
Page 2 of 2

Marshall Steam Station - Soil Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energ}
Calculated
PBTVs
PSRG Protection
of Groundwater
DWR Concurrence
(Acceptable/Not
Acceptable)
Comments
H
S.U.
4.1-6.7
NE
Acceptable
Aluminum
mg/kg
25978
NE
Acceptable
Antimony
mg/kg
NA
0.9
Not Acceptable
Use PSRG of 0.9. To be revised when valid data set is available.
Arsenic
mg/kg
3.7
5.8
Acceptable
Only 3 valid samples in data set.
Barium
mg/kg
312.9
580
Acceptable
Beryllium
m
2.8
63
Not Acceptable
Gamma UTL - 4.52 mg/kg
Boron
mg/kg
56.3
45
Acceptable
Cadmium
mgfkg
NO
3
Acceptable
Calcium
mgfkg
718
NE
Not Acceptable
Normal UTL - 999.1 mg/kg.
Chloride
mg/kg
NO
NE
Acceptable
Chromium
mg/kg
24.64
3.8
Acceptable
Cobalt
mg/kg
46.5
0.9
Acceptable
Copper
m
88.76
700
Acceptable
Iron
mg/kg
78988
150
Acceptable
Lead
m
_ 15.36
270
Acceptable
Magnesium
mg/kg
_
33058
NE
Not Acceptable -
Normal UTL - 14,554 m
Manganese
m
1748
65
Acceptable
Mercury
mg/kg
(1.07778
1
Acceptable
Molybdenum
m
_ 111)
NE
Acceptable
Nickel
mglkg
15.85 _
130
Acceptable
Nitrate as N)
m
NO
�21444
NE
Acceptable
Potassium
mgfkg
NE
Not Acceptable
Normal UTL - 21,063.5 mg/kg.
Selenium
mg/kg
NA
2.1
Not Acceptable
Use PSRG of 2.1. To be revised when valid data set is available.
Sodium
mg/kg
NO
NE
Acceptable
Strontium
mgtkg
9.869
NE
Acceptable
Sulfate
mg/kg
ND
NE
Acceptable
Thallium
mgIkg
N:%
0.28
Not Ace e table
jUse PSRG of 0.28. To be revised when valid data set is available.
Vanadium
mg/kg
2026.
6
Acceptable
Zinc
mg/kg
105.4
1200
Acceptable
NA - Not applicable (dataset contains zero valid samples)
ND - Non -Detect
NE - Not Established
mg/kg - milligrams per kilogram
S.U. - Standard Unit

L. V. Sutton Energy Complex- Groundwater Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energy Calculated PBT\'s
15A NCAC 02L
Standard or
IMAC
DWR Concurrence (Acceptable/Not Ace e table)
Comments
Flow Unit
Flow Unit
Surficial
t pier,
Surilcld Pee Dee
Lower 1'over
Pee flee
Lmvrer
Surficial
Upper
Surficial
Lower
Pee Dee
Upper
Pee Dec
Lower
H
S.U.
3.94 5
__ 5
95a
I
1 J::i,17
4.9 - 7.4 L R.2 - 8.9
9 - 9,7
6.5-8.5
Acceptable
Acceptable
Not Acceptable
Not Acce table
Insufficient datasets for the Upper and Lower Pee Dee. Additional samples am needed for valid
statistical analysis. To be revised when valid data set is available.
Alkalinity
mg/L
171 1 410
7. _ 593
I
464
NE
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Aluminum
µg/L
73
NE
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Antimony
µg/L
1
1
1
10
Acceptable
Acceptable
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Not Acceptable
Not Acceptable
Arsenic
3
Barium
Beryllium
g/L
µ
45
I
_
17
I 1
27
1
391
3520
1
700
4
NE
700
2
Acceptable
Ace table
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Not Acceptable
Not Acceptable
Not Acceptable
Not Acceptable
Not Acce table
Not Acce table
Not Acee table
Not Acceptable
Bicarbonate
mg/L
5
_ _
I'1 402
Boron
50
_
50 3010
Cadmium
1
_
1 1
Calcium
mg/L
0.996
22.6
9.47
48
NE
NE
Acceptable
Acceptable
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Not Acceptable
Not Acceptable
Carbonate
m L
S
5 _ _20
_ _21.o_ 68_0
Chloride
mg/L
4.73
1200
250
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Chromium (VI)
µgH-
0.03
0.11 0.26
0.1
NA
Acceptable
Not Acceptable
Not Acceptable
Not Acceptable
Surficial Lower: Insufficient data set for hex chrome. To be revised when valid data set is available.
insufficient datasets for the Upper and Lower Pee Dec. Additional samples are needed for valid
statistical anaysis. To be revised when valid data set is available.
Chromium
L
1
4
I
3
2
1
1
10
Acc [able
Acceptable
Not Acceptable
Not Acceptable
Insufficient damsels for the Upper and Lower Pee Dee. Additional samples are needed for valid
statistical anaysia To be revised when valid data se[ is available.
Cobalt
1191L
1
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Copper
µg/L
1
I
_
1
1
1000
Acceptable
Acceptable
I Not Acceptable
Not Acceptable
Iron
g/L
1494
13416
336
102
300
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Lead
1
1
1
1
15
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Magnesium
m
0.589
W
13.5
13.7 .
NE
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Manganese
38
746
63
5
50
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Mercury
L
I 0.05
0.05
0.05
0.05
1
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Methane
µg/L
25.8
36.1
121
19.6
NE
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Molybdenum
µ
1
1
20.7
16.1
NE
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Nickel
L
1
I 1
1
3.29
100
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Nitrate+ Nitrite
Potassium
Selenium
mg -NH-
mg/L
0.167
0.738
1
0.098
4.97
I
0.01 0.011
211.5 _ 48
I 5
11 a
NE
20
Acceptable
Acceptable
Acceptable
I Acceptable
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Not Acceptable
I Not Acceptable
Not Acceptable
Not Acceptable
Sodium
mg/L
_
3 _ 18,5 !
8 16-
15.6 16
0.1 _ r 0.1
25 210
_
584 _ 939
232 329
..20 SSU
NE
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Strontium
µ L
NE
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Sulfate
mg/L
250
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Sulfide
m L
1 0.14
1.8
1 NE
Acceptable
Acceptable
Not Acceptable
Not Acceptable
TDS
mg/L
1700
1800
500
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Thallium
p9fL
0.2
0.2
0.2
0.2
0.2
Acceptable
Acceptable
Not Acceptable
Not Acceptable
TOC
mg/L
0.692
6.7
33
6.6
NE
I Acceptable
Acceptable
I Not Acceptable
Not Acceptable
Vanadium
0.621
1.68
1.88
0.481
0.3
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Zinc
µg/L
5
13
_
5
6
1000
Acceptable
Acceptable
Not Acceptable
Not Acceptable
Radium (Total)
Uranium (Total)
Ci/L
/ml,
2.75
0.00035
5.32
030a14
2 4�5.5.1
0.00153
0.00077
NE
NE
Acceptable
Acce table
Acceptable
Acce table
Not Acceptable
Not Aeee table
Not Acce table
Not Acce table
NA- Not Applicable
NO -Not Delected
NE -Not Established
mg/L - milligrams per liter
pCUL - picocuries per liter
Radium (Total) - Radiurn-226 and Radium--228 combined
'The 15A NCAC 02L Standard is 10 mg/L for Nitrate and 1 mg/L for Nitrite (added for a total of I I mg/L)
S.U. -Standard Unit
TOC - Total Organic Carbon
IDS - Total Dissolved Solids
pg/mL - micrograms per milliliter
jig - micrograms per liter
Uraniurn (TOW) - Ursedura-233, Uranimn-234, Uranimn-236, and Umnimn-238 combined

L. V. Sutton Energy Complex - Soil Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energy
�alrulated
PR.I,N s
PSRG Protection
of Groundwater
DWR Concurrence
(Acceptable/Not
Acceptable)
Comments
H
S.U.
NE
Only two valid samples, therefore dataset is insufficient. Additional samples planned for collection. To be revised when valid data set is available.
Aluminum
mg/kg
_
NE
Antimony
mgIkg
0.9
Arsenic
m
5.8
Barium
m
580
Beryllium
mg/kg
63
Boron
mg/kg
45
Cadmium
mg/kg
3
Calcium
m
NE
Chloride
mgtkg
NE
Chromium
m
3.8
Cobalt
mg/kg
0.9
Copper
mg/kg
700
Iron
m
150
Lead
m
270
Magnesium
m
NE
Manganese
mglkg
65
Mercury
mgfkg
1
Molybdenum
mg/kg
NE
Nickel
mg/kg
jja.
130
NE
Nitrate (as N)
mg/kg
Potassium
mg/kg
NE
Selenium
mg/kg
2.1
Sodium
mg/kg
NE
Strontium
mg/kgmg1kg
NE
Sulfate
mgfkg
250
Thallium
mg/kg
0.28
Vanadium
m
6
Zinc
mglkg
1200
NA -Not applicable (dataset contains zero valid samples)
ND - Non -Detect
NE - Not Established
mg/kg - milligatns per kilogram
S-U. - Standard Unit

W. H. Weatherspoon Power Plant- Groundwater Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energy ('alculated PH I V%
llnw Cnit
15A NCAC 02L
Standard or
IMAC
DWR Concurrence (Acceptable/Not Acceptable)
Comments
Flow Unit
Surficial
1'urktown
Pee Dee
Surficial
Yorktown
Pee Dee
H
S.U.
3.21-6.87
5.5.5.7
6.9-8.3
6.5-8.5
Acceptable
Acceptable
Acceptable
Alkalinity
mg/L
36.5
_17.4
89
NE
Acceptable
Acceptable
Acceptable
Aluminum
1191L
_
1460
492
66
NE
Acceptable
Acceptable
Acceptable
Antimony
L
♦D
1
1
1
Not Acceptable
Acceptable
Acceptable
Surficial should be a numeric value, 1 L.
Arsenic
L
1.35
1
1
10
Acceptable
Acceptable
Acceptable
Barium
31.9
21
56
700
Acceptable
Acceptable
Acceptable
Beryllium
991L
ND
1
1
4
Not Acceptable
Acceptable
Acceptable
ISurficial should be a numeric value, 1 L.
Bicarbonate
mgfL
36.5
17.4
89
NE
Acceptable
Acceptable
Acceptable
Boron
W111,
ND
50
50
700
Not Acceptable
Acceptable
Acceptable
JSurficial should be a numeric value, I L.
Cadmium
L
ND
1
1
2
Not Acceptable
Acceptable
Acceptable
Surlicial should be a numeric value, I
Calcium
mgfL
14.5
7.92
M
NE
Acceptable
Acceptable
Acceptable
Carbonate
mg/L
ND
5
10
NE
Not Acceptable
Acceptable
Not Acceptable
Surficial should be a numeric value, 5 mg/L.
MDL for Pee Dee was 5 m l 5z 10 mg/1 only 3z .
Chloride
m
22.2
10
3.4
250
Acceptable
Acceptable
Acceptable
Chromium (VI)
uWL
01147
0.84
0.2
NA
Acceptable
Acceptable
Acceptable
Chromium
uWL
1.63
1 ?4
1
10
Acceptable
Acceptable
Acceptable
Cobalt
L
_
\ D
1
1
20'u
I
t 1
t I550
I
Not Acceptable
Acceptable
Acceptable
Surficial should be a numeric value, I L.
Copper
L
ND
132_31
1000
Not Acceptable
Acceptable
Acceptable
Surficial should be a numeric value I
Iron
300
Not Acceptable
Acceptable
Acceptable
Surficial calculated to be 9422
Lead
SU
1
1
15
Not Acceptable
Acceptable
Acceptable
Surficial should be a numeric value, 1 L.
Magnesium
mg/L
I.39 0.487 _ a 1.11 _
39 _ 20 r 41
ti1105 005
NE
Acceptable
Acceptable
Acceptable
Manganese
50
Acceptable
Acceptable
Acceptable
Mercury
8&1
1
Not Acceptable
Acceptable
Acceptable
Surficial should be a numeric value, 0.05
Methane
L
41'. iOxU 2J8
NE
Acceptable
Acceptable
Acceptable
Molybdenum
- j I 1
_ �D _ - - I _ 1
2.09 _ -0-11-1 11.01
1.16 _ O'shS L62
NE
Not Acceptable
Acceptable
Acceptable
Surficial should be a numeric value 1
Nickel
100
Not Acceptable
Acceptable
Acceptable
Surficial should be a numeric value, 1
Nitrate + Nitrite
mg -NIL
it-
Acceptable
Acceptable
Acceptable
Potassium
mg/L
NE
Acceptable
Acceptable
Acceptable
Selenium
ND
I I
20
Not Acceptable
Acceptable
Acceptable
IStaficial should be a numeric value, 1
Section
m
13
xx
6 _ 272 _
41 164
1.l a 0.24
0.1 b 1 _ _
75 130_
NE
Acceptable
Acceptable
Ace table
Strontium
AWL
NE
Acceptable
Acceptable
Acceptable
Sulfate
IUZIL
13.7
250
Acceptable
Acceptable
Ace ble
Sulfide
ingfL
0.29
NE
Acceptable
Acceptable
Ace ble
TDS
mg/L
90 .3
500
Acceptable
Acceptable
Ace ble
Thallium
L
ND
0.2 0 2
0.2
Not Acceptable
Acceptable
Ace ble
Surficial should be a numeric value, 0.2 µg/L.
TOC
mg/L
7.9
3.5
1.1
NE
Acceptable
Acceptable
Ace table
Vanadium
L
4.65
E.61
0.32
0.3
Not Acceptable
Acceptable
Ace ble
Surficial calculated to be 4.2 L.
Zinc
µ
10
5
5
1000
Acceptable
Acceptable
Acc table
Radium Total
Ci/L
7.09
S.4
3.55
NE
Not Acceptable
Acceptable
A. ptable
JSurficial calculated to be 6.463 i/L.
Uranium (Total)
ggfmL
0.0006
0.001
1 0.6004
NE
Acceptable
Acc table
Acceptable
NA -Not Applicable
ND -Not Detected
NE - Not Established
mg/L -millibar. per Ike,
pCi/L - picocmies per liter
Radium (Total) - Radiun-226 and Radium-228 combined
-The ISA NCAC 02L Standard m 10 mg/L for Nitrate and 1 ,11, for Nitrite (added for a total of I I mg/L)
S.U.-Standard Unit
TUC - Tom[ Organic Carbon
TDS - Total Dissolved Sell&
µg/snL - micrograms per milli@er
µgo - micrograms per liter
Umoiam (Toml) - Uranium-233, Uranium-234, Umnimn-236, and Ummum-238 combined

W. H. Weatherspoon Power Plant - Soil Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energy
Calculated
PB -f%s
PSRG Protection
of Groundwater
DWR Concurrence
(Acceptable/Not
Accepts le)-
Comments
H
S.U.
NE
Insufficient dataset. Additional data to be provided by Duke Energy. To be revised when valid data set is available.
Aluminum
mg/kg
NE
Antimony
mg/kg
0.9
Arsenic
m
5.8
Barium-
m
580
Beryllium
- mg/kg
63
Boron
mg/kg
45
Cadmium
m
3
Calcium
m
NE
Chloride
mglkg
NE
Chromium
mg/kg
3.8
Cobalt
mg/kg
- - - -_
0.9
Copper
mg/kg
700
Iron
m
_—
150
Lead
m
270
Magnesium
m
_ _ _ _
NE
Manganese
mg/kg
65
Mercury
mg/kg
_
1
Molybdenum
mg/kg
NE
Nickel
mg/kg
130
Nitrate (as N)
mg/kg
NE
Potassium
m /k
NE
Selenium
mg/kg
2.1
Sodium
m /kg
NE
Strontium
m
NE
Sulfate
m
250
Thallium
m g
0.28
Vanadium
m /kg
6
Zinc
m o
1200
NA- Not applicable (dataset contains zero valid samples)
ND -Non-Detect
NE - Not Established
mgtkg - milligrams per kilogram
S.U. - Standard Unit

Water Resources .,
Environmental Quality
April 27, 2018
Paul Draovitch
Senior Vice President
Environmental, Health & Safety
Duke Energy
526 South Church Street
Mail Code EC3XP
Charlotte, North Carolina 28202
Subject: Corrective Action Plan Content for Duke Energy Coal Ash Facilities
Dear Mr. Draovitch:
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Interim Director
Attached is guidance related to technical content and format the Department requests be followed
for the upcoming Corrective Action Plan (CAP) Update documents associated with the Duke
Energy coal ash facilities. Please note that pursuant to Title 15A North Carolina Administrative
Code, Subchapter 02L (15A NCAC 02L) Rule .011l(a), any person subject to the requirements
for corrective action specified in 15A NCAC 02L .0106 shall submit to the Director written reports
in such detail as specified by the Director. The CAP shall contain sufficient information for the
Secretary to evaluate the plans in accordance with the specifications in 15A NCAC 02L .0106(i).
The CAP content for Duke Energy coal ash facilities is provided in Attachment 1. If you have any
questions, please feel free to contact me at [phone] or Steve Lanter in the Central Office at
[phone].
Sincerely,
S. Jay 2iinynerman, P.G.
Division of Water Resources
Attachments: Attachment 1 Corrective Action Plan Content for Duke Energy Coal Ash Facilities
cc: WQROS Regional Office Supervisors
WQROS Central File Copy
<-- "Nothing Cornpaires n�,
State of North Carolina I Environmental Quality I Division of Water Resources
Water Quality Regional Operations Section
1636 Mail Service Center I Raleigh, North Carolina 27699-1636
919-707-9129

CORRECTIVE ACTION PLAN CONTENT FOR
DUKE ENERGY COAL ASH FACILITIES
APRIL 27, 2018
Best professional judgement must be applied to generate the Corrective Action Plan (CAP) documents. In
general, all items described in this guidance are expected to be addressed in the CAPs. Duke Energy must
provide justification/rationale concerning any information not provided as stipulated in this guidance.
1 INTRODUCTION
A. Background
B. Purpose and Scope
C. Regulatory basis for closure and corrective action (note that "closure" refers here to source
control and (or) source excavation in accordance with Coal Ash Management Act (CAMA) and
(or) 15A NCAC 02L (02L) .0106, while "corrective action", "remediation", or "remedy" refer
here to the treatment of groundwater contamination)
a. CAMA requirements
b. 02L requirements, including Notice of Regulatory Requirement dated 8/13/14
c. Other requirements such as court order, Federal requirements, etc.
D. List of Criteria for Evaluation of Remediation Alternatives as referenced in 02L .0106 (i)
a. Extent of any violations
b. Extent of any threat to human health or safety
c. Extent of damage or potential adverse effects to the environment
d. Technology available to accomplish restoration
e. Potential for degradation of the contaminants in the environment
f. Time and costs estimated to achieve groundwater quality restoration
g. Public and economic benefits to be derived from groundwater quality restoration.
E. Facility Description (brief summary from Comprehensive Site Assessment [CSA))
a. Location and history of land use (to include period prior to Duke ownership)
b. Operations and waste streams (coal and non -coal)
c. Overview of existing permits and Special Orders by Consent (National Pollutant
Discharge Elimination System, storm water, sediment and erosion control, etc.)
2. RESPONSE TO COMPREHENSIVE SITE ASSESSMENT UPDATE COMMENTS IN SUPPORT OF CAP
DEVELOPMENT
A. Include the Facility -Specific Comprehensive Site Assessment (CSA) Comment Letter from DEQ
to Duke Energy
B. Duke Energy's response to the DEQ's letter. (NOTE: All deficiencies noted during the
Departments' review of the CSA Update report shall be addressed in the CAP.
1

a. For each comment in the letter, note the specific section(s) of the CAP report that
addresses that comment.
b. If specific sections of the CAP report do not fully or directly address the comment,
provide a separate narrative within the Appendix to address.
3 OVERVIEW OF SOURCE AREAS BEING PROPOSED FOR CORRECTIVE ACTION
Each source area has a unique waste footprint, waste volume and configuration, contaminant
configuration and transport characteristics, and receptors. Consequently, each source area will
potentially need to be remediated in a unique way. For purposes of remediation design and
approval, each source area should be addressed separately as described in this document.
Arranging the report in this way will support an organized, orderly, and efficient review of the
proposed remedy. For facilities in which only one source area is defined (or multiple source areas
that can be combined into a single largersource area), the CAP sections which pertain to additional
source areas would not be needed. It is not the intent to require a separate CAP Report submittal
for each source area, rather a single facility CAP (Cliffside, e.g.) submittal may contain the contents
of multiple source areas.
A. Small scale map showing the waste boundary of each source area proposed for corrective
action
a. For cases in which more than one smaller source area is being combined as one larger
source area, show each "sub area" on the waste boundary map (i.e. show the waste
boundaries of the individual smaller source areas that are within the larger source
area)
B. For cases in which there are source areas that are not being addressed within the CAP,
provide:
a. Rationale for omission
b. Certification that consensus was reached with the Division on this point.
c. Description that explains the implications for assessment overlap, corrective action
overlap, design, and approval, performance monitoring, potential corrective action
modification and schedule delays.
4 SUMMARY OF BACKGROUND DETERMINATIONS
A. Map showing all background sample locations for all media (groundwater, surface water, soil,
and sediments)
B. Table of background concentrations for soil. Include the corresponding Protection of
Groundwater (POG) Preliminary Soil Remediation Goal (PSRG). Approved Background
Threshold Values (BTVs) for soil and groundwater will be sent to Duke in a letter separate
from the CSA Comments. Please list the approved BTVs.
C. Table of background concentration for groundwater. Include the appropriate 2L/IMAC
Standards. Approved Background Threshold Values (BTVs) for soil and groundwater will be
sent to Duke in a letter separate from the CSA Comments. Please list the approved BTVs.

D. Table of background concentrations for surface water. Include the appropriate 2B/EPA
standards. Present results of all surface water samples and sample events from upstream
locations.
E. Table of background concentrations for sediments. Present results of all sediment samples
and sample events from upstream or otherwise unimpacted sample locations.
5 SUMMARY OF POTENTIAL RECEPTORS
A. Map of all supply wells identified by receptor surveys and per 130A-309.211(cl).
a. Incorporate the most current alternate water supply efforts. That is, indicate which
well owners selected whole -home filtration systems, public water, or opted -out of
any alternate water supply options.
b. Indicate which homes have whole -house filtration systems installed and which homes
have been connected to public water.
c. Indicate if any homes are remaining to be supplied alternate water and the
anticipated supply date.
B. Map of all surface waters (to include wetlands, pond, unnamed tributaries, seeps, etc.) within
%:-mile of the waste boundary of each source area or known extent of contamination
(whichever is greater).
a. Indicate on map all surface waters that are currently permitted as outfalls, along with
the permitted outfall name and NPDES sampling location
b. Indicate on map all surface waters that are currently covered under a Special Order
by Consent.
c. All of the surface waters within 0.5 miles of the perimeter of an impoundment or
known extent of contamination, whichever is greater.
d. For all surface waters shown, indicate stream classification and nearest downstream
supply intake, if applicable
6. SOURCE AREA 1
Contents listed in Section 6 should be prepared separately for each additional source area (i.e.
Source Area 2, Source Area 3, etc., as applicable) in need of remediation. Discussions with the
DWR Regional Office should be initiated prior to preparation of the CAP in order to determine
which individual source areas are appropriate to combine into larger source areas.
Maps prepared for Source Area 1 should be lame scale, typically 1" = 150 to 200 ft and include
topographic contour intervals as agreed upon. However, scale adjustments may be made to
accommodate far reaching receptors; please discuss with Regional Office if this is necessary.
All plan view maps used in the CAP report should be oriented to extend to all identified receptors
(all supply wells and all surface water features), to the extent possible, based on the map scale
and size of source area being depicted.
A. Extent of Contamination
a. Contamination within waste boundary
L Description of waste material and history of placement
3

L7
ii. Specific waste characteristics of source material
iii. Volume and physical horizontal and vertical extent of source material
mapped in plan -view and multiple cross sections
iv. Volume and physical horizontal and vertical extent of saturated source
material mapped in plan -view and multiple cross sections
v. Calculation of specific storage for Source Area 1 (i.e. amount of contaminated
water and COI mass that can be expelled from Source Area 1)
vi. Chemistry within waste boundary
1. Table of analytical results, subdivided as follows:
1. Ash solid phase
2. Ash SPLP
3. Soil (beneath ash)
4. Soil (beneath ash) SPLP
5. Ash pore water
2. Piper diagram(s) for ash pore water if additional pore water data
have become available since the piper diagrams were developed in
the CSA Updates. Otherwise, reference the location of the piper
diagrams that were presented in the CSA Update.
3. Ash pore water isoconcentration maps for each COI in plan -view and
2 or more cross sections
vii. Other source material (Does source contain other waste products besides
CCR? If so, have these been assessed?)
viii. Interim response actions conducted to date to remove or control source
material, if applicable
1. Source control conducted to date or planned to include but not
limited to excavation, dewatering, boundary control measures (e.g.
extraction wells), etc.
2. Source area stabilization conducted to date or planned (e.g. describe
dam safety, flood plain inundation issues, etc.)
Extent of contamination beyond the compliance boundary or waste boundary
(whatever is the point of compliance depending on whether the source area(s) are
covered by a permit or not)
i. Conceptual model of groundwater flow and transport from source to
receptor
1. Local groundwater flow directions and gradients
2. Particle track results, if available
3. Subsurface heterogeneities affecting flow and transport
4. Onsite and offsite pumping influences affecting flow and transport
5. Role of matrix diffusion in/out of bedrock (bedrock porosity) on
contaminant transport
6. Other influences affecting flow and transport
ii. Plan view map showing COI results (bubble inset at each seep location) for
seeps and SWs
iii. Table of analytical sampling results associated specifically with Source Area
1:
I. Soil, as applicable
2. Groundwater (per individual flow regime [e.g. shallow, deep,
bedrock)
rd

3. Seeps (up-, side-, and down -gradient)
4. SW data (up-, side-, and down -gradient)
5. Sediment (up-, side-, and down -gradient)
6. Supply wells (up-, side-, and down -gradient
iv. Piper diagram(s) for each groundwater flow regime, seeps, and all other SWs.
c. COIs
i. List of COls and their maximum concentrations (within and beyond the point
of compliance) that require corrective action based on 2L/IMAC/background
exceedances:
1. Soil
2. Groundwater
3. other media if applicable
ii. List of Cols that this CAP is designed to remedy:
1. Soil
2. Groundwater
3. other media if applicable
d. Isoconcentration maps in plan -view and two or more cross sections for:
L Contaminated soil (defined as any COI in the sample being above POG PSRG
or approved background concentration)
ii. Horizontal and vertical extent of groundwater in need of restoration for each
COI in each groundwater flow regime (shallow, deep, bedrock)
e. Plume Characteristics
L Movement of conservative COls (e.g. boron, sulfate, chloride) from source to
receptor
1. Describe whether plume is moving and (or) expanding
1. Flow path wells and transect wells used to assess plume
behavior
2. Method(s) used to analyze plume behavior (should be
discussed and agreed upon with Regional Office prior to CAP
submittal)
ii. Movement of non -conservative COls (e.g. Fe, Mn, Co, As, TI, etc.)
1. Conceptual model describing local, source area -specific geochemical
controls on COls
1. Basis for conceptual understanding (e.g. batch PHREEQC
results)
2. Representative flow path(s) used to develop and validate
numerical geochemical model
3. Adsorbent data collected along flow path
4. Aqueous speciation data collected along flow path
5. Simulated versus observed COI concentrations at selected
target wells (i.e. how well does geochemical model simulate
local groundwater chemistry?)
2. Variability of pH along representative flow path(s) and along other
flow paths of interest
3. Variability of Eh along representative flow path(s) and along other
flow paths of interest
5

Receptors associated with Source Area 1
a. Map of all surface waters, including wetlands, ponds, unnamed tributaries, seeps, etc.)
associated with Source Area 1 (up-, side-, and downgradient)
L Indicate on map all surface waters that are currently permitted as outfalls, along
with the permitted outfall name and sample location
ii. Indicate on map all surface waters that are currently covered under a Special
Order by Consent
iii. For all surface waters shown, indicate stream classification and nearest
downstream supply intake, if applicable
iv. Indicate on map (footnote) and in report text whether SW samples have been
collected using Division approved protocols ("21_-213" sampling protocols) to
evaluate whether contaminated groundwater is resulting in 213 violations;
include date(s) of 2L-2B sampling and antecedent rainfall
1. If 2L-2B sampling has been conducted, indicate location of all 2L-2B
sample collection points
2. If 2L-2B sampling has been conducted, indicate results of 2B
exceedances on map; also indicate which of those exceedances is a COI
for groundwater for Source Area 1
3. If 2L-2B sampling has not been conducted, explain why and indicate
whether it is being proposed and the proposed sample collection points
b. Map of all supply wells associated with Source Area 1(up-, side-, and down -gradient)
L Indicate on map which well owners did not accept alternative water
ii. Provide analytical results table for the supply wells; indicate in table whether
each well was determined to be impacted or unimpacted by coal ash
iii. For each supply well determined to be unimpacted by coal ash, provide or
reference evidence that substantiates that position, including water level
measurement -based potentiometric mapping, piper diagrams, assessment of
well -specific geochemical conditions that are affecting certain CON, modeling,
etc. The evidence provided or referenced here will be used to review and
accept or deny Duke's determination that a given well is unimpacted by coal
ash.
c. Map of future groundwater use areas associated with Source Area 1
L Indicate on map whether each parcel has or does not have access to alternative
water
ii. Indicate on map whether each parcel was modeled to be impacted or
unimpacted by coal ash now or in the future
C. Human and Ecological Risks
D. Evaluation of Remedial Alternatives
All contents requested below for Section a. should be re )eated for each remedial alternative
that is considered (i.e. Remedial Alternative 2, Remedial Alternative 3, etc.) as directed and
appropriate.
a. Remedial Alternative 1
Problem statement and remediation goals
1. Map of full 3-dimensional extent of contamination that will be
corrected by this alternative
11

2. List of CON within each groundwater flow unit (shallow, deep,
bedrock) that will be corrected by this alternative
3. Concentration clean up goals for each of the CON identified in D. a. i.
2. above
Conceptual model (i.e. simple description explaining how the proposed
source control/removal and corrective action will reduce COI concentrations
and protect human health and environment)
1. COls addressed
2. COls not addressed
3. For each COI not addressed by the proposed corrective action
describe how the constituent will be remedied along with a schedule
for implementation
Predictive modeling
1. Model used to predict movement conservative (sometimes referred
to as leading edge) COIs
2. Model used to predict movement non -conservative CON
3. Simulated versus observed concentrations at selected target wells
(i.e. how well does transport model simulate local groundwater
chemistry?)
4. For "baseline" predictive modeling that shows source removal
(excavation) and other source control measures but no active
groundwater remediation, provide a comprehensive list of all
potential receptors that are or are predicted to be impacted and a
map for each COI showing the maximum predicted radius of travel of
that COI above 2L/IMAC (or background, if higher than 2L/IMAC)
downgradient. Also determine (i) predicted maximum concentration
of each COI in groundwater and the time that occurs and (ii)
predicted time to reduce all COI concentrations in groundwater to 2L
standards/IMACs or background if higher at the following locations:
a. Along most susceptible portion of the compliance boundary
b. At most susceptible supply well
c. At most susceptible future groundwater use area
d. At most susceptible SW(s)
5. For "groundwater remediation" predictive modeling that shows
source removal (excavation) and other source control measures AND
active groundwater remediation, provide a comprehensive list of all
potential receptors that are or are predicted to be impacted and a
map for each COI showing the maximum predicted radius of travel of
that COI above 02L/IMAC (or background, if higher than 02L/IMAC)
downgradient. Also determine (i) predicted maximum concentration
of each COI in groundwater and the time that occurs and (ii)
predicted time to reduce all COI concentrations in groundwater to
02L standards/IMACs or background if higher at the following
locations:
a. Along most susceptible portion of the compliance boundary
b. At most susceptible supply well
C. At most susceptible future groundwater use area
d. At most susceptible SW(s)
VA

iv. For remedial alternative 1, describe:
1. Protection of human health and the environment
2. Compliance with applicable federal, state, and local regulations
3. Long-term effectiveness and permanence
4. Reduction of toxicity, mobility, and volume
5. Short term effectiveness at minimizing impact on the environment
and local community
6. Technical and logistical feasibility
7. Time required to initiate
8. Predicted time required to meet remediation goals described in D. a.
L 3. above
9. Cost
10. Community acceptance
E. Proposed remedial alternative(s) selected for the source area 1 and/or sub -areas of source
area 1.
Note that multiple corrective actions may be necessary to address different locations within
source area 1 or any of its sub -areas. This could involve "compartmentalizing" the source area
and describing the specific selected corrective actions for each "compartment."
a. Description of proposed remedial alternative and rationale for selection
L Specific section of 02L .0106 being addressed by the proposed remedy [e.g.
02L .0106 (1) or (k)]
ii. Will a hybrid remedy consisting of more than one corrective action be used?
If so, describe.
iii. Will proposed remedy or hybrid remedy meet concentration cleanup goals
defined in D. a. i. 3. above?
iv. Treatability studies
1. Results of post-CSA Update treatability studies, if applicable
v. Additional site characterization needed to support the proposed remedy
1. Locations and specific testing, sampling, modeling, and (or) data
analysis
2. Schedule for data collection and reporting
b. Design details
I. Process flow diagrams for all major components of proposed remedy
ii. Engineering designs with assumptions, calculations, specifications, etc.
iii. Permits needed for proposed remedy and approximate schedule for
obtaining them
iv. Schedule and cost of implementation
v. Measures to ensure the health and safety of all persons on and off site
vi. Description of all other activities and notifications being conducted to ensure
compliance with 02L, CAMA, and other relevant laws and regulations
c. For 02L .0106 (1) CAP, provide requirements outlined in DWR's Monitored Natural
Attenuation for Inorganic Contaminants in Groundwater. Guidance for Developing
Corrective Action Plans Pursuant to NCAC 15A [02L].0106(I).
d. For 02L .0106 (k) CAP, provide requirements outlined in 02L .0106 rule
e. Sampling and reporting
i. Proposed progress (i.e. "effectiveness") reports and schedule
ii. Proposed sampling and reporting plan during active remediation
8

iii. Proposed sampling and reporting plan after termination of active
remediation (if proposed)
1. Decision metrics for termination of active remediation and start of
"monitoring only" phase
A. Proposed wells for COI trend analysis
B. Proposed statistical method for trend analysis
f. Proposed interim activities prior to implementation
g. Contingency plan in case of insufficient remediation performance
i. Description of contingency plan
ii. Decision metrics (triggering events) for implementing contingency plan
7. PROFESSIONAL CERTIFICATIONS
Sealed and notarized professional statements of "true, accurate, and complete".
8. REFERENCES
9. TABLES
10. MAPS AND FIGURES
11. APPENDICES - Flow and Transport Modeling
For Flow model report content, refer to report titled 'Updated groundwater Flow and Transport
Modeling Report for Asheville Steam Electric Plant, Arden, NC (Ronald Falta and others, March
17, 2017). Also include the following:
• List of all model assumptions
• List all model limitations that affect output (including, for example, unconfirmed
boundary positions, unmodeled heterogeneities, scale of cell volume versus scale of well
observations, limited input data, limited data for calibration and calibration assessment,
etc.)
• List of variables for which sensitivity analyses were quantitatively presented
• Describe how model is being used in closure/corrective action design and review
For transport model report content, refer to report titled 'Updated groundwater Flow and
Transport Modeling Report for Asheville Steam Electric Plant, Arden, NC (Ronald Falta and others,
March 17, 2017). Also include the following:
• List of all model assumptions
• List all model limitations (including, for example, limitations of Kd, unconfirmed boundary
positions, unmodeled heterogeneities, scale of cell volume versus scale of well
observations, limited input data, limited data for calibration and calibration assessment,
etc.) that affect output
• List of variables for which sensitivity analyses were quantitatively presented
• Describe how model is being used in closure/corrective action design and review
APPENDICES - Geochemical Modeling
0

For geochemical report content, refer to memorandum titled, 'Geochemical modeling of
constituent behavior at CAMA disposal sites' (Brian Powell, January 29, 2018) and memo titled
'Summary and Comments on Geochemical Modeling Outline with MNA Considerations (Bill
Deutsch, February 7, 2018). Also include the following:
• List of all model assumptions
• List all model limitations (including, for example, lack of pertinent data for points along
an individual flow path, if applicable, heterogeneities, limited input data, etc.) that affect
output
• List of variables for which sensitivity analyses were quantitatively presented
• How model is being used in closure/corrective action design
APPENDICES — Other
10

w
Water Resources
Environmental Quality
May 14, 2018
Paul Draovitch
Senior Vice President
Environmental, Health & Safety
Duke Energy
526 South Church Street
Mail Code EC3XP
Charlotte, North Carolina 28202
Subject: Approval of Revised Background Threshold Values
L. V. Sutton Energy Complex
Dear Mr. Draovitch:
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Interim Director
The North Carolina Department of Environmental Quality's (DEQ) Division of Water Resources
(DWR) has reviewed Duke Energy's calculated revised provisional background threshold values
(PBTVs) for soil and groundwater for the subject facility. DWR reviewed the calculated PBTVs based
on background data provided in the revised Comprehensive Site Assessment (January 2018), using the
Revised Statistical Methods for Developing Reference Background Concentrations for Groundwater
and Soil at Coal Ash Facilities dated May 26, 2017 and additional guidance provided in the December
7, 2017 email from Steve Lanter to Ed Sullivan and John Toepfer. DWR hereby approves all accepted
PBTVs for groundwater and soil as outlined in the attached tables. These accepted PBTVs shall
become the Background Threshold Values (BTVs) for the facility and will serve as a basis for the
proposed remedial alternatives in the upcoming Corrective Action Plans.
Per 15A NCAC 02L .0202(b)(3), where naturally occurring substances exceed the established
groundwater standard, the standard shall be the naturally occurring concentration as determined by the
Director. Therefore, BTVs calculated above the groundwater standards or Interim Maximum
Allowable Concentrations (IMACs) in accordance with the provisions in 15A NCAC 02L .0202 and
accepted by DWR, shall become the enforceable groundwater standard. Otherwise, the enforceable
groundwater standards shall be those listed under 15A NCAC 02L .0202(h) including any effective
IMACs.
For soils, PBTVs that are calculated above the DEQ Division of Waste Management Inactive
Hazardous Sites Branch's (IHSB) Preliminary Soil Remediation Goals (PSRG) for the protection of
groundwater shall become the BTVs for use in developing an appropriate corrective action strategy.
For compounds that do not have an established PSRG, but do have a groundwater standard (i.e. chloride
and sulfate) pursuant to 15A NCAC 02L .0202, use the calculation provided in the PSRG table to
establish a PSRG if the required site -specific data are available. The PSRG table can found under the
IHSB website at: https://d2g.nc.gov/about/divisions/waste-management/superfund-section/inactive-
hazardous-sites-program.
._>^Nothtng Compares
State of North Carolina I Environmental Quality I Division of Water Resources
Water Quality Regional Operations Section
1636 Mail Service Center I Raleigh, North Carolina 27699-1636
919-707-9129

The attached tables outline DWR's concurrence/non-concurrence with Duke Energy's proposed
calculated PBTVs for groundwater and soil. For all of Duke Energy's calculated PBTVs that are listed
as acceptable, DWR hereby approves those values. For those BTVs not found acceptable, justification
is provided on the attachment and Duke Energy is responsible for providing revised values for review
and approval. For any BTVs found to be unacceptable due to an inadequate dataset, Duke Energy shall
continue to collect data until an adequate dataset is achieved and a valid statistical calculation can be
performed.
Along with the specific comments provided on the attachments, DWR offers the following general
comments with regards to the BTVs:
• Please note that the IHSB's PSRG table was revised in February 2018. With respect to the
constituents being evaluated for the CSA, the following PSRG values have been revised.
o PSRG for Aluminum is currently 110,000 mg/kg.
o PSRG for Chromium is currently 3.8 mg/kg.
o PSRG for Molybdenum is currently 7.1 mg/kg.
o PSRG for Vanadium is currently 350 mg/kg.
DWR recognizes that, as new information is gathered going forward, the approved BTVs may be
refined. Thus, there will be need for a periodic review and recalculation of the BTVs. The timeframes
for the periodic review will be established by DWR at a later date and any revised BTVs will be subject
to approval by DWR's Director.
If you have any questions, please contact Geoff Kegley (Wilmington Regional Office) at (910) 796-
7215 or Steve Lanter (Central Office) at [phone].
Sincerely,
Linda Culpepper, Director
Division of Water Resources
Attachments
cc: WIRO WQROS Regional Office Supervisor
WQROS Central File Copy

L. V. Sutton I:nt-%) Cumplrs - Groundwater Bac ground Threshold Values (May 14, 2018)
Parameter
Reporting
Units
Duke Energy Calculated PBTVs from CSA Report
(January 31, 2018)
Flow Unit
15A NCAC 02L
Standard or
IMAC
DWR Concurrence (Acceptable/Not Acceptable)
Comments
Flow Unit
Surficial
Uppwr
Surficial
Lower
Pee Dee
Upper
Pee Dee
Lower
Surfieial
Upper
Surficial
Lower
Pee Dee
Upper
Pee Dee
Lower
H
S.U.
6.5-8.5
4.1- 5.1
7.8 - 9.3
6.9 - 9.7
6.5-8.5
Accestable
Acceptable
Acceptable
Acceptable
Alkalinuv
mg/L,
5
67.92
706.8
656
NE
Acceptable
Acceptable
Acceptable
Acceptable
Aluminum
uu/L
1058
171
518
541.7
NE
Ater table
Acc table
Acceptable
Acceptable
Antimonyµg/L
1
1
1
1
1
Acoa table
Acceptable
Acceptable
Acceptable
Arsenic
r
1
2.93
2.777
3.439
10
Acceptable
Acceptable
Acceptable
Acceptable
Barium
in -,I
45
99.62
18.7
69.95
700
Acca table
I Acceptable
Accc .table
Beryllium
i ,I
1
1
1
1
4
Acceptable
Acceptable
Acceptable
-Acceptable
Acceptable
Bicarbonate
mg'1.
5
67.92
733.6
882.7
NE
Acceptable
Acceptable
Acceptable
Acceptable
Boron
2
50
50
3010
4730
700
Acce table
Acceptable
Acceptable
Acceptable
Bromide
t 2
100
500
4,340
12,189
NE
Acceptable
Acceptable
Acceptable
Accr table
Cadmium
t fl,
1
1
1
1
2
Acceptable
Acceptable
Accc ,table
Accc table
Calcium
m
0.945
17.76
22.93
42.02
NE
Acceptable
Acceptable
Acceptable
Accc table
Carbonatc
m:/L
5
5
5
278.9
NE
Acceptable
Acceptable
Acceptable
Acceptable
Chloride
m+/L
5.143
18
1.932
1 2.567
250
Acceptable
Acccptable
Acceptable
Acceptable
Chromium q
11,
0.03
0.12
0.118
0.15
NA
Acceptable
Accc table
Acceptable
Not Acceptable
Not acceptable - dataset that contains less than 10 valid samples
Chrmmiuin
µg/L
1
I 1
1
1
10
Acceptable
Acceptable
Acceptable
Acceptable
Cobalt
I.
0.945
3.422
1
1
1
Not Acceptable
Acceptable
Acce stable
Acceptable
Should kx 3dt5 1 ma% be a transcri ption error, Appendix H table 4 and table 9 do not match)
Copp--r
t+,L
1
1
1
1
1000
Acce table
Acceptable
Acer table
Acceptable
Iron
re'1
468
%540
304.6
1230
300
Acceptable
Acceptable
Acce table
Acceptable
Lead
µg/L
1
1
1
1
15
Acceptable
Acceptable
Accc table
Acceptable
Magnesium
m¢/L
0.529
3.134
13.5
1 33.2
NE
Acceptable
Acceptable
Accc table
Acceptable
Manganese
µ
43.42
469.6
118.2
93.89
50
Acceptable
Accc table
Acceptable
Acceptable
Mercum
1
0.05
0.05
0.05
0.05
1
Acceptable
Acceptable
Acceptable
Acceptable
Mel lane
e I
25.8
176.8
66.9
10
NE
Accc table
Acceptable
Not Acce table
Not Acceptable
Not acceptable - dataset that contains less than 10 valid samples
Mol bdcnum
11,I
1
1
2531
18.85
NE
_Acceptable
Acceptable
Acceptable
Acceptable
Nickel
1
1
1
1
1 100
Acceptable
Acceptable
Acceptable
Acceptable
Nitrate + Nitrite
mg -NIL
0.146
0.13
0.089
0.013
l l *
Acceptable
Acceptable
Not Acceptable
Not Acce table
Not acce table - dataset that contains less than 10 valid samples
Potassium
m,,/L
0.734
4.97
4631
64.12
NE
Acceptable
Acceptable
Acceptable
Acceptable
Selenium
�q1
1
1
1
1
20
Acceptable
Acceptable
Acceptable
Acceptable
Sodium
mg/L
2.964
12.9
1584
1270
NE
Acceptable
Acceptable
Acceptable
Acceptable
Strontium
PA
8
44.89
232
1003
NE
Acc table
Acceptable
Acceptable
Acce.table
Sulfate
ma/L
15.81
1934
277.1
170.7
250
Acceptable
Acceptable
Acceptable
Accr. table
Sulfide
mg/L
0.1
0.1
0.15
0.6 1
NE
Ace .table
Acceptable
Acceptable
Acceptable
TDS
mg/L
25
1095
2 44
33,400
500
Acceptable
Accc table
Acceptable
Acceptable
Thallium
g,L
0.2
0.2
0.2
0.2
0.2
Acceptable
Accc table
Acceptable
Acceptable
TO
mg/L
0.963
6.2
4.818
14.99
NE
Acceptable
Acceptable
Acceptable
Acceptable
Vanadium
q
0.3
1.448
1.905
0.693
0.3
Acceptable
Accc table
Acceptable
Acceptable
Zinc
6
19.37
5
5
1000
Acceptable
Acceptable
Acceptable
Acceptable
Radium =Total)
i/L
4.123
5.074
4
2.06
NE
Acceptable
Acceptable
Acceptable
Not Acceptable
Not acceptable - dataset that contains less than 10 valid samples
Uranium (Total)
mL
0.0002
0.0002
0.00198
0.00533 1
NE
Acceptable I
Accc stable
Acceptable
Not Acceptable
Not acce ptable - dataset that contains less than 10 valid samples
rvA - Not Appucaure
ND - Not Detected
NE - Not Established
mg/L - milligrams per liter
pCi/L - picocuries per liter
Radium (Total) - Radium-226 and Radium-228 combined
*The 15A NCAC 02L Standard is 10 mg/L for Nitrate and 1 mg/L for Nitrite (added for a total of I 1 mg/L)
S.U. - Standard Unit
TOC - Total Organic Carbon
TDS - Total Dissolved Solids
µg/mL - micrograms per milliliter
µg/L - micrograms per liter
Uranium (Total) - Uranium-233, Uranium-234, Uranium-236, and Uranium-238 combined

L. V. Sutton Energy Complex - Soil Background Threshold Values (May 14, 2018)
Parameter
Reporting
Units
Duke Energy
Calculated PBTVs
from CSA Report
(January 31, 2018)
PSRG Protection
of Groundwater
(as of February
2018)
DWR Concurrence
(Acce
Acceptable)
Comments
H
S.U.
4.8-6.6
NA
Acceptable
Aluminum
mg k •
3846
110,000
Acce )table
....._._........_..
Antimony
mg/kg
0.64
0.9
Acceptable
Arsenic
mg kg
0.772
5.8
Acceptable
Barium
mg,,'kg,
4.99
580
Acceptable
Ber3lium
mg/kgmg/kg
0.0402
63
Acceptable
Boron
mg,,kg
3.3
45
Acceptable
Cadmium
m /kQ
0.032
3
Acceptable
Calcium I
mglkg
340
NE
Acceptable
Chloride
mg'kg
16
NE*
table
Acceptable
Chromium
m T k
3.08
4
Acceptable
Cobalt
m _k
0.89
0.9
Acceptable
Copper
m k
0.59
700
Acceptable
Iron
mg,'kg
2750
150
Acceptable
Lead
mgikg
2.76
270
Acceptable
Magnesium
m : kg
290
NE
Acceptable
Manganese
m.-,kg
5.32
65
Acce table
Mercury
mg, -"kg
0.11
1
Acceptable
Molybdenum
mg,kg
2.7
7.1
Acceptable
Nickel
m k E2.7
130
Acceptable
Nitrate (as N)
mg,'kg
031
NE
Acceptable
Potassium
mg kg
290
NE
Acceptable
Selenium
mg'k�
1.7
2.1
Acceptable
Sodium
mgAg
340
NE
Acceptable
Strontium
mg/kgmg/kg
1.29
NE
Acceptable
Sulfate
m ,-kg
16
NE*
Acceptable
Thallium
mg;kyz
0.17
0.28
Acceptable
Vanadium
mekU
8.16
350
Acceptable
Zinc
m fk
2.9
1200
Acceptable
*Constituent has 21, Standard or IMAC. Use calculation in the PSRG table to determine value.
NA - Not applicable
ND - Non -Detect
NE - Not Established
mg/kg - milligrams per kilogram
S.U. - Standard Unit

'.0
Water Resources
Environmental Quality
June 11, 2018
Paul Draovitch
Senior Vice President
Environmental, Health & Safety
Duke Energy
526 South Church Street
Mail Code EC3XP
Charlotte, North Carolina 28202
Subject: 2018 Comprehensive Site Assessment Update Comments
L. V. Sutton Energy Complex
Dear Mr. Draovitch:
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Interim Director
On January 31, 2018, the North Carolina Department of Environmental Quality's (DEQ's) Division of
Water Resources (DWR) received the Comprehensive Site Assessment (CSA) Update for the subject
facility. Based on the review conducted to date, the DWR has concluded that sufficient information
has been provided in the report to allow preparation of the Corrective Action Plan (CAP); however,
there are data gaps that must be addressed prior to, or in conjunction with, preparation of an approvable
CAP.
As described in the attached itemized list of CSA Update comments (Attachment 1), additional data
and/or data analysis will be needed to address data gaps, complete evaluation of exposure pathways,
predict time and direction of contaminant transport, and ultimately refine remedial design. The
assessment of all primary and secondary source areas (including, but not limited to, impoundments,
cinder storage areas, coal piles, and contaminated soils) must be included in the CAP, or in a CAP
amendment. The DWR expects that information collected regarding the source areas will be used to
formulate the CAP recommendations. For source areas where this may not be possible or areas where
pollutants may be hydraulically isolated, please contact me to discuss.
In an email dated April 18, 2018, Duke Energy proposed a CAP submittal date of January 31, 2019.
However, as you are aware, Duke Energy and the DEQ are currently discussing revisions to the CAP
deadlines and the frlal revised date for CAP submittal will be communicated to Duke Energy in a
separate correspondence.
An overview of CSA Update data gaps includes the following:
0 The distribution of constituents of interest related to the coal ash impoundments and other
primary sources (i.e. Former Ash Disposal Area) does not clearly delineate exceedances of
15A NCAC 2L standards above the site -specific background levels which could suggest
commingling of the contaminant plumes.
-5"P°"Nothing Campams: -_,
State of North Carolina I Environmental Quality I Division of Water Resources
Water Quality Regional Operations Section
1636 Mail Service Center I Raleigh, North Carolina 27699-1636
919-707-9129

The characterization of other primary and secondary sources other than impoundments that
contribute to the groundwater plumes is inadequate.
As detailed more fully in the attached document, additional data gaps remain concerning
characterization of impacts from coal ash at the facility.
The data gaps related to the site assessment at the facility, including those related to primary and
secondary sources other than impoundments, may limit the cleanup remedy and site management
strategies for a source area. The lack of a well -documented interpretation of the existing data, or
missing data that the DEQ believes will be necessary to support proposed corrective action, may limit
DEQ's ability to approve certain corrective action measures [e.g. 15A NCAC 02L .0106(1)]. For
example, monitored natural attenuation cannot be approved for source areas where surface water
samples have not been collected (but could be collected) and that demonstrate the groundwater
discharge does not result in exceedances of 15A NCAC 2B .0200 regulatory standards.
Please refer to the letter to Duke Energy dated May 14, 2018, for approved background threshold
values developed for the facility as part of the CSA Update.
Duke Energy should contact the Wilmington Regional Office to initiate the scheduling of a meeting
between DWR and Duke Energy's technical staff (including contractors) to discuss data gaps in greater
detail. Promoting regular dialogue in a small group format assists in addressing questions and
problems that may come up during the development of the CAP, and better ensures that Duke Energy
is meeting DWR's expectations.
If you have any questions, please feel free to contact me at [phone]. Please contact Geoff
Kegley (Wilmington Regional Office) at [phone] to discuss any additional questions regarding
the CSA Update data gaps in more detail.
Sincerely,
r
,ton Ri ard, Section Chief
Division of Water Resources
Attachment: L. V. Sutton Energy Complex CSA Update Comments
cc: WIRO WQROS Regional Office Supervisor
WQROS Central File Copy

Comments for L.V. Sutton Enemy Complex Comprehensive Site Assessment Update
Submitted January 31, 2018
Delineation of Groundwater Contamination
Questions remain concerning the accuracy of the delineation of horizontal extent of groundwater
contamination, which is a requirement of Coal Ash Management Act (CAMA) and 15A NCAC
02L .0106. The Corrective Action Plan (CAP) shall include updated maps and data summary that
address the following:
There is an effluent discharge canal located between the 1971 Ash basin and the Former
Ash Disposal Area (FADA) and adjacent former coal stockpile area. This discharge canal
may act as a hydraulic divide for shallow groundwater.to some extent, but there is likely
some potential that the plume from the 1971 ash basin is impacting this downgradient area
in the lower surficial aquifer (and therefore commingling of the contaminant plumes.) This
interpretation is not depicted on the submitted isoconcentration maps and cross -sections
submitted in the updated Comprehensive Site Assessment (CSA). Furthermore, the
contaminant plume has not been fully delineated south of the FADA. Further assessment
is needed in the FADA and in the former coal stockpile area.
All of the Coal Combustion Residual (CCR) data should be incorporated as part of the site
assessment and CAP.
Provide an interpretation as to how the geochemical conditions affect or control the
distribution of Constituents of Interest (COIs) with site specific data (COI concentrations
vs. geochemical parameter levels, identified with well IDs.)
Groundwater Flow, Contaminant Flow and Transport, Geochemical Modeling
• Continue evaluation of the groundwater flow system with respect to the large and dynamic
changes currently impacting - the flow system and how it may affect any proposed CAP.
(i.e. groundwater extraction system impacts, supply well pumping, ash excavation
removing the hydraulic head that was previously present in the ash basins, reduction in the
recharge area from the construction of the lined CCR landfill and from the increased
recharge from expanding neighboring sand quarry.)
• Groundwater flow, contaminant flow and transport modeling, geochemical modeling (and
the additional hydrous ferric hydroxide (HFO) and hydrous aluminum oxide (HAO)
sampling, as proposed), need to be performed/updated and submitted with the CAP.
• All COIs should be modeled unless a rationale for not doing so is provided.
Other Potential Primgg and SecoAdary Sources
As discussedpreviously, other primary and secondary sources must be assessed regarding impacts
to groundwater. Sources contributing to groundwater contamination associated with the
impoundments (commingled) must be assessed and the results incorporated into the CAP. Sources
that have impacted, or have the potential to impact groundwater (contaminated soils, stockpiles,
etc.,) that are not known or believed to have commingled with the areas impacted by the
impoundment may be assessed separately in accordance with a schedule approved by the
Department. Additional information needed includes the following:
• Soil contamination should be delineated to either site -specific background threshold values
(BTVs) or Protection of Groundwater (POG) Preliminary Soil Remediation Goals (PSRGs)
Page 1 of 2

levels, whichever are higher. If appropriate, use the equation provided in the PSRG table
to establish a POG PSRG for a constituent with 02L standard that does not have one.
• Provide plan view maps and cross -sections (where applicable) to demonstrate that soil
contamination (POG PSRGs or BTVs, whichever are higher) has been vertically and
horizontally delineated
Maps. Figures and Tables
• Because of the large changes at the facility and surrounding area impacting the
groundwater flow system (mentioned above), all isoconcentration maps should be updated
with latest complete groundwater sampling events (including CCR wells) and be presented
in the CAP.
• All BTVs that were approved (May 14, 2018 letter, and any subsequent updates) should be
incorporated throughout the site assessment, isoconcentration maps and forthcoming CAP.
02L/02B Surface Water Sam lin
Collection of surface water samples to evaluate impacts from contaminated groundwater is
necessary to understand the impacts associated with the migration of contaminates from the
groundwater system. Failure to adequately characterize known and potential impacts to surface
waters from the groundwater will affect the corrective actions strategies that can be proposed and
ultimately considered for approval by the department. Comments include the following:
• Additional surface water sampling is needed to complete the site assessment and to
evaluate Monitored Natural Attenuation as a possibility for corrective action (assess
potential near bank impacts from groundwater discharge to the west and south of the basins,
and the FADA/former coal stockpile area.) A surface water evaluation plan was submitted
by Duke Energy on April 25, 2018 and approved on May 10, 2018 with one minor change.
The agreed upon evaluation must be completed in accordance with the guidelines, dated
October 31, 2017, and included in the CAP.
Receptors
• Provide an updated status of the surrounding private water supply wells within the 0.5-mile
radius. Include any additional sampling that has been performed and the current status of
providing an alternative water supply, to include any additional efforts to contact non-
responsive properties.
Page 2 of 2

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
Paul Draovitch
Senior Vice President
Environmental, Health & Safety
Duke Energy
526 South Church Street
Mail Code EC3XP
Charlotte, North Carolina 28202
NORTH CAROLINA
Environmental Quality
October 12, 2018
Subject: Completion of Permanent Alternate Water Supply Requirements Under General
Statute 13 OA-3 09.211(c 1)
L. V. Sutton Energy Complex
Dear Mr. Draovitch:
On August 10, 2018, the North Carolina Department of Environmental Quality (DEQ) received a
request from Duke Energy for L. V. Sutton Energy Complex for confirmation of completion of
the permanent alternate water provision under the Coal Ash Management Act (CAMA) General
Statute (G.S.) 130A-309.211(cl). Based on our review of the submitted documentation, DEQ
hereby confirms that Duke Energy has satisfactorily completed the alternate water provision under
CAMA G.S. 130A-309.211(cl) at the Sutton facility.
Please note that, since Duke Energy is still in the process of submitting or finalizing the Corrective
Action Plan for the Sutton facility and the results of groundwater modeling have not yet been
received, DEQ reserves the right to determine that additional households are eligible and shall be
provided permanent alternate water solutions per G.S. 130A-309.211(cl) based on any new
information provided. Any future determination of additional eligible households by DEQ will not
affect this confirmation of Duke's compliance with the October 15, 2018 deadline in G.S. 130A-
309.211(cl). Further, this confirmation letter does not constitute a final classification for any
impoundment under G.S. 130A-309.213(d).
X-2A
.ter.} ■� Q Aj
North Carolina Department of Environmental Quality
217 West Jones Street 11601 Mail Service Center I Raleigh, North Carolina 27699-1601
919.707.8600

If you have any questions, please feel free to contact Debra Watts at [phone].
Sincerely,
Sheila Holman
Assistant Secretary for Environment
cc: Jessica Bednarcik, Duke Energy, 526 South Church Street, Mail Code EC 12J, Charlotte,
NC 28202
WQROS WIRO Supervisor
WQROS Central File Copy
North Carolina Department of Environmental Quality
217 West Jones Street 11601 Mail Service Center I Raleigh. North Carolina 27699-1601
919.707.8600

Duke Energy Interpretation of Corrective Action Plan Content Guidance Provided by the
North Carolina Department of Environmental Quality
January 23, 2019
Introduction
The purpose of this document is to provide the North Carolina Department of Environmental
Quality (NCDEQ) Division of Water Resources (DWR) with Duke Energy's proposed approach for
preparing the groundwater Corrective Action Plans (CAPs) within the structure of the NCDEQ's
guidance titled "Corrective Action Plan Content for Duke Energy Coal Ash Facilities" [CAP
Guidance] dated April 27, 2018. This guidance provides the technical content and format
requested by the NCDEQfor preparing the CAPs associated with Duke Energy coal ash facilities.
Duke Energy's overall goal is to submit high quality CAPs that meet the regulatory requirements
found in 15A NCAC 2L .0106 based on the large datasets generated at each site by working with
the NCDEQ to gain clarity early in the CAP preparation process regarding what is required.
On January 3, 2019, representatives from NCDEQ met with Duke Energy and SynTerra to discuss
the CAP guidance. During the meeting it was agreed that Duke Energy would prepare our
interpretation of working within the CAP guidance framework and provide this interpretation to
the NCDEQ for review. Therefore, the following four documents are attached:
1. Duke Energy's proposed adjustments to the April 2018 CAP Guidance.
2. A table that provides supporting rationale for the proposed adjustments.
3. A general list of appendices common to all CAPs to provide clarity regarding the full
scope of the CAP submittal.
4. An example figure that uses an exceedance ratio approach that Duke Energy believes is
an effective way to present site data while reducing the total number of figures
requested on the CAP guidance.
Overall, we have adjusted the guidance to:
• Reflect our improved understanding of site conditions due to the substantial amount of
data collection and progress made since April 2018.
• Place more emphasis on corrective action analysis while recognizing that
Comprehensive Site Assessment (CSA) comments will be addressed as an appendix to
the CAP.
• Enable a more efficient CAP preparation and review process.
In some cases, we have either added a section (Executive Summary), or made a section more
prominent due to its importance (Conceptual Site Model), which will provide the basis for the
corrective action approach proposed. In other cases, we have adjusted the guidance to address
conflicting or redundant sections, or to place more emphasis on corrective action analysis
rather than representing assessment information previously provided to the NCDEQ.
In closing, Duke Energy believes that the attached documents provided herein have been
prepared within the framework of the NCDEQ's CAP guidance while adjusting it to enhance the

technical quality, the manageability of the CAP preparation and review process, and to facilitate
technical decision -making regarding site -specific approaches for corrective action.
Duke Energy appreciates the opportunity to provide this submittal and would be glad to discuss
the CAP approach to address any comments you may have.

Attachment 1
CORRECTIVE ACTION PLAN CONTENT FOR
DUKE ENERGY COAL ASH FACILITIES
Proposed Duke Energy Content
January 18, 2019
Best professional judgement must be applied to generate the Corrective Action Plan (CAP) documents. In
general, all items described in this guidance are expected to be addressed in the CAPS with the interpreted
adjustments included herein. Duke Energy is to provide justification/rationale concerning information not
provided as stipulated in this guidance.
EXECUTIVE SUMMARY
1. INTRODUCTION
A. Background
B. Purpose and Scope
C. Regulatory basis for closure and corrective action (note that "closure" refers here to source
control and (or) source excavation in accordance with Coal Ash Management Act (CAMA) and
(or) 15A NCAC 02L (02L) .0106, while "corrective action", "remediation", or "remedy" refer
here to the treatment of groundwater contamination)
a. CAMA requirements
b. 02L requirements
c. Other requirements such as court order, Federal requirements, etc.
D. List of Considerations by the Secretary for Evaluation of Corrective Action Plans as referenced
in 02L .0106 (i). This section will be addressed with a general written description of how these
items are considered in the CAPS.
a. Extent of any violations
b. Extent of any threat to human health or safety
c. Extent of damage or potential adverse effects to the environment
d. Technology available to accomplish restoration
e. Potential for degradation of the contaminants in the environment
f. Time and costs estimated to achieve groundwater quality restoration
g. Public and economic benefits to be derived from groundwater quality restoration.
E. Facility Description (summary from Comprehensive Site Assessment [CSA])
a. Location and history of land use (to include period prior to Duke ownership)
b. Operations and waste streams coincident with the ash basin (coal and only those non -
coal waste streams that may affect subsurface conditions at, or proximate to, the coal
ash basins or coincident sources.)
c. Overview of existing permits and Special Orders by Consent (National Pollutant
Discharge Elimination System, storm water, sediment and erosion control, etc.)
1

Attachment 1
2. RESPONSE TO COMPREHENSIVE SITE ASSESSMENT UPDATE COMMENTS IN SUPPORT OF CAP
DEVELOPMENT
For ease of review, NCDEQ's comment letters and Duke Energy's responses will be addressed in
an appendix to the CAPS. A summary table that identifies where these items are addressed will
also be included in the appendix to facilitate NCDEQ's review.
A. Include the Facility -Specific Comprehensive Site Assessment (CSA) Comment Letter from DEQ
to Duke Energy.
B. Duke Energy's response to the DEQ's letter. (NOTE: All deficiencies noted during the
Departments' review of the CSA Update report shall be addressed in an appendix to the
CAP.)
a. For each comment in the letter, note the specific section(s) of the CAP report that
addresses that comment in a table to be included in the appendix.
3. OVERVIEW OF SOURCE AREAS BEING PROPOSED FOR CORRECTIVE ACTION
Each source area has a unique waste footprint, waste volume and configuration, contaminant
configuration and transport characteristics, and potential receptors, if any. Consequently, each
source area will potentially need to be remediated in a unique way. For purposes of remediation
design and approval, each source area should be addressed separately as described in this
document. Arranging the report in this way will support an organized, orderly, and efficient
review of the proposed remedy. For facilities in which only one source area is defined (or
multiple source areas that can be combined into a single larger source area), the CAP sections
which pertain to additional source areas would not be needed. It is not the intent to require a
separate CAP Report submittal for each source area, rather a single facility CAP (Cliffside, e.g.)
submittal may contain the contents of multiple source areas. Please note that source control for
ash basins will in large part be performed through decanting of free water in the ash basin
followed by implementation of the approved closure plans. These source control actions are key
components of the overall groundwater corrective action program for each site. An overview of
source control and the approved closure plans for the source area(s) will be provided in the CAP.
Additional source areas may require additional corrective action and will be addressed in the CAP
as needed.
A. Small scale map showing the waste boundary of each source area proposed for corrective
action. The sources areas for each site were provided in a letter from the NCDEQ letter titled
"Final Comprehensive Site Assessment and Corrective Action Plans Approvals for Duke Energy
Coal Ash Facilities", dated [Insert date of final letter].
For cases in which more than one smaller source area is being combined as one larger
source area, show each "sub area" on the waste boundary map (i.e. show the waste
boundaries of the individual smaller source areas that are within the larger source
area)
2

Attachment 1
B. For source areas that are not hydrologically connected to the impoundments that will be
addressed in subsequent CSAs, provide a brief description of the source and schedule
(reference letter titled "Final Comprehensive Site Assessment and Corrective Action Plans
Approvals for Duke Energy Coal Ash Facilities", [Insert date]).
4. SUMMARY OF BACKGROUND DETERMINATIONS
A. Map showing all background sample locations for all media (groundwater, surface water, soil,
and sediments)
B. Table of background concentrations for soil. Include the corresponding Protection of
Groundwater (POG) Preliminary Soil Remediation Goal (PSRG). Approved Background
Threshold Values (BTVs) for soil and groundwater will be sent to Duke in a letter separate
from the CSA Comments. Please list the approved BTVs. A discussion of regional background
concentrations for similar geologic settings may be provided as context for BTVs.
C. Table of background concentration for groundwater. Include the appropriate 2L/IMAC
Standards. Approved Background Threshold Values (BTVs) for soil and groundwater will be
sent to Duke in a letter separate from the CSA Comments. Please list the approved BTVs. A
discussion of regional background concentrations for similar geologic settings may be
provided as context for BTVs.
D. Table of background concentrations for surface water. Include the appropriate 2B standards
and EPA recommended criteria. Present results of all surface water samples and sample
events from upstream locations.
E. Table of background concentrations for sediments. Present results of all sediment samples
and sample events from upstream or otherwise unimpacted sample locations.
5. CONCEPTUAL SITE MODEL
A. The conceptual site model (CSM) will present Duke Energy's interpretation of relevant site
conditions based on multiple lines of technical evidence developed through the collection of
a large multi -media dataset for each site. The CSM will in turn be used to form the basis of
the site -specific corrective action approach planned at each site. The following includes the
items from previous Section 6.A.b.i along with additional items to make the overall CSM more
robust.
a. Description of key site factors concerning the site geologic and hydrogeologic setting.
i. Local groundwater flow directions and gradients (current and following
closure).
ii. Particle tracking results, if available.
iii. Subsurface heterogeneities and other potential factors affecting flow and
transport including geochemical conditions.
iv. The role of matrix diffusion in/out of bedrock (bedrock porosity) on
constituent transport where appropriate.
v. Discuss onsite and offsite pumping influences affecting flow and transport.
vi. Other factors affecting flow and transport under current and future site
conditions.
3

Attachment 1
vii. The effects of naturally occurring constituents in site groundwater.
Location of source areas within the hydrogeologic setting (current and following
closure).
c. Describe potential on -site and off -site receptors and whether or not they are affected
by site related constituents above applicable criteria.
d. A description of the human health and ecological risk assessment results.
SOURCE AREA 1
Contents listed in Section 6 should be prepared separately for each additional source area (i.e.
Source Area 2, Source Area 3, etc., as applicable) in need of remediation.
Maps prepared for Source Area 1 should be large scale, typically 1" = 150 to 200 ft. and include
topographic contour intervals as agreed upon. However, scale adjustments may be made to
accommodate for reaching receptors; please discuss with Regional Office if this is necessary.
All plan view maps used in the CAP report should be oriented to extend to relevant identified
receptors (hydraulically downgradient supply wells and surface water features), to the extent
possible, based on the map scale and size of source area being depicted. Duke will provide
justification for selection of water supply wells and downgradient surface water features.
Constituents of interest (COls) considered for corrective action are those constituents with
concentrations consistently greater than the applicable standard at or beyond the compliance
boundary (whatever is the point of compliance depending on whether the source area(s) are
covered by a permit). 1 The following references to COls in this guidance and the CAP are
considered to be COls considered for corrective action.
A. Extent of Constituent Distribution
a. Source material within waste boundary. The Information requested below is to be
provided only to the extent the requested information was not provided in previous
submittals. A reference to the submittal where the requested information is provided
will be included in the CAP.
i. Description of waste material and history of placement
ii. Specific waste characteristics of source material
iii. Volume and physical horizontal and vertical extent of source material
mapped in plan -view and multiple cross -sections
iv. Volume and physical horizontal and vertical extent of anticipated saturated
source material mapped in plan -view and multiple cross -sections following
implementation of the approved closure option
v. Description of how the saturated ash is anticipated to affect the groundwater
concentrations overtime based upon modeling information
vi. Chemistry within waste boundary
1 The applicable standard or concentration for groundwater COIs would be the 2L standard, the IMAC
concentration or the BTV, whichever is greater. For unsaturated soil COIs the applicable standard is
the PSRG POG or BTV, whichever is greater.
4

Attachment 1
1. Table of analytical results, subdivided as follows:
1. Ash solid phase
2. Ash SPLP
3. Ash Leaching Environmental Assessment Framework (LEAF)
4. Soil (beneath ash)
5. Soil (beneath ash) SPLP
6. Ash pore water
2. Piper diagram(s) for ash pore water if additional pore water data
have become available since the piper diagrams were developed in
the CSA Updates. Otherwise, reference the location of the piper
diagrams that were presented in the CSA Update.
3. Ash pore water isoconcentration maps for each COI in plan -view or
use of alternative figures such as exceedance ratio maps showing the
combined ash porewater and surrounding areas and 2 or more cross
sections
vii. Other source material identified through the additional source area
assessments.
viii. Interim response actions conducted to date to remove or control source
material, if applicable
1. Source control conducted to date or planned to include but not
limited to excavation, dewatering, boundary control measures (e.g.
extraction wells), etc.
2. Source area stabilization conducted to date or planned (e.g. describe
dam safety, flood plain inundation issues, etc.)
b. Extent of constituent migration beyond the compliance boundary or waste boundary
(whatever is the point of compliance depending on whether the source area(s) are
covered by a permit) based upon groundwater data collected through June 2019:
i. Plan view map showing COI results (bubble inset at each seep location) for
groundwater, seeps and SWs. COI results presented are to be based on
consideration of geometric mean concentrations and/or time vs.
concentrations relationships or similar approach based on historical data
collected through June 2019.
ii. Table of analytical sampling results associated specifically with Source Area
1:
1. Soil, as applicable
2. Groundwater (per individual flow regime [e.g. shallow, deep,
bedrock)
3. Seeps (up-, side-, and down -gradient)
4. SW data (up-, side-, and down -gradient)
5. Sediment (up-, side-, and down -gradient)
iii. Piper diagram(s) for each groundwater flow regime, seeps, and other SWs
where the applicable water quality data is available.
C. COIs
List of COls and their maximum concentrations beyond the point of
compliance that require corrective action based on 2L/IMAC/background
exceedances:
1. Soil (unsaturated)
2. Groundwater
5

Attachment 1
3. other media if applicable
d. Isoconcentration maps, or use of alternative figures types such as exceedance ratio
maps, in plan -view and two or more cross sections for:
i. COls in unsaturated soil (defined as any COI in the sample being above POG
PSRG or approved background concentration in unsaturated soil)
ii. Horizontal and vertical extent of groundwater in need of restoration for each
COI identified for remediation in each groundwater flow regime (shallow,
deep, bedrock).
e. COI Distribution in Groundwater
i. Movement of conservative COls (e.g. boron, sulfate, chloride) from source to
receptor.
1. Describe whether plume is stable or expanding
1. Flow path wells and transect wells used to assess plume
behavior
2. Method(s) used to analyze plume behavior (should be
discussed and agreed upon with Regional Office prior to CAP
submittal)
ii. Distribution of non -conservative COls (e.g. Fe, Mn, Co, As, TI, etc.)
1. Discussion of site geochemical conditions that may affect COls
behavior in the groundwater system with details included in the
geochemical modeling report.
B. Receptors associated with Source Area 1
a. Map of surface waters (to include wetlands, pond, unnamed tributaries, seeps, etc.)
within %-mile of the waste boundary and hydraulically downgradient of Source Area 1
or known extent of contamination (whichever is greater).
i. Indicate on map all surface waters that are currently permitted as National
Pollution Discharge Elimination System (NPDES) outfalls, along with the
permitted outfall name and NPDES sample location
ii. Indicate on map all surface waters that are currently covered under a Special
Order by Consent
iii. For all surface waters shown, indicate stream classification and nearest
downstream supply intake, if applicable
iv. Indicate on map (footnote) and in report text whether SW samples have been
collected using Division approved protocols ("2L-2B" sampling protocols) to
evaluate whether contaminated groundwater is resulting in 2B violations;
include dates) of 2L-2B sampling and antecedent rainfall
1. If 2L-2B sampling has been conducted, indicate location of all 2L-2B
sample collection points
2. If 2L-2B sampling has been conducted, indicate results of 2B
exceedances on map; also indicate which of those exceedances is a COI
for groundwater for Source Area 1
3. If 2L-2B sampling has not been conducted, explain why and indicate
whether it is being proposed and the proposed sample collection points
b. Map of all supply wells associated with Source Area 1 identified by receptor surveys and
per 130A-309.211(cl) (up-, side-, and down -gradient)
i. Indicate on map the results of the permanent water solution program
completed under House Bill 630 and show which well owners did and did not
accept alternative water
0

Attachment 1
ii. Provide analytical results table for the supply wells; indicate in table whether
each well was determined to be impacted or unimpacted by coal ash
iii. For each supply well determined to be unimpacted by coal ash, provide or
reference evidence that substantiates that position, including water level
measurement -based potentiometric mapping, piper diagrams, assessment of
well -specific geochemical conditions that are affecting certain COls, modeling,
etc. The evidence provided or referenced here will be used to review and
accept or deny Duke's determination that a given well is unimpacted by coal
ash.
c. Map of future groundwater use areas associated with Source Area 1
i. Indicate on map whether each parcel has or does not have access to alternative
water by referring to the figure provided in Section 6.B.b.i above.
ii. Indicate on map whether each parcel was modeled to be impacted or
unimpacted by coal ash now or in the future, or provide a written explanation
that off -site parcels will not be affected based on groundwater modeling
C. Human and Ecological Risks
D. Evaluation of Remedial Alternatives
All contents requested below for Section a. should be repeated for each remedial alternative
that is considered (i.e. Remedial Alternative 2, Remedial Alternative 3, etc.) as directed and
appropriate.
a. Remedial Alternative 1
i. Problem statement and remedial goals.
1. List of COls within each groundwater flow unit (shallow, deep,
bedrock) that will be corrected by this alternative
2. Concentration clean up goals for each of the Cols identified in D. a. i.
1. above
ii. Conceptual model (i.e. simple description explaining how the proposed
source control/removal and corrective action will reduce COI concentrations
and protect human health and environment)
1. COls addressed
2. COls not addressed
3. For each COI not addressed by the proposed corrective action
describe how the constituent will be addressed.
iii. Predictive modeling
Robust predictive groundwater models have been developed for each coal
ash site subject to corrective action. These models will be used to evaluate
potential remedial options as needed. Preliminary detailed groundwater
modeling reports have been prepared consistent with NCDEQ's groundwater
modeling policy document and submitted to the Department. Final modeling
reports are to be prepared consistent with this format, adjusted to include
use of the models for corrective action planning and submitted as an
appendix to the CAPS.
iv. For remedial alternative 1, evaluate it using the following criteria:
1. Protection of human health and the environment
2. Compliance with applicable federal, state, and local regulations
7

Attachment 1
3. Long-term effectiveness and permanence
4. Reduction of toxicity, mobility, and volume
5. Short term effectiveness at minimizing impact on the environment
and local community
6. Technical and logistical feasibility
7. Time required to initiate
8. Predicted time required to meet remediation goals described in D. a.
i. 3. above
9. Cost
10. Community acceptance
E. Proposed remedial alternative(s) selected for the source area 1 and/or sub -areas of source
area 1.
Note that multiple corrective actions may be necessary to address different locations within
source area 1 or any of its sub -areas. This could involve "compartmentalizing" the source area
and describing the specific selected corrective actions for each "compartment."
a. Description of proposed remedial alternative and rationale for selection
i. Specific section of 02L .0106 being addressed by the proposed remedy [e.g.
02L .0106 (1) or (k)]
ii. Will a hybrid remedy consisting of more than one corrective action be used?
If so, describe.
iii. Will proposed remedy or hybrid remedy meet concentration cleanup goals
defined in D. a. i. 3. above?
iv. Treatability studies
1. Results of post-CSA Update treatability studies, if applicable
v. Additional site characterization needed to support the proposed remedy
1. Locations and specific testing, sampling, modeling, and (or) data
analysis
2. Schedule for data collection and reporting
b. Design details — Provide the following information at the conceptual design level
i. Process flow diagrams for all major components of proposed remedy
ii. Engineering designs with assumptions, calculations, specifications, etc.
iii. Permits needed for proposed remedy and approximate schedule for
obtaining them
iv. Schedule and approximate cost of implementation
v. Measures to ensure the health and safety of all persons on and off site
vi. Description of all other activities and notifications being conducted to ensure
compliance with 02L, CAMA, and other relevant laws and regulations
c. For 02L .0106 (1) CAP, provide requirements outlined in DWR's Monitored Natural
Attenuation for Inorganic Contaminants in Groundwater: Guidance for Developing
Corrective Action Plans Pursuant to NCAC 15A [02L] .0106(I).
d. For 02L .0106 (k) CAP, provide requirements outlined in 02L .0106 rule
e. Sampling and reporting
i. Proposed progress (i.e. "effectiveness") reports and schedule
ii. Proposed sampling and reporting plan during active remediation
iii. Proposed sampling and reporting plan after termination of active
remediation (if proposed)
W

Attachment 1
1. Decision metrics for termination of active remediation and start of
,'monitoring only' phase
A. Proposed wells for COI trend analysis
B. Proposed statistical method for trend analysis
f. Proposed interim activities prior to implementation
g. Contingency plan in case of insufficient remediation performance
i. Description of contingency plan
ii. Decision metrics (triggering events) for implementing contingency plan
7. PROFESSIONAL CERTIFICATIONS
Sealed and notarized professional statements of "true, accurate, and complete".
8. REFERENCES
9. TABLES
10. MAPS AND FIGURES — Note: Duke Energy proposes to adjust the figure requirements to allow for
greater focus on figures needed to provide the basis for the site -specific corrective action approaches and
alternate figures types such as exceedance ratio maps that can present multiple constituents on one
figure.
11. APPENDICES — See attached Summary
APPENDICES — Flow and Transport Modeling
For Flow model report content, refer to report titled 'Updated groundwater Flow and Transport
Modeling Report for Asheville Steam Electric Plant, Arden, NC (Ronald Falta and others, March
17, 2017). Also include the following:
• List of all model assumptions
• List all model limitations that affect output (including, for example, unconfirmed
boundary positions, unmodeled heterogeneities, scale of cell volume versus scale of well
observations, limited input data, limited data for calibration and calibration assessment,
etc.)
• List of variables for which sensitivity analyses were quantitatively presented
• Describe how model is being used in closure/corrective action design and review
For transport model report content, refer to report titled 'Updated groundwater Flow and
Transport Modeling Report for Asheville Steam Electric Plant, Arden, NC (Ronald Falta and others,
March 17, 2017). Also include the following:
• List of all model assumptions
• List all model limitations (including, for example, limitations of Kd, unconfirmed boundary
positions, unmodeled heterogeneities, scale of cell volume versus scale of well
observations, limited input data, limited data for calibration and calibration assessment,
etc.) that affect output
0

Attachment 1
• List of variables for which sensitivity analyses were quantitatively presented
• Describe how model is being used in closure/corrective action design and review
APPENDICES - Geochemical Modeling
For geochemical report content, refer to memorandum titled, 'Geochemical modeling of
constituent behavior at CAMA disposal sites' (Brian Powell, January 29, 2018) and memo titled
'Summary and Comments on Geochemical Modeling Outline with MNA Considerations (Bill
Deutsch, February 7, 2018). Also include the following:
• List of all model assumptions
• List all model limitations (including, for example, lack of pertinent data for points along
an individual flow path, if applicable, heterogeneities, limited input data, etc.) that affect
output
• List of variables for which sensitivity analyses were quantitatively presented
• How model is being used in closure/corrective action design
10

Attachment 2
Supporting Rationale for Proposed Interpretation and Adjustments to the Corrective
Action Plan Content Guidance (NCDEQ April 2018)
January 2019
CAP Guidance Section*
Rationale for Proposed Adjustments
Executive Summary
• Added Executive Summary to provide a high-level
summary of the Corrective Action Plan's (CAP) conceptual
site model (CSM) and the site -specific corrective action
approach proposed based on the CSM.
1. INTRODUCTION
1.C.b.
• Deleted text referring to the Notice of Regulatory
Requirements (NORR). These NORR requirements are
focused on the Comprehensive Site Assessments (CSAs)
and are not directly relevant to the CAP.
LD
• Added text to clarify that the CAP will provide a general
written description of how these items were considered
during the CAP preparation process per 02L .0106(i). This
is also intended to clarify that the criteria provided in
Section 7.D.a.iv.1-10 will be used for evaluation and
selection of remedial alternatives in the CAPs.
1.E.b.
Added text to clarify that only non -coal waste streams that
may affect the subsurface conditions at or proximate to coal
ash basins or coincident source areas will be included to
maintain focus on the Coal Ash Management Act
requirements.
2. RESPONSE TO COMPREHENSIVE SITE ASSESSMENT UPDATE COMMENTS
IN SUPPORT OF CAP DEVELOPMENT
2. and 2.B.
• The note at the top of the section clarifies how responses to
the NCDEQ CSA comment letters will be addressed in the
CAP to facilitate the NCDEQ's review. Modification to the
text in Section 2.B.a.&b. has been revised to reflect this
approach.
3. OVERVIEW OF SOURCE AREAS BEING PROPOSED FOR CORRECTIVE
ACTION
• Added a note that describes the role of ash basin decanting
and ash basin closure plans as source removal/control
methods that are linked to the groundwater corrective action
plan for each site. Duke Energy will add a discussion of the
source control measures (the approved Closure Plan) and
the benefits to groundwater restoration and integration into
the corrective action program.
3.A.
• Added reference to the NCDEQ letter providing the list of
sources for each site to be addressed in CAP.

Attachment 2
Supporting Rationale for Proposed Interpretation and Adjustments to the Corrective
Action Plan Content Guidance (NCDEQ April 2018)
January 2019
CAP Guidance Section*
Rationale for Proposed Adjustments
3.13.
• Revised text to reference NCDEQ letter providing list of
sources for each site that will be addressed in subsequent
and separate CSAs.
• Previously numbered items a, b, c are no longer needed due
to the clarification provided by the NCDEQ's letter and
were deleted.
4. SUMMARY OF BACKGROUND DETERMINATIONS
4.B.
• Added text to provide discussion of regional background
concentrations for similar geologic settings as context for
soil background Threshold Values (BTVs).
4.C.
• Added text to provide discussion of regional background
concentrations for similar geologic settings as context for
groundwater BTVs.
4.1).
• Revised text to indicate that referenced EPA values are
recommended "criteria". EPA Nationally Recommended
Water Quality Criteria for Aquatic Life & Human Health
(EPA NRWQC) have not been universally adopted under
15A NCAC 02B. Sample results will be compared to those
criteria found in 15A NCAC 02B .0211(11) with values for
EPA NRWQC provided for reference.
SUMMARY OF POTENTIAL
RECEPTORS
• Removed this section and consolidated potential receptor
information into Section 6.B. This will avoid presenting
redundant information.
5. CONCEPTUAL SITE
MODEL (CSM) — New Section
• Placed CSM into a more prominent position in the guidance
document to emphasize the importance of the CSM to
support corrective action decision -making. All elements
from Section 6.A.b.i. were included along with additional
items to make the CSM more robust.
6. SOURCE AREA 1

Attachment 2
Supporting Rationale for Proposed Interpretation and Adjustments to the Corrective
Action Plan Content Guidance (NCDEQ April 2018)
January 2019
CAP Guidance Section*
Rationale for Proposed Adjustments
6. Opening Section
• Paragraph 1 - Deleted text referring to discussions with
Paragraphs
regional DWR office to identify source areas. This item
was resolved by NCDEQ letter identifying source areas.
These sources will be considered for corrective action based
on the results of the site assessments currently in progress.
• Paragraph 3- Edited text to identify water supply wells and
surface water features hydraulically downgradient relevant
to Source Area 1 to focus only on those areas that could
potentially be affected to facilitate the corrective action
preparation process. The CAP will provide justification for
selection of water supply wells and downgradient surface
water features relevant to each source area.
• Paragraph 4 - Added text to define constituents of Interest
(COIs) for corrective action. This is consistent with 15
NCAC 02L. 0106(e)(4) corrective action requirements to
address constituents with concentrations greater than 21,
applicable values at or beyond the compliance boundary.
This approach will focus the information presented and the
corrective action to the constituents exceeding the
applicable standard (2L/IMAC/BTV) at the relevant point
of compliance.
6.A.a
• Added text to reduce representing data previously provided
to NCDEQ with the intent of leaving more time to focus on
corrective action analysis.
6.A.a.v.
• Revised text to remove the reference to the calculation of
specific storage. Specific storage is a general aquifer
parameter that represents the amount of groundwater per
unit volume of a saturated formation that is lost or gained
from storage due to the compressibility of the mineral
framework that comprises the formation and the pore water
per unit change in head rather than being used to evaluate
COIs in groundwater. The groundwater flow and transport
model will estimate the COI concentrations over time for
the evaluation of remedial alternatives. This approach
provides a more meaningful representation of the
performance of the remedial alternatives over time
compared to a calculation of specific storage.
6.A.a.vi.1.
• Added Ash Leachate Environmental Assessment
Framework LEAF sample data.

Attachment 2
Supporting Rationale for Proposed Interpretation and Adjustments to the Corrective
Action Plan Content Guidance (NCDEQ April 2018)
January 2019
CAP Guidance Section*
Rationale for Proposed Adjustments
6.A.a.vi.3
• Added text to allow for figure preparation flexibility such as
the use of exceedance ratio maps and including the
surrounding area.
6.A.a.vii
• Revised text to indicate "other source material", if any, will
be addressed based on the results of the additional source
area assessments currently underway.
6.A.b.
. Added text to clarify that the discussion regarding the extent
of COIs will include data collected through June 2019. This
will provide Duke Energy with the needed time to reduce
site data and include it in the interpretation of site
conditions.
6.A.b.i.1-6.
• Removed text to the newly created Section 5 above to place
eater emphasis on the CSM.
6.A.b.11.
. Added text that COI results presented are to be based on
consideration of geometric mean concentrations and/or time
vs. concentrations relationships based on historical data
collected through June 2019. This approach will provide
more appropriate concentration results for corrective action
planning by eliminating anomalous or inconsistent data
likely associated with transient geochemical variations.
6.A.b.111.1.6.
• Eliminated table of analytical results for supply wells in this
section since the same information is requested in Section
B.b.ii. to eliminate redundant information.
6.A.c.1-11.
• Removed this section since very similar information is
requested in Section 6.D.a.i-ii which is more focused on
corrective action analysis.
6.A.d.ii.
• Added to text to clarify that isoconcentration maps will be
included for COIs identified for remediation.
6.A.e.
• Changed section title from Plume Characteristics to COI
Distribution in Groundwater to reflect the fact that not all
inorganic COIs behave as a "plume" and are often isolated
and/or transient due to geochernical conditions.
6.a.e.i.1.
• Revised text to say `stable' to `expanding' rather than
`moving' and (or) expanding since `moving' is very similar
to expanding. This wording is also consistent with NCDEQ
and USEPA MNA guidance concerning the description of
plume behavior.

Attachment 2
Supporting Rationale for Proposed Interpretation and Adjustments to the Corrective
Action Plan Content Guidance (NCDEQ April 2018)
January 2019
CAP Guidance Section*
Rationale for Proposed Adjustments
6.a.e.ii.1.
Revised text to provide a general discussion of site
geochemical conditions in the body of the CAP recognizing
that the detailed geochemical items listed will be included
in the geochemical modeling report which will be presented
in the appendices.
6.B.a
• Revised text to clarify that only those surface waters that
are hydraulically downgradient that could be affected by
site -related COIs will be identified on the map to maintain
focus on those areas that may need to be addressed under
the CAP.
6.B.b.
• Revised to provide clarity regarding identification of water
supply wells.
6.D.a.i.1.
• Removed text regarding a 3-dimensional (3-D) map. A 3-D
block diagram figure will be included as part of the CSM.
6.D.a.iii.
• Removed this section on predictive modeling. Duke Energy
proposes to consolidate this section into the groundwater
modeling report that will be presented as an appendix to the
CAP. The groundwater modeling will be used to inform
corrective action decision -making.
6.E.b.
• Added text to indicate information requested will be
provided at conceptual design level.
6.E.b.iv.
Added "approximate" to costs since information will be at
conceptual level.
10. MAPS and FIGURES
• Added note that describes Duke Energy's approach for
figures to be included in the CAP with an emphasis on
making the CAP more manageable on a practical basis and
focusing on those figures necessary to support our
corrective action approach.
11. APPENDICES
• Added a general planned list of CAP appendices to clarify
what will be included in the CAP deliverables. The
appendices may be adjusted on a site -specific basis as
needed.
Notes
*If a section is not included in this table no changes were made to it.
5

Attachment 3
General List of Appendices for the Groundwater Corrective Action Plans for Duke Energy
Facilities*
January 2019
Appendix A Key Regulatory Correspondence
1) Approval of Provisional Background Threshold Values (September 1,
2017 and [Date] 2019)
2) Special Order by Consent
Appendix B
Comprehensive Site Assessment Update Report North Carolina
Department of Environmental Quality (NCDEQ) Review Comments
and Responses
1) Comprehensive Site Assessment Update NCDEQ Comment Letters
2) Duke Energy Response to Comments and Summary Table
3) NCDEQ Meeting Minutes
4) Additional Assessment Report(s) [including delineation of constituents
in soil, background evaluation, additional source areas, deep bedrock
assessment and pumping test report(s)]
Appendix C
Updated Comprehensive Analytical Data Table
Appendix D
HB 630 — Provision of Water Supply Completion Reports
Appendix E
Updated Human Health and Ecological Risk Assessments
Appendix F
Final Flow and Transport Model Reports
Appendix G
Final Geochemical Model Reports
Appendix H Monitored Natural Attenuation Report
Appendix I Interim Corrective Action Construction Drawings (as applicable)
Appendix J Surface Water Evaluation Report for Compliance with 2L (k) or (1)
*The above represents common items to be included in the Groundwater Corrective Action
Plans. The actual list will be tailored to each site's specific requirements as needed.

LEGEND
MONITORING WELLS
GENERALIZED EXCEEDANCE 1.0 CONTOUR
AREAL EXTENT OF CONSTITUENTS OF INTEREST
REPRESENTED BY NCAC 02L EXCEEDANCES
■ SELECTED SURFACE WATER SAMPLE LOCATIONS
ASH BASIN WASTE BOUNDARY
ASH BASIN COMPLIANCE BOUNDARY
STATION BOUNDARY
DESIGNATED EFFLUENT CHANNEL
STREAM (AMEC NRTR 2015)
WETLANDS (AMEC NRTR REPORT, 2015)
4
:..
�.tt,:
�`'
•'�' _
,,,� � a�
��`
�
-
GWA-24S
��-
,�`
e
�
p.
a � • s., j.C` �
_ A. .. a� a
•
F' ' .ram rya.,- - _
t ;
GWA-30S
GWA
4 � i
Arsenic /L
Symbol
As
Standard
10
Barium /I_
Ba
700
Boron /I_
B
700
Chloride /I_
CI
250
Chromium /L
Cr
10
/L
Mn
50
-Manganese
Selenium /L
Se
20
Total Dissolved Solids (mg/0
TDS
500
S . MW-200S
Cr: 1.1 -
GWA-1S x Mn:1.3,.:�� is
B: 1.4 GWA-32S
Mn: 3.2 , -` `• As: 2.3
Mn: 210
.. ,'•.ice
'As:
1.3
h
r:4.6
Mn: 4.1
Mn:4.5
•�
CCR-04S
-,
B: 11.5
g
�-
Cl: 1.3
TDS: 1.3
GWA-20SA
B• 15 0
C I : 1.6
ti
GWA-27S
Mn: 101
TDS: 2.0
B: 1.2
GWA-19SA
"-
Mn:39.2
a
CCR-02S
Mn: 40.6
- As: 1.4
Se: 1.3
+ B: 10.8
Cl: 1.3
g Q�Cr: 1.4
GWA-10S
; ::- TDS:1.5
Mn:44
.'
GWA-18SA
�.. ,. As: 1.0
Mn: 30
j
CCR-01 S
CCR-05S
B: 16.1
Cl: 1.6
TDS: 2.0
ABA S
B: 10.4
Cl: 1.4
Mn: 33.2
TDS: 1.8
16'
synTerra
DUKE
° ENERGY
CCR-07S
MW-103S
As: 7.5
B: 1.9
Cl: 1.0
Mn: 169
TDS: 1.1
AB-2S
Mn: 16.6
CCR-08S
B: 14.7
Cl: 1.6
Cr: 1.5
TDS: 1.8
AB-3S
B: 13.3
Cl: 1.4
Mn: 67.4
TDS: 1.8
NOTES
1) Exceedance ratio is defined as the constituent concentration divided by the
selected comparative criteria (for example: [COI]/2L Standard).
2) Ratio numbers >1 indicate an exceedance of comparative criteria (2L, IMAC, BTV);
ratio numbers <1 indicate constituent concentrations within acceptable limits relative to
comparative criteria.
3) Posted data is from April 2018 (the most recent comprehensive validated
data set available).
4) Manganese (Mn) not contoured due to inconsistent distribution.
125 0 125 250
GRAPHIC SCALE IN FEET
148 RIVER STREET, SUITE 220
GREENVILLE, SOUTH CAROLINA 29601
PHONE [phone]
www.svnte rracor'COm
DRAWN BV: A- FEIGL DATE: O1/15/2019
PROJECT MANAGER: C. EADV
CHECKED BY: T. PLATING
EXAMPLE MAP
EXCEEDANCE RATIOS -
2L STANDARD
BELEWS CREEK STEAM STATION
DUKE ENERGY CAROLINAS, LLC
BELEWS CREEK, NORTH CAROLINA

� DUKE 4i0S.Wilmington Street.
Raleigh, NC 27601
E N E RGY® Mailing Address
Mail Code NC 15
Raleigh, NC27601
March 20, 2019
North Carolina Department of Environmental Quality
Attn: Mr. Jon Risgaard
Chief, Animal Feeding Operations and Groundwater Section
1636 Mail Service Center
Raleigh, NC 27699 - 1636
Re: Optimized Interim Monitoring Plans (IMP) for 14 Duke Energy Facilities — Modification Request
Annual Reports— Modification Request
Dear Mr. Risgaard,
On December 21, 2018, Duke Energy (Duke) received the North Carolina Department of Environmental
Quality (DEQ) approval via email for the Optimized Interim Monitoring Plans (IMP) for the following 14
facilities:
• Allen Steam Station (Allen);
• Asheville Steam Electric Plant (Asheville);
• Belews Creek Steam Station (Belews Creek);
• Buck Combined Cycle Station (Buck);
• Cape Fear Steam Electric Plant (Cape Fear);
• James E. Rogers Energy Complex (Cliffside);
• Dan River Combined Cycle Station (Dan River);
• HF Lee Energy Complex (HF Lee);
• Marshall Steam Station (Marshall);
• Mayo Steam Electric Plant (Mayo);
• Riverbend Steam Station (Riverbend);
• Roxboro Steam Electric Plant (Roxboro);
• L.V. Sutton Energy Complex (Sutton); and
• W.H. Weatherspoon Power Plant (Weatherspoon).
Duke would like to provide clarification and request respective concurrence on a few items related to the
December 21, 2018 approved IMP.
Item 1:
Duke understands that DEQ expects newly installed monitoring wells to be sampled for the minimum
suite of Coal Ash Management Act (CAMA) parameters (as listed in the former Fourth Quarter 2018
IMP), and on a quarterly basis for a minimum of four events. Duke believes this expectation may not
have been clearly noted in the proposed and subsequently approved December 2018 Optimized IMP.
Duke would like to clarify via this letter that newly installed monitoring wells for investigation of
potential primary and secondary source assessments or DEQ required data gaps under the CAMA
program will be sampled for the former Fourth Quarter 2018 minimum suite of CAMA parameters, as

March 20, 2019
Risgaard Letter
well as some voluntary parameters (for geochemical modeling purposes). Such new wells will be
sampled on a quarterly basis for at least four events.
To address, attached Table 1 lists the parameters to be included for such new wells. The attached
Tables 2.1 through 2.14 include modified versions of the IMP Optimization summaries of wells,
frequency and constituents for each of the 14 Duke facilities, respectively.
Item 2:
Specifically, after receiving DEQ's approval of the Optimized IMP for the respective 14 facilities, Duke
noticed that four sites (Allen, HF Lee, Riverbend and Weatherspoon) had mistakenly listed
Comprehensive Water Level Sweeps for quarterly rather than semi-annually. The attached Tables 2.1,
2.8, 2.11 and 2.14 now list comprehensive water level sweeps on a semi-annual basis, consistent with
the other 10 facilities.
Another change on Tables 2.1 through 2.14 is previously discontinued parameters, total aluminum and
dissolved metals, have been re -added to select sites voluntarily to support geochemical modeling.
Specifically, dissolved metals may be analyzed for at select well locations (yet to be determined) at
some sites during dewatering of the ash basins to help determine if the dewatering process affects the
total to dissolved ratio of some metals. Other voluntary parameters have also been added in support of
geochemical modeling, but unlike total aluminum and dissolved metals, they were not specifically listed
previously as discontinued parameters.
Item 3:
Duke would like to take this opportunity to propose a revised CAMA quarterly data submittal schedule
to better correspond to our 2019 plans for sampling. The current CAMA quarterly data submittal
schedule was approved by DEQ via email on June 6, 2018. A revised schedule has been attached as
Table 3.
Item 4:
Another condition of the June 6, 2018 CAMA quarterly data submittal approval issued by DEQ was for
each of Duke's Subject Matter Expert to provide updates to the Division of Water Resources (DWR)
Regional Office individually on a monthly basis to discuss work done in the previous month and any
upcoming work scheduled or proposed for the following month. Duke requests concurrence to provide
monthly updates to DWR Regional Offices by the end of each month, rather than mid -month, as is the
current practice for some of the sites. This will also allow for monthly updates to be completed with data
submittals.
Upon approval of the items discussed above, this information and respective attachments will replace the
December 21, 2018 versions of the Optimized IMPS for the 14 sites, and will supersede the June 6, 2018
CAMA quarterly data submittal approval.
Item 5:
Also within the DEQ letter dated December 21, 2018 is a requirement for annual monitoring reports due by
April 30. Duke has been in discussions with DEQ staff over the past few weeks and understands DEQ is
open to a modification in schedule. As such, Duke proposes the following schedule for 2019 submittal of
2

March 20, 2019
Risgaard Letter
annual reports along with annual effectiveness monitoring reports for three sites that have implemented
accelerated remediation:
• Annual Monitoring Reports Due April 30, 2019 —Allen, Belews Creek, Cliffside, Marshall, Mayo and
Roxboro facilities (no change proposed);
• Annual Monitoring Reports Due July 31, 2019 — Asheville, Buck, Cape Fear, Dan River, HF Lee,
Riverbend, Sutton and Weatherspoon facilities;
• Annual Effectiveness Monitoring Report Due May 15, 2019 — Sutton (no change proposed);
0 Annual Effectiveness Monitoring Reports Due July 31, 2019 — Asheville and Belews Creek.
The accelerated remediation system at Asheville went into service in March 2018. The system was shut off
as requested by DEQ for pump tests completed at the site. The pump tests were completed from May to
July 2018. Once the system was to be re -activated, Duke learned the system was struck by lightning
sometime during the period of the pump tests. Multiple parts with long -lead times were ordered and the
system finally returned to service in February 2019. As the system has not operated much of 2018, an
extension to the effectiveness report will allow additional data to be collected and included.
For Belews Creek, an extended timeframe for evaluation of the accelerated remediation system will assist in
determining the effects of ash basin decanting/dewatering. Operational lowering of the ash basin is
underway. Decanting, followed by dewatering, is anticipated to begin in late March/early April 2019 and
expected to continue through September 2020. The fate and transport model predicts that decanting will
significantly change groundwater conditions in the area of the remediation system. The model predicts that
groundwater levels will decrease and that the flow direction may change, strengthening a groundwater
divide along Middleton Loop Road. These changes could significantly affect the performance and utility of
the remediation system. Extending the submittal of the Belews Creek Effectiveness Monitoring report to the
end of July 2019 will provide several months of extraction system data collected during ash basin decanting
progress and be very valuable in assessing the extraction system's performance in regards to significant
changing site conditions.
If you have any questions or need any clarification regarding the information provided, feel free to
contact me at [e-mail] or at 919-546-7863 at your convenience.
Respectfully submitted,
AohnToepfer, PPE
Lead Engineer, Duke Energy EHS CCP
Waste & Groundwater Programs

March 20, 2019
Risgaard Letter
cc (via e-mail): Steve Lanter - NCDEQ CRO
Eric Smith - NCDEQ CRO
Brandy Costner— Mooresville Regional Office
Shuying Wang —Winston-Salem Regional Office
Ted Campbell —Asheville Regional Office
Eric Rice — Raleigh Regional Office
Will Hart —Washington Regional Office
Geoff Kegley — Wilmington Regional Office
Kent White — Fayetteville Regional Office
Ed Sullivan - Duke Energy
Bryan Moeller— Duke Energy
Kathy Webb—SynTerra Corp.
Attachments: Table 1— Summary of Analytical Parameters for Newly Installed Wells
Table 2.1- Summary of Wells, Frequency, & Parameters —Allen
Table 2.2 - Summary of Wells, Frequency, & Parameters —Asheville
Table 2.3 - Summary of Wells, Frequency, & Parameters — Belews Creek
Table 2.4 - Summary of Wells, Frequency, & Parameters — Buck
Table 2.5 - Summary of Wells, Frequency, & Parameters — Cape Fear
Table 2.6 - Summary of Wells, Frequency, & Parameters — Cliffside
Table 2.7 - Summary of Wells, Frequency, & Parameters — Dan River
Table 2.8 - Summary of Wells, Frequency, & Parameters — HF Lee
Table 2.9 - Summary of Wells, Frequency, & Parameters — Marshall
Table 2.10 - Summary of Wells, Frequency, & Parameters — Mayo
Table 2.11- Summary of Wells, Frequency, & Parameters — Riverbend
Table 2.12 - Summary of Wells, Frequency, & Parameters — Roxboro
Table 2.13 - Summary of Wells, Frequency, & Parameters — Sutton
Table 2.14 - Summary of Wells, Frequency, & Parameters — Weatherspoon
Table 3 - Proposed Sampling Schedules & Respective CAMA Data Submittals
4

TABLE 1
IMP Optimization
Summary of Analytical Parameters for Newly Installed Wells
(to begin Q1 2019)
For each of Duke Energy's 14 North Carolina facilities, new wells installed as part of the CAMA program will be
monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th
Quarter 2018 IMP and additional constituents analyzed voluntarily. After four quarterly events, the monitoring
frequency and/or parameter list for the new wells will be re-evaluated with NCDEQ and may be reduced and/or
optimized. A summary of analytical parameters to include under this criteria is provided below.
SUMMARY OF ANALYTICAL PARAMETERS FOR NEWLY INSTALLED WELLS
Minimum CAMA Parameters per Q4 2018 IMP
(Metals are Totals)
Additional Voluntary Parameters
[Dissolved (0.45 micron filter)]
Aluminum
Mercury
Molybdenum
Aluminum
Antimony
Mercury
Molybdenum
Nickel
Alkalinity (CO3/HCO3)
Antimony
Nickel
Arsenic
Arsenic
Potassium
Barium
Phosphorus
Barium
Radium (226 + 228)
Beryllium
Potassium
Beryllium
Selenium
Boron
Selenium
Boron
Sodium
Cadmium
Silver
Cadmium
Strontium
Calcium
Sodium
Calcium
Sulfate
Chromium
Strontium
Chloride
Sulfide
Cobalt
Thallium
Chromium
Total Dissolved Solids (TDS)
Copper
Vanadium
Cobalt
Thallium
Iron
Zinc
Copper
Total Organic Carbon (TOC)
Lead
Hexavalent Chromium
Uranium (233+234+236+238)
Lithium
Iron
Lead
Total Suspended Solids (TSS)
Magnesium
IManganese
Vanadium
Magnesium
Zinc
Additional Voluntary Parameters
(Totals)
Manganese
Fluoride
Lithium
Nitrate + Nitrite
Phosphorus
Methane*
Additional Field Water Quality Parameters
A� = A
Dissolved Oxygen (DO)
Oxidation -Reduction Potential (ORP)
Redox Potential (Eh)
Turbidity
Temperature
Specific Conductance
pH
* W.H. Weatherspoon Power Plant only

Table 2.1- Allen
Wells for Quarterly
Monitoring (33)
AB-21SS*
AB-25SS*
AB-29SS*
AB-32D
AB-33D
AB-33SS*
AB-34S
AB-35PWS*
AB-38SS*
AB-10BR*/ BRL*
GWA-3BRL*
GWA-4BRL*
GWA-5BRL*
GWA-6BRL*
CP-1S*/D*
CP-2S*/D*
CP-3S*/D*
CP-4S*/D*
CP-5S*/D*
CP-6S*/D*/BR*
BG-1BR*
CCR-26S* / D* / BR*
CCR-16BR*
Allen Steam Station - IMP Optimization
Summary of Wells, Frequency, & Parameters
(to begin Q1 2019)
Comprehensive Water Level Sweep to occur Semi -Annually
- March 2019
Wells for Semi -Annual Monitoringt (103)
-A i
AB-04S / D / BR
GWA-05S / D / BRA
AB-06R
GWA-06S / DA / BRA
AB-09S / D
GWA-07S / D
AB-10S / D
GWA-08S
AB-13S / D
GWA-09S / D / BR
AB-14D / BR
GWA-14S / DA
AB-20S / D
GWA-15S / D
AB-21S / SL / D** / BRL
GWA-19S / D**
AB-22S / D / BR / BRL
GWA-22S / D
AB-24S / SL / D** / BR
GWA-23S / D**
AB-25S / SL / BRU** / BR**
GWA-24SA / D / BR
AB-26S / D
AB-12S / D
AB-30S
BG-01S / DA
AB-32S
BG-2S / D / 2BRA2
AB-33S
BG-3S / D
AB-34D
BG-4S / D / BR
AB-35S / D** / BR
GWA-16S / D
AB-36S / D
GWA-21S / DA / BR
AB-37S / D
GWA-26S / D
AB-38S / D / BR
Comprehensive Water
Level Sweeps
(includes wells in Semi-
Annual, Quarterly, and
Discontinued Monitoring
Lists)
AB-39S / D
GWA-01S / D / BR
GWA-02S / D
GWA-03S / D / BRA
GWA-04S / D / BR
Optimized Quarterly & Semi -Annual Parameters for "Non -New Wells"
Additional Water Quality
2018 CSA Update COIs
(Total & Dissolved Where Applicable)
Parameters (Total & Dissolved
Where Applicable)
Antimony
---------------------------------
Lithium
---------------------------------
Aluminum
-----------------------------------------
Arsenic
---------------------------------
Manganese
---------------------------------
Alkalinity (CO3/HCO3)
-----------------------------------------
Beryllium
Molybdenum
Calcium
---------------------------------
Boron
---------------------------------
Nickel
-----------------------------------------
Chloride
---------------------------------
Cadmium
---------------------------------
---------------------------------
Selenium
---------------------------------
-----------------------------------------
Dissolved Oxygen (DO)
-----------------------------------------
Chromium (total)
Strontium
Redox Potential (Eh)
---------------------------------
Chromium (hexavalent)
---------------------------------
-----
------------------------------------------------------------
Sulfate
------------- --------------------
---------
Magnesium
-----------------------------------------
Cobalt
Thallium
Nitrate + Nitrite
---------------------------------
Iron
---------------------------------
Total Dissolved Solids (TDS)
-----------------------------------------
Oxidation -Reduction Potential (ORP)
Vanadium pH
---------------------------------
_________ Potassium
Specific Conductance
---------------------------------
Sodium
Total Organic Carbon (TOC)
-------------------------------
Temperature
-------------------------------
Turbiditv
MP = Interim Monitoring Plan
CSA = Comprehensive Site Assessment
COls = Constituents of Interest
CAMA = Coal Ash Management Act
CDEQ = North Carolina Department of Envrionmental Quality
Discontinue Sampling
Wells/Water Level Only (23)
A B-01 R
AB-02/D
AB-05
AB-06A
AB-11D
AB-23S / BRU**
AB-27S /D / BR
AB-28S / D
AB-29S / SL / D
AB-30D
AB-31S
GWA-08D
GWA-17S / D
GWA-18S / D
To Be Replaced
No well replacements planned
at this time
To be Abandoned
GWA-6D
i-Annual monitoring events are scheduled to be performed concurrently with two Quarterly monitoring events per year and will include the wells listed under Quarterly for
ctive events.
New wells installed as part of the CAMA program will be monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th
Zuarter 2018 IMP and additional constituents analyzed voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells will
ie re-evaluated with NCDEQ and may be reduced and/or optimized. Replacement wells will not be considered "new wells" and will follow the respective monitoring protocol for
he well in which they replace; however, additional parameters may be included voluntarily.
** Denotes well was previously approved by DEQ to be sampled for boron and sulfate only in historic versions of the IMP due to elevated pH. Respective well is proposed to
remain a boron -and -sulfate -only sample location; however, if the pH improves with redevelopment to fall <_ 8.5 at such well, the well will be sampled for the complete appropriate
parameter suite for that well; i.e. "optimized non -new well" or "new well" lists as proposed herein.

Table 2.2 - ASHEVILLE
Asheville Steam Electric Plant - IMP Optimization
Summary of Wells, Frequency, & Parameters
(to begin Q1 2019)
Comprehensive water sweep to occur semi-annually.
Modification - March 2019
Wells for Quarterly Monitoring (51)
AS-513R (pH)
MW-15BRL+
C13-6
MW-16A+
C13-7
M W-16D+
CB-8+
MW-16BR+
CB-8BR+
MW-16BRL+
CCR-100SL+
MW-16BRLL+
CCR-100BR+
MW-17A+
CCR-100BRL+
MW-17BRL+
CCR-101BR+
MW-18D
CCR-102S+
MW-18BR+
CCR-102D+
MW-18BRL+
CCR-103D
MW-20A
CCR-103BR
MW-20BR+
EXT-01+
MW-20BRL+
EXT-02
MW-26S
EXT-A
M W-26BR+
GW-2+
PZ-17BRL+
MW-5D
CPA-1D*
MW-51311
CPA-1BR*
MW-8S+
CPA-2D*
MW-9S+
CPA-2BR*
M W-9 D+
CPA-4D*
MW-9BR+
CPA-4BR*
MW-15A+
CPA-3D*
MW-15D+
CPA-3BR*
Wells for Semi -Annual Monitoringt (35)
AMW-03B+
MW-13D
C13-1+
MW-13BR
CB-1D+
M W-24S+
CB-3 R+
M W-25S
C13-4+
MW-25BR
C13-413+
MW-25BRL
CB-5
P-103
CB-9
PZ-17S+
CB-9SL
PZ-17D+
CB-91311
PZ-19
CCR-104D+
CCR-105BR
CCR-105D+
GW-1+
GW-1D
GW-1BR
GW-3+
G W-4+
MW-3D+
MW-6S+
MW-6D+
Comprehensive Water Level Sweeps
(includes wells in Semi -Annual,
Quarterly, and Discontinued
Monitoring Lists)
MW-6BR+
MW-10+
MW-11
MW-11D
Optimized Quarterly & Semi -Annual Parameters for "Non -New" Wells
(Total & Dissolved Where Applicable)
Antimony
--------------------------------------
Manganese
--------------------------------------------
Alkalinity (CO3/HCO3)
-----------------------------------------
Arsenic
Selenium
Calcium
Beryllium
--------------------------------------
Strontium
--------------------------------------------•-----------------------------------------
Dissolved Oxygen (DO)
Boron
Sulfate
Redox Potential (Eh)
Cadmium
Total Radium (226 + 228)+
Magnesium
Chloride
Total Dissolved Solids (TDS)
Potassium
Chromium (total)
Total Uranium (233+234+236+238)+
Sodium
Chromium (hexavalent)
Vanadium
Nitrate + Nitrite
Cobalt
Lithium
Iron
Molybdenum
Nickel
-----------------------------------------
Oxidation-Reduction Potential (ORP)
•-----------------------------------------
pH
•-----------------------------------------
Specific Conductance
•-----------------------------------------
Thallium
•-----------------------------------------
Total Organic Carbon (TOC)
•-----------------------------------------
Temperature
•-------------------------------------
Turbidity--
Discontinue Sampling
Wells/Water Level Only (21)
MW-14BR
MW-23DU
MW-23DL
MW-23BR
AMW-1B
ABMW-11BR
AMW-2A
AMW-2B
APZ-30
B-1
B-1-A
B-2
CB-1BR
CB-I-BRL
CB-2
CB-8D
GW-5
MW-7BR
MW-15BR
MW-19BR
P-102
EXT-D
MW-8BR
MW-26BRL+
AS-5BRL
To Be Replaced
No well replacements planned at
this time
Abandoned(3)
MW-21D
MW-22D
MW-22BR
Notes:
IMP = Interim Monitoring Plan
CSA = Comprehensive Site Assessment
COls = Constituents of Interest
CAMA = Coal Ash Management Act
NCDEQ = North Carolina Department of Envrionmental Quality
tSemi-Annual monitoring events are scheduled to be performed concurrently with two Quarterly monitoring events per year and will include the wells listed under Quarterly for respective events.
+ Indicates the well to be sampled and analyzed for total radium (226 +228) and total uranium (233+234+236+238).
*New wells installed as part of the CAMA program will be monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th Quarter 2018 IMP and
additional constituents analyzed voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells will be re-evaluated with NCDEQ and may be
reduced and/or optimized. Replacement wells will not be considered "new wells" and will follow the respective monitoring protocol for the well in which they replace; however, additional parameters
may be included voluntarily.

Wells for Quarterly Monitoring (31)
AB-04 Lower Ash/SAP
CCR-2S/D
CCR-13S*/D*/BR*
EXO B-01
EXOB-02
GWA-01S
GWA-10S(+)
GWA-11S/D
GWA-18SA
GWA-19SA/D
GWA-20SA/D(+)
GWA-21S/D
GWA-27S/D(+)
LRB-01S/D/BR
LRB-02S/D/BR
MW-104BRA(+)
MW-200BR
M W-04
Table 2.3 - Belews Creek
Belews Creek Steam Station - IMP Optimization
Summary of Wells, Frequency, & Parameters
(to begin Q1 2019)
Comprehensive water level sweep to occur semi-annually
tion - March 2019
Wells for Semi -Annual Monitoringt (56)
AB-1BR
GWA-26S/D/BR
AB-2S/D
GWA-27BR
AB-31)
GWA-30S/D
AB-4S/D/BR/BRD**
GWA-31S/D
AB-6SL
GWA-32S/D
AB-7S
GWA-3S (att)
BG-01S(att)/D
GWA-6S
BG-02S/D/BRA
GWA-7SA
BG-03S/D
GWA-8S/D
GWA-10DA
GWA-9BR
GWA-16S/DA/BR* *
M W-03
GWA-17S
MW-20OS/D
GWA-18D
MW-202S(+)/D(+)/BR(+)
GWA-19BR
MW-204D
GWA-01D/BR**
Comprehensive Water Level
Sweeps (includes wells in
Semi -Annual, Quarterly, and
Discontinued Monitoring Lists)
GWA-20BR
GWA-22S/D
GWA-24S/D/BR (att)
GWA-25BR
Optimized Quarterly & Semi -Annual Parameters for "Non -New Wells"
2017 CSA Update COls
Additional Water Quality Parameters (Total & Dissolved Where
Total & Dissolved Where Applicable)
Applicable)
Antimony
---------------------------------
Iron
-----------------------------------------
Aluminum
----------------------------------------------------------------------------------
Arsenic
Manganese
Alkalinity (CO3/HCO3)
---------------------------------
------------Barium------------
-----------------------------------------
- -----------Molybdenum------------
----------------------------------------------------------------------------------
------------------------------------Calcium------------------------------------
Beryllium
Selenium
Dissolved Oxygen (DO)
Boron
Strontium
Lithium
---------------------------------
Cadmium
-----------------------------------------
Sulfate
----------------------------------------------------------------------------------
Redox Potential (Eh)
---------------------------------
-----------------------------------------
Total Dissolved Solids (TDS)
----------------------------- -----------------------
Magnesium
------------
Chromium (total)
Thallium
Nitrate + Nitrite
Chromium (hexavalent)
Vanadium
Oxidation -Reduction Potential (ORP)
Cobalt
-
pH
----------------------------------------------------------------------------------
Potassium
----------------------------------------------------------------------------------
Radium (total) (+)
----------------------------------------------------------------------------------
Specific Conductance
----------------------------------------------------------------------------------
Sodium
----------------------------------------------------------------------------------
Total Organic Carbon (TOC)
----------------------------------------------------------------------------------
Temperature
----------------------------------------------------------------------------------
Turbidity
------------------------------ -----------------------------
Uranium (total) (+)
Discontinue Sampling
Wells/Water Level Only (39)
AB-1S/D
AB-3S
AB-4SL (pH)
AB-5S/SL/D
AB-6S/D
AB-7D
AB-8S/SL/D
AB-9S/D/BR/BRD**
GWA-12S/D/BR (SF)
GWA-17D
GWA-23S/D (SF)
GWA-2S/D
GWA-3D
GWA-6D
GWA-7D
GWA-9S/D
MW-104S/D/BR**
MW-201D/BR
M W-203S/D/BR
M W-204S
To Be Replaced
No well replacements planned at
this time
To be Abandoned
No wells are scheduled to be
abandoned at this time.
Notes: owilill
IMP = Interim Monitoring Plan
CSA = Comprehensive Site Assessment
COls = Constituents of Interest
CAMA = Coal Ash Management Act
NCDEQ = North Carolina Department of Envrionmental Quality
tSemi-Annual monitoring events are scheduled to be performed concurrently with two of the Quarterly monitoring events and will include the wells listed under Quarterly for respective events.
*New wells installed as part of the CAMA program will be monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th Quarter 2018 IMP
and additional constituents analyzed voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells will be re-evaluated with NCDEQ and
may be reduced and/or optimized. Replacement wells will not be considered "new wells" and will follow the respective monitoring protocol for the well in which they replace; however,
additional parameters may be included voluntarily.
** Denotes well was previously approved by DEQ to be sampled for boron and sulfate only in historic versions of the IMP due to elevated pH. Respective well is proposed to remain a boron -and -
sulfate -only sample location; however, if the pH improves with redevelopment to fall 158.5 at such well, the well will be sampled for the complete appropriate parameter suite for that well; i.e.
`optimized non -new well' or "new well' lists as proposed herein.
(+) -Select wells to be sampled for total radium (226 and 228) and total uranium (233, 234, 236, and 238). Wells GWA-10S, GWA-20D, GWA-27D and MW-104BR had at least one or more
concentration(s) of total radium (only) reported greater than the Federal MCL, including the latest sample event. MW-104BR was replaced with monitoring well MW-104BRA, due to high pH.
Wells GWA-10S, GWA-20D, GWA-27D and MW-104BRA are to be monitored for total radium and total uranium; if results are less than the Federal MCL, revaluation may indicate of historical
exceedances are anomalous and a revision to the routine monitoring plan will be considered. Background well cluster MW-202S/D/BR will also be included in semiannual sampling of total
radium and total uranium for ongoing comparative purposes.
(SF) - GWA-12S/D/BR and GWA-23S/D will be included as part of the Structural Fill assessment monitoring
(att) - well is typically dry but will not be replaced; attempt to sample (BG-1S, GWA-3S, GWA-24S)

Table 2.4 - Buck
LWellsor Quarterly
itoring (32)
AB-01Dx
AB-02Sx / SLx / Dx / BR
AB-3Sx / Dx
AB-04S / BRL
AB-05S
AB-09BRA
AB-10Sx / Dx / BRx / BRLx
AS-01Sx / Dx
AS-02Dx
AS-03Sx / Dx
BG-01 DA
GWA-015
GWA-09S / D / BRA
GWA-10S / D
GWA-14D
GWA-15BR
MW-01D
M W-08B RA
MW-11BRL
Buck Steam Station - IMP Optimization
Summary of Wells, Frequency, & Parameters
(to begin Q1 2019)
Comprehensive Water Level Sweep to occur Semi -Annually
tion - March 2019
Wells for Semi -Annual Monitoringt (74)
AB-04S L
M W-06 B R
AB-05SL
MW-07S / D
AB-06BRU
MW-08S / D
AB-07S / BRU
MW-09S / D
AB-8S / BRU
MW-11S / D / BR
AB-09S / BRUA
MW-12S / D
BG-01S / BRA
MW-13D
BG-02S / D
GWA-14S / D
BG-03S / BRU
GWA-15S / D
GWA-01D
GWA-16S / D / BR
GWA-02S / BRA / BRU
MW-08S / D
GWA-11S / D
GWA-7S / D
GWA-12S / BRU
GWA-8D
GWA-13SR / D
GWA-9S / D
GWA-14S
GWA-18S
GWA-15S / D
GWA-20S
GWA-16S / D/ BR
Comprehensive Water
Level Sweeps
(includes wells in Semi -
Annual, Quarterly, and
Discontinued Monitoring
Lists)
GWA-17S
GWA-18S / DA
GWA-19S / D
GWA-20S / D
GWD
MW-03S
3S / D
M W-04S / D
MW-5S / D
Optimized Quarterly & Semi -Annual Parameters for "Non
-New Wells"
(Total & Dissolved Where Applicable)
Antimony
Iron
Aluminum
Arsenic
Manganese
Alkalinity (CO3/HCO3)
Calcium
Barium Nickle
Boron
Selenium
Chloride
Chromium (total)
Sulfate
Dissolved Oxygen (DO)
Chromium (hexavalent)
Thallium
Lithium
Cobalt
Total Dissolved Solids (TDS)
Magnesium
Vanadium
Nitrate + Nitrite
Oxidation -Reduction Potential (ORP)
pH
Phosphorus
Potassium
Redox Potential (Eh)
Sodium
Specific Conductance
Strontium
Temperature
Turbidity
IMP = Interim Monitoring Plan
CSA = Comprehensive Site Assessment
COls = Constituents of Interest
CAMA = Coal Ash Management Act
NCDEQ= North Carolina Department of Envrionmental Quality
Discontinue Sampling
Wells/Water Level Only (7)
AB-04BRU
AB-05BRU
GWA-06S
GWA-14BR
MW-01S
MW-06D
M W-06S
To Be Replaced
AB-04BRL, BG-01DA, GWA-
09BRA,GWA-09D, GWA-09S,
GWA-14D
To be Abandoned
None planned at this time,
except for wells to be replaced
mi-Annual monitoring events are scheduled to be performed concurrently with two Quarterly monitoring events per year and will include the wells listed under Quarterly for respective
nts.
*New wells installed as part of the CAMA program will be monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th Quarter 2018
IMP and additional constituents analyzed voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells will be re-evaluated with
NCDEQ and may be reduced and/or optimized. Replacement wells will not be considered "new wells" and will follow the respective monitoring protocol for the well in which they replace;
however, additional parameters may be included voluntarily.
Well located in basin; will be sampled quarterly until closed for excavation.

Wells for Quarterly
Monitoring (3)
M W-25BR*
MW-25BRL*
MW-25BRLL*
Table 2.5 - Cape Fear
Cape Fear Steam Electric Plant - IMP Optimization
Summary of Wells, Frequency, & Parameters
(to begin Q1 2019)
Comprehensive Water Level Sweep to occur Semi -Annually
Modification - March 2019
Wells for Semi -Annual Monitoringt (61)
ABMW-01 / S / BR
MW-17SU / SL / BR
ABMW-02SU / SL
MW-21SU / SL / BR
ABMW-03 / SR / BR
MW-22S / BR
ABMW-04 / S
MW-23S / D / BR
ABMW-05S / BR
MW-24S / BR
BG M W-04
PZ-01
BGTM W-04
PZ-02
CMW-01
PZ-03S / D
CMW-02
PZ-04
CMW-03
PZ-05
CMW-05R
PZ-06
CMW-06
PZ-08
CMW-07
Comprehensive Water
Level Sweeps
(includes wells in Semi -
Annual, Quarterly, and
Discontinued Monitoring
Lists)
CMW-08
CTM W-01
CTM W-02
CTMW-07
CTMW-08
MW-06BR
MW-09 / BR
MW-10 / D / BR / BRL
MW-11
MW-12 / BR
MW-15SU / SL / BR
MW-16S / BR
Optimized Quarterly & Semi -Annual Parameters for "Non -New Wells"
(Total and Dissolved as Applicable)
Aluminum
Manganese
Alkalinity (CO3/HCO3)
-----------------------------------------
Calcium
-----------------------------------------
Antimony
----------- ----------------------
---------------------------------
Molybdenum
---------------------------------
Arsenic
Nickel
Chloride
---------------------------------
Barium
---------------------------------
---------------------------------
Selenium
---------------------------------
-----------------------------------------
Dissolved Oxygen (DO)
-----------------------------------------
Beryllium
---------------------------------
Strontium
---------------------------------
Redox Potential (Eh)
-----------------------------------------
Boron
---------------------------------
Sulfate
---------------------------------
Magnesium
-----------------------------------------
Chromium(total)
Thallium
Nitrate + Nitrite
---------------------------------
Chromium (hexavalent)
---------------------------------
---------------------------------
Total Dissolved Solids (TDS)
---------------------------------
-----------------------------------------
Oxidation -Reduction Potential (ORP)
-----------------------------------------
Cobalt
---------------------------------
Vanadium
---------------------------------
pH
-----------------------------------------
Iron
---------------------------------
Zinc
---------------------------------
Potassium
-----------------------------------------
Lithium
Specific Conductance
-----------------------------------------
Sodium
-----------------------------------------
Total Organic Carbon (TOC)
-----------------------------------------
Temperature
----------------- -----------------------
Turbidity
Discontinue Sampling
Wells/Water Level Only (9)
ABMW-5
MW-13
MW-18S
MW-19S
MW-20S / BR
MW-5BRR
PZ-07
PZ-09
PZ-10
To Be Replaced
No well replacements planned
at this time
To be Abandoned
No well replacements planned
at this time
Notes:
IMP = Interim Monitoring Plan
CSA = Comprehensive Site Assessment
Cols = Constituents of Interest
CAMA = Coal Ash Management Act
NCDEQ = North Carolina Department of Envrionmental Quality
tSemi-Annual monitoring events are scheduled to be performed concurrently with two Quarterly monitoring events per year and will include the wells listed under Quarterly for
respective events.
*New wells installed as part of the CAMA program will be monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th
Quarter 2018 IMP and additional constituents analyzed voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells will
be re-evaluated with NCDEQ and may be reduced and/or optimized. Replacement wells will not be considered "new wells" and will follow the respective monitoring protocol for
the well in which they replace; however, additional parameters may be included voluntarily.

Table 2.6 - Cliffside
Cliffside Steam Station - IMP Optimization
Summary of Wells, Frequency, & Parameters
(to begin Q1 2019)
Comprehensive Water Level Sweep to occur Semi -Annually
Modification - March 2019
Wells for Quarterly Monitoring (106)
AB -IS / D / BROR
AB-2S/ D / BRO
GWA-64BRL*
GWA-65BR* / BRL*
AB-3S1 / SL1 / MA15* / I / BRUA / BR / BRA
GWA-66BRL*
AB-4S1 / SL1 / UA15* / LA15* / D / BR
GWA-67BR* / BRL*
AS-4S
AS-7S1 / 1* / BRL
AS-8S / D
GWA-68BRL*
IB-6S* / D*
IB-7S* / D*
BG-1BRA
MW-11S1 / DA / BRO / BRL*
CCR-8BR*
MW-20D / DR
CCR-12BR*
MW-30DA1
CCR-17BR*
U5-1S
CCR-IB-3BR*
U5-2S-SLA1
CCR-U5-4BR*
U5-6S
CLMW-2
AB-7S2 / D2 / BR
CLMW-3S1 / D1
AB-8S2 / D2 / BR
GWA-11BR* / BRL*
AB-9S2 / D2 / BR
GWA-20S1 / D1 / BR
AS-8BR2
GWA-21S1 / BRU1 / BR' / BRL*
AS-9S2 / D2
GWA-22S1 / BRU
GWA-57S2 / D2 / BR
GWA-34BR*
GWA-58S2 / D2 / BR
GWA-38S
GWA-59S2 / D2 / BR
GWA-39S*
GWA-60S2/ D2 / BR
GWA-40S*
GWA-61S2 / D2 / BR
GWA-47D
GWA-62S2 / D2 / BR
GWA-54S / D / BRO
GWA-63S2 / D2
Wells for Semi -Annual Monitoringt (147)
AB-5S1/ BRU / BR
GWA-31D / BRA
AB-6S1 / D / BR
GWA-33S / D / BR
AS-1SB / D
GWA-34S
AS-2S1 / D1 / BR
GWA-35S / D
AS-3BRU
AS-41D
AS-5S / BRU / BR
GWA-36S1 / D1
GWA-37S / D
GWA-38D
AS-6S / D / BRA
GWA-42S*
AS-713 / BRA
GWA-43S / D
BG-1S1 / D1
GWA-44S / D / BR
CCPMW-IS' / D1
GWA-45D
CCR-7S / D
GWA-46D
CCR-81)
GWA-48BR
CCR-12S / D
GWA-51D
CCR-13D
GWA-56S / D
CCR-15D
MW-213A
CCR-IB-1S / D
MW-8S1 / D
CCR-IB-3S / D
MW-10S / D
CCR-U5-3S / D
M W-21D / BR
CCR-U5-4S / D
MW-22BR / DR
CLMW-11
MW-23S / D / DR
CLMW-5S
MW-24D1 / DR1
CLMW-6
MW-25DR
CLP-1***
MW-30S1 / D1
CLP-2***
MW-32S1 / D1 / BR
GWA-1BRU
MW-34S / BRU
GWA-2S1 / BRU'/ BR1
MW-36S / BRU
GWA-31)1
MW-38S1 / D1 / BR1
GWA-4S1 / D1
MW-40S / BRU
GWA-5S / BRU
MW-42S / DA
GWA-10S / D
U5-113
GWA-11S1 / BRU1
U5-21)1 / BR
GWA-12S / BRU
GWA-13BR
U5-4S / D / BRA
U5-5D1 / BR
GWA-14S / D / BR
U5-61)
GWA-23D
U5-8S / D / BR
GWA-24S / D / BR
Comprehensive Water
Level Sweeps
(includes wells in Semi -
Annual, Quarterly, and
Discontinued Monitoring
Lists)
GWA-25S
GWA-26S
GWA-27DA1 / BR1
GWA-28S /BRU / BR
GWA-29D1 / BRA
GWA-30S / BR
Optimized Quarterly & Semi -Annual Parameters for "Non -New Wells"
2018 CSA Update COls
Additional Water Quality Parameters
(Total & Dissolved Where Applicable)
(Total & Dissolved Where Applicable)
Arsenic
Aluminum
---------------------------------------------------------------------------------------------------------
Boron
-------------------------------------------------------------------------------------
Alkalinity--------(CO3/HCO3)
------------------------------------------------- --------------------------------------------------------
Chromium (total)
-----------------------------------------------------------------------------
Barium
---------------------------------------------------------------------------------------------------------
Hexavalent----------------Chromium---------
-------------------------------------------------------------------------------------
Beryllium
--------------------------------------------------------------------------------
Cobalt
------------------------------------------------------------------------------------
-
Calcium
---------------------------------------------------------------------------------------------------------
Iron
-------------------------------------------------------------------------------------
Chloride
---------------------------------------------------------------------------------------------------------
Manganese
-------------------------------------------------------------------------------------
Oxygen (DO)
---------------------------------------------------------------------------------------------------------
Radium (226+228)1
-------------------------------Dissolved
------------------------------------------------------
Fluoride
---------------------------------------------------------------------------------------------------------
Strontium
-------------------------------------------------------------------------------------
Lithium
--------------------------------- ---------------------------------------------------------------------------------------------------------------
Sulfate
---------------------------------------------------------------------------------------------------------
-----------------------------------------------
Magnesium
-------------------------------------------------------------------------------------
Thallium
Nitrate + Nitrite
---------------------------------------------------------------------------------------------------------
Total Dissolved Solids (TDS)
---------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------
Oxidation -Reduction Potential (ORP)
-------------------------------------------------------------------------------------
Uranium (233+234+236+238)
---------------------------------------------------------------------------------------------------------
pH
-------------------------------------------------------------------------------------
Vanadium
Potassium
-------------------------------------------------------------------------------------
Redox Potential (Eh)
-------------------------------------------------------------------------------------
Selenium
------------------------------------------------------------------------------------
Specific Conductance
------------------------------------------------------------------------------------
Sodium
------------------------------------------------------------------------------------
Phosphorus
------------------------------------------------------------------------------------
Total Organic Carbon (TOC)
---------------------------------Temperature ---------------------------------
-------------------------------------Tu
rbid ity------------------------------------
Discontinue Sampling Wells/Water
Level Only (22)
BG-2D
CCPMW-2S / D
CCPMW-3S / D
CCPMW-4
CCPMW-5
CCPMW-6S / D
CCPTW-IS / D
CCPTW-2
CCR-6S / D
GWA-6S / D
GWA-25D
GWA-26D
GWA-30BRU
GWA-32D / BR
GWA-45S
To Be Replaced
AS-7BRA
GWA-2BR
U5-2S-SLA
rNotes:
IMP = Interim Monitoring Plan
CSA = Comprehensive Site Assessment
COls = Constituents of Interest
CAMA = Coal Ash Management Act
NCDEQ = North Carolina Department of Envrionmental Quality
tSemi-Annual monitoring events are scheduled to be performed concurrently with two Quarterly monitoring events per year and will include the wells listed under Quarterly for respective events.
*New wells installed as part of the CAMA program will be monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th Quarter 2018 IMP and additional
constituents analyzed voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells will be re-evaluated with NCDEQ and may be reduced and/or
optimized. Replacement wells will not be considered "new wells" and will follow the respective monitoring protocol for the well in which they replace; however, additional parameters may be included
voluntarily.
**Wells were previously approved by DEQ to be sampled for boron and sulfate only in historic versions of the IMP due to elevated pH. Wells that exhibit elevated pH are proposed to remain a boron -and -sulfate -
only sample location; however, if the pH improves with redevelopment to fall <_8.5 at such well, the well will be sampled for the complete appropriate parameter suite for that well; i.e. "optimized non -new well"
or "new well" lists as proposed herein. No wells are currently flagged with this note but maybe in the future.
***Wells were previously approved by DEQ to be sampled for boron only in historic versions of the IMP due to these locations being installed as piezometers intended for water level only.
1Select wells to be sampled for Radium (226+228)
2Quarterly sampling includes additional assessment monitoring wells scheduled to be installed in 2019. The proposed monitoring well locations are based on additional data needs and as requested by NCDEQ.
Actual well installation locations will be determined based on field conditions.

Table 2.7 - Dan River
Wells for Quarterly
Monitoring (7)
BG-1DA
GWA-4S/D
GWA-5BR/BRD
GWA-6BR
GWA-9BR
Dan River Steam Station - IMP Optimization
Summary of Wells, Frequency, & Parameters
(to begin Q12019)
Comprehensive water level sweep to occur semi-annually
- March 2019
Wells for Semi -Annual Monitoringt (44)
BG-5S/D MW-22S/D/BR
----------------------------------------- ---------------------------
BG-10S/D/BR
-----------------------------------------T---------------------------
MW-23D/BR
MW_317BR/BRL----
--------------GWA-6S/D ---
-----------------
GWA-7S/D MW-20S/D
-----------------------------------------�---------------------------
GWA-8S/D/BR
CCR-03S/D
--------------------------,---------------------------
GWA9S/D LF-CCR04S/D -------------- --------------1-
---- _------
GWA-10D
LF-CCR-05S/D
------------------------------t---------------------------
GWA12S/
�-------------4
--------------
-------------GWA_14S/D--------------
Comprehensive Water
---------------GWA_ 15 D--------------4
Level Sweeps
GWA-16S/D I
------------------------------------------
(includes wells in Semi-
GWA-17D
------------------------------------------0
Annual, Quarterly, and
GWA-20S/D
Discontinued Monitoring
--------------- ----------
MW-12/D
Lists
------------------------------------------
MW-21S/D
Optimized Quarterly & Semi -Annual Parameters for "Non -New Wells"
(Total)
Antimony
Manganese
Aluminum
•---------------------------------
Arsenic
•---------------------------------
---------------------------------
Molybdenum
---------------------------------
-----------------------------------------
Alkalinity (CO3/HCO3)
-----------------------------------------
Beryllium
•---------------------------------
Nickel
---------------------------------
Calcium
-----------------------------------------
Boron
Selenium
Chloride
•--------------------------------
Beryllium
---------------------------------
Strontium
-----------------------------------------
Dissolved Oxygen (DO)
•---------------------------------
Chromium (total)
---------------------------------
Sulfate
-----------------------------------------
Redox Potential (Eh)
•---------------------------------
Chromium (hexavalent)
---------------------------------
Total Dissolved Solids (TDS)
-----------------------------------------
Lithium
Cobalt
Vanadium
]--Oxidation-Reduction
Magnesium
Iron
Potential (ORP)
--------------------------------------
pH
---------------------------
Phosphorus
Potassium
Specific Conductance
-------------------------------
Sodium
-------------------------------
Radium (226+228)
-------------------------------
Total Organic Carbon (TOC)
-------------------------------
Temperature
-------------------------------
Turbiditv
IMP = Interim Monitoring Plan
CSA = Comprehensive Site Assessment
COls = Constituents of Interest
CAMA = Coal Ash Management Act
NCDEQ= North Carolina Department of Envrionmental Quality
Discontinue Sampling
Wells/Water Level Only (1)
GWA-10S
To Be Replaced (1)
BG-1D (replaced)
None
Semi -Annual monitoring events are scheduled to be performed concurrently with two Quarterly monitoring events per year and will include the wells listed under Quarterly for
(respective events.
*New wells installed as part of the CAMA program will be monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th
Quarter 2018 IMP and additional constituents analyzed voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells will
be re-evaluated with NCDEQ and may be reduced and/or optimized. Replacement wells will not be considered "new wells" and will follow the respective monitoring protocol for
the well in which they replace; however, additional parameters may be included voluntarily.

Table 2.8 - H.F. Lee
Wells for Quarterly
Monitoring (12)
Active Basin
ABMW-1S
AMW-15S
BGMW-9
CMW-5
DMW-2
MW-1
MW-3
Inactive Basins
IABMW-3S
IMW-4S
IMW-6S*
IMW-7S*
DMW-3
H.F. Lee Energy Complex - IMP Optimization
Summary of Wells, Sampling Frequency, & Parameters
(to begin Q1 2019)
Comprehensive Water Level Sweep to occur Semi -Annually
Modification - March 2019
Wells for Semi -Annual Monitoringt (50)
Active Basin
Inactive Basins
ABMW-1
AMW-6RBC
IABMW-1/S
IABMW-2S
AMW-11S/BC
IABMW-3
AMW-12S/BC
IMW-1S/BC
AMW-13S/BC
IMW-2BC
AMW-14S/BC
IMW-3S/BC
AMW-15BC
IMW-4BC
AMW-16BC
IMW-5S/BC
AMW-17S/BC
SMW-3
AMW-18S
SMW-4
AMW-19S/BC
BW-1
AMW-20S/BC
CW-1
AMW-22S/BC
CW-3
AMW-23S/BC
CW-4
CCR-100S
SMW-5
CMW-6R
CTMW-1
MW-2
Comprehensive Water
Level Sweeps
(includes wells in Semi-
Annual, Quarterly, and
Discontinued Monitoring
Lists)
LOLA
LLMW-1/S
LLM W-2/S
Optimized Quarterly & Semi -Annual Parameters for "Non -New Wells"
(Total)
Antimony
-------------------------------
Selenium
----------------------------------
Alkalinity (CO3/HCO3)
Arsenic
Strontium
Aluminum
-------------------------------
Barium
----------------------------------
Sulfate
Calcium
-------------------------------
Boron
----------------------------------
Thallium
Dissolved Oxygen (DO)
-------------------------------
Chloride
----------------------------------
Total Dissolved Solids (TDS)
Hexavalent Chromium
-------------------------------
Chromium (total)
-------------------------------
----------------------------------
Vanadium
Redox Potential (Eh)
Cobalt
-------------------------------
Magnesium
Iron
Nitrate + Nitrite
-------------------------------
Lithium
-------------------------------
Oxidation -Reduction Potential (ORP)
Manganese
pH
Phosphorus
Potassium
Specific Conductance
Sodium
Temperature
Turbiditv
otes
IMP = Interim Monitoring Plan
CSA = Comprehensive Site Assessment
COIs = Constituents of Interest
CAMA = Coal Ash Management Act
Discontinue Sampling
Wells/Water Level Only (9)
Active Basin
AMW-9BC
AMW-21S/BC
BGMW-10
CMW-7
CMW-8
CMW-10
DMW-1
Inactive Basins
CW-2
To Be Replaced
No well replacements planned
at this time
To be Abandoned (2)
Wells within the footprint of the
Active Basin are slated for
abandonment in 2019.
ABMW-11S
CDEQ = North Carolina Department of Envrionmental Quality
iemi-Annual monitoring events are scheduled to be performed concurrently with two quarterly monitoring events per year and will include the wells listed under "Wells for Quarterly
lonitoring" for respective events.
New wells installed as part of the CAMA program will be monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th Quarter
018 IMP and additional constituents analyzed voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells will be re-
valuated with NCDEQ and may be reduced and/or optimized. Replacement wells will not be considered "new wells" and will follow the respective monitoring protocol for the well in
thich they replace; however, additional parameters may be included voluntarily.

Wells for Quarterly Monitoring
(62)
AB-10SL/D/BR/BRL3*
AB-12S3/D3/BR3
AB-14D/DU
AB-15SL
AB-16DU
AB-1S3/D3/BR3/BRL3/BRLL3/BRLLL3*
AB-20S
AB-21S
AB-2BR3*
AB-3S
AB-5S3/D3/DU3/BR3
AB-6S/D/BRA/BRL
AB-7DU
AB-8DU
AL-1S3/D3/BR3/BRL3*
AL-2S/D/BR/BRL/BRLL/BRLLL3*
AL-3D/BR
AL-4D/BR/BRL
CCR-9SVDA1
GWA-2 DA
GWA-10S
GWA-15S3/D3
MW-14BR3/BRL*3
MW-6S3/D3
MW-7S3/D3
MW-8S3/D3
MW-9S3/D3
Table 2.9 - Marshall
Marshall Steam Station - IMP Optimization
Summary of Wells, Frequency, & Parameters
(to begin Q1 2019)
Comprehensive Water Level Sweep to occur Semi -Annually
Modification - March 2019
Wells for Semi -Annual Monitoringt (59)
AB-12SL3
GWA-6S3/D3
AB-14S
GWA-7S/D
AB-15D/BR
GWA-8S/D
AB-20D
GWA-9BR
AB-21D
GWA-10D
AB-2S3/D3
GWA-11S3/D3/BR3
AB-3 D
GWA-12S3/D* */BR3
AB-9S/D/BR
GWA-13S/DA**
AL-3S
GWA-14S/D
BG-1S3/D3/BRA3
MW-1
BG-2S3/BR3
M W-43/D3
BG-3S3/D3/BR3
MW-7
GWA-IS3/D3/BR3
MW-12S/D
GWA-3S/D
MW-13S/D
GWA-4S/D
MW-14S3/D3
GWA-5S/D
OB-1 (Dry Ash Landfill)
Comprehensive Water Level Sweeps (includes wells in Semi -Annual, Quarterly,
and Discontinued Monitoring Lists)
Optimized Quarterly & Semi -Annual Parameters for "Non -New" Wells
2018 CSA Update COls (Total & Dissolved if Applicable)
Additional Water Quality
Parameters (Total & Dissolved if
Applicable)
Antimony
Manganese
Aluminum
Arsenic
Molybdenum
Alkalinity (CO3/HCO3)
Barium
Nickel
Calcium
Beryllium
Radium (226+228) 3
Dissolved Oxygen (DO)
Boron
Selenium
Fluoride
Cadmium
Strontium
Lithium
Chloride
Sulfate
Magnesium
Chromium (total)
Total Dissolved Solids (TDS)
Nitrate + Nitrite
Chromium (hexavalent)
Thallium
Oxidation -Reduction Potential (ORP)
Cobalt
Vanadium
pH
Iron
Potassium
Specific Conductance
Sodium
Temperature
Total Organic Carbon (TOC)
Turbidity
Notes:
IMP = - Interim - Monitoring- -
Plan
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
CSA = Comprehensive Site Assessment
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
COIs = Constituents of Interest
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
CAMA = Coal Ash Management Act
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
NCDEQ = North Carolina Department of Envrionmental Quality
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
tSemi-Annual monitoring events are scheduled to be performed concurrently with two Quarterly monitoring events per year and will include the wells listed under Quarterly for
respective events.
*New wells installed as part of the CAMA program will be monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th Quarter
2018 IMP and additional constituents analyzed voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells will be re-
evaluated with NCDEQ and may be reduced and/or optimized. Replacement wells will not be considered "new wells" and will follow the respective monitoring protocol for the well in
which they replace; however, additional parameters may be included voluntarily.
** Denotes well was previously approved by DEQ to be sampled for boron and sulfate only in historic versions of the IMP due to elevated pH. Respective well is
proposed to remain a boron -and -sulfate -only sample location; however, if the pH improves with redevelopment to fall <_8.5 at such well, the well will be sampled for the
complete appropriate parameter suite for that well; i.e. "optimized non -new well" or "new well" lists as proposed herein.
1 Indicates CCR network well added to IMP per Brandy Costner request (conference call 9/5/18)
2 Well currently included on IMP list that is proposed to be removed from IMP (CAMA) sampling; will continue to be sampled under applicable landfill permit
requirements.
3Total radium to be analyzed at select locations in accordance with Q4 2018 IMP
Discontinue Sampling Wells/Water
Level Only (27)
AB-10S
AB-11S/D
AB-13S/D
AB-16S/D
AB-4S/SL/D
AB-7S/D
AB-8S/D
GWA-2S
MS-82
MS-102
MS-112
MS-132
MW-10S/D
MW-11S/D
M W-22
M W-32
M W-52
OB-1 (Ash Basin)
Recently Abandoned (5)
AB-17S/D
AB-18S/D/DU
To Be Replaced (2)
AB-17S/D

Wells for Quarterly
Monitoring (5)
ABMW-4X1
CW-21
MW-16S / D1 / BR'
Table 2.10 - Mayo
Mayo Steam Electric Plant - IMP Optimization
Summary of Wells, Frequency, & Parameters
(to begin Q1 2019)
Modification - March 2019
Wells for Semi -Annual Monitoringt (29)
ABMW-11
MW-3BR
ABMW-2 / BR / BRL
MW-SBR
ABMW-3 / S
MW-9BRL
ABMW-4D / BR
MW-12S1 / D1
BG-11
MW-13BR
BG-21
MW-18D / BR
CW-1 / D
MW-19D / BR
CW-2D1
CW-3
Comprehensive Water
Level Sweeps
CW-4
CW-5
(includes wells in Semi -
Annual, Quarterly, and
CW-61
Discontinued Monitoring
Lists)
M W-2
M W-31
Optimized Quarterly & Semi -Annual Parameters for "Non -New Wells"
Additional Water Quality
2017 CSA Update COls
(Total & Dissolved Where Applicable)
Parameters (Total & Dissolved
Where Applicable)
Arsenic
-----------------------------------
Manganese
----------------------------------
Alkalinity (CO3/HCO3)
---------------------------------------
Bariu
Molybdenum
Calcium
----------------------m -------------
Boron
----------------------------------
Radium (226+228)
---------------------------------------
Chloride
-----------------------------------
Chromium (total)
-----------------------------------
----------------------------------
Strontium
----------------------------------
---------------------------------------
Magnesium
---------------------------------------
Chromium(hexavalent)
Sulfate
Nitrate + Nitrite
------------------------------- ------------------
Cobalt
-----------------------------------
---------------------
Total Dissolved Solids (TDS)
----------------------------------
---------------------------------------
pH
---------------------------------------
Iron
-----------------------------------
Uranium (233+234+236+238)
----------------------------------
Potassium
---------------------------------------
Vanadium
____ _ Sodium ____
Total Organic Carbon (TOC)
otes
MP = Interim Monitoring Plan
k = Comprehensive Site Assessment
Is = Constituents of Interest
11CAMA = Coal Ash Management Act
CDEQ = North Carolina Department of Envrionmental Quality
Discontinue Sampling
Wells/Water Level Only (4)
M W -4
MW-8BR
MW-10BR
MW-14BR
To Be Replaced
No well replacements planned
at this time
To be Abandoned (1)
ABMW-4
nual monitoring events are scheduled to be performed concurrently with two Quarterly monitoring events per year and will include the wells listed under Quarterly
r respective events.
New wells installed as part of the CAMA program will be monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th
.uarter 2018 IMP and additional constituents analyzed voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells
,ill be re-evaluated with NCDEQ and may be reduced and/or optimized. Replacement wells will not be considered "new wells" and will follow the respective monitoring
rotocol for the well in which they replace; however, additional parameters may be included voluntarily.
Select wells to be sampled for radium 226 and 228. These select wells are to be monitored for total radium. If concentrations are greater than the Federal MCL, sample
uarterly. If concentrations are less than the Federal MCL, reduce total radium sampling to semi-annually and reevaluate historical exceedances as possibly anomalous. If
etermined to be anomalous, discontinue sampling for total radium. Background wells BG-1 and BG-2 will also be included in semiannual sampling of total radium for ongoing
arative pu

Table 2.11 - Riverbend
Wells for Quarterly
Monitoring (23)
CPA-1S*/D*
CPA-2S*/D*
CPA-3S*/D*
CPA-4S*
CPA-5S*/D*
CPA-6S*
CPA-7S*/D*
GWA-11S/D
GWA-12S/D
GWA-20S
GWA-2BRU
GWA-3SA/D/BR
GWA-9D
MW-6D
Riverbend Steam Station - IMP Optimization
Summary of Wells, Frequency, & Parameters
(to begin Q1 2019)
Comprehensive Water level Sweep to Occur Semi -Annually
Modification - February 2019
Wells for Semi -Annual Monitoringt (68)
A13-8S/D
MW-1S/D
BG-1S/DA
MW-2SA/D
BG-4S/D
MW-3S/D
BG-5D/BR
MW-4S/D
GWA-1S/BRU
MW-5S/D
GWA-2S/BR
MW-6S
GWA-4S/D/BR
MW-7SR/D/BRA
GWA-5S/D
MW-8S/I/D
GWA-6S/D
M W-9/9DA/9BRA
GWA-7S/D/BR
MW-10
GWA-8S/D
MW-11SR/DR
GWA-9S/BR
MW-13
GWA-10S/BRU
MW-14
GWA-13S1
MW-15/15DA/15BR
GWA-14S/D
OB-1(water level only)
GWA-15S/D
OB-2 (water level only)
GWA-20DA/BR
Comprehensive Water
Level Sweeps
(includes wells in Semi -
Annual, Quarterly, and
Discontinued Monitoring
Lists)
GWA-22S/D/BRA
Optimized Quarterly & Semi -Annual Parameters for "Non -New Wells"
(Total)
Antimony
Iron
Aluminum
Arsenic
Manganese
Alkalinity (CO3/HCO3)
Beryllium
Strontium
Calcium
Boron
Sulfate
Dissolved Oxygen (DO)
Chromium (total)
Total Dissolved Solids (TDS)
Redox Potential (Eh)
Chromium (hexavalent)
Vanadium
Lithium
Cobalt
Magnesium
Molybdenum
Nickel
Nitrate + Nitrite
Oxidation -Reduction Potential (ORP)
pH
Phosphorus
Potassium
Sodium
Specific Conductance
Temperature
Thallium
Turbidity
Not
IIMP = Interim Monitoring Plan
, = Comprehensive Site Assessment
s = Constituents of Interest
CIA = Coal Ash Management Act
INCDEQ = North Carolina Department of Environmental Quality
Discontinue Sampling
Wells/Water Level Only (10)
BG-2S/D/BR
BG-3S/D
BG-4BR
GWA-13D
GWA-21S/D/BR
To Be Replaced (4)
GWA-9BRA
GWA-20BRA
GWA-22SA
MW-4SA
7 7GWA-23ST/DA/7
B
ItSemi-Annual monitoring events are scheduled to be performed concurrently with two Quarterly monitoring events per year and will include the wells listed under Quarterly for
respective events.
*New wells installed as part of the CAMA program will be monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th Quarter
2018 IMP and additional constituents analyzed voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells will be re-
evaluated with NCDEQ and may be reduced and/or optimized. Replacement wells will not be considered "new wells" and will follow the respective monitoring protocol for the well in
which they replace; however, additional parameters may be included voluntarily.
1 GWA-13S will be temporarily sampled until replacement well GWA-22SA is installed. After GWA-22SA is installed:
1. Sampling of GWA-13S will be discontinued
2. Semi-annual water level measurements of GWA-13S will continue
3. Semi-annual sampling and water level measurements of GWA-22SA will begin

Table 2.12 - Roxboro
Wells for Quarterly Monitoring* (5)
CCR-113BR
CCR-113D
HWMW-1BR
GMW-08R
MW-21BRLR
Roxboro Steam Electric Plant - IMP Optimization
Summary of Wells, Frequency, & Parameters
(to begin Q1 2019)
Modification - March 2019
Wells for Semi -Annual Monitoringt (73)
ABMW-01 (+)
GPMW-1BR
MW-17BR(+)
ABMW-01BR (+)
GPMW-ID
MW-18BR (+)
ABMW-02 (+)
GPMW-1S
MW-18D (+)
ABMW-02BR (+)
GPMW-2BR
MW-19BRL (+)
ABMW-03
GPMW-2D
MW-20BRL
ABMW-03BR
GPMW-3BR
MW-22BR
ABMW-03BRL
GPMW-3D
MW-22D
ABMW-05D (+)
MW-01BR
MW-23BRR
ABMW-06
MW-02 (+)
MW-24BR
ABMW-06BR
MW-02BR
MW-26BR
ABMW-07BR
MW-03BR (+)
MW-27BR
ABMW-07BRL
MW-04BR
MW-28BR
BG-01 (+)
MW-05BR (+)
MW-29BR
BG-01BR (+)
MW-05D (+)
MW-30BR
BG-01BRLR (+)
MW-06BR (+)
MW-31BR
BG-2BR (+)
MW-06D (+)
MW-32BR
CW-01
CW-02 (+)
MW-07BR
MW-08BR
MW-33BR**
Comprehensive Water
Level Sweeps
(includes wells in
Semi -Annual,
Quarterly, and
Discontinued
Monitoring Lists)
CW-02D (+)
MW-09BR (+)
CW-03
MW-10BR (+)
CW-03D
MW-11BR (+)
CW-04
MW-11D (+)
CW-05 (+)
MW-12BR
GMW-06
MW-13BR (+)
GMW-07
MW-14BR (+)
GMW-09
MW-15BR (+)
GMW-10
MW-15D (+)
GMW-11
MW-16BR (+)
Optimized Quarterly & Semi -Annual Parameters for "Non -New Wells"
2017 CSA Update COls
Additional Water Quality Parameters (Total & Dissolved
(Total & Dissolved Where Applicable)
Where Applicable)
Antimony
Sulfate
Aluminum
Boron
Total Dissolved Solids (TDS)
Alkalinity (CO3/HCO3)
Chromium (hexavalent)
Uranium (233+234+236+238)
Arsenic
Chromium (total)
Vanadium
Calcium
Cobalt
Chloride
------------- --------------------
Iron
-----------------------------------------
•--------------------------------------------------------------------------------
Dissolved Oxygen (DO)
Manganese
Redox Potential (Eh)
Molybdenum
Lithium
Selenium
---------------------------------
-----------------------------------------
Magnesium
•--------------------------------------------------------------------------------
Strontium
Nitrate + Nitrite
----------------------- ----------------------------------------------------------
Oxidation-Reduction Potential (ORP)
----------- ------
pH
-------------------------------------------
7-------------------------------------
Potassium
•--------------------------------------------------------------------------------
Radium (226+228) (+)
---------------------------- ----------------------
Specific Conductance
•--------------------------------------------------------------------------------
Sodium
- - - - - - - - - - - - - - - - - - - - - - - - - -
Total Organic Carbon (TOC)
Temperature
Turbidity
Discontinue Sampling
Wells/Water Level Only (2)
ABMW-05
MW-25BR
To Be Replaced
No well replacements planned at
this time
To be
No wells are schedu7tobeabandoned at thi
Notes:
IMP = Interim Monitoring Plan
CSA = Comprehensive Site Assessment
COls = Constituents of Interest
CAMA = Coal Ash Management Act
NCDEQ= North Carolina Department of Environmental Quality
tSemi-Annual monitoring events are scheduled to be performed concurrently with two Quarterly monitoring events per year and will include the wells listed under Quarterly
for respective events.
*New wells installed as part of the CAMA program will be monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th
Quarter 2018 IMP and additional constituents analyzed voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells
will be re-evaluated with NCDEQ and may be reduced and/or optimized. Replacement wells will not be considered "new wells" and will follow the respective monitoring
protocol for the well in which they replace; however, additional parameters may be included voluntarily.
** Denotes well was previously approved by DEQ to be sampled for boron and sulfate only in historic versions of the IMP due to elevated pH. Respective well is proposed to
remain a boron -and -sulfate -only sample location; however, if the pH improves with redevelopment to fall <_8.5 at such well, the well will be sampled for the complete
appropriate parameter suite for that well; i.e. "optimized non -new well" or "new well" lists as proposed herein.
(+) -Select wells to be sampled for total radium (226 + 228).

Table 2.13 - Sutton
L.V. Sutton Energy Complex - IMP Optimization
Summary of Wells, Frequency, & Parameters
(to begin Q1 2019)
Comprehensive Water Level Sweep to occur Semi -Annually
Modification - March 2019
Wells for Quarterly Monitoring (38)
Wells for Semi -Annual Monitoringt (48)
MW-12R
MW-45B*
AW-03C
MW-40C
M W-33C
M W-45C*
AW-04C
SMW-04C
SMW-01C
MW-46B*
AW-05C
SMW-05C
SMW-02C
MW-46C*
AW-08C
SMW-06C
SMW-03C
MW-47B*
AW-09C
MW-05C
MW-08B
MW-47C*
MW-07C
MW-05CD
MW-08D
MW-41B
MW-41C
MW-48B*
MW-48C*
MW-49B*
MW-16D
MW-05D
MW-05R-E
MW-08
MW-20
MW-20D
MW-41D
MW-49C*
MW-21C
MW-08E
FPA-1B*
MW-50B*
MW-22C
MW-37B
FPA-1C*
MW-50C*
MW-23B
MW-37C
FPA-2B*
MW-23C MW-37CD
MW-23D MW-37D
MW-23E MW-37E
MW-24RB MW-41E
MW-24RC ABMW-02D
MW-27B ABMW-02S
MW-27C MW-16
MW-28C MW-36B
MW-31R-C SMW-01B
MW-36C SMW-05B
MW-38C SMW-06B
MW-39C MW-05B
Comprehensive Site Semiannual water level sweep (includes wells in
Semi -Annual, Quarterly, and Discontinued Monitoring Lists)
FPA-2C*
FPA-3B*
FPA-3C*
FPA-4B*
FPA-4C*
MW-13R*
MW-13R-D*
MW-15R*
MW-15R-D*
MW-43B*
MW-43C*
MW-44B*
M W-44C*
Optimized Quarterly & Semi -Annual Parameters for "Non -New" Wells
(Total)
Arsenic
Strontium
Alkalinity (CO3/HCO3)
Boron
Sulfate
Aluminum
Chloride
TDS (Total Dissolved Solids)
Barium
Chromium (hexavalent)
Vanadium
Calcium
Cobalt
Dissolved Oxygen (DO)
Iron
----------------------------------------
-------------------------------------------
Lithium
--------------------------------------------------------
Manganese
Magnesium
Molybdenum
Nitrate + Nitrite
pH
Oxidation -Reduction Potential (ORP)
Selenium
Potassium
Redox Potential (Eh)
•--------------------------------------------------------
Sodium
•--------------------------------------------------------
Specific Conductance
--------------------------------------------------------
Temperature
•--------------------------------------------------------
Total Organic Carbon (TOC)
•-----------------------Fluoride ----------------------
------------------------ -------------------------------
Turbidity
Discontinue Sampling Wells/Water
Level Only
(20)
AW-01C
AW-02C
AW-02 D
AW-05 D
AW-06R-D
AW-06R-E
AW-07R-D
AW-09 D
MW-11
MW-19
MW-22B
MW-28B
MW-32C
MW-38B
MW-38D
MW-39B
MW-39D
M W-40 B
MW-40D
SMW-06D
To Be Replaced
No well replacements planned at this
time
Abandoned/To be Abandoned
No wells are scheduled to be
abandoned at this time.
IMP = Interim Monitoring Plan
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
CSA = Comprehensive Site Assessment
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
COIs = Constituents of Interest
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
CAMA = Coal Ash Management Act
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
NCDEQ = North Carolina Department of Envrionmental Quality
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
tSemi-Annual monitoring events are scheduled to be performed concurrently with two Quarterly monitoring events per year and will include the wells listed under Quarterly for respective events.
Twi-w ---wells------installed----------as---part------of----the-------CAMA------------program wi-----ll--be----monitored----------------------quarterly.-------Samples----------from---these----------lls---will-----be------------analyzed---for---------parameters------------formerly--------
in----cluded-----as---part------of----the---4th-----Quarter-----------2018------IMP-------and ----------
*Newe
additional constituents analyzed voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells will be re-evaluated with NCDEQ and may be
reduced and/or optimized. Replacement wells will not be considered "new wells" and will follow the respective monitoring protocol for the well in which they replace; however, additional parameters
may be included voluntarily.

Wells for Quarterly Monitoring
(20)
BW-4DA*
CPA-1S*/I*
CPA-21 *
CPA-3S*/I *
CPA-4S*/I*
CPA-5S*/I *
CPA-6S*/I*
CPA-7S*/I*
CPA-8S*/I*
MW-2 (fuel oil well)*
MW-4 (fuel oil well)*
M W-5511
PW-1 (DEP #2)
Table 2.14 - Weatherspoon
Weatherspoon Power Plant - IMP Optimization
Summary of Wells, Frequency, & Parameters
(to begin Q1 2019)
Comprehensive Water Level Sweep to occur Semi -Annually
Modification - March 2019
Wells for Semi -Annual Monitoringt (26)
AW-02S
MW-33S/I/D
AW-03S/l
MW-411
BW-2S1
MW-521
BW-3S1/11
AW-04S
BW-4S1/11
AW-05S
CCR-101-BG1
AW-06S
CW-2
BW-5S
CW-31
CCR-1071
MW-11
MW-41
MW-21
MW-51
M W-31
Comprehensive Water Level Sweeps(includes wells in Semi -Annual,
Quarterly, and Discontinued Monitoring Lists)
Optimized Quarterly & Semi -Annual Parameters for "Non -New Wells"
(Total)
Aluminum
Manganese
Alkalinity (CO3/HCO3)
Arsenic
Molybdenum
Calcium
Barium
Nickel
Dissolved Oxygen (DO)
Beryllium
Radium (226 + 228)
Fluoride
Boron
Selenium
Lithium
Chloride
Strontium
Magnesium
Chromium (total)
Sulfate
Nitrate + Nitrite
Chromium (hexavalent)
Thallium
Oxidation -Reduction Potential (ORP)
Cobalt
Total Dissolved Solids (TDS)
pH
Copper
Vanadium
Potassium
Iron
Uranium (233+234+236+238)
Specific Conductance
Lead
Zinc
Sodium
Temperature
Turbidity
Redox Potential (Eh)
Discontinue Sampling Wells/Water
Level Only (14)
AW-01S/I/D
AW-02D
AW-03D
BW-01
BW-3D
BW-4D
CW-1
MW-41D
MW-531/D
M W-54D
MW-55D
To Be Replaced (2)
MW-6 (replaced by CCR-107)
MW-7 (replaced by CCR-107)
To Be Abandoned (2)
M W-6
M W-7
Notes:
IMP = Interim Monitoring Plan
CSA = Comprehensive Site Assessment
CCIs = Constituents of Interest
CAMA = Coal Ash Management Act
NCDEQ= North Carolina Department of Envrionmental Quality
1 - Wells to be sampled for radionuclides (also bolded text)
tSemi-Annual monitoring events are scheduled to be performed concurrently with two Quarterly monitoring events per year and will include the wells listed under Quarterly for respective events.
*New wells installed as part of the CAMA program will be monitored quarterly. Samples from these wells will be analyzed for parameters formerly included as part of the 4th Quarter 2018 IMP and additional constituents analyzed
voluntarily (see Table 1). After four quarterly events, the monitoring frequency and/or parameter list for the new wells will be re-evaluated with NCDEQ and may be reduced and/or optimized. Replacement wells will not be
considered "new wells" and will follow the respective monitoring protocol for the well in which they replace; however, additional parameters may be included voluntarily.

TABLE 3
Proposed Sampling Schedules & Respective CAMA Data Submittals
Duke Energy - 14 North Carolina Facilities
(to begin Q1 2019)
Facility Name
a
L
s
N
L
L
L
£_
L
to
Q,
ate+
>
V
of
O
Z
C
Allen
C
Q
SA
D
Q
D
SA
Asheville
SA
Q
SA
D
Q
D
Belews Creek
SA
Q
SA
D
Q
D
Buck
D
Q
SA
D
Q
D
SA
Cape Fear*
D*
SA/
Q
D
SA
D
Q
Cliffside
SA
Q
D
SA
D
Q
D
Dan River
SA
D
Q
D
SA
D
Q
H.F. Lee**
SA
Q
D
SA
Q
Marshall
SA
Q
D
SA
D
Q
Mayo
Q
SA
Q
D
SA
D
Riverbend*
SA
Q
SA
Q
Roxboro**
Q
SA
Q
D
SA
D
Sutton
Q
D
SA
D
Q
D
SA
Weatherspoon
Q
D
SA
D
Q
D
SA
D
* There will be (1) Q1 Data Submittal per site per year; however, for Cape Fear and Riverbend, the Data
Submittal months for Q1 2019 are not the same as what is planned for 2020 and beyond. This effect is due to
the timing of the previous Q4 2018 sampling event. For Cape Fear, the Q1 Data Submittal will be a February
submittal in 2019 only and will shift to a January submittal in 2020. For Riverbend, the Q1 Data Submittal will
be a March submittal in 2019 only and will shift to a January submittal beginning in 2020.
**NPDES Ash Basin Sampling could cease upon receipt of NPDES Permit Modification
D = Data Submittal (End of Month)
Q = Quarterly CAMA event
SA = Semi annual CAMA event
Non-CAMA Compliance Categories
NPDES Ash Basin and Landfill Sampling
NPDES Ash Basin Sampling
Landfill Sampling

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 Quality
April 4, 2019
Subject: Response to the Optimized Interim Monitoring Plans (IMP) for 14 Duke Energy
Facilities - Modification Request Annual Reports - Modification Request
Dear Mr. Draovitch:
On March 20, 2019, the North Carolina Department of Environmental Quality Division of Water
Resources (Division) received the proposed Optimized IMP for 14 Duke Energy Facilities -
Modification Request Annual Reports - Modification Request (Modification Request). This letter
requested changes to direction provided to Duke Energy by the Division in the December 21, 2018
correspondence concerning the Optimized IMP along with proposed changes to the scope and/or
reporting schedule for Interim Action Effectiveness Reports for the Asheville, Belews Creek, and
Sutton facilities.
Modification of Interim MonitoringPlan
lans
The Division has reviewed and hereby approves Modification Request for implementation of the
Optimized IMPS apart from the following which require justification subject to approval. The
following changes were noted from the previous optimized IMPs approved by the Division on
December 21, 2018.
• Asheville
O Wells EXT-D and MW-8BR were moved from quarterly sampling to water
level only. Please provide justification for this change.
• Belews Creek
O Wells AB-1BRD, AB-2BR, AB-2BRD, and AB-3BRD were removed from
quarterly sampling. Please provide justification for this change.
North Carolina Department of Environmental Quality I Division of Water Resources
QE J 512 North Salisbury Street 1 1636 Mail Service Center I Raleigh, North Carolina 27699-1636
919.707.9000

• Roxboro
o Wells ABMW-7BRLL, MW-01BRL, MW-108BRL, MW-205BRL, and
MW-208BRL were removed from quarterly sampling. Please provide
justification for this change.
IMP Annual Monitoring Reports
The Division has reviewed and hereby approves the Modification Request concerning the due
dates for the IMP Annual Monitoring Reports. The due dates for these reports shall be as follows:
• April 30, 2019 —Allen, Belews Creek, Cliffside, Marshall, Mayo, and Roxboro.
• July 31, 2019 — Asheville, Buck, Cape Fear, Dan River, H. F. Lee, Riverbend, Sutton,
and Weatherspoon.
Interim Action Effectiveness Reports
The Division has reviewed and hereby approves Modification Request concerning Interim Action
Effectiveness Reports. The due dates for these reports shall be as follows:
May 15, 2019 — Sutton
July 31, 2019 — Asheville and Belews Creek
Revisions to the tables in the Modification Request are expected based on the detailed review items
documented in this letter unless compelling rationale is provided to substantiate these changes to
the December 21, 2018 Optimized IMP direction. The Division may require changes to the content,
format and schedule of the IMP Annual Monitoring Reports and Interim Action Effectiveness
Reports after review of the pending submittals.
If you have any questions, please contact Steve Lanter (Central Office) at [phone].
Sincerel , l
Jon Risga a d, Chief
Animal Feeding Operations and Groundwater Section
cc: WQROS Regional Offices
WQROS Central File Copy

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
Paul Draovitch
Senior Vice President
Environmental, Health, & Safety
Duke Energy
526 South Church Street
Mail Code EC3XP
Charlotte, North Carolina 28202
NORTH CAROLINA
Environmental Quality
April 5, 2019
Subject: Final Comprehensive Site Assessment and Corrective Action Plan Approvals for
Duke Energy Coal Ash Facilities
Dear Mr. Draovitch:
The purpose of this letter is to establish submittal dates for Comprehensive Site Assessments (CSAs)
and Corrective Action Plans (CAPS) for all 14 Duke Energy Coal Ash Facilities (Facilities). The
schedule provided includes:
• Restatement of schedules for the six Facilities that were established in the North Carolina
Department of Environmental Quality (DEQ) October 8, 2018 letter.
• Clarification that the March 31, 2020 submittal date for evaluation of sources at the Facilities
that are not associated with the coal ash impoundments is for CSA Reports.
• Establishment of CSA and CAP submittal dates for the remaining eight Facilities considering
the November 5, 2018 Duke Energy proposed schedule and additional information regarding
justification for proposed submittal dates.
• List of primary sources to be included in each facility CSA or CAP.
The following is the approved schedule for the submittal of CSAs and CAPs for each facility.
Allen Steam Station
• Due December 1, 2019 — Updated CAP for impoundments and other primary and secondary
sources hydrologically connected to impoundments including the coal pile, retired ash basin
landfill, two structural fills, and two dry ash storage areas.
• Due March 31, 2020 — CSA for primary and secondary sources not associated with
impoundments including the gypsum pad.
-eo:: f Q. E� N
���
North Carolina Department of Environmental Quality
217 West Jones Street 1 1601 Mail Service Center I Raleigh. North Carolina 27699-1601
919.707.8600

Asheville Steam Electric Plant
• Due June 1, 2020 —Updated CSA for impoundments and other primary and secondary sources
including the raw coal pile.
• Due March 1, 2021 — Updated CAP for impoundments and other primary and secondary
sources.
Belews Creek Steam Station
• Due December 1, 2019 —Updated CAP for impoundments and other primary and secondary
sources hydrologically connected to impoundments including the Pine Hall Road Landfill.
• Due March 31, 2020 — CSA for primary and secondary sources not associated with
impoundments including the structural fill and coal pile.
Buck Combined Cycle Station
• Due October 1, 2020 — Updated CSA for impoundments and other primary and secondary
sources including the coal pile.
• Due July 1, 2021— Updated CAP for impoundments and other primary and secondary sources.
Cape Fear Steam Electric Plant
• Due September 1, 2020 — Updated CSA for impoundments and other primary and secondary
sources including the former coal pile storage areas.
• Due June 1, 2021— Updated CAP for impoundments and other primary and secondary sources.
James E. Rogers EnerRv Com lex
• Due December 1, 2019 — Updated CAP for impoundments and other primary and secondary
sources hydrologically connected to impoundments including the ash storage areas and newly
identified source east of Unit 6 and west of Suck Creek.
o Duke Energy has indicated that investigation of the newly identified source east of Unit
6 and west of Suck Creek may require additional well installation that would require
that the CAP due December 2019 not include this source area. In the event that this is
the case, Duke shall notify DWR, and provide a summary of up-to-date findings so an
appropriate schedule for this area can be established.
• Due March 31, 2020 — CSA for primary and secondary sources not associated with
impoundments including the raw coal piles north of Unit 6, switchyard ash disposal area, and
gypsum pile.
Dan River Combined Cycle Station
• Due July 1, 2020 — Updated CAP for impoundments and other primary and secondary sources
including the former coal yard.
H. F. Lee Energy Com lex
• Due October 1, 2020 — Updated CSA for impoundments and other primary and secondary
sources including the coal staging area/coal pile and lay of land area.
• Due July 1, 2021 — Updated CAP for impoundments and other primary and secondary sources.
Marshall Steam Station
• Due December 1, 2019 — Updated CAP for impoundments and other primary and secondary
sources hydrologically connected to impoundments including the coal pile and gypsum pile.
ceo:f RE Q�
North Carolina Department of Environmental Quality
217 West Jones Street 1 1601 Mall Service Center I Raleigh, North Carolina 27699-1601
919.707.8600

Mavo Steam Electric Plant
• Due December 1, 2019 — Updated CAP for impoundments and other primary and secondary
sources hydrologically connected to impoundments which may include the active coal storage
pile areas.
• Due March 31, 2020 — CSA for primary and secondary sources not associated with
impoundments including the gypsum pad and low volume wastewater pond.
Riverbend Steam Station
• Due May 1, 2020 —Updated CAP for impoundments and other primary and secondary sources
including the former coal yard.
Roxboro Steam Electric Plant
• Due December 1, 2019 — Updated CAP for impoundments and other primary and secondary
sources hydrologically connected to impoundments including the West Ash Basin Extension
Impoundment and associated discharge canal and the East Ash Basin Extension Impoundment
and associated discharge canal.
• Due March 31, 2020 — CSA for primary and secondary sources not associated with
impoundments including the coal storage pile.
L. V. Sutton Ener;;y Complex
• Due May 1, 2020 — Updated CAP for impoundments and other primary and secondary sources
including the former ash disposal area, former process area, and former coal stockpile area.
W. H. Weatherspoon Power Plant
• Due June 1, 2020 — Updated CSA for impoundments and other primary and secondary sources
including the coal storage area and cooling pond.
• Due March 1, 2021 — Updated CAP for impoundments and other primary and secondary
sources.
Any required assessment of source areas not permitted by the Division of Water Resources and not
hydrologically associated with the CCR impoundments (such as a solid waste landfill) will be at the
discretion of the permitting division/section of DEQ. If you have any questions, please contact me at
[phone].
Sincerely,
Sheila Holman
Assistant Secretary for Environment
Cc: Bill Lane
Ed Mussler, DWM
Jon Risgaard, DWR
George Eller, DEMLR
WQROS Regional Office Supervisors
DEQ Central File Copy
PO V_.;
North Carolina Department of Environmental Quality
217 West Jones Street 1 1601 Mail Service Center I Raleigh, North Carolina 27699-1601
919.7078600

ROY COOPER
Governor
HCHAEL S. REGAN
Secretory
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
Envkmmental Qual ty
September 10, 2019
Subject: Duke Energy Interpretation of Corrective Action Plan Content Guidance (January 23,
2019) — North Carolina Department Environmental Quality Response and Conditional
Approval
Dear Mr. Draovitch:
On January 23, 2019, the North Carolina Department of Environmental Quality's (DEQ) Division of Water
Resources (DWR) received the Duke Energy Interpretation of Corrective Action Plan (CAP) Content
Guidance Provided by the DEQ. That document describes Duke Energy's proposed approach for preparing
the groundwater CAPS within the structure of the DWR's guidance titled "CAP Content for Duke Energy
Coal Ash Facilities" dated April 27, 2018. DWR has reviewed the proposed approach regarding CAP
development and conditionally approves its implementation with the following considerations and
conditions: In addition, DWR has provided the attached comments on Duke Energy's Supporting Rationale
for the Proposed Interpretations and Adjustments to the CAP Content Guidance that was produced with
respect to the April 27, 2018 letter (Attachment 2).
• Section 1.C.b. — Keep text that references the Notice of Regulatory Requirements (NORR).
Information related to the NORR needed to address DEQ Comprehensive Site Assessment (CSA)
Update comments shall be provided in the body of the CAPS in a comprehensive manner to
adequately evaluate site conditions and to refine remedial design to facilitate decision making
regarding corrective action.
• Section 1.D. — The proposed additional text is acceptable; however, the criteria that will be used
for evaluation and selection of remedial alternatives in the CAPS should be provided in Section 6.
• Section 1.E.b. — Duke Energy's clarification is acceptable, however, please acknowledge and
identify any other primary and secondary sources, non -coincident with the ash basins, that are on -
site and are currently or were formerly under the jurisdiction of DEQ.
• Sections 4.B. and 4.C. — A discussion of background concentrations in other similar settings is
acceptable; however, site -specific data will be the primary consideration for determination of
background threshold values (BTVs) for both soil and groundwater.
MENorth
� Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 1 1636 Mail Service Center I Raleigh, North Carolina 27699-1636
mra� /'�� 919.707.9000

• Section 4.D. — Application of United States Environmental Protection Agency Nationally
Recommended Water Quality Criteria for Aquatic Life & Human Health by the DEQ is authorized
in the context of using narrative regulations for toxic controls where no surface water quality
standard has been adopted into state regulations. This is consistent with state authority under the
Clean Water Act, as well as state administrative code with respect to corrective action. DEQ will
work with Duke Energy to determine the appropriate response to exceedances of the 15A NCAC
02B surface water quality standards where applicable.
• Section 5 — Please include a 3-dimensional figure that illustrates groundwater impacts.
• Summary of Potential Receptors/Section 6 — The process of identifying potential receptors should
acknowledge that the hydraulics and groundwater/surface water flow patterns near the ash basins
have potentially changed over the years due to mounding and other site conditions; therefore, the
area that may have been impacted by may be more extensive than the area affected by current site
operations.
• Section 6 — Constituents of interest (COIs) that are subject to corrective action shall be constituents
with concentrations greater than the 15A NCAC .02L Groundwater Standards, Interim Maximum
Allowable Concentrations, or BTVs at or beyond the point of compliance, as well as, any
constituents within the compliance boundary that are predicted to cause a violation of any standard
in adjoining classified groundwaters, as directed by 15A NCAC .02L .0107(k). This concept shall
be reflected in any revised text.
• Section 6.A. — While the overall concept for data reduction to focus CAP development is
acceptable, sufficient data must be included to justify any proposed corrective action and an
agreement must be reached between Duke Energy and the DWR Regional Offices concerning
which COIs to address for corrective action. Also, providing data or responses to CSA Update
comments only in an appendix is not acceptable.
• Section 6.A.a.vi.3. — Consideration of constituents that will be mapped in the CAPS shall be based
on a review of site factors that affect flow and transport, including geochemical conditions, as well
as, public concern. The specific constituents that will be mapped in the CAPs shall be determined
by consensus between Duke Energy and the DEQ Regional Offices. If constituents display a
limited or discontinuous distribution that does not lend well to conventional mapping, then a
discussion of related site conditions should be provided in a manner that could understood by the
general public.
• Section 6.A.b. — The June 2019 cut-off date for inclusion of data into a CAP is acceptable for sites
where document submittals are scheduled for December 2019. However, CAPs due at later dates
should have different data cut-off dates based on Duke Energy's internal review process.
• Section 6.A.b.ii. —All 15A NCAC .02L Groundwater Standard exceedances should be
acknowledged and discussed. An agreement must be reached between Duke Energy and the
respective DWR Regional Offices concerning which COIs to address for corrective action.
• Section 6.A.c.i-ii — Removal of this section is acceptable. Under Section 6.D.a.i.ii, also list the
maximum concentrations of the COIs within and beyond the point of compliance for each media
(soil, groundwater, sediment, etc.).

• Section 6.B.a. — The process ofidentifying identifying potential receptors should acknowledge that the
hydraulics and groundwater/surface water flow patterns near the ash basins have potentially
changed over the years due to mounding and other site conditions, and therefore the area that may
have been impacted by past site operations may be more expanded than current site operations.
• Section 6.D.a.ii. — List the maximum concentrations of the COIs within and beyond the point of
compliance for each media (soil, groundwater, sediment, etc.).
• Section 6.D.a.iii. — Keep this Section and provide a succinct summary of modeling results,
including modeled concentrations above the 2L standards at or beyond the point of compliance for
the modeled time frame.
• Section 6.E.b and 6.E.b. iv. — Provide enough information and detail for the various remedial
alternatives considered to facilitate review. A higher level of cost detail shall be provided for the
remedial alternative selected in order to provide adequate information for decision making.
Otherwise, additional documentation may be required before an alternative is approved.
• Section 10 —Where applicable, isoconcentration maps shall provide mapping of analytical results
to background or non -detect levels to depict concentration gradients related to COI distribution. In
addition, all data points must be illustrated on maps. This level of detail is needed to evaluate
remedial design and address CSA Update document comments.
• Section 11. — Final content concerning appendices should be based on an agreement between Duke
Energy and the DEQ Regional Offices and should include all supporting documentation for
remedial alternative design.
Please include this correspondence as part of the CAP Update documents. If you have any questions, please
feel free to contact Steve Lanter (Central Office) at [phone].
Sincerely,
Ji �reggson, Deputy Director
Division of Water Resources
Attachments: (1) Duke Energy Interpretation of Corrective Action Plan Content Guidance Provided by
the North Carolina Department of Environmental Quality — January 23, 2019
(2) Supporting Rationale for Proposed Interpretation and Adjustments to the Corrective
Action Plan Content Guidance (NCDEQ April 2018) by Duke Energy January 2019
cc: WQROS Regional Office Supervisors
WQROS Central File Copy

North Carolina Department of Environmental Quality's (NCDEQ's) Review Position concerning:
Attachment 2
Supporting Rationale for Proposed Interpretation and Adjustments to the
Corrective Action Plan Content Guidance (NCDEQ April 2018) by
Duke Energy January 2019
CAP Guidance
Duke Energy's
DEQ's Position regarding
Section*
Rationale for Proposed Adjustments
Duke Energy's Proposed
Adjustments
Executive Summary
• Added Executive Summary to provide a
Acceptable.
high-level summary of the Corrective Action
Plan's (CAP) conceptual site model (CSM)
and the site -specific corrective action
approach proposed based on the CSM.
1. INTRODUCTION
1.C.b.
• Deleted text referring to the Notice of
Deleting text concerning the
Regulatory Requirements (NORR). These
NORR in the section is not
NORR requirements are focused on the
acceptable and related content
Comprehensive Site Assessments (CSAs) and
must be reflected in the CAP.
are not directly relevant to the CAP.
The information in the NORR
required by rule was not
provided in a complete manner
in the CSA documents;
whereas, the information in
the letters generated by the
Regional Offices identified
what is needed. This
information was not provided
in previous submittals and shall
be included in the CAPS.
1.D
• Added text to clarify that the CAP will
The proposed additional text is
provide a general written description of how
acceptable; however, the
these items were considered during the CAP
criteria that will be used for
preparation process per 02L .0106(i). This is
evaluation and selection of
also intended to clarify that the criteria
remedial alternatives in the
provided in Section 7.D.a.iv.1-10 will be used
CAPS should be provided in
for evaluation and selection of remedial
Section 6.
alternatives in the CAPS.
July 29, 2019

Page 2 of 11
CAP Guidance
Duke Energy's
DEQ's Position regarding
Section*
Rationale for Proposed Adjustments
Duke Energy's Proposed
Adjustments
1.E.b.
• Added text to clarify that only non -coal
Acceptable. Acknowledge and
waste streams that may affect the
identify other primary and
subsurface conditions at or proximate to
secondary sources present that
coal ash basins or coincident source areas
are not under the jurisdiction
will be included to maintain focus on the
of CAMA. Provide DEQ Division
Coal Ash Management Act requirements.
oversight and Incident Number
if relevant.
2. RESPONSE TO COMPREHENSIVE SITE ASSESSMENT UPDATE COMMENTS IN SUPPORT OF CAP
DEVELOPMENT
2. and 2.13.
• The note at the top of the section clarifies
Acceptable. Revised
how responses to the NCDEQ CSA comment
interpretations of site
letters will be addressed in the CAP to
conditions that address
facilitate the NCDEQ's review. Modification
Department concerns
to the text in Section 2.13.a.&b. has been
identified in the CSA comment
revised to reflect this approach.
letters shall be provided in the
documents to support
determination of appropriate
remedial alternatives.
3. OVERVIEW OF SOURCE AREAS BEING PROPOSED FOR CORRECTIVE ACTION
Added a note that describes the role of ash
Acceptable.
basin decanting and ash basin closure plans
as source removal/control methods that are
linked to the groundwater corrective action
plan for each site. Duke Energy will add a
discussion of the source control measures
(the approved Closure Plan) and the benefits
to groundwater restoration and integration
into the corrective action program.
3.A.
• Added reference to the NCDEQ letter
Acceptable.
providing the list of sources for each site to
be addressed in CAP.
DEQ Position Duke Energy's Proposed CAP Guidance Revisions January 2019

Page 3 of 11
CAP Guidance
Duke Energy's
DEQ's Position regarding
Section*
Rationale for Proposed Adjustments
Duke Energy's Proposed
Adjustments
3.B.
• Revised text to reference NCDEQ letter
Acceptable.
providing list of sources for each site that
will be addressed in subsequent and
separate CSAs.
• Previously numbered items a, b, c are no
longer needed due to the clarification
provided by the NCDEQ's letter and were
deleted.
4. SUMMARY OF
BACKGROUND DETERMINATIONS
4.B.
• Added text to provide discussion of
Acceptable. However, site -
regional background concentrations for
specific background data
similar geologic settings as context for soil
collected proximal to the
background Threshold Values (BTVs).
subject facilities are the basis
for corrective action decisions.
4.C.
• Added text to provide discussion of
Acceptable. However, site -
regional background concentrations for
specific background data
similar geologic settings as context for
collected proximal to the
groundwater BTVs.
subject facilities are the basis
for corrective action decisions
DEQ Position Duke Energy's Proposed CAP Guidance Revisions January 2019

Page 4 of 11
CAP Guidance
Section*
Duke Energy's
Rationale for Proposed Adjustments
DEQ's Position regarding
Duke Energy's Proposed
Adjustments
4.D.
• Revised text to indicate that referenced
This proposed change is not
EPA values are recommended "criteria". EPA
acceptable since application of
Nationally Recommended Water Quality
EPA NRWQC by DEQ is
Criteria for Aquatic Life & Human Health
authorized in the context of
(EPA NRWQC) have not been universally
using narrative regulations for
adopted under 15A NCAC 02B. Sample
toxic controls where no surface
results will be compared to those criteria
water quality standard has
found in 15A NCAC 02B .0211(11) with
been adopted into state
values for EPA NRWQC provided for
regulations. This is consistent
reference.
with state authority under
Clean Water Act directives as
well as state administrative
code with respect to corrective
action.
Stream segments near samples
that exhibit exceedances or
that demonstrate impacts
attributable to coal ash should
be evaluated for potential
groundwater/ surface water
discharge and appropriate
remedial measures shall be
considered for corrective
action.
Direction concerning
evaluation of 15A NCAC 2B
standards was provided in an
email from Eric Smith to John
Toepfer on July 19, 2018. The
process for evaluating state
water quality standards,
criteria, and protective values
should be followed as
described in the website
regarding 15A NCAC 02B
surface water standards:
https://deg.nc.gov/nc-
stdstable-09222017
DEQ will work with Duke
Energy to determine the
appropriate response to
exceedances of the 15A NCAC
DEQ Position Duke Energy's Proposed CAP Guidance Revisions January 2019

Page 5 of 11
CAP Guidance
Duke Energy's
DEQ's Position regarding
Section*
Rationale for Proposed Adjustments
Duke Energy's Proposed
Adjustments
02B surface water quality
standards where applicable.
Removed Section - SUMMARY OF POTENTIAL RECEPTORS
• Removed this section and consolidated
Acceptable. Note that since the
potential receptor information into Section
hydraulics and
6.13. This will avoid presenting redundant
groundwater/surface water
information.
flow patterns near the ash
basins have changed over the
years, all areas that may have
been impacted should be
considered with respect to
potential receptors.
5. CONCEPTUAL SITE MODEL (CSM) — New Section
• Placed CSM into a more prominent
Acceptable. A figure that
position in the guidance document to
illustrates groundwater
emphasize the importance of the CSM to
impacts with a 3-dimensional
support corrective action decision -making.
perspective should be included
All elements from Section 6.A.b.i. were
as part of the revised CSM.
included along with additional items to
make the CSM more robust.
DEQ Position Duke Energy's Proposed CAP Guidance Revisions January 2019

Page 6 of 11
6. SOURCE AREA 1
6. Opening Section
• Paragraph 1 - Deleted text referring to
Overall, the proposed changes
Paragraphs
discussions with regional DWR office to
to the text are acceptable.
identify source areas. This item was resolved
However, observations
by NCDEQ letter identifying source areas.
concerning proposed changes
These sources will be considered for
to specific paragraphs include:
corrective action based on the results of the
site assessments currently in progress.
Concerning proposed text
revision in Paragraph 3, note
• Paragraph 3- Edited text to identify water
that since the hydraulics and
supply wells and surface water features
groundwater/surface water
hydraulically downgradient relevant to
flow patterns near the ash
Source Area 1 to focus only on those areas
basins have changed over the
that could potentially be affected to
years, all areas that may have
facilitate the corrective action
been impacted should be
preparation process. The CAP will provide
considered with respect to
justification for selection of water supply
potential receptors.
wells and downgradient surface water
features relevant to each source area.
Concerning proposed text
revisions in Paragraph 4, while
• Paragraph 4 - Added text to define
the definition of COI presented
constituents of Interest (COls) for corrective
is consistent with15 NCAC 02L.
action. This is consistent with 15 NCAC 02L.
0106(e)(4) corrective action
0106(e)(4) corrective action requirements to
requirements, any constituent
address constituents with concentrations
identified by the Department
greater than 2L applicable values at or
that has migrated across, or
beyond the compliance boundary. This
has potential to migrate across,
approach will focus the information
the compliance boundary shall
presented and the corrective action to the
be considered as part of any
constituents exceeding the applicable
remedial design. This concept
standard (2L/IMAC/BTV) at the relevant
shall be reflected in the CAPS.
point of compliance.
Refer to requirements related
to 2L .0107(k).
DEQ Position Duke Energy's Proposed CAP Guidance Revisions January 2019

Page 7 of 11
6.A.a
• Added text to reduce representing data
Not acceptable. This proposed
previously provided to NCDEQ with the
change is problematic since a
intent of leaving more time to focus on
complete and defensible data
corrective action analysis.
set was not provided in the
past. Sufficient data must be
included to justify any
proposed corrective action.
Duke may not rely on
previously submitted data to
justify such proposed
corrective action. Additionally,
consensus concerning which
Cols to analyze for corrective
action must be reached
between Duke Energy and the
respective Regional Offices.
The data needed to address
NCDEQ CSA Update comments
shall be provided in the body of
the CAP. In summary, the
Department does not believe
that all data have been
provided in a comprehensive
manner at this time to
adequately evaluate site
conditions and refine remedial
design to facilitate decision
making regarding corrective
action. Also, providing data or
responses to CSA Update
comments only in an appendix
is not acceptable.
6.A.a.v
• Revised text to remove the reference to
Acceptable.
the calculation of specific storage. Specific
storage is a general aquifer parameter that
represents the amount of groundwater per
unit volume of a saturated formation that is
lost or gained from storage due to the
compressibility of the mineral framework
that comprises the formation and the pore
water per unit change in head rather than
being used to evaluate COls in groundwater.
The groundwater flow and transport model
will estimate the COI concentrations over
time for the evaluation of remedial
alternatives. This approach provides a more
meaningful representation of the
performance of the remedial alternatives
DEQ Position Duke Energy's Proposed CAP Guidance Revisions January 2019

Page 8 of 11
over time compared to a calculation of
specific storage.
6.A.a.vi.1.
• Added Ash Leachate Environmental
Acceptable.
Assessment Framework (LEAF) sample data.
6.A.a.vi.3
• Added text to allow for figure preparation
The overall concept of
flexibility such as the use of exceedance
flexibility with respect to figure
ratio maps and including the surrounding
generation for the CAPs is
area.
acceptable, but the specific
constituents that will be
mapped in the documents shall
be determined by consensus
with the DEQ Regional Offices.
The Department acknowledges
that the isolated and irregular
spatial distribution exhibited by
some constituents does not
translate well to the
conventional illustration of
groundwater plumes.
Consideration of constituents
that will be mapped in the
CAPs shall be based on a
review of site factors that
affect flow and transport,
including geochemical
conditions, as well as what is
needed to explain site
conditions and risk to the
public. Duke Energy should
initiate dialogue with the DEQ
Regional Offices to facilitate
agreements concerning
constituents that will be
mapped in the CAPs.
6.A.a.vii
• Revised text to indicate "other source
Acceptable.
material", if any, will be addressed based on
the results of the additional source area
assessments currently underway.
6.A.b.
• Added text to clarify that the discussion
Acceptable. The June 2019 cut -
regarding the extent of COls will include
off date for inclusion of data
data collected through June 2019. This will
into a CAP is acceptable for
provide Duke Energy with the needed time
sites where document
to reduce site data and include it in the
submittals are scheduled for
interpretation of site conditions.
December 2019. However,
CAPs due at later dates should
DEQ Position Duke Energy's Proposed CAP Guidance Revisions January 2019

Page 9 of 11
will have different data cut-off
dates based on Duke Energy's
internal review process.
6.A.b.i.1-6.
• Removed text to the newly created
Acceptable.
Section 5 above to place greater emphasis
on the CSM.
6.A.b.ii.
• Added text that COI results presented are
This proposed change is not
to be based on consideration of geometric
acceptable since any 2L
mean concentrations and/or time vs.
Standard exceedances
concentrations relationships based on
detected at a site are relevant
historical data collected through June 2019.
and should be acknowledged
This approach will provide more appropriate
and discussed. Discussions
concentration results for corrective action
concerning specific COls that
planning by eliminating anomalous or
will be considered for
inconsistent data likely associated with
corrective action will
transient geochemical variations.
commence on March 15, 2019.
See time -frame reference with
respect to data that shall be
incorporated into the
documents in response to
proposed 6.A.b. text changes.
6.A.b.iii.1.6.
• Eliminated table of analytical results for
Acceptable.
supply wells in this section since the same
information is requested in Section B.b.ii. to
eliminate redundant information.
6.A.c.i-ii.
• Removed this section since very similar
Not acceptable. Do not
information is requested in Section 6.D.a.i-ii
remove. Keep the section and
which is more focused on corrective action
provide a list of COls for each
analysis.
area that require corrective
action.
6.A.c.i-ii.
• Added to text to clarify that
Acceptable.
isoconcentration maps will be included for
COls identified for remediation.
6.A.e.
• Changed section title from Plume
Acceptable.
Characteristics to COI Distribution in
Groundwater to reflect the fact that not all
inorganic COls behave as a "plume" and are
often isolated and/or transient due to
geochemical conditions.
DEQ Position Duke Energy's Proposed CAP Guidance Revisions January 2019

Page 10 of 11
6.a.e.i.1.
• Revised text to say 'stable' to expanding'
Acceptable.
rather than 'moving' and (or) expanding
since 'moving' is very similar
to expanding. This wording is also consistent
with NCDEQ and USEPA MNA guidance
concerning the description of plume
behavior.
6.a.e.ii.1.
• Revised text to provide a general
Acceptable. Provide content
discussion of site geochemical conditions in
that was directed in the CSA
the body of the CAP recognizing
Update document comments.
that the detailed geochemical items listed
will be included in the geochemical
modeling report which will be presented
in the appendices.
6.B.a
• Revised text to clarify that only those
Acceptable. Note that since the
surface waters that are hydraulically
hydraulics and
downgradient that could be affected by
groundwater/surface water
site -related COls will be identified on the
flow patterns near the ash
map to maintain focus on those areas that
basins have changed over the
may need to be addressed under the CAP.
years, all areas that may have
been impacted should be
considered with respect to
potential receptors.
6.B.b.
• Revised to provide clarity regarding
Acceptable.
identification of water supply wells.
6.D.a.i.1.
• Removed text regarding a 3-dimensional
Acceptable.
(3-D) map. A 3-D block diagram figure will be
included as part of the CSM.
6.D.a.iii.
• Removed this section on predictive
Not acceptable. Keep this
modeling. Duke Energy proposes to
section and provide a succinct
consolidate this section into the
summary of modeling results.
groundwater modeling report that will be
presented as an appendix to the CAP. The
groundwater modeling will be used to
inform corrective action decision -making.
DEQ Position Duke Energy's Proposed CAP Guidance Revisions January 2019

Page 11 of 11
6.E.b.
• Added text to indicate information
Acceptable. Provide enough
requested will be provided at conceptual
information and detail for the
design level.
various remedial alternatives
considered to facilitate review.
A higher level of cost detail
shall be provided for the
remedial alternative selected in
order than others considered
to provide adequate
information for decision
making. Otherwise, additional
documentation may be
required before an alternative
is approved.
6.E.b.iv.
• Added "approximate" to costs since
See comments above
information will be at conceptual level.
concerning Section 6.E.b.
10. MAPs AND FIGURES
• Added note that describes Duke Energy's
Acceptable. Isoconcentration
approach for figures to be included in the
maps shall provide mapping of
CAP with an emphasis on
analytical results to
making the CAP more manageable on a
background or non -detect
practical basis and focusing on those figures
levels to depict concentration
necessary to support our corrective action
gradients related to COI
approach.
distribution. In addition, all
data points must be illustrated
on maps. This level of detail is
needed to evaluate remedial
design and address CSA Update
document comments.
11. APPENDICES
Added a general planned list of CAP
Acceptable. Final content
appendices to clarify what will be included
should be based on a
in the CAP deliverables. The
consensus developed between
appendices may be adjusted on a site-
Duke Energy and the respective
specific basis as needed.
DEQ Regional Offices and
should include all supporting
documentation for remedial
alternative design.
*Refers to the proposed revised CAP guidance section and supporting rationale provided in
Attachment 2 of Duke Energy Interpretation of Corrective Plan Content Guidance Provided by the
North Carolina Department of Environmental Quality January 23, 2019
DEQ Position Duke Energy's Proposed CAP Guidance Revisions January 2019

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 Quality
October 24, 2019
Subject: Approach to Managing Constituents of Interests for Purposes of Corrective Action
Plans
Dear Mr. Draovitch:
On September 4, 2019 Duke Energy presented a Constituent of Interest (COI) Management Plan (Plan) to
facilitate Corrective Action Plan (CAP) development required at its coal combustion residuals (CCR)
facilities. In lieu of a document to review, the North Carolina Department of Environmental Quality (DEQ)
has reviewed the content of the presentation to develop a position regarding the subject matter. The COI
Plan as presented to date is conditionally acceptable with notable revisions described in Attachment 1.
These revisions will assist Department review and ensure a consistent approach across the CCR facilities.
DEQ staff welcome the opportunity to discuss related COI Plan issues with Duke Energy, including
attending other facility -specific presentations. If you have questions or concerns regarding the
Department's position relative to the COI Plan provided in this correspondence, please contact Steve Lanter
in the DWR Central Office at [phone] and he will coordinate with the respective Regional Offices
to initiate discussion.
Sincerely,
Jtl�son, Deputy Director
Division of Water Resources
Attachments
Attachment 1 - Approach to Managing Constituents of Interests for Purposes of Corrective Action Plans
cc: WQROS Regional Offices (electronic copy)
GWRS Central File Copy
North Carolina Department of Environmental Quality 1 Division of Water Resources
�
D_E � 512 North Salisbury Street 1 1636 Mail Service Center I Raleigh, North Carolina 27699-1636
�0-ft 919.707.9000

October 22, 2019 Attachment 1- Approach to Managing COls for Purposes of CAPS
Attachment 1
Approach to Managing Constituents of Interests for Purposes of Corrective Action Plans
On September 4, 2019, Duke Energy presented a Constituent of Interest (COI) Management Plan (Plan)
for Corrective Action Plan (CAP) development required at its coal combustion residuals (CCR) sites.
The presented Plan is conditionally acceptable with notable revisions described below. These revisions
Will assist Department review and ensure a consistent approach across coal ash facilities.
Framework as Presented by Duke on 9/04/19. As described in the 9/04/19 Duke presentation, COls
that occur above the criterion (defined as the greater of 15A NCAC 02L standards [02L], interim
maximum allowable concentrations [IMACs], or background threshold values [BTUs]) at/beyond the
compliance boundary (CB) will be identified for corrective action. Depending on their
observed/modeled occurrence and distribution and a "groundwater (GW) exceedance ratio", Duke
Energy proposes to map some COIs; other CON will, as proposed, be unmapped and only listed in a
table. The typical mobility of each COI will be described along with conditions that affect its mobility.
Attenuation mechanisms will be described for each COI along with the expected long-term stability of
those mechanisms.
Framework Response by DWR with Revisions. This COI Management Framework is a process
developed to facilitate corrective action planning. The Framework helps identify the areas and COls in
need of corrective action and the potential remedies that could be effective. Corrective actions are
being implemented in conjunction with and to support and augment basin closures. When CBs are
modified or expire, and compliance has not been achieved in an area no longer covered by a CB,
corrective actions will be required in those areas. Corrective actions may or may not need to be
"active" depending on factors evaluated in the Framework such as, for example, mobility of the CON in
question, stability of attenuation mechanism(s), remediation goals for the COls, etc. Rather than
computing a maximum mean and a GW exceedance ratio, use of a lower confidence limit (LCL)95 (95%
lower confidence limit)' is a more appropriate metric to identify and document areas in need of
corrective action. For each monitoring well, Duke Energy shall compute an LCL95 for the COI in
1 See, for example, United States Environmental Protection Agency (EPA) Unified Guidance (March 2009) and ProUCL
Technical guidance (2013), including discussion of parametric and non -parametric 95% LCLs. Note that if the well
sample dataset is shown to be trending for a given COI, an LCL95 may be computed on the trendline.
Page 1 of 4

October 22, 2019 Attachment 1- Approach to Managing COls for Purposes of CAPs
question by using data from all sample events at the wel12. If the computed LCL95 exceeds the
applicable criterion then that well -COI would be identified in the CAP as a localized area in need of
corrective action. If the localized area for the identified COI is isolated and does not represent a larger
scale plume, it may be mapped accordingly in the CAP by simply showing a large scale plan view map
with the well that contains the exceeding LCL95, along with the LCL95 value, representative pH and Eh
values, Kd, ratio of species concentrations for the C01 in question (if applicable and assuming
speciations have been measured/computed), and a dashed line containing the area in need of
corrective action. As described in the 9/4/19 presentation, a table(s) will also be provided containing
the list of CON, and their corresponding typical speciation (anion, cation, neutral), mobility under
acidic/alkaline conditions, mobility under reducing/oxidizing conditions, localized conditions that affect
mobility, propensity for sorption, ion exchange, and (or) precipitation, and expected long term stability
of the attenuation mechanisms. Influence of hyporheic zone on geochemical conditions and COI
mobility, if applicable, should also be considered/discussed, as should the influence of potential
surface water mixing on geochemical conditions and mobility during storm -induced rises in surface
water levels that can, in some cases, reverse groundwater gradients. The extent of boron above
background is to be shown on all maps as an approximate extent of hydraulic influence from the basin.
If the modeled boron plume has not yet stabilized (is continuing to move in time) then the extent of
boron above background at future year 2120 should also be shown on the maps to indicate the
predicted future extent of basin influence.
Transects referred to in the CAP shall be shown (a) in a plan view map along with the observed head
contours and corresponding flow lines, (b) in a plan view map along with modeled head contours, and
(c) in cross section with modeled head contours and velocity vectors.
Dissolved Groundwater Concentrations. Unfiltered (total) concentrations of constituents are
measured for most groundwater samples. However, for geochemical modeling purposes, dissolved
concentrations must be used in the input file of the computer code. For each CCR basin, a conceptual
2 Rather than using only data from 2018 to 2019 as presented by Duke, data from all sample events should be used. If
a technical reason exists to omit a portion of the historic dataset, an appendix may be provided that includes the well,
all values in the historic record for the COI in question, the values that should be omitted, and rationale for the
omission (e.g. early break-in issues, COI concentration -time trends, pH or turbidity issues, etc.). Future monitor wells
would also undergo LCL95 computation to identify additional areas in need of corrective action.
Page 2 of 4

October 22, 2019 Attachment 1- Approach to Managing Cols for Purposes of CAPS
geochemical model will be developed to represent current conditions and estimate how COI
concentrations may change in the future in response to changes in environmental conditions, such as
redox change due to decanting/dewatering. The results of ion speciation and mineral equilibrium
calculations from groundwater data along flowpaths from the source areas to downgradient locations
will be used to develop the geochemical conceptual site models. Dissolved concentration data for all
parameters (major/minor ions and COls) must be collected from the monitoring wells along the
flowpaths to develop these models. This will also be done for areas where anomalous geochemical
conditions occur such as the low pH area at Allen. In most cases, dissolved sampling conducted under
the Interim Monitoring Plans will be sufficient for modeling purposes.
Valence State Measurements. Several of the potential CON are redox-sensitive and occur in more
than one valence state [e.g., As (III,V), Se (-II, 0, IV, VI), Fe {II,III), Mn (II, III, IV)]. Because of the
perceived difficulty of preserving samples in the field for redox species measurement in the laboratory,
redox speciation is being calculated from the measured pH and Eh using a geochemical modeling code.
This method assumes redox equilibrium and may not always be appropriate. In situations where
anomalous groundwater concentrations of a redox-sensitive COI are present, it would be beneficial to
conduct sampling and laboratory analyses for the redox species of the COI to determine if speciation is
a factor leading to the anomalous behavior. This would require appropriate preservation of water
samples in the field for lab measurements of the specific redox species.
Additional sampling and analysis of redox species in selected wells would help to demonstrate that the
modeled speciations that have been calculated under an assumption of equilibrium conditions are
appropriately determined. The number and location of wells used for this purpose should be
appropriate to demonstrate confidence in the modeling approach, input data, and results.
COI Identification. The Plan process discussed in the meeting included a comparison of groundwater
concentrations to relevant regulatory criteria in order to select Cols based on exceedances of their
respective criteria. Consideration should also be given for those constituents that do not currently
exceed their criteria but may feasibly exceed that criteria in the future if environmental conditions
change. For example, if the arsenic criterion is 10 µg/L and the measured groundwater concentration
is 5 µg/L, then arsenic would be included in predictive geochemical modeling to determine if corrective
Page 3 of 4

October 22, 2019 Attachment 1- Approach to Managing COls for Purposes of CAPs
actions produce conditions that elevate the arsenic concentration above its criterion. For practical
purposes, constituents that are currently measured in a groundwater well beneath or downgradient of
a basin at an LCL95 concentration at or above 50% of the criterion (i.e. LCL95 >= COI criterion x 0.5)
would be included in the modeling of future conditions to estimate whether or not those future
conditions increase the groundwater level to a concentration greater than the criterion.
Conclusions and Discussion in CAPS. Findings and conclusions presented in the CAPS should pertain
to a specifically identified local area beneath and (or) downgradient of a basin. Each area identified for
corrective action, whether it be a plume, an isolated, localized area, or an anomalous area, should be
discussed individually and specifically. For consistency in the CAP, discussions and tables related to COI
management generally should refer to the LCL95 (rather than the mean or geomean) and the COI
criterion (rather than 2L, IMAC, or background). Where the CAP discusses performance or
effectiveness monitoring that will be conducted as part of corrective action implementation, an upper
confidence limit 95% (UCL95) would be the appropriate evaluation metric rather than the LCL95 (i.e.
corrective action continues until the UCL95 is below the cleanup criterion').
s See EPA (2018) Groundwater Statistics Tool — User's Guide.
Page 4 of 4

ROY COOPER
Governor
MICHAEL S. REGAN
Secretory
January 31, 2020
Paul Draovitch
Senior Vice President
Environmental, Health & Safety
Duke Energy
526 South Church Street
Mail Code EC3XP
Charlotte, North Carolina 28202
Mr. Draovitch,
NORTH CAROLINA
Environmental Quality
On December 31, 2019, Duke Energy submitted closure plans and corrective action plans
("CAPs") for the Allen, Belews Creek, Cliffside/Rogers, Marshall, Mayo and Roxboro Steam
Stations. The North Carolina Department of Environmental Quality ("DEQ") is currently
reviewing those plans pursuant to N.C. Gen. Stat. § 130A-309.214(c) and N.C. Gen. Stat. §
130A-309.211(b), respectively. The issues below related to implementation of these plans at
these sites require further consultation.
1. Implementation of CAPs: Proposals to streamline reviews and approvals necessary for
implementation of the CAPs to ensure that groundwater remediation is proceeding as
safely and expeditiously as practicable.
2. Post -closure monitoring and care: A process for determining which wells and
parameters will continue to be monitored, and the sampling frequency of such
monitoring, as part of the post -closure monitoring and care required by N.C. Gen. Stat.
§ 130A-309.214 or groundwater rules set forth in 15A NCAC 02L.
3. Completion of site assessment. Whether further site assessment is needed or whether
sufficient information is contained in the comprehensive site assessments to allow for the
preparation and implementation of the CAPs.
4. Periodic updating of groundwater modeling: A timeline for periodic updating of
groundwater modeling during the closure and post -closure process, and procedures for
determining when monitoring results indicate that such updating may be necessary.
S. Permitting: Strategies for ensuring that DEQ is able to approve necessary permits in a
timely manner to ensure that closure and corrective action are proceeding as safely and
expeditiously as practicable. For example, DEQ is considering potential mechanisms for
expediting the approval process for landfills proposed to be sited within the footprint of
North Carolina Department of Environmental Quality
217 West Jonrc Street 11601 Mail Service Center I Raleigh, North Carolina 276994601
919.707.8600

former impoundments by including the groundwater and elevation monitoring data
already available at these sites.
We understand that you would like to continue our discussion of the appropriate methodology
for determining background threshold values at these sites. We also understand that you have
information that you believe warrants setting an alternative remedial target for certain
constituents at some of these sites, including boron. DEQ is also willing to discuss these issues.
We also understand you would like to discuss whether streamlined site -specific CAPs would be
appropriate for Asheville, Buck, Cape Fear, Dan River, H.F. Lee, Riverbend, Sutton, and
Weatherspoon Steam Stations, in order to reduce the level of detail based on the removal of the
source at these sites.
Please submit any information you would like DEQ to consider in advance of any meetings.
DEQ understands that Duke Energy would like to prioritize discussion of potential streamlining
of (1) site -specific CAPS for Asheville, Buck, Cape Fear, Dan River, H.F. Lee, Riverbend,
Sutton, and Weatherspoon Steam Stations and (2) reviews and approvals necessary for
implementation of any of the CAPS.
M�.
Sheila C. Holman
Assistant Secretary for the Environment
NCDEQ
1601 Mail Service Center
Raleigh, NC 27699-1601
Phone/Fax: [phone]
deq.nc.gov
sheila.holmanoncdenngov
Y it • ",W �
North Cariollna Department vvf Environmental Quality
217 West Jones Street 1160J Mail Service Center I Raleigh, North Carolina 27690+ 01
919.707.86[()

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
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 Quality
February 26, 2020
Subject: February 14, 2020 Request for Report Submittal Extension — Approval
Dear Mr. Draovitch:
On February 14, 2020 the North Carolina Department of Environmental Quality (DEQ) Division
of Water Resources (Division) received Duke Energy's request to extend the deadline for various
upcoming Updated Comprehensive Site Assessments (CSAs) and Updated Corrective Action
Plans (CAPS). In response to your request, DEQ has revised the deadlines for submission of the
following documents, summarized in Table 1:
Table
1
Original
Original
Revised Due
Revised Data
Facility
Report
Due Date
Data Cutoff
Date
Cutoff Date
Date
CSA for primary
and secondary
Allen Steam
sources notassociated with
March 31,
Q4 2019
September 1,
Q1 2020
Station
impoundments
2020
2020
(including the
sum ad)
CSA for primary
and secondary
sources not
Belews Creek
associated with
March 31
September 1,
Steam Station
impoundments
2020
Q4 2019
2020
Q2 2020
(including the
structural fill, coal
pile, and gypsum
ad)
'i North Carolina Department of Environmental Quality 1 Division of Water Resources
512 North Salisbury Street 1 1611 Mail Service Center I Raleigh, North Carolina 27699-1611
iv�an. •_F.;c w+
n o 919.707.9000

CSA for primary
and secondary
sources not
associated with
James E. Rogers
impoundments
March 31
December 18
Energy Complex
(including the raw
2020
Q4 2019
2020
Q2 2020
(Cliffside)
coal piles north of
Unit 6, Unit 6 area,
switchyard ash
disposal areas, and
gypsumpile)
CSA for primary
and secondary
sources not
Mayo Steam
associated with
March 31
Q4 2019
December 31
Q3 2020
Electric Plant
impoundments
2020
2020
(including the
gypsum pad and
coal pile)
CSA for primary
and secondary
sources not
Roxboro
associated with
March 31,
2020
Q4 2019
March 31,
2021
Q4 2020
impoundments
(including the coal
pile)
Updated CSA for
impoundments and
Asheville*
other primary and
June 1,
Q4 2019
December 1,
secondary sources
2020
2020
Q2 2020
(including the raw
coalpile)
Updated CSA for
impoundments and
Buck*
otherprimaryand
October 1,
Q12020
February 1,
Q2 2020
secondary sources
2020
2021
(including the
former coalpile)
Updated CSA for
impoundments and
Cape Fear*
other primary and
September
Q12020
December 1,
Q2 2020
secondary sources
1, 2020
2020
(including the
former coalpile)

Updated CAP for
impoundments and
other primary and
secondary sources
Dan River
(including the
July 1,
Q12020
November 2,
Q2 2020
former coal pile,
2020
2020
former CT area
and construction
warehouse
area)
Updated CSA for
impoundments and
other primary and
October 1
December 1
H.F. Lee*
secondary sources
2020
Q2 2020
2020
Q2 2020
(including former
coal pile and lay of
land area)
Updated CAP for
impoundments and
Riverbend
other primaryand
May 1,
Q4 2019
November
Q2 2020
secondary sources
2020
2,2020
(including the
former coalpile)
Updated CAP for
impoundments and
other primary and
secondary sources
August 3,
Sutton
(including the
2020
Q4 Q4 2019
2020
Q12020
former ash disposal
area, former
process area, and
former coalpile)
UpdatedCSAfor
impoundments and
otherprimaryand
August 3,
Weatherspoon*
secondary sources
20201'
Q4 2019
2020
Q12020
(including former
coal pile and
cooliepond)
*Updated OAPs for these facilities are due six months after DEQ approval of the Updated CSA.

Please note that these revised deadlines are specifically for the documents referenced in Table 1
of this letter only. If you have any questions, please contact Steve Lanter or me at [phone].
Sincerely,
Ric Bolich, L.G., Chief, Ground Water Resources Section
Division of Water Resources
Attachment: Duke Energy February 14, 2020 letter
cc: WQROS Regional Offices
GWRS Central File Copy

(' DUKE
ENERGY
March 4, 2020
Ms. Sheila C. Holman
Assistant Secretary for the Environment
North Carolina Dept. of Environmental Quality
1601 Mail Service Center
Raleigh, NC 27699-1601
Paul Draovitch
Senior Vice President
Environmental, Health & Safety
and Operations Support
526 S. Church Street
Mail Code: EC3XP
Charlotte, NC 28202
[phone]
RE: North Carolina Department of Environmental Quality Letter dated January 31, 2020,
Issues Related to Implementation of Closure Plans and Groundwater Corrective Action
Plans (CAPS)
Duke Energy is in receipt of your letter dated January 31, 2020 which identified several issues
"which require further consultation" related to implementation of Closure Plans and
Groundwater Corrective Action Plans (CAPs), some of which Duke Energy submitted to the
North Carolina Department of Environmental Quality (NCDEQ) on December 31, 2019. Duke
Energy understands that the NCDEQ would like to work with the company to reach a common
understanding on items identified in the letter and submits the information provided below to
clarify and further that understanding. Overall, the comments provided herein are intended to
move the focus towards implementing groundwater remediation in an efficient, expeditious
manner utilizing the extensive amount of environmental data collected at each site. Duke Energy
recognizes that proactive implementation of the CAPs is in the best interest of the environment.
Below, in bold/italic font, are the items listed in the above -referenced NCDEQ letter followed by
Duke Energy's response.
I. Implementation of CAPS: Proposals to streamline reviews and approvals necessary for
implementation of the CAPs to ensure that groundwater remediation is proceeding as safely
and expeditiously as practicable.
It is the objective of both the NCDEQ and Duke Energy to implement Corrective Action Plans
(where necessary) as expeditiously as possible. As outlined in the December 2019 settlement
agreement, Duke Energy has a 2029 deadline at three sites (Belews Creek, Marshall and
Roxboro), to bring groundwater within 2L standards at the geographic limitation. At the
remaining sites that do not have a 2029 deadline, prompt commencement of remedial activities is
also a key objective.
Duke Energy appreciates NCDEQ's prompt issuance of the approval to commence pilot tests at
five sites. As outlined in that approval letter dated February 10, 2020, Duke Energy will prepare
and submit pilot test work plans for review by the Department. In addition, Duke Energy will
also conduct quarterly update meetings or calls with the Department as needed. A similarly
prompt approval for future steps in the implementation process will be necessary to keep the
projects on schedule for timely implementation.

2. Post -closure monitoring and care: A process for determining which wells and parameters will
continue to be monitored, and the sampling frequency of such monitoring, as part of the post -
closure monitoring and care required by N.C. Gen. Stat. § 130A-309.214 or groundwater rules
set forth in ISA NCAC 021.
Duke Energy's current and former coal-fired sites are likely the most extensively investigated
sites in the State, with assessment efforts exceeding those at most active and inactive hazardous
sites or Superfund sites. The amount of data collected through December 2019 is considerable
(Attachment 1). The data shows that a majority of constituent concentrations in groundwater are
stable or have decreasing trends.
Presently, all Duke Energy sites have an approved Interim Monitoring Plan (IMP) which
specifies the monitoring wells to be sampled (and frequency) along with which constituents are
to be analyzed. The recently submitted CAPs include an effectiveness monitoring program
(EMP) which is meant to bridge the gap until basin closure when the monitoring would revert to
post -closure monitoring. Separate from that, certain wells will be needed to determine how well
the groundwater extraction system (corrective action) is functioning. In many instances, these
separate monitoring systems overlap, are redundant (e.g. Sutton) and need to be optimized.
Duke Energy proposes to work with NCDEQ at the Corrective Action Plan approval stage to
optimize these separate sampling programs.
Optimization of the monitoring networks should be based on actual site data. Items to consider
include the following:
• Most existing site wells were installed for investigation purposes and, while they are appropriate
for assessment, they are not located for effective long-term monitoring purposes.
• Utilize monitoring wells appropriate for the scale of the site including all flow zone depths.
• Reduce "source area", side -gradient, and redundant background and down -gradient wells.
• Optimize the constituent list:
o Refine parameter list based on site data and COI management review process.
o Limit analysis of major ions for "charge balance" which tend not to change significantly
over time.
• Evaluate constituent and well lists periodically based on monitoring results:
o Discontinue monitoring for constituents and locations at wells that are non -detect (ND)
or consistently less than 50% COI criterion.
3. Completion of site assessment: Whether further site assessment is needed or whether
sufficient information is contained in the comprehensive site assessments to allow for the
preparation and implementation of the CAPs.
As stated above, the Duke Energy coal ash sites have a considerable amount of data for
groundwater and other media which has been collected since site assessment activities began in
2015. This data has been thoroughly evaluated that has resulted in a detailed understanding of
site conditions.
2

Furthermore, much has changed since 2015 as a few sites have completed excavation, permanent
water solutions have been implemented and approved by NCDEQ at all sites, assessment results
indicate that there are no significant impacts to receptors at any site, 2L/2B assessments show no
impacts to surface water at sites where studies have been completed, and constituent transport is
limited to areas in the immediate vicinity of the ash basins. Considering this information, it is
appropriate to shift focus from refining assessment information to corrective action planning and
execution. For future CSAs associated with additional source areas, Duke Energy proposes that
we leverage existing site data where possible, complete assessment activities in the CSA phase,
and focus CAPS on remedy identification and design. (This suggested approach is in contrast to
the process followed for previous basin CAPs where the CAPs repeated much of the information
from the CSA phase.) We believe this approach will enable a more expeditious corrective action
program.
4. Periodic updating of groundwater modeling: A timeline for periodic updating of groundwater
modeling during the closure and post -closure process, and procedures for determining when
monitoring results indicate that such updating may be necessary.
The fate & transport models and geochemical models were, and continue to be, developed by
PhD modeling experts using industry -standard methods. The models are very well calibrated to
site conditions based on the extensive groundwater and chemical data collected to date.
For the six sites (Allen, Belews Creek, Cliffside, Marshall, Mayo and Roxboro) that submitted
updated CAPs at the end of December 2019, robust groundwater models have been developed
and validated. Hundreds of modeling simulations were run to evaluate the relative effectiveness
of postulated remedial approaches. The models have served that purpose well, and those results
were included in the CAPs. Duke Energy believes the best approach at this point is to focus on
implementing the remedies proposed in the CAPs. Once remediation has been implemented and
has been operational for an appropriate time period, the models can then be refined based on
actual site conditions.
For the remaining sites, Duke Energy will be submitting updated fate & transport models within
future updated CAPs.
S. Permitting: Strategies for ensuring that DEQ can approve necessary permits in a timely
manner to ensure that closure and corrective action are proceeding as safely and expeditiously
as practicable. For example, DEQ is considering potential mechanisms for expediting the
approval process for landfills proposed to be sited within the footprint of former
impoundments by including the groundwater and elevation monitoring data already available
at these sites.
The recent settlement includes provisions for accelerated permitting by expeditious review
(Settlement Paragraph #38). Both Duke Energy and NCDEQ mutually share the objective of ash
3

basin closure and groundwater remediation as safe and expeditiously as possible. As there are
multiple NCDEQ Divisions requiring reviews and approvals of the Closure Plans and CAPs, a
"typical" permitting process may not be effective in meeting our common goals. Duke Energy
suggests that NCDEQ establish a Coal Ash Permit Coordinator reporting to the appropriate level
within the Department. The role of this Coordinator would be to expedite permit approvals
throughout the various divisions and provide regular updates to Department management on
permit applications received as well as the review status and anticipated permit issuance dates.
6. Soil and groundwater background threshold values (BTVs --appropriate methodology for
determining BTVs)
Duke Energy is in the process of updating soil BTVs at Allen, Belews Creek, Cliffside, Marshall,
Mayo and Roxboro following the same methodology as completed in June 2019 for updating
groundwater BTVs. The methodology Duke Energy followed is consistent with EPA -approved
methodologies and the NCDEQ approved document Statistical Methods for Developing
Reference Background Concentrations for Groundwater and Soil at Coal Ash Facilities, dated
May 2017 and prepared by HDR, Inc. and SynTerra Corp. However, it appears Duke Energy
and DEQ differ with regards to evaluation of data set outliers, and, in the most recent review, the
NCDEQ removed certain data points without explanation.
As an example, NCDEQ removed the radium value of 11.14 pCi/L from the Marshall
background data set without explanation. This resulted in a decrease in background
concentration from 7pCi/L (Duke calculation) to 2.88 pCi/L (NCDEQ calculation) which results
in five additional deep bedrock wells exceeding the radium BTV.
The BTV approach submitted in 2019 by Duke Energy was carefully developed based on
multiple lines of technical evidence consistent with USEPA guidance. To resolve the matter,
Duke Energy proposes a meeting with DEQ technical staff in the near future to discuss and
address the details of outstanding BTV issues.
7. Remediation Strategy for Boron (...alternative remedial target for certain constituents at some
of these sites, including boron)
As mentioned previously, there is an abundance of data that has been collected for these sites.
The data clearly shows that the majority of the constituents of interest are limited to the area
directly downgradient of the basins. Evaluation of the data indicates that there are no identifiable
impacts to receptors (drinking water, surface water, etc.) and that the most common constituent
in groundwater above the 2L standard is Boron. Consequently, Boron becomes a driver for a
significant portion of the active groundwater corrective action. A review of the 2L standard for
Boron indicates that this value may be inappropriately low for driving corrective action
(particularly at a site with no receptors and anticipated deed restrictions on future groundwater
use). Therefore, Duke Energy proposes that the NCDEQ consider the application of a more-
EI

suitable Boron remedial target (i.e. in line with EPA) when determining where active
remediation is required.
As described in detail in Attachment 2, when calculating the 2L standard for Boron, a relative
source contribution (RSC) factor of 0.1 was used. However, if a more scientifically supportable
RSC factor of 0.8 is used based on guidance from EPA (as described in Attachment 3), the 2L
standard for Boron would be 5,600 ug/1 compared to the present 2L standard of 700 ug/l.
The EPA has not established a Maximum Contaminant Level (MCL) for boron but has
established an adult drinking water lifetime health advisory of 5,000 ug/L for boron and a
regional screening level for residential tapwater at Superfund sites of 4,000 ug/l for Boron.
Apart from these two values, EPA has proposed a groundwater protection standard (GWPS) for
boron under the Federal CCR rule of 4,000 ug/11. EPA explains that this proposed standard is at
a concentration level "to which the human population could be exposed to on a daily basis
without an appreciable risk of deleterious effects over a lifetime".
Based on the EPA -generated values shown above for boron in drinking water, a remedial target
of 5,600 ug/L would be a realistic and appropriate remediation level for boron rather than 700
ug/l.
& Streamlined CAPS (...discuss whether streamlined site -specific CAPs)
Duke Energy understands that uncertainties associated with subsurface conditions in and around
the coal ash basins several years ago resulted in the CAP content guidance provided by the
NCDEQ. The six CAPS submitted to the NCDEQ on December 31, 2020 contained a combined
total of over 23,000 pages of technical information. Since the original versions of the CAP
content guidance were developed, Duke Energy has evaluated the extremely large amount of
multi -media data generated at each site and has developed a detailed understanding of site
conditions. We have confirmed that there is a consistent general Conceptual Site Model (CSM)
for sites in the Piedmont/Blue Ridge region that can be applied to all our stations in these
regions. Furthermore, Duke Energy believes the CSM combined with the extensive dataset
collected at each site now allows us to focus CSA reports and CAPs on what is important and
place emphasis on identifying the right corrective action strategy for each site and implementing
the approach in a more expeditious manner. We believe this approach is in the best interest of
the environment. Attachment 3 contains additional supporting information for adjusting the
CSA and CAP content at this time along with adjusted outlines for each. Duke Energy
recognizes that each site may have unique site -specific conditions that may cause a need to
adjust the CSA or CAP content.
For reference purposes, Duke Energy conducted a review of other non -Duke Energy NCDEQ-
approved CAPs in the state and found that on average that Duke Energy CAPs are 32 times
1 Federal Register -July 30, 2018
5

larger in page counts and 95 times larger in electronic file size compared to a similar sample size
(see Attachment 4). Even acknowledging that Duke Energy sites are generally larger sites, this
represents a significant disparity compared to other sites in the state. As stated in the paragraph
above, we respectfully request that the NCDEQ consider these adjustments of future CSA and
CAP content based on our increased understanding of site conditions and the opportunity to
accelerate corrective action implementation.
9. Geographic Limitation
Although not specifically noted in the NCDEQ letter dated January 31, 2020, the settlement
agreement dated December 31, 2019 includes paragraph #52 which specifies a `geographic
limitation' and states that active remediation will not be required in the area within 500 feet of
the waste boundary in addition to other conditions. Although this settlement is specific to the
Allen, Belews Creek, Cliffside, Marshall, Mayo and Roxboro sites, Duke Energy requests the
same conditions specified in paragraph #52 be applied to the remaining coal ash sites in North
Carolina. As the remaining eight sites are currently in the process of updating CSAs and/or
CAPs, it is imperative that Duke Energy receive timely guidance from the NCDEQ on the use of
the geographic limitation for all its coal ash facilities.
Duke Energy appreciates the opportunity to provide this information, and we welcome the
opportunity to further this discussion.
Since r ly,
G.�
P, 1 Draovitch
Senior Vice President
Environmental, Health & Safety and Operations Support
cc: Mr. Ed Sullivan — Duke Energy
Mr. Jim Wells — Duke Energy
Attachment list follows
2

Attachment 1— Summary of Coal Ash Management Assessment Activities for the Allen,
Asheville, Belews Creek, Buck, Cape Fear, Cliffside, Dan River, HF Lee, Marshall, Mayo,
Riverbend, Roxboro, Sutton, Weatherspoon Stations from 2015 through December 2019, Duke
Energy
Attachment 2 — Gradient Memorandum, "A Revised Drinking Water Standard for Boron Based
on a More Scientifically Supportable Relative Source Contribution Factor", January 23, 2020, by
A. Lewis
Attachment 3 — Updated Corrective Action Plan and Comprehensive Site Assessment Content
for Remaining Coal Ash Sites
Attachment 4 — Duke Energy CAP Documents Compared to Other NCDEQ Approved OAPs
7

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ATTACHMENT 2
Memorandum
To: Ed Sullivan, Duke Energy
From: Ari Lewis
to GRADIENT
Date: January 23, 2020
Subject: A Revised Drinking Water Standard for Boron Based on a More Scientifically Supportable
Relative Source Contribution Factor
Overview
■ The North Carolina Department of Environmental Quality (NCDEQ) has established a 2L
groundwater quality standard for boron of 700 µg/L.
■ The current 2L standard for boron includes the application of a relative source contribution (RSC)
factor of 0.1 for inorganic compounds.
■ Based on available information on sources of boron other than drinking water, an RSC of 0.8 is
more supportable.
■ An RSC of 0.8 is consistent with the United States Environmental Protection Agency's (US EPA's)
assessment of lifetime health -based standards for boron in drinking water.
■ Using a more supportable RSC of 0.8, and keeping all other assumptions consistent with NCDEQ's
Standard Operating Procedures (SOPs) for deriving 2L standards, results in a revised 2L standard
for boron of 5,600 µg/L.
Derivation of the North Carolina 2L Standard for Boron
NCDEQ has established "groundwater quality standards for the protection of the groundwaters of the state"
(NCDEQ, 2013). Specifically, the standards are developed to be protective of humans consuming
groundwater as drinking water. The procedure for developing the 2L standard for non -carcinogens is
presented in "The Division of Water quality (DWQ) Standard Operating Procedure (SOP) for Reviewing
Groundwater Standards Established Pursuant to 15A NCAC 02L.0200" (NCDEQ, 2010). The equation
used to derive the 2L standard is presented below:
µg RfD ( mg ) x 1,000 () x BW (kg) x RSC (unitless)
NC 2L standard (L) = kg — day mg
WC(d�
G:\Projects\215030_NAMAB\WorkingPiles\Boron 2L Memomndum_012319 doca
20 University Road, Cambridge, MA 02138 1617-395-5000 1 www.gradientcorp.com

ATTACHMENT 2
Where:
RfD = The reference dose is the chronic oral toxicity criterion established by US EPA's Integrated
Risk Information System (IRIS)
BW = An adult body weight of 70 kg
RSC = A relative source contribution factor of 0.1 for inorganics and 0.2 for organics
WC = An average water consumption rate of 2 liters/day
Using this equation, NCDEQ has developed a 2L standard for boron of 700 µg/L. This was derived using
the boron reference dose (RfD) from IRIS of 0.2 mg/kg-day, as well as other exposure -related inputs,
including an adult body weight of 70 kg, an average water consumption rate of 2 liters/day, and an RSC
factor of 0.1 (because boron is an inorganic constituent). The derivation of the boron -specific 2L standard
is presented below:
0.2 ( mg')x1,000 (Ug) x 70 (kg) x 0.1
NC 2L boron standard = kg —day L mg = 700 µg/L
2 (day)
Chemical -specific RSC for Boron
The RSC is an adjustment factor that accounts for the relative amount of a constituent that is allowed for
oral intake of drinking water, considering that the same chemical may be ingested from other sources (e.g.,
via the diet). US EPA explains that the RSC "is applied to the Rf) to determine the maximum amount of
the RfD'apportioned' to drinking water" (US EPA, 2000). The RSC is important because some constituents
are largely ingested through consuming food, as opposed to drinking water, and therefore the general
population is already exposed to some level of the constituent before the addition of any exposure from
drinking water.
To account for the situation where a chemical might be present from non -drinking water, NCDEQ uses an
RSC of 0.1 to derive 2L standards for inorganic compounds. What this basically means is that the health -
protective 2L standards are developed assuming that 10% of a person's exposure to the constituent will
come from drinking water and 90% will come from other sources.
The application of an RSC is not unique to the 2L standard. US EPA has developed a procedure for RSC
application in their report, "Methodology for Deriving Ambient Water Quality Criteria for the Protection
of Human Health" (US EPA, 2000). Overall, US EPA's approach applies a default RSC of 0.2 if
information on possible other exposures to the constituent is inadequate. However, there is an explicit
provision to allow for the use of a higher RSC when it can be demonstrated that drinking water would be
the primary source of exposure and non -drinking water sources would comprise only a small fraction of the
RfD (e.g., US EPA, 2008). US EPA specifically states that an RSC of 80% as a ceiling and 20% as a floor
should be used (US EPA, 2000).
According to dietary intake data from the third National Health and Nutrition Examination Survey, mean
intake of boron in US individuals 6 years and older is 1.15 mg/day (Trumbo, 2001). This is less than 10%
of the Rf) (14 mg/day for a 70 kg adult), which means that an adult could get 90% of their boron from
water and still be exposed to a safe level of boron (i.e., a level of boron below the RfD). Using the more
scientifically supportable RSC of 0.9 (90%) instead of the 0.1 (10%) default value for inorganics results in
a revised 2L standard for boron of 6,300 µg/L.
GRADIENT

ATTACHMENT 2
The revised RSC of 0.9 is based on the assumption that dietary boron is the only non -drinking water source
of boron. While the diet is expected to be the most significant source of boron exposure, the RSC could be
conservatively set to 0.8, which is consistent with US EPA guidance (see below for more details). Setting
the RSC to 0.8 would result in a 2L standard for boron of 5,600 µg/L:
0.2 ( mg ) x 1,000 (4g) x 70 (kg) x 0.8
NC 2 Lboron standard = kg — day L mg = 5,600 µg/L
2 (day)
US EPA's Lifetime Drinking Water Advisory Level for Boron
US EPA has specifically considered an appropriate RSC application when developing a drinking water
criterion for boron. In the absence of a Maximum Contaminant Level, in 2008, US EPA developed a
lifetime health advisory level for boron using an RSC of 0.8 (US EPA, 2008). Aside from the RSC, the
only difference between the lifetime health advisory level US EPA developed and the 2L standard is that
US EPA considered a pregnant woman with a weight of 67 kg instead of the generic adult body weight of
70 kg. As shown below, the lifetime health advisory developed by US EPA using the RSC of 0.8 was
5,400 µg/L (rounded).
US EPA Lifetime Helath Advisory=
0.2 ( mg ) x 1,000 (Ug) x 67 (kg) x 0.8
kg —day mg = 5,400 µg/L
2 (L
day)
In applying the RSC of 0.8 to the derivation of the lifetime health advisory level, US EPA (2008, p. 34)
provided the following justification:
The relative source contribution is determined using the Exposure Decision Tree approach
described in the Methodology for Deriving Ambient Water Quality Criteria for the
Protection of Human Health (USEPA, 2000). The target population is pregnant women
because the in utero developmental endpoint is the most sensitive. Available data are
considered adequate to describe anticipated exposures. The RSC subtraction calculation
method is considered appropriate since there are no other existing health -based numeric
criteria for boron. Dietary sources represent the main background intake for boron (IOM,
2001). IOM (2001) reported a mean boron intake value of 1.0 mg/day from food sources
for women of childbearing age and pregnant women. The background dietary intake value,
when adjusted to the recommended 67 kg body weight for women of childbearing age,
corresponds to a daily intake value of 0.015 mg/kg/day. When subtracted from the
Reference Dose (RfD) of 0.2 mg/kg/day, 0.185 mg/kg/day remains. This latter value
represents approximately 93 percent of the RfD. Therefore, the RSC ceiling value of 80
percent is applied, consistent with both the 2000 Human Health Methodology and past
drinking water program regulatory practice.
GRADIENT

ATTACHMENT 2
Conclusion
An RSC is used to account for constituent exposure from non -drinking water sources when setting a
drinking water standard protective of human health. The application of a default RSC of 0.1 for the
derivation of the 2L standard for boron is not supported by information on boron exposure from non -
drinking water sources. The main source of boron is the diet; for an average adult, the mean daily intake
of boron is 1.15 mg/day. This intake is less than 10% of the safe level of boron exposure, as reflected in
the Rf 3 of 14 mg/day (based on an RfD of 0.2 mg/kg-day for a 70 kg adult). If non -drinking water sources
of exposure account for only 10% of the safe dose, this means that 90% of exposure could come from
drinking water and the RSC could be as high as 0.9. However, an RSC of 0.8 would be more conservative
by accounting for dietary boron as well as other miscellaneous exposures, and would be consistent with US
EPA's derivation of a health -based drinking water level for boron. Using the more scientifically supportable
RSC of 0.8, in conjunction with the other factors specified in NCDEQ's SOP, would result in a revised 2L
standard for boron of 5,600 µg/L.
GRADIENT

ATTACHMENT 2
References
North Carolina Dept. of Environmental Quality (NCDEQ). 2010. "The Division of Water Quality (DWQ)
Standard Operating Procedure (SOP) for Reviewing Groundwater Standards Established Pursuant to 15A
NCAC 02L .0200." Division of Water Quality (DWQ). 5p., September.
North Carolina Dept. of Environmental Quality (NCDEQ). 2013. "Groundwater Quality Standards." 15A
NCAC 02L .0202. 5p.
Trumbo, P; Yates, AA; Schlicker, S; Poos, M. 2001. "Dietary reference intakes: Vitamin A, vitamin K,
arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and
zinc." J. Am. Diet. Assoc. 10 1 (3):294-30 1.
US EPA. 2000. "Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human
Health (2000) (Final)." Office of Water, Office of Science and Technology, EPA-822-B-00-004, 185p.,
October.
US EPA. 2008. "Drinking Water Health Advisory for Boron." Office of Water, EPA 822-R-08-013, 65p.,
May.
GRADIENT

ATTACHMENT 3
UPDATED CORRECTIVE ACTION PLAN AND COMPREHENSIVE SITE ASSESSMENT CONTENT
FOR REMAINING COAL ASH SITES
Introduction
The purpose of this document is to provide the North Carolina Department of Environmental Quality
(NCDEQ) with Duke Energy's rationale and proposed approach for adjusting future groundwater Corrective
Action Plans (CAPs) submitted for Duke Energy ash basins and additional source areas. Duke Energy
believes there are multiple reasons for adjusting the CAP and Comprehensive Site Assessment (CSA)
content at this time including:
Advancement in the Project Lifecycle — The original extensive CAP and CSA requirements were
understandable at the time because site conditions were not well known and constituent of interest
(COI) distribution was not well understood. Today, extensive amounts of data have been collected
and analyzed at each site and subsurface conditions are well understood. A summary of the data
collected at each site is presented in Table 1. Data collected to date indicate that the Conceptual
Site Models for valley fill ash basins in the Piedmont are consistent in their hydraulic behavior. As a
result, COI distribution is generally consistent across all sites.
2. Potential risks have been significantly mitigated —The extensive site assessment data
collected along with substantial risk mitigation activities completed at each site combine to
reduce or eliminate potential or perceived risks at each site. These risk mitigation items include:
■ Resolution regarding the excavation of coal ash at each site has been achieved
■ Groundwater protection programs for each site have been or soon will be completed
■ No significant impacts to potential human or ecological receptors have been identified based
on risk assessments completed to date
■ There have been no surface water impacts above state 2B standards in the 21J2B studies
completed to date
■ COI transport is generally limited to areas directly around ash basins
■ Assessment data for the remaining sites in need of CAPs and CSAs indicate that they are
generally less impacted than six sites for which CAPs were submitted on December 31,
2019 (e.g., see groundwater data for the Riverbend and Dan River stations)
3. Updated CAP and CSA formats allow for reduced time to corrective action implementation —
By focusing the CAPs on areas requiring attention, appropriate remedies can be developed and
implemented more rapidly which is beneficial to the environment and concerned stakeholders.
Two attachments are presented herein. Attachment 1 presents an updated version of the CAP content
outline. Attachment 2 presents an updated version of the CSA outline.
Duke Energy looks forward to working with the NCDEQ on completing the remaining CSA and CAPs.

ATTACHMENT 3A
Updated Corrective Action Plan Content for
Duke Energy Coal Ash Facilities and Additional Source Areas
Best professional judgement must be applied to generate the Corrective Action Plan (CAP) documents.
EXECUTIVE SUMMARY
1. INTRODUCTION
A. Background
B. Purpose and Scope
C. Regulatory Basis for Closure and Corrective Action
D. Facility Description (summary from Comprehensive Site Assessment [CSA])
a. Location and history of land use.
b. Operations and waste streams coincident with the ash basin (coal and only those non -
coal waste streams that may affect subsurface conditions at, or proximate to, the coal
ash basins or coincident sources).
c. Overview of existing permits and Special Orders by Consent (National Pollutant
Discharge Elimination System, storm water, sediment and erosion control, etc.).
2. OVERVIEW OF SOURCE AREAS BEING PROPOSED FOR CORRECTIVE ACTION
A. Map showing the boundary of each source area proposed for corrective action.
3. SUMMARY OF BACKGROUND DETERMINATIONS
A. Map showing all background sample locations for all media (groundwater, surface water, soil,
and sediments).
B. Table of background concentrations for soil. Include the corresponding Protection of
Groundwater (POG) Preliminary Soil Remediation Goal (PSRG). A discussion of regional
background concentrations for similar geologic settings may be provided as context for
Background Threshold Values (BTVs).
C. Table of background concentrations for groundwater. Include the appropriate 2L/IMAC
Standards. A discussion of regional background concentrations for similar geologic settings
may be provided as context for BTVs.
D. Table of background concentrations for surface water. Include the appropriate 2B standards
and EPA recommended criteria. Present results of all surface water samples and sample
events from upstream locations.
E. Table of background concentrations for sediments. Present results of all sediment samples
and sample events from upstream or otherwise unimpacted sediment sample locations.

4. CONCEPTUAL SITE MODEL
A. The conceptual site model (CSM) will present Duke Energy's interpretation of relevant site
conditions based on multiple lines of technical evidence developed through the collection of a
large multi -media dataset for each site. The CSM will in turn be used to form the basis of the
site -specific corrective action approach planned at each site. CSM elements will include:
a. Description of key site factors concerning the site geologic and hydrogeologic setting.
i. Local groundwater flow directions and gradients (current and following closure).
ii. Subsurface heterogeneities and other potential factors affecting flow and
transport including geochemical conditions.
iii. The role of matrix diffusion in/out of bedrock (bedrock porosity) on constituent
transport where appropriate.
vii. The effects of naturally occurring constituents in site groundwater.
b. Location of source areas within the hydrogeologic setting (current and following closure).
c. Describe potential on -site and off -site receptors and whether or not they are affected by
site related constituents above applicable criteria.
d. A summary of the human health and ecological risk assessment results.
5. SOURCE AREA(s)
Contents listed in Section 5 should be tailored to areas requiring corrective action based on the
CSA results.
Maps prepared for Source Area(s) should be large scale, typically I" = 150 to 200 ft. and include
topographic contour intervals at 5 to 10 feet to reduce electronic file size and allow for electronic
file manageability.
The following references to COls for corrective action are based on the COI management
approach developed in coordination with the NCDEQ in 2019.
A. Extent of Constituent Distribution
a. Source material within waste boundary. The Information requested below is to be
provided only to the extent the requested information was not provided in previous
submittals. A reference to the submittal where the requested information is provided will
be included in the CAP.
i. Description of waste material and history of placement
ii. Specific waste characteristics of source material
iii. Interim response actions conducted to date to remove or control source material,
if applicable
1. Source control conducted to date or planned to include but not limited to
excavation, dewatering, boundary control measures (e.g. extraction
wells), etc.

2. Source area stabilization conducted to date or planned.
b. Extent of constituent migration beyond the geographic limitation or waste boundary
(whatever is the point of compliance depending on whether the source area(s) are
covered by a permit) based upon groundwater data collected through agreed upon
timeframes with the NCDEQ:
i. Plan view map showing COI results (bubble inset at each seep location) for
groundwater, seeps, and surface water using the COI management approach
developed with the DEQ in 2019.
ii. Table of analytical sampling results associated with Source Area(s):
1. Soil, as applicable
2. Groundwater (per individual flow regime (e.g. shallow, deep, bedrock)
3. Seeps (up-, side-, and down -gradient)
4. Surface water (up-, side-, and down -gradient)
5. Sediment (up-, side-, and down -gradient)
c. Isoconcentration maps, or cross sections for:
i. Horizontal and vertical extent of groundwater in need of restoration for COls
identified for remediation in each groundwater flow regime (e.g., shallow,
deep, bedrock).
d. COI Distribution in Groundwater
i. Distribution of COls in groundwater based on the COI management program
developed with the NCDEQ in 2019.
1. Describe whether plume is stable or expanding based on plume
stability analysis.
2. Discussion of site geochemical conditions that may affect COls
behavior in the groundwater system with details included in the
geochemical modeling report.
B. Summary of Human and Ecological Risks
C. Evaluation of Remedial Alternatives
a. Remedial Alternative
i. Problem statement and remedial goals.
1. List of COls within each groundwater flow unit (shallow, deep, bedrock)
that will be corrected by this alternative
ii. Simple description explaining how the proposed source control/removal and
corrective action will reduce COI concentrations and protect human health and
environment. Include how models were used to inform decision -making.

iii. For remedial alternative, evaluate alternative(s) using the following criteria:
1. Protection of human health and the environment
2. Compliance with applicable federal, state, and local regulations
3. Long-term effectiveness and permanence
4. Reduction of toxicity, mobility, and volume
5. Short term effectiveness at minimizing impact on the environment and
local community
6. Technical and logistical feasibility
7. Time required to initiate
8. Predicted time required to meet remediation goals
9. Cost
10. Community acceptance
D. Proposed remedial alternative(s) selected for the source area(s)
a. Description of proposed remedial alternative and rationale for selection
i. Specific section of 02L .0106 being addressed by the proposed remedy [e.g.
02L .0106 (1) or (k)]
b. Design Details — Provide the following information at the conceptual design level.
i. Process flow diagrams for all major components of proposed remedy.
ii. Engineering designs with assumptions, calculations, specifications, etc.
iii. Permits needed for proposed remedy and approximate schedule for obtaining
them.
iv. Schedule and approximate cost of implementation.
v. Measures to ensure the health and safety of all persons on and off site.
c. For 02L .0106 (1) CAP, provide requirements outlined in DWR's Monitored Natural
Attenuation for Inorganic Contaminants in Groundwater. Guidance for Developing
Corrective Action Plans Pursuant to NCAC 15A [02L] .0106(l).
d. For 02L .0106 (k) CAP, provide requirements outlined in 02L .0106 rule.
e. Sampling and Reporting
i. Proposed progress (i.e. "effectiveness") reports and schedule.
ii. Proposed sampling and reporting plan during active remediation.
iii. Proposed sampling and reporting plan after termination of active remediation (if
proposed).

1. Decision metrics for termination of active remediation and start of
"monitoring only" phase.
A. Proposed wells for COI trend analysis.
B. Proposed statistical method for trend analysis.
f. Proposed interim activities prior to implementation.
g. Contingency plan in case of insufficient remediation performance.
i. Description of contingency plan.
ii. Decision metrics (triggering events) for implementing contingency plan.
6. PROFESSIONAL CERTIFICATIONS
Sealed and notarized professional statements of "true, accurate, and complete"
7.
REFERENCES
8.
TABLES
9.
MAPS AND FIGURES
10.
APPENDICES

ATTACHMENT 3B
Comprehensive Site Assessment Outline for Remaining Duke Energy Ash Basins and
Additional Source Areas
The updated CSA outline proposed below for the remaining Duke Energy ash basins and additional
sources areas is presented below. This outline is taken from the NCDEQ Division of Water Resources
guidance document titled "Guidelines for the Investigation and Remediation of Soil and Groundwater
Contamination", 2017. Duke Energy believes this format provides the appropriate level of detail needed
to complete representative CSAs and is consistent with NCDEQ guidance. The details of each CSA
submitted can be adjusted based on site -specific conditions.
■ TITLE PAGE
■ EXECUTIVE SUMMARY
■ TABLE OF CONTENTS
o Site History and Source Characterization
o Receptor Information
o Regional Geology and Hydrogeology
o Site Geology and Hydrogeology
o Soil and Sediment Sampling Results
o Groundwater and Surface Water Sampling Results
o Hydrogeological Investigation
o Groundwater Modeling Results
o Discussion
o Conclusions and Recommendations
o Maps and Figures
o Tables
o Appendices

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From: Bolich, Rick [mailto:[e-mail]]
Sent: Tuesday, May 5, 2020 12:55 PM
To: Davies, Scott E. <[e-mail]>
Cc: Sullivan, Ed M <[e-mail]>; Toepfer, John R <[e-mail]>; Julie K. Sueker -
ARCADIS U.S., Inc. ([e-mail]) <[e-mail]>; Campbell, Ted <[e-mail]>;
Lanter, Steven <[e-mail]>; Smith, Eric G <[e-mail]>
Subject: LCL95 Use
*** Exercise caution. This is an EXTERNAL email. DO NOT open
attachments or click links from unknown senders or unexpected
email. ***
Hi Scott;
We have evaluated the use of Central Tendency Values (CTVS) for Constituent of Interest (COI) management and have
concluded that the use of CTV methodologies is appropriate when there are fewer than four (4) valid samples for a given
well, and where 50% or more of the values are non -detects. All other COls should be evaluated using the LCL95
methodology as described in the October 24, 2019 letter to Paul Draovitch that was signed by Jim Gregson. Please
ensure that all groundwater monitoring wells located at or beyond the compliance boundary/geographic area of
limitations are included in the calculation of COls for the Constituent of Interest Management Plans.
Please let me know if you have any questions or concerns.
rb
Rick Bolich, L.G.
Chief, Groundwater Resources Section
Division of Water Resources, NC Dept. of Environmental
1636 Mail Service Center
Raleigh, NC 27699-1636
[phone]
[e-mail]

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
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 Quality
June 18, 2020
Subject: Surface Water Evaluation Report Comments
L. V. Sutton Energy Complex
Dear Mr. Draovitch:
On January 17, 2020, the North Carolina Department of Environmental Quality (DEQ) received
the Surface Water Evaluation Reports for the subject facility and is providing the following
comments.
• There were some exceedances of the listed 15A NCAC 02B Surface Water Standards
including exceedances of the United States Environmental Protection Agency Nationally
Recommended Water Quality Criteria noted for constituents such as copper, however, the
data do not appear to indicate that these exceedances are attributed to the facility operations
through groundwater discharging to surface water.
• The April 25, 2018 technical memorandum work plan submitted by Synterra and approved
by the Division on May 10, 2018 included plans for sediment sampling and evaluation.
These analytical results and related discussion were not included in the Surface Water
Evaluation Report.
The surface water sampling and sediment results shall be documented and summarized in the
upcoming Comprehensive Site Assessment (CSA) Report due on December 1, 2020. DEQ
reserves the right to request additional surface water sampling based on review of the CSA and
may also request additional surface water sampling be performed either prior to, and as part of, the
effectiveness monitoring programs.
North Carolina Department of Environmental Quality I Division of Water Resources
KQ 512 North Salisbury Street 1 1636 Mail Service Center I Raleigh, North Carolina 27699-1636
NorrrH cnaaiw
919.707.9000

If you have any questions, please contact Steve Lanter (Central Office) at [phone].
Rick Bolich, L.G., Chief
Ground Water Resources Section
Division of Water Resources
cc: WIRO Regional Office
GWRS Central File Copy
Page 2 of 2

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
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 Quality
June 26, 2020
Subject: Updated Corrective Action Plan and Comprehensive Site Assessment Content
Duke Energy Coal Ash Facilities
Dear Mr. Draovitch:
On March 3, 2020, Duke Energy submitted the proposed Updated Corrective Action Plan (CAP)
and Comprehensive Site Assessment (CSA) Content for Remaining Coal Ash Sites dated February
24, 2020 to the North Carolina Department of Environmental Quality (DEQ). The DEQ conducted
an evaluation of these proposed revisions compared to requirements of Subchapter L of Chapter 2
of Title 15A of the North Carolina Administrative Code and prior communication concerning
guidance related to CSA and CAP content including:
• 2014 Guidelines (DEQ 2014),
• CSA Guidelines Adjustments (Duke Energy Track Changes Version May 14, 2015)
• CSA Guideline Adjustments (DEQ June 2015),
• DRAFT Final DEQ CSA Table of Contents (September 29, 2017 email S. Lanter [DEQ]
to Ed Sullivan and John Toepfer [Duke Energy]),
• CAP Content Guidance (DEQ April 27, 2018),
• Supporting Rationale for Proposed Interpretation and Adjustments to the CAP Content
Guidance (Duke Energy January 2019), and
• DEQ Review Position concerning Attachment 2 of Duke Energy's January 2019
Supporting Rationale for Proposed Interpretation and Adjustments to the CAP Content
Guidance (DEQ September 10, 2019).
x North Carolina Department of Environmental Quality I Division of Water Resources
_ �� 512 North Salisbury Street 1 1636 Mail Service Center I Raleigh, North Carolina 27699-1636
�a�r1 r 919.707.9000

DEQ's comments and position concerning the February 24, 2020 proposed Updated CAP Content
for Remaining Coal Ash Sites is summarized below:
Guidance provided to Duke Energy from DEQ in the July 29, 2019 correspondence stated
that the purpose of Section LD of the CAP content was to provide a description of how the
CAP process followed 15A NCAC 02L .0106(i). While the proposed text revision
contained in the February 24, 2020 proposed Updated CAP Content is acceptable, DEQ
has directed Duke to provide appropriate details in Section 6, which is now proposed to be
Section 5, with respect to criteria used to evaluate remedial alternatives and proposed
design. Please note that Duke Energy did not specify either a 15A NCAC 02L .0106(k) or
(1) CAP in this section, which was an expectation that was previously communicated.
Duke Energy has proposed to eliminate Section 2 of the DEQ April 27, 2018 CAP Content
Guidance. The proposed exclusion of this section and related information is acceptable.
The Overview of the Source Areas Proposed for Corrective Action is now proposed to be
Section 2 of the Updated CAP Content. Other than a map for a source area, no information
regarding the level of detail to be presented in this section was provided. The level of detail
DEQ requested in our January 23, 2019 letter is consistent with the perspective the agency
has maintained that the Duke Energy facilities are large, hydrogeologically complex sites.
Any changes to this section require further discussion with DEQ.
Migration pathways and exposure routes, including impacts from pumping wells, are likely
reflected in the integrated summaries of site conditions, but it is not apparent how modeling
results are incorporated into Section 4 of the Updated CAP Content, the Conceptual Site
Model (CSM). A summary of relevant modeling results shall be incorporated into the CSM
(Section 4). A subsection that briefly discusses relevant information and assumptions
concerning site conditions that were developed from modeling results is warranted, with
references to related content in Section 5 of the Updated CAP Content.
Section 5 of the Updated CAP Content is now the source area(s) summary. There is a
summary of waste material, history of placement, and related specific waste characteristics
proposed as part of the content in this section. The resulting streamlined discussion is
acceptable since excavation has been determined to be the source control measure, or the
closure method, for all of the sites. In addition, relevant information pertaining to source
material has been incorporated into groundwater models, so a detailed documentation of
source characteristics in the Updated CAP Content is not required.
Maps proposed for the forthcoming CAP Update documents will mirror the Constituent of
Interest Management Plan as noted in DEQ's October 24, 2019 letter. The suggested map
and cross-section content should be adequate to illustrate site conditions to evaluate
remedial design.
There is no specific mention of plume status analysis and groundwater modeling in the
proposed Updated CAP Content, which are both critical components of the planning and
evaluation of remedial design for the upcoming CAPs. Relevant information and
assumptions concerning simulations and the overall evaluation of site conditions shall be
provided in Section 5.A.d and in the Appendices of the Updated CAPs.
The proposed level of detail in Section 5.13 of the Updated CAP Content concerning
wetlands, surface water, and water supply wells is less than directed by DEQ in the July
29, 2019 DEQ correspondence. Results of 2L/2B sampling and the related evaluation of
groundwater discharge into surface water shall be included and discussed in an appropriate
level of detail in this Section of the Updated CAPs.

• Other proposed omissions from the previous CAP content correspondence not captured in
the above comments are acceptable but additional information may be required based on
the review of the Updated CAPs.
DEQ's comments and position concerning Attachment 2 of the February 24, 2020 proposed
Updated CSA Content for Remaining Coal Ash Sites is summarized below:
• No detail regarding any discussion or reference to regulatory compliance is provided in the
proposed Duke Energy Updated CSA Content; however, DEQ requests this information to
be summarized in the documents. In this proposed outline, the related discussion shall be
included in Section 1 - Site HistoKy and Description.
• No details regarding soil and sediment background threshold values (BTVs) in the CSA
Updates are provided. While Duke Energy had proposed to discuss BTVs in the upcoming
CAP Updates, discussion of this subject matter is needed in the CSAs in Section 5 — Soil
and Sediment Sampling Results.
• No details regarding surface water and groundwater BTVs are provided. While Duke
Energy had proposed to discuss BTVs in the upcoming CAP Updates, discussion of this
subject matter is needed in the CSA Updates in Section 6 — Groundwater and Surface Water
Sampling Results.
• Other proposed omissions from the previous CSA content correspondence not captured in
the above comments are acceptable, but additional information may be required based on
the review of the CSA.
Duke Energy has provided no details related to Figures, Tables, and Appendix content for either
the upcoming CAP or CSA Updates. Best professional judgment concerning related content
should be applied. As stated in previous communications, providing information solely in a data
summary format will not be acceptable.
If you have any questions, please contact me at [phone].
Sincerely,
Rick Bolich, L.G., Chief
Ground Water Resources Section
cc: Sheila Holman - via email
WQROS Regional Offices Supervisors - via email
Ground Water Resources Section Central File Copy

AG"a
NCDENR
North Carolina Department of Environment and Natural Resources
Division of Land Resources
Land Quality Section
James D. Simons, PG. PE
Director and State Geologist
September 29, 2010
NOTICE OF INSPECTION
Progress Energy Carolinas, Inc. - L.V. Sutton Electric Plant
Mr. R. Kent Tyndall, Environmental Specialist
801 Sutton Steam Plant Road
Wilmington, NC 28401-8357
Dear Mr. Tyndall:
Beverly Eaves Perdue, Governor
Dee Freeman, Secretary
9OP'NOWE
QGT - { zm P
Progress Energy
L. V. Sutton Plant
RE: Sutton Plant 1984 Ash Pond Dam - NE'WHA-005
New Hanover County, North Carolina
Cape Fear River Basin
The Dam Safety Law of 1967, as amended. provides for the certification and inspection of dams in the
interest of public health, safety and welfare, in order to reduce the risk of failure of such dams; to prevent injuries
to persons. damage to property. and to insure that maintenance of stream flows.
On September 27, 2010. staff of our office met with you and others on the 1984 Ash Pond Dam at the
location of its breach. Enclosed is our Incident Report of that inspection for your review. We will inspect again
shortly to determine the progress in the breach repairs.
Your cooperation and consideration in maintaining a safe dam is appreciated. Should you have questions
concerning our inspection, please contact me at [phone].
Sincerely, ,
Daniel Sains, PE
Wilmington Office Regional Engineer
Land Quality Section
cc: State Dam Safety Engineer
Wilmington Regional Office File
1612 Mail Service Center, Raleigh; North Carolina 27699-1612 • Telephone [phone] FAX: [phone]
127 Cardinal Drive Ext., Wilmington, NC 28405 • Internet:hdp:llwww.dir.enr.state,nc.usipages/Iandqualitysection html
An Equal Opportunity / Affirmative Action Employer- 50% Recyded 110% Post Consumer Pape,

Incident Report
Dam Failure
Investigation date: September 28, 20I0
Progress Energy Sutton Plant, Wilmineon. NC
Sutton 1984 Ash Pond Dam (NEWHA-005)
A breach occurred in the southeast corner of the subject dam sometime between 4:30 PM and 8:30 PM
on September 27, 2010. The general area of the plant had received heavy rains in the previous 24 hour
period. A representative of Progress Energy (Mr. Fred Holt) reported the incident to Steve McEvoy of
the LQS at approximately 10:45 AM on Tuesday September 28, 2010.
This dam is a containment structure completely encompassed by a circumferential earthen dam. Much
of the internal reservoir area, including the area where the breach occurred, has been fully loaded and
no longer receives sluiced ash material waste. The dam is constructed of pervious sand material Nvith
an interior clay blanket liner. Average dam embankment height is approximately 30 feet and the total
internal reservoir area is approximately 28 acres. The total circumferential dam structure length is
approximately 9,300 feet. The dam is of low hazard classification.
The dam is located on the east side of the 1972 Cooling Pond (NEWHA-003) which is classified as
low hazard. The 1972 Cooling Pond is in the east side of the Cape Fear River which runs directly
adjacent to the plant site.
The breach occurred in an area of the dam embankment where a vehicular access ramp exists. Over
time, the dam embankment crest in the area had developed a low spot from continuous vehicular
traffic. The internal reservoir area directly adjacent to the breach was completely full of dewatered ash
waste material and an earthen cap had been constructed over the wasted ash material. Over time, this
area had subsided to an elevation lower than the crest of the dam embankment creating an area where
surface water could pool. Dulling the previous period rains this area filled with surface water and
overtopped the low area of dam embankment. This overtopping event eroded a breach area in the dam
embankment approximately 80 feet in length, 22 feet in width, and 9 feet in depth. A plume of
embankment and ash material extended out from the breach approximately 60 feet but was contained
completely in the general area. Progress Energy was taking the following emergency action on
September 28, 2010 under consultation with Mactec Engineering:
1. Placed a rip rap/wash stone check dam at the top end of the breached area to prevent additional
movement of contained material.
2. Constructed silt fence around the sediment plume to halt further migration of impounded
material (material did not leave the property boundaries).
3. Continue to divert runoff from the breached area by pumping standing water on the south side of
the 1984 Ash Pond into a waste water truck.
4. Excavated a water containment area near the embankment between the 1971 and 1984 ponds to
cistern future accumulated stormwater. Constructed drainage diversions to that contairvnent area.
LQS staff will continue to periodically monitor the situation until stabilization is confirmed..
Inspection By:
DanieI Sams, PE; Carol Miller, CPESC; Gary Beecher; Wilmington Regional Office, ' ICDENR

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