HF Lee CBE_Closure Plan_Rev1_20200402

wood.
April 2, 2020
ELECTRONIC MAIL
Ms. Sheila Holman
Assistant Secretary for Environment
North Carolina Department of Environmental Quality
1611 Mail Service Center
Raleigh, North Carolina 27699-1611
Subject: HF Lee Station Ash Basin Closure Plan Revision
Dear Ms. Holman:
In accordance with the requirements of N.C.G.S. § 130A-309. 214(a)(4), Duke Energy provides
the enclosed revised plan for basin closure by excavation. Errata Sheets reflecting replacement
language for the following sections are attached to this letter.
• Cover Sheet
• Section 3.2.2 pg. 6
• Section 3.3 pg. 6
• Section 4.2 pg. 7
• Section 4.3 pg. 7
• Section 4.5 pg. 9
• Section 4.6 pg. 9
• Section 4.7 pg. 9
• Section 4.8 pg. 9
• Section 5.0 pg. 9
• Section 5.1 pg. 9
• Section 5.2 pg. 9
• Section 5.3 pg. 9
• Section 11.1 pg. 16
• Section 12.2 pg. 17
Replace Cover Sheet, Page 6, Page 7, Page 9, Page 16 and Page 17.
Duke Energy remains committed to safely and permanently closing basins in ways that continue
to protect people and the environment and welcomes the opportunity to work constructively with
NCDEQ to move forwa
Sincerely, ���' N. • • • ROB
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SEAL
022943
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William A. Wi$ i;,<P�,itPQ..� Q�� Christopher T. Keenan, PE
Senior Civil Er%% t••...••'•��` Senior Associate Engineer
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Wood Environment & In as ns
4021 Stirrup Creek Drive, Suite 100 Registered in North Carolina
Durham, North Carolina 27703 Engineering and Land Surveying License No. F-1253
919-331-9900 Geology License No. C-247
woodplc.com ® •

HF Lee Steam Station Errata Summ
Section Change
Cover Rev. 1, date, seal
3.2.2 This information was submitted to NCDEQ in September 2016 as part of the Update
to Drinking Water Well and Receptor Survey for HF Lee Energy Complex prepared
separately for Duke Energy. The Update to Drinking Water Well and Receptor
Survey document is herein incorporated by this reference, but its content was not
prepared by Wood.
3.3 This information was submitted to NCDEQ on July 30, 2019 as part of the CAMA
Annual Interim Monitoring Report prepared separately for Duke Energy. The CAMA
Annual Interim Report is herein incorporated by this reference, but its content was
not prepared by Wood.
Locations of the existing groundwater monitoring wells are shown in the Closure Plan
Drawings included in Appendix D, but the CAMA Annual Interim Report should be
consulted for details of well locations, names, and status.
4.2 This information was submitted to NCDEQ on August 4, 2015 as part of the CSA and
on September 16, 2016 in an updated CSA Supplement 1 prepared separately for
Duke Energy. The CSA and CSA Supplement 1 are herein incorporated by this
reference, but their content was not prepared by Wood.
4.3 This information was submitted to NCDEQ on August 4, 2015 as part of the CSA and
on September 16, 2016 in an updated CSA Supplement 1 prepared separately for
Duke Energy. The CSA and CSA Supplement 1 are herein incorporated by this
reference, but their content was not prepared by Wood.
4_5 This information was submitted to NCDEQ on August 4, 2015 as part of the CSA and
on September 16, 2016 in an updated CSA Supplement 1 prepared separately for
Duke Energy. The CSA and CSA Supplement 1 are herein incorporated by this
reference, but their content was not prepared by Wood.
4_6 Duke Energy provides CAMA groundwater monitoring results to NCDEQ on a
quarterly basis. Additionally, historical groundwater monitoring results have been
submitted in multiple reports such as the August 2015 CSA, the September 2016
CSA Supplement 1, and the 2018 CAMA Annual Interim Monitoring Report prepared
separately for Duke Energy. These documents are herein incorporated by this
reference but were not prepared by Wood.
4.7 Groundwater level maps for each designated flow zone were submitted to NCDEQ
on July 30, 2019 as part of the CAMA Annual Interim Monitoring Report prepared
separately for Duke Energy. The CAMA Annual Interim Report is herein incorporated
by this reference, but its content was not prepared by Wood.
4_8 This information was submitted to NCDEQ on August 4, 2015 as part of the CSA and
on September 16, 2016 in an updated CSA Supplement 1 prepared separately for
Duke Energy. The CSA and CSA Supplement 1 are herein incorporated by this
reference, but their content was not prepared by Wood.

5.0 This information was submitted to NCDEQ on November 2, 2015 as part of the CAP
Part 1 prepared separately for Duke Energy. The CAP Part 1 is herein incorporated
by this reference, but its content was not prepared by Wood.
5.1 This information was submitted to NCDEQ on November 2, 2015 as part of the CAP
Part 1 prepared separately for Duke Energy. The CAP Part 1 is herein incorporated
by this reference, but its content was not prepared by Wood.
5.2 This information was submitted to NCDEQ on November 2, 2015 as part of the CAP
Part 1 prepared separately for Duke Energy. The CAP Part 1 is herein incorporated
by this reference, but its content was not prepared by Wood.
5_3 This information was submitted to NCDEQ on November 2, 2015 as part of the CAP
Part 1 prepared separately for Duke Energy. The CAP Part 1 is herein incorporated
by this reference, but its content was not prepared by Wood.
11.1 This information was submitted to NCDEQ on July 30, 2019 as part of the CAMA
Annual Interim Monitoring Report prepared separately for Duke Energy. The CAMA
Annual Interim Report is herein incorporated by this reference, but its content was
not prepared by Wood.
12.2 Corrective action costs are included as part of the updated CAP being prepared
separately by SynTerra for Duke Energy and will be submitted to NCDEQ by July 1,
2021. The CAP is herein incorporated by this reference, but its content is not the
work product of Wood.

DUKE ENERGY wood.
H.F. LEE STATION
COAL COMBUSTION RESIDUALS SURFACE
IMPOUNDMENT CLOSURE PLAN
CLOSURE BY EXCAVATION
1982 Ash Basin
Basins 1, 2 and 3
Closure Plan Report
Final Submittal
Prepared for
DUKE
ENERGY®
GAR
550 South Tryon Street
�OQ�, `< S
Charlotte, North Carolina 28202
022 43 . aO
Revision 1
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Issue Date 2 April 2020
Prepared by
Wood Environment & Infrastructure Solutions, Inc.
4021 Stirrup Creek Drive, Suite 100
Durham, North Carolina 27703
Project No. 7812180091

Wood Environment &Infrastructure Solutions, Inc. wood.
Energy Coal Combustion Residuals Management Program
HF Lee Station Basin CAMA Closure Plan
TABLE OF CONTENTS
EXECUTIVE SUMMARY..........................................................................................................iiv
1.0 INTRODUCTION............................................................................................................... 1
1.1 Background...................................................................................................................................... 1
1.2 Closure Plan Objectives................................................................................................................... 1
1.3 Report Organization......................................................................................................................... 2
2.0 GOVERNING LAWS......................................................................................................... 2
K�+>•y_[fI14kCd0:&*]N1;i0[a]:I_321183:FJ 311►[�-]kf PJ:1 _
3.1 Surface Impoundment Description................................................................................................... 3
3.1.1 Site History and Operations.....................................................................................................3
3.1.2 Estimated Volume of CCR in Impoundments..........................................................................
3
3.1.3 Description of Surface Impoundments Structural Integrity......................................................4
3.1.4 Sources of Discharges into Surface Impoundments...............................................................5
3.1.5 Existing Liner System..............................................................................................................5
3.1.6 Inspection and Monitoring Summary.......................................................................................5
3.2 Site Maps.........................................................................................................................................
6
3.2.1 Summary of Existing CCR Impoundment Related Structures.................................................6
3.2.2 Receptor Survey......................................................................................................................
6
3.2.3 Existing On -Site Landfills.........................................................................................................6
3.3 Monitoring and Sampling Location Plan..........................................................................................
6
4.0 RESULTS OF HYDROGEOLOGIC, GEOLOGIC, AND GEOTECHNICAL
INVESTIGATIONS............................................................................................................
i
4.1 Background......................................................................................................................................
7
4.2 Hydrogeology and Geologic Descriptions........................................................................................
7
4.3 Stratigraphy of the Geologic Units Underlying Surface Impoundments ..........................................
7
4.4 Geotechnical Properties...................................................................................................................
7
4.4.1 CCR Within the Basins............................................................................................................8
4.4.2 Liner Material Properties..........................................................................................................8
4.4.3 Subsurface Soil Properties......................................................................................................
8
4.5 Chemical Analysis of Impoundment Water, CCR and CCR Affected Soil .......................................
9
4.6 Historical Groundwater Sampling Results.......................................................................................
9
4.7 Groundwater Potentiometric Contour Maps.....................................................................................
9
4.8 Estimated Vertical and Horizontal Extent of CCR within the Impoundments ..................................
9
5.0 GROUNDWATER MODELING ANALYSIS......................................................................
9
5.1 Site Conceptual Model Predictions..................................................................................................
9
5.2 Geochemical Site Conceptual Model...............................................................................................
9
5.3 Groundwater Trend Analysis...........................................................................................................
9
6.0 BENEFICIAL USE AND FUTURE USE...........................................................................1a
6.1 CCR Use........................................................................................................................................
10
6.2 Site Future Use..............................................................................................................................
10
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7.0 CLOSURE DESIGN DOCUMENTS.................................................................................1
a
7.1 Engineering Evaluations and Analyses..........................................................................................
10
7.2 Closure Plan Activities...................................................................................................................
11
7.3 Design Drawings............................................................................................................................
11
7.4 Description of Construction Quality Assurance and Plan..............................................................
12
8.0 MANAGEMENT OF WASTEWATER AND STORMWATER...........................................13
8.1 Anticipated Changes in Wastewater and Stormwater Management .............................................
14
8.2 Wastewater and Stormwater Permitting Requirements.................................................................
15
9.0 DESCRIPTION OF FINAL DISPOSITION OF CCR.........................................................is
10.0 APPLICABLE PERMITS FOR CLOSURE.......................................................................1
5
11.0 DESCRIPTION OF POST -CLOSURE MONITORING AND CARE..................................1
S
11.1 Groundwater Monitoring Program................................................................................................
16
12.0 PROJECT MILESTONES AND COST ESTIMATES........................................................16
12.1 Project Schedule..........................................................................................................................
16
12.2 Closure and Post -Closure Cost Estimate.....................................................................................16
13.0 REFERENCES.................................................................................................................18
Tables
Table 2-1 CAMA Closure Plan Requirements Summary and Cross Reference Table
Table 4-1 Summary of Typical Material Properties
Table 10-1 H.F. Lee Plant Regulatory Permits, Approvals, or Requirements for Basin
Closure by Excavation
Fi ures
Figure 1-1 Vicinity Map and Site Plan
Figure 1-2 Overall Existing Conditions Plan
Aapendices
Appendix A
Estimated Volume of CCR in Impoundments
Appendix B
Geotechnical Data and Properties
Appendix C
Engineering Evaluations and Analyses
Appendix D
Closure Plan Drawings
Appendix E
Excavation Soil Sampling Plan
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HF Lee Station Basin CAMA Closure Plan
EXECUTIVE SUMMARY
In accordance with N.C.G.S. § 130A-309.214(a)(4), Duke Energy has prepared this Closure Plan
to describe the closure of the coal combustion residuals (CCR) surface impoundments (Basins) at
the H.F. Lee Station (HF Lee). The HF Lee Basins closure will consist of closure by excavation,
whereby CCR in the Basins will be excavated, processed, and transported off -site for beneficial
re -use as a concrete amendment. The removal of CCR and closure of the Basins will be in
accordance with all applicable provisions of the North Carolina Coal Ash Management Act of 2014,
Sess. L. 2014-122, as amended (codified at N.C.G.S. § 130A-309.200, et seq.) (CAMA). CCR
processing will be done using on -site STAR° (Staged Turbulent Air Reactor) Technology, a
patented thermal beneficiation process to transform coal ash from CCR surface impoundments
into a high -quality, sustainable product for the concrete industry.
Duke Energy will periodically review the progress of the excavation and STAR' processing as it
relates to achieving full CCR removal by the required end date of December 31, 2029. Duke
Energy will implement a concurrent excavation plan in which the remaining excavated CCR will
be transported to an approved landfill facility in order to meet the end date of December 31, 2029
for complete removal.
HF Lee is owned and operated by Duke Energy Progress, LLC (Duke Energy). The approximately
2,200-acre HF Lee site is located at 1677 Old Smithfield Road, Wayne County, approximately 4
miles west of Goldsboro, North Carolina.
Commercial operations of the station began in 1951. The three coal-fired units were retired in
September 2012 followed by the retirement of four oil -fueled combustion turbine units in October
2012. A natural gas -fired combined cycle plant started operations in December 2012. Demolition
of the plant was completed in 2017. There are no coal-fired units currently in operation at HF Lee
and CCR disposal operations ceased in 2012.
This Closure Plan covers the four Basins located at HF Lee identified in the North Carolina
Department of Environmental Quality (NCDEQ) Dam Safety Inventory of Dams as follows:
• HF Lee Active Ash Basin Dike - NC Dam Safety ID WAYNE-022 (identified in this report
as the 1982 Basin and in some references as the Active Ash Basin or Active Ash Pond)
• HF Lee Inactive Ash Basin #1 Dike - NC Dam Safety ID WAYNE-031 (identified in this
report as Basin 1 and in some references as the Inactive Ash Pond 1)
• HF Lee Inactive Ash Basin #2 Dike - NC Dam Safety ID WAYNE-032 (identified in this
report as Basin 2 and in some references as Inactive Ash Pond 2)
• HF Lee Inactive Ash Basin #3 Dike - NC Dam Safety ID WAYNE-033 (identified in this
report as the Basin 3 and in some references as Inactive Ash Pond 3)
During operation, CCR was transported from the plant to the Basins by hydraulic (wet) sluicing.
With the permanent retirement of the coal-fired generating units, there are no longer any CCR
disposal operations within the Basin areas.
The four Basins are unlined and the depth of CCR within these basins varies between 10 to 40
feet. Information provided by Duke Energy (with updated inventory data through July 31, 2019)
indicates that the current estimated volume of CCR in the four Basins is approximately 6.23 million
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tons (5.2 million cubic yards assuming a conversion factor of 1.2 tons/cy). It should be noted that
the CCR volume/tonnage estimates are approximations since they are based on assumed pre -
basin grades.
Upon approval of the Closure Plan by NCDEQ, additional activities to complete closure of the
Basins will commence, including beginning excavation of the CCR from the Basins, establishing
final grades using soil fill where required to properly drain the Basin areas, breaching/removing
the Basin dikes following removal of CCR (soil material removed from the Basin dikes will remain
on -site and will be incorporated into the final site grading plan), and development of stormwater
features and vegetative covers.
This document also includes a description of the future Post -Closure Care Plan, which provides
a description of the inspection, monitoring and maintenance activities required to be performed
for the HF Lee site for a minimum of 30 years.
This document provides a summary of properties of the site, as well as geotechnical properties
of CCR and natural soils to support engineering analyses of the selected closure design. These
analyses indicate that closure by excavation, as detailed in the Closure Plan, meets regulatory
requirements for the stability of the site, management of stormwater runoff, and access for
effective maintenance over the post -closure care period. The CCR basin dikes are proposed to
be removed or breached as part of closure and will be removed from the state's regulatory
jurisdiction inventory.
In a letter dated April 5, 2019, NCDEQ established submittal dates for an updated Comprehensive
Site Assessment (CSA) and updated Corrective Action Plan (CAP) for CCR surface
impoundments and other primary and secondary sources. Consistent with this direction, Duke
Energy will submit to NCDEQ the updated CSA for HF Lee by October 1, 2020, and the updated
CAP by July 1, 2021. The CAP sets out corrective action measures for the restoration of
groundwater quality as required under CAMA and the state's groundwater quality regulations.
Although this Closure Plan contains references to the CAP, all specific relevant details to
groundwater and related actions will be contained in the CAP and not in this Closure Plan.
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HF Lee Station Basin CAMA Closure Plan
1.0 INTRODUCTION
1.1 Background
The approximately 2,200-acre HF Lee site is located at 1677 Old Smithfield Road, Wayne County,
near Goldsboro, North Carolina, adjacent to the Neuse River. Commercial operations at the
station began in 1951. The three coal-fired units were retired in September 2012 followed by the
retirement of four oil -fueled combustion turbine units in October 2012. A natural gas -fired
combined cycle plant started operations in December 2012. The HF Lee Plant ceased all waste
flows to the Basins in 2012, and demolition of the coal-fired plant was completed in 2017.
This Closure Plan is being submitted for approval by NCDEQ and reflects closure by excavation
of the CCR from the HF Lee site. Processing of the excavated CCR will be done using STAR°
Technology, a patented thermal beneficiation process to transform CCR from the Basins into a
high -quality, sustainable product for the concrete industry. Figure 1-1 presents a Vicinity Map
and Site Plan of HF Lee.
The HF Lee site has four regulated impoundment structures (Figures 1-1 and 1-2). This Closure
Plan covers the four CCR Basins at HF Lee that are identified (and regulated by) the North
Carolina Department of Environmental Quality (NCDEQ) Dam Safety as follows:
• HF Lee Active Ash Basin Dam - NC Dam Safety ID WAYNE-022 (identified in this
report as the 1982 Basin and in some references as the Active Ash Basin or Active
Ash Pond)
• HF Lee Inactive Ash Basin #1 Dike - NC Dam Safety ID WAYNE-031 (identified in this
report as Basin 1 and in some references as the Inactive Ash Pond 1)
• HF Lee Inactive Ash Basin #2 Dike - NC Dam Safety ID WAYNE-032 (identified in this
report as Basin 2 and in some references as the Inactive Ash Pond 2)
• HF Lee Inactive Ash Basin #3 Dike - NC Dam Safety ID WAYNE-033 (identified in this
report as Basin 3 and in some references as the Inactive Ash Pond 3)
This Closure Plan has been prepared for the review and approval of NCDEQ.
1.2 Closure Plan Objectives
The primary objective of this Closure Plan is to address the closure by excavation of the CCR
from the Basins at HF Lee pursuant to North Carolina Coal Ash Management Act of 2014, Session
L. 2014-122, as amended (CAMA). A further objective is to obtain approval from the NCDEQ to
proceed and develop the additional details (as described further within this Closure Plan) and
working documents necessary to complete the closure actions. Duke Energy is requesting
approval of this Closure Plan with the knowledge that other details will follow. This Closure Plan
describes and communicates the key actions and activities necessary to close the Basins in
accordance with the requirements for written closure plans for CCR surface impoundments in
N.C.G.S. § 130A-309.214(a)(4). Planned closure activities include:
• Removal of free water/bulk water volume via permitted outfall (i.e., decanting)
• Construction/installation of stormwater management best management practices features
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• Installation and operation of a temporary water management system (WMS) to manage
discharges in compliance with the NPDES permit during closure
• Development of infrastructure for CCR excavation, construction of haul roads for
transportation, and construction of the STAR° Unit for processing of CCR for beneficial
re -use
• Development of sump areas in the Basins to collect and convey waters to the water
management system
• Dewatering the CCR to allow for safe access. CCR excavation and conditioning prior to
transport to the STAR® unit
• Excavate CCR from the basin, with sequencing determined for optimal progression.
Stockpile CCR and provide conditioning prior to transport to the on -site STAR' system.
Construction dewatering to be used as needed to provide safe and stable work areas and
slopes
• Complete closure by excavation verification
• Breaching of the Basin dikes
• Grading the perimeter dikes into each of the four Basins with a grading plan that will
establish drainage to promote flow of stormwater away from the former Basins in a manner
protective of area soils and water
1.3 Report Organization
This document is structured to follow the requirements of N.C.G.S. § 130A-309.214(a)(4).
2.0 GOVERNING LAWS
In August 2014, the North Carolina General Assembly enacted CAMA, which contains specific
statutory requirements applicable to CCR surface impoundments. Relative to the HF Lee Station,
"coal combustion residuals surface impoundment," as defined in N.C.G.S. § 130A-309.201(6), is
interpreted to include the plant's Basins.
In July 2016, the North Carolina General Assembly enacted House Bill 630, which added
N.C.G.S. §130A-309.216 requiring Duke Energy to identify three sites in North Carolina at which
to install and operate Ash Beneficiation projects capable of processing CCR to specifications
appropriate for cementitious products. The statute requires Duke Energy to use commercially
reasonable efforts to produce 300,000 tons of useable CCR at each site annually. On December
13, 2016, Duke Energy selected HF Lee as one of the three Ash Beneficiation sites. Pursuant to
subsection (c) of N.C.G.S. § 130A-309.216, CCR surface impoundments located at a site at which
an Ash Beneficiation project is installed, and operating shall be closed no later than December
31, 2029.
The Excavation Soil Sampling Plan for HF Lee (presented in Appendix E), represents activities to
satisfy the requirements set forth in the NCDEQ's November 4, 2016 letter and attachment titled
"CCR Surface Impoundment Closure Guidelines for Protection of Groundwater."
In a letter dated April 5, 2019, NCDEQ established submittal dates for an updated CSA and
updated CAP for CCR surface impoundments and other primary and secondary sources.
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Consistent with this direction, Duke Energy will submit to NCDEQ the updated CSA for HF Lee
by October 1, 2020, and the updated CAP by July 1, 2021.
In addition to the above requirements, National Pollutant Discharge Elimination System (NPDES)
permit program compliance, Special Order by Consent (which commits Duke Energy to initiate
and complete decanting of the Basins by certain dates) compliance, dam safety approvals for
modifications to regulated CCR Basin dikes, and environmental permitting requirements must be
considered during closure.
3.0 FACILITY DESCRIPTION AND EXISTING SITE FEATURES
3.1 Surface Impoundment Description
This section provides details on the CCR-related features at HF Lee.
3.1.1 Site History and Operations
Figure 1-1 shows locations of the four CCR Basins (1982 Basin, Basin 1, Basin 2, and Basin 3)
at the HF Lee site. Figure 1-2 shows the overall existing conditions at the HF Lee Station.
The HF Lee Station is located adjacent to the Neuse River in Wayne County, North Carolina near
the city of Goldsboro. Review of available information indicates that the property, totaling
approximately 2,200 acres, is owned by Duke Energy, and is reported to have begun commercial
operation in 1951 with of three coal fired units. Cooling was provided by cycling water through a
cooling pond, the level of which is controlled by pumping water into the cooling pond from the
intake canal off the bypass canal of the Neuse River. CCR generated from coal combustion was
transported by sluicing to and stored in four on -site Basins. Basins 1, 2, and 3 have been
historically referenced as the 1950 Pond, the 1955 Pond, and the 1962 Pond respectively, for the
assumed start -of -service dates. Basins 1 and 2 were both taken out of service around 1969. Basin
3 was used to deposit CCR until construction of the 1982 Basin was completed. Construction of
the 1982 Basin started around 1978 and was completed around 1980. In 2012, the coal burning
plant was taken out of service and was replaced with new gas -fired combined cycle units across
the bypass canal from the original plant. There are no longer any CCR disposal operations within
the Basins with the permanent retirement of the coal-fired generating units. The 1982 Basin has
been inactive since April 2019. Elements of the coal plant (boilers and stacks) were demolished
in 2013 and 2014, with final demolition of the plant completed in 2017.
3.1.2 Estimated Volume of CCR in Impoundments
Based on CCR inventory data provided by Duke Energy as of July 31, 2019, the approximate
volume of CCR in the Basins is listed in the table below. To compute the estimated volume of
CCR in place, an assumed density of 1.2 tons per cubic yard was used, which is the Duke Energy
fleet -wide assumption. See Appendix A for the Estimated Volume of CCR in the Impoundments
data sheet.
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HF Lee Station Basin CAMA Closure Plan
Impoundment
Estimated CCR Material
Volume (cy)
Estimated CCR Material
Weight (tons)*
1982 Basin
3,763,333
4,516,000
Basin 1
224,167
269,000
Basin 2
440,833
529,000
Basin 3
759,167
911,000
TOTAL
5,187,500
6,225,000
Estimated CCR Material is based on updated CCR Inventory Data provided by Duke Energy as of
July 31, 2019. To compute the estimated volume of CCR in place an assumed density of 1.2 tons
per cubic yard was used, which is the Duke Energy fleet wide assumption.
3.1.3 Description of Surface Impoundments Structural Integrity
The purpose of this section is to summarize the Basins' structural integrity evaluations based on
current existing information. This section includes brief summaries of the Geotechnical and
Hydrology and Hydraulics (H&H) capacity analyses results. Duke Energy provided Wood with
pertinent information regarding the integrity of the embankments, which had already been
compiled and analyzed. In summary, the structural integrity of the CCR impoundments and
subsequent dike inspection reports meet the regulatory requirements of EPA's CCR Rule (40
CFR 257.73). Duke Energy's certifications of these requirements for the 1982 Basin are available
on Duke Energy's publicly -accessible CCR Rule Compliance Data and Information website.
Slope Stability:
Slope stability was analyzed by Wood in 2015 at critical cross section locations for the Basins
at HF Lee. Two of the cross sections located on the southern side of Basin 1/2 (along Half -
Mile Branch) indicated low factors of safety. Geosyntec performed remedial action of armoring
the slope with riprap. Subsequent slope stability analyses by Geosyntec showed acceptable
factors of safety. Low (but acceptable) factors of safety identified for the 1982 Basin were
remediated in 2016. The slope stability analysis results indicate that minimum factors of safety
for static long-term maximum storage pool, static maximum surcharge pool, sudden
drawdown conditions, and pseudo -static seismic conditions meet regulatory and
programmatic criteria.
• Liquefaction Conditions (where susceptible) and Liquefaction Potential:
Embankment and foundation soils associated with these dikes are not susceptible to
liquefaction or cyclic softening, and risk of excessive deformation or settlement of the
embankments is considered negligible during the Maximum Design Earthquake (MDE).
• Hydrology and Hydraulics (H&H) Capacity Analyses:
In April 2019, the NCDEQ promulgated new dam safety rules and, per the dam safety High
Hazard Classification, each basin is required to pass a full Probable Maximum Precipitation
(PMP). Each basin is classified as high hazard by NCDEQ due to the potential for
environmental impacts greater than $200,000, if the basin failed. In response, Wood
performed H&H analysis for each of the basins at the HF Lee site. Based upon the results of
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these analyses, Basins 1, 2, and 3 will flood from overtopping of the Neuse River (within the
100-year flood zone). The 1982 Basin has the capacity to contain and release 80 percent of
the detained storm volume within 15 days following the design storm peak (6-hour PMP) as
required by the North Carolina dam safety rules. These analyses are included in Appendix
C.
3.1.4 Sources of Discharges into Surface Impoundments
Duke Energy has decommissioned the coal-fired power plant at this site. Since it is now
permanently retired from service, CCR is no longer sluiced into the Basin system, and the Basin
system is inactive. Because the Basins are surrounded by perimeter dikes, stormwater runoff
from adjacent drainage areas does not enter the Basins. As a result, only direct precipitation on
the pond surface collects within the Basins. Basins 1, 2, and 3 are surrounded by perimeter dikes
and runoff from adjacent areas does not enter the Basins except during extreme rain events when
the Neuse River floods.
3.1.5 Existing Liner System
The Basins located at HF Lee do not include geomembrane or clay liner systems and are
considered to be unlined.
3.1.6 Inspection and Monitoring Summary
Duke Energy conducts routine weekly, monthly, and annual inspections of the Basins, consistent
with North Carolina's dam safety requirements and the federal CCR rule.
Weekly Basin inspections have been on -going since 2014, and include observation of upstream
slopes and shorelines, crest, downstream slopes, toes, abutment contacts and adjacent drainage
way(s), spillway(s) and associated structure(s), and other structures and features of the dikes.
Monthly inspections of the Basins include the weekly monitoring elements with the addition of
piezometer and observation well readings, water level gauges/sensors, and visual observations
and documentation.
Daily inspections of the Basins are not routinely required; however, on a case -by -case basis, the
Basins may be inspected daily beginning at such times and continued for the duration as specified
by plant management. Such daily inspections might be initiated during a repair activity on the dike
or in response to a specific imposed regulatory agency requirement.
The Basins are inspected annually by an independent third -party consultant. In a letter dated
August 13, 2014, NCDEQ requires these inspections to be conducted annually at all of Duke
Energy's CCR impoundments in North Carolina. These inspections are intended to confirm
adequacy of the design, operation, and maintenance of the surface impoundments in accordance
with accepted engineering standards. Reports are to be submitted to the NCDEQ within 30 days
of the completion of the inspection.
The results for the annual inspections are used to identify needed repairs, repair schedules, to
assess the safety and operational adequacy of the dike, and to assess compliance activities
regarding applicable permits and environmental and dam regulations. Annual inspections are also
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performed to evaluate previous repairs. The annual inspections of the dikes have been ongoing
since 2012, with five-year inspections conducted between 1999 and 2009.
The 2015 through 2019 annual inspections did not identify features or conditions in the Basin
dikes or their outlet structures or spillways, that indicate an imminent threat of impending failure
hazard. Review of analyses indicated the design conforms to current engineering state of practice
to a degree that no immediate actions are required other than the recent and ongoing surveillance
and monitoring activities already underway.
Special inspections of the HF Lee Basins may be performed during episodes of high -flow,
earthquake, emergency, or other extraordinary events. Visual inspections are performed after a
heavy precipitation event when accumulation of four inches of rainfall or greater occurs within a
24-hour period. An internal inspection will be performed if an earthquake is felt locally or detected
by the US Geological Survey measuring greater than a Magnitude 3 and with an epicenter within
50 miles of the dikes. A special inspection would also be performed during an emergency, such
as when a potential dike breach condition might be identified or when construction activities (e.g.,
basin cleanout) are planned on or near the dikes. Special inspections are also conducted when
the ongoing surveillance program identifies a condition or a trend that warrants special evaluation.
3.2 Site Maps
3.2.1 Summary of Existing CCR Impoundment Related Structures
A site map showing property boundary, location of HF Lee Station and Basins with their
boundaries, and topographic and bathymetric contours are shown on Figure 1-2.
3.2.2 Receptor Survey
This information was submitted to NCDEQ in September 2016 as part of the Update to Drinking
Water Well and Receptor Survey for HF Lee Energy Complex prepared separately for Duke
Energy. The Update to Drinking Water Well and Receptor Survey document is herein
incorporated by this reference, but its content was not prepared by Wood.
3.2.3 Existing On -Site Landfills
There are no known on -site landfills at the HF Lee Station.
3.3 Monitoring and Sampling Location Plan
This information was submitted to NCDEQ on July 30, 2019 as part of the CAMA Annual Interim
Monitoring Report prepared separately for Duke Energy. The CAMA Annual Interim Report is
herein incorporated by this reference, but its content was not prepared by Wood.
Locations of the existing groundwater monitoring wells are shown in the Closure Plan Drawings
included in Appendix D, but the CAMA Annual Interim Report should be consulted for details of
well locations, names, and status.
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4.0 RESULTS OF HYDROGEOLOGIC, GEOLOGIC, AND GEOTECHNICAL
INVESTIGATIONS
4.1 Background
An overall boring and existing monitoring well location plan, indicating the locations of recent and
historical borings, monitoring wells, piezometers, and Cone Penetration Test (CPT) soundings, is
shown on drawing Figure 4 in Appendix D.
This chapter summarizes the site geology and hydrogeology; site stratigraphy of the geologic
units underlying the surface impoundments; hydraulic conductivity of CCR and the soils
underlying the surface impoundment; geotechnical properties of the CCR and the uppermost
stratigraphic unit under the surface impoundment; and the CCR and CCR-affected soils. Duke
Energy provided Wood with pertinent documentation regarding the site geology and hydrologic
information, which had already been compiled.
4.2 Hydrogeology and Geologic Descriptions
This information was submitted to NCDEQ on August 4, 2015 as part of the CSA and on
September 16, 2016 in an updated CSA Supplement 1 prepared separately for Duke Energy.
The CSA and CSA Supplement 1 are herein incorporated by this reference, but their content was
not prepared by Wood.
4.3 Stratigraphy of the Geologic Units Underlying Surface Impoundments
This information was submitted to NCDEQ on August 4, 2015 as part of the CSA and on
September 16, 2016 in an updated CSA Supplement 1 prepared separately for Duke Energy.
The CSA and CSA Supplement 1 are herein incorporated by this reference, but their content was
not prepared by Wood.
4.4 Geotechnical Properties
This section provides a summary of geotechnical conditions and properties found from
investigations performed within the Basins and Basin dike areas. The presented information was
obtained from previous geotechnical investigations at the site and recent investigation activities
conducted to support the Closure Plan development. The geotechnical conditions within the
Basins generally consist of CCR material (primarily interbedded layers of fly ash and bottom ash,
along with coal slag, unburned coal, and plant stormwater) placed in the basin primarily by
hydraulic sluicing, underlain by residual soil, saprolite, partially weathered rock (PWR), and
bedrock.
For purposes of discussion of the geotechnical properties of the materials, the saprolite material
is described as residual material. General properties of the various materials encountered within
and surrounding the Basins are described below. A range of measured material properties of
laboratory tests performed by Wood and SynTerra for the subsurface explorations completed
within the Basins is presented in Appendix B. A summary of typical measured properties for
different material types is presented in Table 4-1. A summary of laboratory test data obtained in
support of the closure design is also presented in Appendix B.
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4.4.1 CCR Within the Basins
The CCR within the Basins consist primarily of layers and mixtures of bottom ash and fly ash.
Other CCR materials such as slag are also typically encountered. The bottom ash generally
consists of very loose to loose, moist to wet, dark gray to gray, silty sand (SM) or silt and sandy
silt (ML). At some drilling locations, a surficial layer of CCR fill material (SP or SW or SW-SM)
was encountered that was used for boring access road construction.
The fly ash generally consists of very soft to soft, moist to wet, light to medium gray sandy silt and
silt (ML).
Further information is included as part of the updated CSA being prepared separately by SynTerra
for Duke Energy and will be submitted to NCDEQ by September 1, 2020. The CSA is herein
incorporated by this reference, but its content is not the work product of Wood.
4.4.2 Liner Material Properties
The Basins at the HF Lee Station are unlined, so there are no associated material properties.
4.4.3 Subsurface Soil Properties
The site is in the transition from the Piedmont to the Coastal Plan physiographic provinces. The
surficial materials are interlayered sandy clays and clayey sands that are typical of the Inner
Coastal Plain while the deeper materials are residual silty soils derived from chemical and
physical weathering of metavolcanic rocks. With increasing depth, the residual soils become hard
and transition to partially weathered rock and rock. Partially weathered rock is a term applied for
engineering used to designate residual materials having Standard Penetration Test (SPT) N-
values greater than 100 blows per foot.
Based on review of the deep borings performed at the 1982 Basin, it appears that the transition
from the coastal deposits to the residual soils (Piedmont) is 20 to 40 feet below the bottom of the
basin embankments. Around Basins 1, 2 and 3, it appears that the transition is 10 to 20 feet below
the bottom of the basin embankments.
The foundation soils consist of interbedded layers of sand with varying amounts of fines, silt, and
clay. The foundation soils were found to be about 10 to 40 feet thick below the pond dikes or
CCR. The SPT N-values of the foundation soils indicate that the soils range from loose to dense
and soft to stiff. The soils become denser/stiffer with depth.
Partially Weathered Rock (PWR) was encountered in eight of the exploratory borings at Basins
1, 2, and 3, and in four borings performed at the 1982 Basin. The PWR was sampled as sandy
silt with rock fragments. At the 1982 Basin, the PWR was encountered at depths ranging from 42
to 87 feet below the crest of the dikes (Elevations 4 to 47 feet. The PWR was shallowest at the
northwest corner of the basin and was deeper toward the southeast corner. At Basins 1, 2 and 3,
the PWR was encountered at depths ranging from 11 to 27 feet below the ground surface
(Elevations 69 to 52 feet).
Surficial deposits overlie the Cape Fear Formation near Basins 1, 2, and 3 and in the area west
of the 1982 Basin. The Black Creek Formation underlies surficial deposits at the 1982 Basin and
to the east. The contact between the CCR and underlying soils in Basin borings was visually
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distinct. Surficial deposit material west of the 1982 Basin were determined by grain size analysis
to be silty fine to medium sands and silty fine to coarse sands. Surficial deposit sediments
identified as Cape Fear Formation to the northwest of the 1982 Basin were determined to be silty
fine to coarse sands.
4.5 Chemical Analysis of Impoundment Water, CCR and CCR Affected Soil
This information was submitted to NCDEQ on August 4, 2015 as part of the CSA and on
September 16, 2016 in an updated CSA Supplement 1 prepared separately for Duke Energy.
The CSA and CSA Supplement 1 are herein incorporated by this reference, but their content was
not prepared by Wood.
4.6 Historical Groundwater Sampling Results
Duke Energy provides CAMA groundwater monitoring results to NCDEQ on a quarterly basis.
Additionally, historical groundwater monitoring results have been submitted in multiple reports
such as the August 2015 CSA, the September 2016 CSA Supplement 1, and the 2018 CAMA
Annual Interim Monitoring Report prepared separately for Duke Energy. These documents are
herein incorporated by this reference but were not prepared by Wood.
4.7 Groundwater Potentiometric Contour Maps
Groundwater level maps for each designated flow zone were submitted to NCDEQ on July 30,
2019 as part of the CAMA Annual Interim Monitoring Report prepared separately for Duke Energy.
The CAMA Annual Interim Report is herein incorporated by this reference, but its content was not
prepared by Wood.
4.8 Estimated Vertical and Horizontal Extent of CCR within the Impoundments
This information was submitted to NCDEQ on August 4, 2015 as part of the CSA and on
September 16, 2016 in an updated CSA Supplement 1 prepared separately for Duke Energy.
The CSA and CSA Supplement 1 are herein incorporated by this reference, but their content was
not prepared by Wood.
5.0 GROUNDWATER MODELING ANALYSIS
This information was submitted to NCDEQ on November 2, 2015 as part of the CAP Part 1
prepared separately for Duke Energy. The CAP Part 1 is herein incorporated by this reference,
but its content was not prepared by Wood.
5.1 Site Conceptual Model Predictions
This information was submitted to NCDEQ on November 2, 2015 as part of the CAP Part 1
prepared separately for Duke Energy. The CAP Part 1 is herein incorporated by this reference,
but its content was not prepared by Wood.
5.2 Geochemical Site Conceptual Model
This information was submitted to NCDEQ on November 2, 2015 as part of the CAP Part 1
prepared separately for Duke Energy. The CAP Part 1 is herein incorporated by this reference,
but its content was not prepared by Wood.
5.3 Groundwater Trend Analysis
This information was submitted to NCDEQ on November 2, 2015 as part of the CAP Part 1
prepared separately for Duke Energy. The CAP Part 1 is herein incorporated by this reference,
but its content was not prepared by Wood.
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6.0 BENEFICIAL USE AND FUTURE USE
6.1 CCR Use
Duke Energy has developed plans for on -site recovery and reclamation/recycling of a significant
portion of the CCR at HF Lee, in accordance with rate established by N.C.G.S. § 130A-309.216.
Duke Energy will implement a concurrent excavation plan in which the remaining excavated CCR
will be transported to an approved landfill facility in order to meet the end date of December 31,
2029 for complete removal.
The beneficial use activities consist of removing and transporting CCR from the Basins for
processing at a STAR' facility to be constructed on -site west of the combined cycle plant. The
STAR° facility will process the reclaimed CCR to a level of quality and condition suitable for future
reuse in the concrete industry.
6.2 Site Future Use
At this time, Duke Energy has not identified any future use of the land reclaimed by the dewatering
and excavation of the Basins.
Since this Closure Plan details a closure by excavation method, no recording of a notation on the
deed to the property is required.
7.0 CLOSURE DESIGN DOCUMENTS
Closure of the HF Lee Basins will be completed in two phases. Phase 1 is excavation (and
beneficiation program) and Phase 2 will be the final decommissioning of the basin dikes and final
grading.
7.1 Engineering Evaluations and Analyses
Engineering evaluations and analyses to support closure of the Basins at HF Lee, as detailed in
this Closure Plan, are provided in Appendix C. Based on the final post -closure configuration of
the Basins and absence of engineered fill features, no geotechnical calculations accompany the
Closure Plan presented herein. Calculations related to dike removal will be included in the dike
modification permit applications.
Safe and effective access to the Basins is critical to CCR excavation and the completion of
closure. Access road locations into or across the Basins cannot be reliably established until
detailed phasing of closure is developed, and a contractor is selected to complete the work. A
variety of mitigation techniques are commonly applied, such as installation of a geogrid and
crushed stone aggregate, placement and spreading of dry CCR over the Basin surfaces to
establish access and use of low ground pressure or light weight construction equipment.
Areas for stockpiling or conditioning(drying) of CCR are generally needed. These areas must be
established within the limits of the CCR unit and require placement or stacking of CCR excavated
from other areas of the Basins. They can be established in areas where all or most of the CCR
has been removed, or on areas where a significant depth of CCR remains in place. Sluiced CCR
forming the foundation of stockpiles or conditioning (drying) areas may be subject to bearing
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capacity or slope failures from the additional vertical compressive stress imparted by the stacked
CCR and hauling equipment.
During excavation of CCR, interim or temporary excavated CCR slopes are commonly created.
These slopes vary in height and the duration they will have to stand. Some slopes are subject to
potential loading from hauling or stockpiling operations. The location and geometry of such slopes
generally cannot be established during design. These elements depend on the means and
methods employed by the construction contractor, site conditions, schedule, and other site
conditions. Excavation in CCR creates significant safety risks that need further evaluation and will
require the means and methods inputs from a contractor to fully address before closure
excavation work commences. A detailed phasing and excavation plan will be developed after this
Closure Plan is approved by NCDEQ.
7.2 Closure Plan Activities
The primary activities associated with closure by excavation are as follows:
• Decant by using floating pumps, screened intakes, and pumping through the existing
NPDES discharge outlet.
• Construct required haul roads and the STAR° unit for processing the CCR for beneficial
re -use.
• Install stormwater diversion or retention controls to minimize stormwater flow impacts to
the CCR within the Basins.
• Operate the on -site pumping and water management system to manage interstitial/pore
water and contact stormwater during construction.
• Dewatering the CCR to allow for safe access. CCR excavation and conditioning prior to
transport to the STAR® unit.
• Start CCR excavation from the basin, with sequencing determined for optimal progression.
Stockpile CCR and provide conditioning prior to transport to the on -site STAR° system.
Construction dewatering to be used as needed to provide safe and stable work areas and
slopes.
• Maintain required hydraulic storage capacity throughout the excavation process.
• Manage dusting from closure activities through the use of appropriate controls.
• Complete closure by excavation verification (see Appendix E for sampling grid). Grade
the area to promote positive drainage and seed for vegetative growth.
• Sequence final dike breach with inflow design flood management.
Additional information and details pertaining to the closure design are provided in the Closure
Plan drawings, which can be found in Appendix D.
7.3 Design Drawings
Closure Plan drawings are provided for the 1982 Basin and Basins 1, 2, and 3. The Closure Plan
drawings found in Appendix D include the following for the 1982 Basin:
• Sheet 1 — Cover sheet
• Sheet 2 — General Project Notes
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• Sheet 3 — Existing Overall Aerial
• Sheet 4 — Existing Conditions
• Sheet 5 — Estimated Bottom of Ash Grades
• Sheet 6 — Proposed Final Conditions
• Sheet 7 — Cross -Sections
The Closure Plan drawings found in Appendix D include the following for Basins 1, 2, and 3:
• Sheet 1 —
Cover sheet
• Sheet 2 —
General Project Notes
• Sheet 3 —
Existing Overall Aerial
• Sheet 4 —
Existing Conditions
• Sheet 5 —
Estimated Bottom of Ash Grades
• Sheet 6 —
Basins 1 & 2 Proposed Final Conditions
• Sheet 7 —
Basins 1 & 2 Cross -Sections
• Sheet 8 —
Basin 3 Proposed Final Conditions
• Sheet 9 —
Basin 3 Cross -Section
These Closure Plan drawings will be further developed and refined to develop construction -level
drawings during subsequent stages following NCDEQ approval of the Closure Plan. In addition,
supplemental drawing sets will be prepared on an as -needed basis to support dike modification
and/or decommissioning permits, erosion, and sediment control permits, NPDES permit
modifications, and any other related permits.
Once the excavation grades shown on the Closure Plan drawings have been achieved, the
procedures described in the Duke Energy Excavation Soil Sampling Plan (Appendix E) will be
followed to confirm that closure by excavation has been achieved.
7.4 Description of Construction Quality Assurance and Plan
A Construction Quality Assurance (CQA) Plan will be developed following NCDEQ approval of the
Closure Plan for closure of the CCR Basins located at the HF Lee Station site. This CQA Plan
description has been prepared to address N.C.G.S. § 130A-309.214(a)(4)(g) of CAMA, and its
purpose is to provide a description of the CQA program to be adhered to in execution of the final
closure activities at the HF Lee Station, being the construction of the dike breach and stormwater
channels. The CQA Plan will be a component of the dam decommissioning package and will
include a description of the roles and responsibilities for monitoring and testing activities and
provides guidance on the methodology to be used for evaluating whether the construction has
been performed in accordance with the approved Closure Plan. The CQA Plan will also detail the
material testing frequencies; methods for transportation, handling, and storage of materials; test
methods and verifications; manufacturer, field, and laboratory testing; field activities for
construction monitoring and oversight; and reporting and documentation requirements. Technical
specifications to be developed as part of the construction -level design packages for contractor
bidding will present specific material properties and specifications.
The items that will be included in the CQA Plan will address materials and CQA activities
associated with the following components:
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• Earthwork
• Stormwater Channels
• HDPE Piping
• As -Built Conditions
• Record Documentation Report
8.0 MANAGEMENT OF WASTEWATER AND STORMWATER
• Existing Wastewater and Stormwater Conditions
The Basins at HF Lee are impounded by raised perimeter dikes. There are no surface water run-
on flows into the Basins. However, Basins 1, 2, and 3 may become inundated during Neuse River
flooding events.
In April 2019, NCDEQ promulgated new dam safety requirements and, per the dam safety High
Hazard Classification, each CCR basin is now required to pass a full PMP storm event. The HF
Lee Basins are classified as High Hazard by NCDEQ due to the potential for environmental
impacts greater than $200,000, if the Basins failed. The PMP event will produce 29.5 inches of
rainfall (HMR-51, 6-hour, 10 mi2, All -Season PMP Isopluvial Map) at HF Lee.
Wood evaluated the site for the full PMP rainfall event and results indicated that the 1982 Basin
has the capacity to contain and release the full PMP storm event. The Basins 1, 2, and 3 do not
have operating outlet structures. Therefore, pursuant to the 2019 dam safety rules, these Basins
would require the capacity to capture and store back-to-back design storm events. However,
these basins are located adjacent to the Neuse River, and within the 100-year flood zone. In the
event of a storm event exceeding the 100-year storm, waters from the Neuse River would flow
into Basins 1, 2 and 3, until such time as the Neuse River receded to below flood stage. The
modeling results that indicate that the 1982 Basin has the storage capacity to hold and release
the full PMP storm event are included in Appendix C.
The HF Lee Station operates under a NPDES permit issued by the NCDEQ. Permit number
NC0003417, effective July 1, 2019 through March 31, 2024, authorizes four discharge points that
flow into the Neuse River. Outfall 001 is the associated outfall for the 1982 Basin discharges.
None are associated with discharges from Basins 1, 2, or 3.
• Wastewater and Stormwater Management During CCR Excavation
The 1982 Basin discharges will continue to be in service to meet the NPDES permit discharge
requirements as it goes through the phases of: (1) free (bulk) water removal, treatment, and
discharge via the permitted outfall during closure initiation (decanting); and (2) interstitial water
treatment and discharge via permitted outfall during closure construction (dewatering and
groundwater extraction), and (3) interstitial water treatment and discharge via permitted outfall
during final closure construction (groundwater extraction). Dewatering is currently proceeding via
mechanical pumping. The pumping system is expected to draw down the stored water after storm
events, route through the treatment system if necessary, and discharge via the permitted outfall.
When dewatering of the CCR begins, all discharge flows are anticipated to be routed through the
water management system (WMS) in order to meet the permitted discharge limits. The WMS
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utilizes submersible pumps installed on floating structures in the 1982 Basins to supply feed water
to the system. WMS at HF Lee includes a physical -chemical treatment system designed to meet
the requirements of the discharge permit, including continuous monitoring for pH and Total
Suspended Solids. The system is setup for remote monitoring of flows, basin level, chemical
levels, pressures, and alarms.
The discharge of the WMS must be under the outfall limits prescribed in the NPDES permit. It is
expected that bulk water from the basins will meet discharge limits without treatment as the
untreated free water is expected to meet permitted discharge limits. Duke Energy is in the process
of applying for additional NPDES outfalls to facilitate dewatering during closure of Basins 1, 2,
and 3.
Dewatering will be performed to remove the interstitial or pore water from the CCR to facilitate
excavation, to access in -place CCR or to establish safe slopes prior to and after CCR excavation.
It is anticipated that performance criteria will be established in the construction -level
documentation to identify required vertical and horizontal limits of interstitial water removal at
critical locations and for critical conditions during closure.
Excavated CCR will have to be conditioned (screened) prior to transport to the STAR' unit.
Consideration of required conditioning and management of contact water during excavation will
be included in the development of closure phasing.
Post -Closure Stormwater Management
The post -closure grading is anticipated to provide sheet flow to discharge points flowing to the
Neuse River with no detention. Up to and including the last phase of closure before the basin
dikes are breached, the Basins will maintain the capacity to contain the required storm size/flows.
The concept plans for post -closure grading are based conservatively on 100-year storm events.
Appendix C presents the results of the post -closure stormwater management calculations.
8.1 Anticipated Changes in Wastewater and Stormwater Management
Closure of the Basins has necessitated changes in the management of a number of wastewater
and process streams. Wastewater and process streams previously discharging to the Basins have
been rerouted to new station outfalls.
A temporary WMS will be installed for the closure of the Basins. A floating intake suction pump
and screen (followed by a sump upon sufficient dewatering), will be placed at the location of the
lowest elevation within the Basins. The system design, including pump capacity and filter size,
are such that the existing NPDES Outfall 001 effluent discharge limits (or future NPDES Outfalls),
or other limits as directed by the NCDEQ, will be met throughout the duration of dewatering and
closure.
Erosion and Sediment Control Plans for different phases of the excavation will be developed as
part of the excavation packages for field implementation and formal Erosion and Sediment Control
Plan permit submittal. The Basins are NPDES permitted wastewater treatment units. Therefore,
only activities that can impact the areas outside the Basins will need to be addressed as part of
the Erosion and Sediment Control Plan. However, water quality of discharges from the Basins
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during excavation may be impacted due to activities within the Basins, and appropriate planning
and control measures will need to be implemented. This will be addressed during subsequent
stages of the design, and calculations to support the Erosion and Sediment Control Plans will be
developed during future stages of the design, which will follow NCDEQ approval of this Closure
Plan. In addition, erosion and sediment control measures may be installed and removed in phases
as stabilization is achieved.
8.2 Wastewater and Stormwater Permitting Requirements
Information on required permits is described in Section 10.
9.0 DESCRIPTION OF FINAL DISPOSITION OF CCR
CCR materials in the Basins at the HF Lee Station will be excavated, processed, and beneficially
reused for HF Lee to achieve project goals in accordance with applicable state and federal
requirements and beneficial reuse contracts. CCR processing will be done using STAR'
Technology, a patented thermal beneficiation process to transform CCR into a high -quality,
sustainable product for the concrete industry.
An estimate of 6.2 million tons (5.17 million cubic yards) of CCR are currently stored in the Basins
at the HF Lee Station (refer to section 3.1.2 for a detailed discussion and to Appendix A for
quantities). At full production, the STAR° facility is designed to process 400,000 tons of CCR
material per year (based on information provided by Duke Energy). Assuming 10-years of
processing (2020-2029), this would allow approximately 4 million tons of CCR material to be
processed for beneficial re -use, leaving 2.2 million tons which would potentially require handling
by another process.
In order to meet the CCR removal deadline, Duke Energy will periodically review the progress of
the excavation and STAR° processing as it relates to achieving full CCR removal by the required
end date of December 31, 2029. Duke Energy will implement a concurrent excavation plan in
which excavated CCR will be transported to a permitted facility in order to meet the end date of
December 31, 2029 for complete removal.
Vegetation encountered or removed during the progression of the work will be managed in
accordance with state regulations for handling and disposal.
10.0 APPLICABLE PERMITS FOR CLOSURE
Refer to Table 10-1 for detailed information on the potential and applicable permitting/approval
needed to implement this Closure Plan. Development of permitting package submittals and/or
regulatory approval requests will follow NCDEQ approval of the Closure Plan.
11.0 DESCRIPTION OF POST -CLOSURE MONITORING AND CARE
A Post -Closure Care Plan will be developed following NCDEQ approval of the Closure Plan for
closure of the CCR Basins located at the HF Lee Station site. The purpose of the Post -Closure
Care Plan will be to provide a description of the inspection, monitoring, and maintenance activities
required to be performed throughout the minimum 30-year post -closure care period for the closed
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CCR Basins at the HF Lee site. The Basins at the HF Lee site are detailed in this Closure Plan
as being closed by excavation.
The Post -Closure Care Plan will be developed to meet the requirements of N.C.G.S. § 130A-
309.214(a)(4)(k). The items that are included in the Post -Closure Care Plan for HF Lee include:
• Name, address, phone number, and email address of the responsible office or person;
• Means and methods of managing affected groundwater and stormwater;
• Maintenance of the groundwater monitoring systems;
• Regular inspection and maintenance of the final cover system;
• Groundwater and surface water monitoring and assessment program;
• Post -closure inspection checklist to guide post -closure inspections;
• Description of planned post -closure uses; and
• Financial assurance estimates for post -closure operations and maintenance and
remedial action.
11.1 Groundwater Monitoring Program
This information was submitted to NCDEQ on July 30, 2019 as part of the CAMA Annual Interim
Monitoring Report prepared separately for Duke Energy. The CAMA Annual Interim Report is
herein incorporated by this reference, but its content was not prepared by Wood.
12.0 PROJECT MILESTONES AND COST ESTIMATES
12.1 Project Schedule
In December 2016, Duke Energy selected HF Lee as an Ash Beneficiation site as required by
N.C.G.S. § 130A-309.216. Excavation of CCR from the HF Lee site for beneficial use will occur
over multiple project phases. Activities started in 2018 and will continue until all CCR is removed
in 2029, then continuing until approximately 2030, when final site restoration is completed.
A Closure Project high-level milestone schedule has been prepared by Duke Energy and the
major activities and milestones are provided below:
Engineering, Dewatering Ongoing
Complete CCR Excavation Q4-2029
Site Restoration Q4-2030
12.2 Closure and Post -Closure Cost Estimate
Cost estimates for closure and post -closure care of the CCR Basins at HF Lee were developed
by Duke Energy and provided to Wood. These cost estimates are not a work product of Wood.
These are Class 5 estimates as the detailed and final design has not been developed at this stage
of the closure project. Following approval of this Closure Plan by NCDEQ and further development
of the project plans and engineering designs, the cost estimate will be refined and updated.
The cost to complete the closure by excavation is estimated to be $524 million.
Rev. 1
2 April 2020 16

Wood Environment &Infrastructure Solutions, Inc. wood.
Duke Energy Coal Combustion Residuals Management Program
HF Lee Station Basin CAMA Closure Plan
The cost to perform the 30-year post -closure activities and monitoring is estimated as $33 million.
The cost estimates include the following major activities:
• Mobilization and Site Preparation
• Dewatering, Earthwork, and Subgrade Preparation
• CCR Excavation
• Stormwater Management, Erosion and Sediment Control, and Site Restoration
• Engineering Support (Design and CQA)
• Post -Closure — Groundwater Monitoring
• Post -Closure — Operations and Maintenance
• Contingency
Corrective action costs are included as part of the updated CAP being prepared separately by
SynTerra for Duke Energy and will be submitted to NCDEQ by July 1, 2021. The CAP is herein
incorporated by this reference, but its content is not the work product of Wood.
Rev. 1
2 April 2020 17

Wood Environment &Infrastructure Solutions, Inc. wood.
Energy Coal Combustion Residuals Management Program
HF Lee Station Basin CAMA Closure Plan
13.0 REFERENCES
North Carolina General Assembly, Session Law 2014-122, Coal Ash Management Act, as
amended
North Carolina Department of Environmental Quality report, "Coal Combustion Residual
Impoundment Risk Classification" (2016)
North Carolina Department of Environmental Quality, 15A N.C.A.0 02K — North Carolina dam
safety rules
North Carolina Department of Environmental Quality, 15A N.C.A.C. 02L - North Carolina
groundwater rules
United States Environmental Protection Agency, Coal Combustion Residuals (CCR) Rule 40
C.F.R. Part 257, subpart D
Rev. 0
11 December 2019 18

Wood Environment &Infrastructure Solutions, Inc. wood.
Energy Coal Combustion Residuals Management Program
HF Lee Station Basin CAMA Closure Plan
TABLES

Wood Environment &Infrastructure Solutions, Inc. wood.
Energy Coal Combustion Residuals Management Program
HF Lee Station Basin CAMA Closure Plan
Table 2-1: CAMA Closure Plan Requirements
Summary and Cross Reference Table
Duke Energy, HF Lee Station
No.
Description
Corresponding
Closure Plan Section
Part II. Provisions for Comprehensive Management of Coal Combustion
Residuals § 130A-309.212(a)(4) Closure Plans for all impoundments shall
include all of the following:
a. Facility and coal combustion residuals surface impoundment— A
description of the operation of the site that shall include, at a minimum, all
of the following:
Site history and history of site operations, including details on the
1
manner in which coal combustion residuals have been stored and
3.1.1
disposed of historically.
2
Estimated volume of material contained in the impoundment.
3.1.2
3
Analysis of the structural integrity of dikes or dams associated with
3.1.3
impoundment.
4
All sources of discharge into the impoundment, including volume
3.1.4
and characteristics of each discharge.
5
Whether the impoundment is lined, and, if so, the composition
7.1
thereof.
A summary of all information available concerning the
6
impoundment as a result of inspections and monitoring conducted
3.1.6
pursuant to this Part and otherwise available.
b. Site maps, which, at a minimum, illustrate all of the following:
All structures associated with the operation of any coal
combustion residuals surface impoundment located on the site.
1
For purposes of this sub -subdivision, the term "site" means the
3.2.1
land or waters within the property boundary of the applicable
electric generating station.
All current and former coal combustion residuals disposal and
storage areas on the site, including details concerning coal
2
combustion residuals produced historically by the electric
3.3
generating station and disposed of through transfer to structural
fills.

Wood Environment &Infrastructure Solutions, Inc. wood.
Energy Coal Combustion Residuals Management Program
HF Lee Station Basin CAMA Closure Plan
No.
Description
Corresponding
Closure Plan Section
3
The property boundary for the applicable site, including
3.3
established compliance boundaries within the site.
4
All potential receptors within 2,640 feet from established
3 2 2
compliance boundaries.
Topographic contour intervals of the site shall be selected to
5
enable an accurate representation of site features and terrain and
3.3
in most cases should be less than 20-foot intervals.
Locations of all sanitary landfills permitted pursuant to this Article
6
on the site that are actively receiving waste or are closed, as well
3.2.3
as the established compliance boundaries and components of
associated groundwater and surface water monitoring systems.
All existing and proposed groundwater monitoring wells
7
associated with any coal combustion residuals surface
3.3
impoundment on the site.
All existing and proposed surface water sample collection
8
locations associated with any coal combustion residuals surface
3.3
impoundment on the site.
c. The results of a hydrogeologic, geologic, and geotechnical investigation of
the site, including, at a minimum, all of the following:
1
A description of the hydrogeology and geology of the site.
4.1
A description of the stratigraphy of the geologic units underlying
2
each coal combustion residuals surface impoundment located on
4.2
the site.
The saturated hydraulic conductivity for (i) the coal combustion
residuals within any coal combustion residuals surface
3
impoundment located on the site and (ii) the saturated hydraulic
4.3
conductivity of any existing liner installed at an impoundment, if
any.

Wood Environment &Infrastructure Solutions, Inc. wood.
Energy Coal Combustion Residuals Management Program
HF Lee Station Basin CAMA Closure Plan
No.
Description
Corresponding
Closure Plan Section
The geotechnical properties for (i) the coal combustion residuals
within any coal combustion residuals surface impoundment
located on the site, (ii) the geotechnical properties of any existing
liner installed at an impoundment, if any, and (iii) the uppermost
4
identified stratigraphic unit underlying the impoundment, including
4.4
the soil classification based upon the Unified Soil Classification
System, in -place moisture content, particle size distribution,
Atterberg limits, specific gravity, effective friction angle, maximum
dry density, optimum moisture content, and permeability.
A chemical analysis of the coal combustion residuals surface
5
impoundment, including water, coal combustion residuals, and
4.5
coal combustion residuals -affected soil.
Identification of all substances with concentrations determined to
be in excess of the groundwater quality standards for the
6
substance established by Subchapter L of Chapter 2 of Title 15A
4.6
of the North Carolina Administrative Code, including all laboratory
results for these analyses.
7
Summary tables of historical records of groundwater sampling
4.6
results.
A map that illustrates the potentiometric contours and flow
directions for all identified aquifers underlying impoundments
8
(shallow, intermediate, and deep) and the horizontal extent of
4.7
areas where groundwater quality standards established by
Subchapter L of Chapter 2 of Title 15A of the North Carolina
Administrative Code for a substance are exceeded.
Cross -sections that illustrate the following: the vertical and
horizontal extent of the coal combustion residuals within an
impoundment; stratigraphy of the geologic units underlying an
9
impoundment; and the vertical extent of areas where groundwater
4.8
quality standards established by Subchapter L of Chapter 2 of
Title 15A of the North Carolina Administrative Code for a
substance are exceeded.
d. The results of groundwater modeling of the site that shall include, at a
minimum, all of the following:

Wood Environment &Infrastructure Solutions, Inc. wood.
Energy Coal Combustion Residuals Management Program
HF Lee Station Basin CAMA Closure Plan
No.
Description
Corresponding
Closure Plan Section
An account of the design of the proposed Closure Plan that
is based on the site hydrogeologic conceptual model
developed and includes (i) predictions on post -closure
groundwater elevations and groundwater flow directions
1
and velocities, including the effects on and from the
5.1
potential receptors and (ii) predictions at the compliance
boundary for substances with concentrations determined to
be in excess of the groundwater quality standards for the
substance established by Subchapter L of Chapter 2 of Title
15A of the North Carolina Administrative Code.
Predictions that include the effects on the groundwater chemistry
and should describe migration, concentration, mobilization, and
fate for substances with concentrations determined to be in
2
excess of the groundwater quality standards for the substance
5.2
established by Subchapter L of Chapter 2 of Title 15A of the North
Carolina Administrative Code pre- and post -closure, including the
effects on and from potential receptors.
A description of the groundwater trend analysis methods used to
demonstrate compliance with groundwater quality standards for the
substance established by Subchapter L of Chapter 2 of Title 15A of
3
the North Carolina Administrative
5.3
Code and requirements for corrective action of groundwater
contamination established by Subchapter L of Chapter 2 of Title
15A of the North Carolina Administrative Code.
e. A description of any plans for beneficial use of the coal combustion
residuals in compliance with the requirements of Section .1700 of
Subchapter B of Chapter 13 of Title 15A of the North Carolina
Administrative Code (Requirements for Beneficial Use of Coal Combustion
6.1
By -Products) and Section .1205 of Subchapter T of Chapter 2 of Title 15A
of the North Carolina Administrative Code (Coal Combustion Products
Management).
f. All engineering drawings, schematics, and specifications for the proposed
Closure Plan. If required by Chapter 89C of the General Statutes,
7 1 7 2
engineering design documents should be prepared, signed, and sealed by
a professional engineer.
g. A description of the construction quality assurance and quality control
program to be implemented in conjunction with the Closure Plan, including
7.3
the responsibilities and authorities for monitoring and testing activities,
sampling strategies, and reporting requirements.

Wood Environment &Infrastructure Solutions, Inc. wood.
Energy Coal Combustion Residuals Management Program
HF Lee Station Basin CAMA Closure Plan
No.
Description
Corresponding
Closure Plan Section
h. A description of the provisions for disposal of wastewater and
8
management of stormwater and the plan for obtaining all required permits.
i. A description of the provisions for the final disposition of the coal
combustion residuals. If the coal combustion residuals are to be removed,
the owner must identify (i) the location and permit number for the coal
combustion residuals landfills, industrial landfills, or municipal solid waste
landfills in which the coal combustion residuals will be disposed and (ii) in
the case where the coal combustion residuals are planned for beneficial
use, the location and manner in which the residuals will be temporarily
stored. If the coal combustion residuals are to be left in the impoundment,
the owner must (i) in the case of closure pursuant to sub -subdivision
9
(a)(1)a. of this section, provide a description of how the ash will be
stabilized prior to completion of closure in accordance with closure and
post -closure requirements established by Section .1627 of Subchapter B
of Chapter 13 of Title 15A of the North Carolina Administrative Code and
(ii) in the case of closure pursuant to sub -subdivision (a)(1)b. of this
section, provide a description of how the ash will be stabilized pre- and
post -closure. If the coal combustion residuals are to be left in the
impoundment, the owner must provide an estimate of the volume of coal
combustion residuals remaining.
j. A list of all permits that will need to be acquired or modified to complete
10
closure activities.
k. A description of the plan for post -closure monitoring and care for an
impoundment for a minimum of 30 years. The length of the post -closure
care period may be (i) proposed to be decreased or the frequency and
parameter list modified if the owner demonstrates that the reduced period
or modifications are sufficient to protect public health, safety, and welfare;
the environment; and natural resources and (ii) increased by the
Department at the end of the post -closure monitoring and care period if
there are statistically significant increasing groundwater quality trends or if
contaminant concentrations have not decreased to a level protective of
11
public health, safety, and welfare; the environment; and natural resources.
If the owner determines that the post -closure care monitoring and care
period is no longer needed and the Department agrees, the owner shall
provide a certification, signed and sealed by a professional engineer,
verifying that post -closure monitoring and care has been completed in
accordance with the post -closure plan. If required by Chapter 89C of the
General Statutes, the proposed plan for post -closure monitoring and care
should be signed and sealed by a professional engineer. The plan shall
include, at a minimum, all of the following:
1
A demonstration of the long-term control of all leachate, affected
11.1
groundwater, and stormwater.

Wood Environment &Infrastructure Solutions, Inc. wood.
Energy Coal Combustion Residuals Management Program
HF Lee Station Basin CAMA Closure Plan
No.
Description
Corresponding
Closure Plan Section
A description of a groundwater monitoring program that includes
(i) post -closure groundwater monitoring, including parameters to
2
be sampled and sampling schedules; (ii) any additional monitoring
11.2
well installations, including a map with the proposed locations and
well construction details; and (iii) the actions proposed to mitigate
statistically significant increasing groundwater quality trends.
I. An estimate of the milestone dates for all activities related to closure and
12.1
post -closure.
m. Projected costs of assessment, corrective action, closure, and post -closure
12.2
care for each coal combustion residuals surface impoundment.
n. A description of the anticipated future use of the site and the necessity for
the implementation of institutional controls following closure, including
property use restrictions, and requirements for recordation of notices
6.2
documenting the presence of contamination, if applicable, or historical site
use.
§ 130A-309.212(b)(3) No later than 60 days after receipt of a proposed Closure Plan, the Department shall
conduct a public meeting in the county or counties proposed Closure Plan and alternatives to the public.
§ 130A-309.212(d) Within 30 days of its approval of a Coal Combustion Residuals Surface Impoundment
Closure Plan, the Department shall submit the Closure Plan to the Coal Ash Management Commission.

Wood Environment &Infrastructure Solutions, Inc. wood.
Energy Coal Combustion Residuals Management Program
HF Lee Station Basin CAMA Closure Plan
Table 4-1: Summary of Typical Material Properties
Duke Energy, HF Lee Station
Properties
1 x
CCR within the basins
Foundation Soil (Residual) below the
1 z
CCR Basins
Fill Soil within the Embankment
Dikes
Foundation Soil (Residual) below
the Embankment Dikes
Weathered Rock (W R)'
Soil Type
Silt/Sandy Silt (MQ - Predominantly
Fly Ash, Silty Sand (SM) -
Predominantly Bottom Ash
SC, 5M, ML, CH, and CL
SC, SM, SP-SM, CH, CL, and ML
SC, 5M, CH, CL, and ML
Breaks down to Sandy Silt and Silty Sand
with rack fragments
Color
Gray, dark gray, and black
Brown, tan, gray, while, and red
Tan, red, orange, and gray
Brown, tan, gray, and red
Brown, gray, and red
Plasticity
Predominantly Non Plastic
19 - 32
NP - 18
NP - 28
Liquid Limit
Predominantly Non Plastic
28 - 56
NP - 39
NP -74
Plasticity Index
Predominantly
Non Plastic
8-25
NP - 22
NP - 53
Representative
Rangege
Geometric Mean
Representative
Geometric Mean
Representative Range
Natural Moisture Content [96J
23%- 7796
431"
1796 - 29%
21%
12%- 341Y.
121A- 43%
**
Fines Content
39% - 85%
69%
8% 46%
28%
1% - 67%
2%- 72%
**
Clay Content
2% - 481X�
12%
2% - 479S
205%
2% - 51%
D%- 681Y.
**
Blow Count - Uncorrected N Value (bpf)
WOH - 8
2
2 - 26
9
4 - 39
2 - 85
solo" - 50/5"
Moist Unit Weight
55 - 98 pcf
83 pcf
132 pcf
*
118 - 140 pcf
126 - 132 pcf
**
Dry Unit Weight
45 - 62 pcf
55 pcf
112 pcf
*
89 - 125 pcf
89 - 108 pcf
**
Specific Gravily
2.1-2.7
2.3
2.9
*
**
**
**
Horizontal Hydraulic Conductivity (cm/sec)
9.5E-05 - 2.0E-04
7.1E-05
9.5E-08
*
**
**
**
Vertical Hydraulic Conductivity (cm/sec)
**
**
**
**
**
**
**
Notes:
Outlier values were not inlcuded in the table above. For additional laboratory testing information, see attached Appendix
NP: Non Plastic
pcf: Pounds per cubic foot (Ib/ft)
bpf: blows per foot
WOH: Weight of hammer
*Only one lab test available
**No lab data available
11-aboratory information and results for the Ash Basin and Ash Basin Foundation Soil were obtained from the following field explorations/reports: 2015 Synterra, 2015 Geosyntec, and 2013 Geosyntec
2Information for the uncorrected N Values of Ash and Ash Basin Foundation Soil were obtained from within the 2013 Geosyntec Field Exploration and Report.
;Data obtained for the uncorrected N Values of Weathered Rock were obtained from the 2014 Amec Foster Wheeler Field Exploration.

Wood Environment &Infrastructure Solutions, Inc. wood.
Energy Coal Combustion Residuals Management Program
HF Lee Station Basin CAMA Closure Plan
Table 10-1: Regulatory Permits, Approvals, or Requirements for
Basin Closure by Excavation
Duke Energy, HF Lee Station
Permit/Approval
Existing
Type of
General Permit
Regulating
Permit No.
Regulatory
Comments
Name or Subject
Agency
(if
Approval
applicable)
Mechanism or
Not Required
Air Quality
NCDEQ
Not Anticipated
Building Permit
Wayne County
Not Anticipated
Modification or
abandonment of
CAMA program
CAMA Monitoring
Written NCDEQ
NCDEQ
monitoring wells
Plan
DWR approval
require the approval of
the Division of Water
Resources (DWR)
CCR Impoundment
US EPA
Required postings to
Self -Regulating
Closure
CCR Rule
public Record
Maintain CCR GW
monitoring network
CCR Impoundment
US EPA
Self -Regulating
and requirements as
Monitoring Network
CCR Rule
stated in 257.90 -
257.98
Clean Water Act
Not Anticipated
401
Clean Water Act
Not Anticipated
404
Cutting Trees
Not Anticipated

Wood Environment &Infrastructure Solutions, Inc. wood.
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Permitting is required
to modify or abandon
WAYNE-022
wells and
WAYNE-031
Certificate of
instrumentation on
Dam Safety
NCDEQ
regulatory dams
WAYNE-032
Approval to Modify
through the Division of
WAYNE-033
Energy, Mineral, and
Land Resources
(DEMLR)
Ash Basin Dam -
Permitting is required
to modify the dam in
accordance with the
WAYNE-022
Dam Safety Law of
WAYNE-031
Certificate of
1967, 15A NCAS
Dam Safety
NCDEQ
WAYNE-032
Approval to Modify
02K.0201 (b)(2); an
application must be
WAYNE-033
filed with the Division
of Energy, Mineral, and
Land Resources
(DEMLR)
DOT - General
Not Anticipated
Driveway Permit
NCDOT
Not Anticipated
No land disturbance
activities outside of the
ash basin are
Erosion and
anticipated. In
NCDEQ and
Sediment Control
Not Anticipated
conformance with 15A
Wayne County
(E&SC)
NCAC 04, no E&SC
Permit is anticipated to
be required from Land
Quality.

Wood Environment &Infrastructure Solutions, Inc. wood.
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Removal from or
import of material
could be restricted
Restriction not
Fire Ants
dependent on the
likely
potential for fire ants
and geographic regions
involved
No development
activities are
anticipated within
Floodplain
Wayne County
Not Anticipated
FEMA mapped Special
Development
Flood Hazard Areas for
the Flood Insurance
Rate Maps
Multi -State
Not Anticipated
Agreement
NPDES (National
Pollution Discharge
NCDEQ
NC0003417
Not Anticipated
Elimination System)
Removal from or
import of vegetated
material could be
Noxious Weeds
Not Anticipated
restricted dependent
on the vegetation and
geographic regions
involved
Construction activities
adjacent to
Railroad Easement,
tracks/ballast or a new
Access, or Crossing
Not Anticipated
railroad crossing
Permit
require an agreement
or permit

Wood Environment &Infrastructure Solutions, Inc. wood.
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In accordance with the
SPCC (Spill
federal Water Pollution
Prevention Control
Control Act (Clean
and
NCDEQ
Not Anticipated
Water Act) of 1974,
Countermeasure)
Title 40, Code of
Plan
Federal Regulations,
Part 112.
Federal and/or state
Threatened or
regulations may apply
Endangered
including agency
Species: Candidate
consultation and
Conservation
performing site -
Agreement
specific surveys within
Avian Protection
NCDEQ
the proper survey
Plan(s)
Not Anticipated
period (e.g., flowering
Bird and Bat
And EPA
period for listed plant)
Conservation
to determine if
Strategies
Threatened or
Eagle Conservation
Endangered Species or
Plan
their habitat exist
Eagle Take Permit
within the limits of
disturbance
Solid Waste Site
No new CCR Landfill
NCDEQ
Not Anticipated
Suitability
planned
Solid Waste Permit
No new CCR Landfill
NCDEQ
Not Anticipated
to Construct
planned
Solid Waste Permit
No new CCR Landfill
NCDEQ
Not Anticipated
to Operate
planned
County Approval -
No new CCR Landfill
Wayne County
Not Anticipated
zoning
planned

Wood Environment &Infrastructure Solutions, Inc. wood.
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FIGURES

.'7
7
F
OLD 'SMITHFIELD ROAD
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e
LEGEND
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APPROXIMATE LIMIT OF WASTE
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VICINITY MAP AND SITE PLAN
SCALE: 1" = 400'
400 0 400 800 FT
INCHES 1 2 3 TENTHS 10 20 30 4
5
REVI DATE
00
JOB NO. PROJECT TYPE DES I DFTR I CHKD I ENGR I APPD
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MAP SOURCE: ESRI WORLD TOPOGRAPHIC BASEMAP
TITLE COAL COMBUSTION RESIDUALS SURFACE
wood.
IMPOUNDMENT CLOSURE PLAN
HF LEE ENERGY COMPLEX
Environment & Infrastructure Solutions
4021 STIRRUP CREEK DRIVE, SUITE 100
DURHAMNC20
TEL: [phone] VICINITY MAP AND SITE PLAN
FAX: [phone]LICENFOR
NCENGSF-11253 ISSUED FOR REVIEW - NOT FOR CONSTRUCTION
NC GEOLOGY: C-247
SEAL SCALE: AS SHOWN DES: WMN
DUKE DWG TYPE: DWG DFTR: WMN
ISSUED FOR ENE"'
JOB NO: 7812180091 CHKD: BBC
REVIEW DATE: 12/10/2019 ENGR: WAW
NOT FOR FILENAME: HFL_ EXISTING OVERALL AERIAL.dwg APPD: CRK
CONSTRUCTION DWG SIZE DRAWING NO. REVISION
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Plotted By: Nichols, William Sheet Set: HF Lee Layout: EXISTING OVERALL AERIAL December 10, 2019 10: 18: 03am Q:\Duke Energy\HF Lee\_7812180091 _HF Lee CAMA Closure Plan\Concept\HFL_ EXISTING OVERALL AERIAL.dwg

2 3 4 5 6 7 s FIGURE 1-2 REV.
OVERALL EXISTING CONDITIONS PLAN T°OLD SMITHFIELDROAD
SCALE: 1 400'
400 0 400 800 FT
/ HF LEE ENTRANCE ROAD /%/ i� i /
�� — — �� '
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LEGEND TITLE COAL COMBUSTION RESIDUALS SURFACE
100 EXISTING MAJOR CONTOURS ¢ EXISTING ELECTRIC UTILITY POLE GEOSYNTEC BORINGS wood
IMPOUNDMENT CLOSURE PLAN
EXISTING MINOR CONTOURS ® EXISTING ELECTRIC UTILITY TOWER GEOSYNTEC CPTS & SCPTS REFERENCES: HF LEE ENERGY COMPLEX
F EXISTING GRAVEL ROAD MW e EXISTING MONITORING WELL GEOSYNTEC PIEZOMETERS 1. EXISTING TOPOGRAPHY AND SURVEY PROVIDED BY WSP DATED JULY 2015. Environment & Infrastructure Solutions
2. EDGE OF WATER PROVIDED IN SURVEY BY WSP FOR DUKE ENERGY PROGRESS, LLC. 4021 STIRRUP CREEK DRIVE, SUITE 100
EXISTING ROAD WV 9 EXISTING WATER UTILITY ® SYNTERRA MONITORING WELLS TITLED "AERIAL TOPOGRAPHIC SURVEY HF LEE ENERGY COMPLEX," REVISION 1, DATED 24 DURHAM NC 27703
OVERALL EXISTING CONDITIONS PLAN
TEL:[phone]
EXISTING TREE LINE JULY 2015, FILE NAME: "HF LEE FINAL - REV 07-27-2015.DWG". FAX: [phone]
❑T EXISTING UTILITY TELEPHONE ® S&ME MONITORING WELLS 3. LOCATION OF ANY AND ALL UTILITIES SHOWN IS BASED ON PHOTOGRAMMETRIC MAPPING LICENSURE: FOR
—X—X—X—X— EXISTING SITE FENCE — FLOOD HAZARD LINE CATLIN MONITORING WELLS AND IS APPROXIMATE. CONTRACTOR SHALL VERIFY LOCATION OF UTILITIES PRIOR TO NCNC ENG: GEOLOGY: C 247 ISSUED FOR REVIEW - NOT FOR CONSTRUCTION
COMMENCEMENT OF CONSTRUCTION.
«+E EXISTING OVERHEAD ELECTRIC LINES APPROXIMATE PROPERTY LINE EXISTING PIEZOMETERS 4. EXISTING STREAMS AND WETLANDS PROVIDED BY MCKIM & CREED DATED OCTOBER 9, SEAL SCALE: AS SHOWN DES: WMN
2017. DUKE
EXISTING WATER � � � � � APPROXIMATE LIMIT OF WASTE DWG TYPE: DWG DFTR : WMN
EXISTING WETLANDS EXISTING STREAMS ISSUED FOR ENEK%%7YJOB NO: 7812180091 CHKD: BBC
EXISTING RIP RAP WELL LOCATIONS AS PROVIDED BY SYNTERRA TO DUKE ENERGY/WOOD REVIEW® DATE: 12/10/2019 ENGR: WAW
❑ O EXISTING STRUCTURES (VARIOUS) MW ' EXISTING MONITORING WELL
� NOT FOR FILENAME: HFL_EXISTINGOVERALL TOPOGRAPHY.dwg APPD: CRK
EXISTING UTILITY LIGHT AMEC BORINGS DWG SIZE DRAWING NO. REVISION
EXISTING FIRE HYDRANT MACTECBORINGS CONSTRUCTION
o � ANSI FIGURE 1-2
s EXISTING SEWER MANHOLE LAW BORINGS 22"x34"
REV DATE JOB NO. PROJECT TYPE DES DFTR CHKD ENGR APPD DESCRIPTION
INCHES 1 2 3 TENTHS 10 20 30 4 5 6 7 8 9 101
I I I I I I I
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Plotted By: Nichols, William Sheet Set: HF Lee Layout: EXISTING OVERALL TOPOGRAPHY December 10, 2019 10: 20: 05am Q:\duke energy\HF Lee\_7812180091_hf lee cama closure plan\Concept\HFL_EXISTING OVERALL TOPOGRAPHY.dwg