Cliffside_ActiveBasin_ClosureOptionsAnalysis_20181114

Rogers Energy Complex – Cliffside Steam Station Active Ash Basin
Closure Options Evaluation
Summary Report
This summary report (Report) presents the Closure Options evaluation for the Duke Energy Carolinas'
Rogers Energy Complex (Cliffside Steam Station) Active Ash Basin, located at 573 Duke Power Road,
Mooresboro, Cleveland County, North Carolina. The Closure Options evaluation involved developing and
evaluating ash basin closure options relative to one another to determine which option to advance to
detailed engineering and closure plan development. The strategies discussed in the Closure Options
evaluation are representative of the range of possible approaches for basin closure, and do not
constitute final closure plans as described in N.C. Gen. Stat. sec. 130A-309.214(a)(4). Final closure plans
will be submitted in 2019, as required by law, supported by detailed engineering designs and any
necessary updates to groundwater modeling and related analysis.
Duke Energy developed programmatic guidance for the closure evaluation effort in early 2016 to
promote fleet-wide consistency in developing ash basin closure plans. Duke Energy developed a relative
weighting and scoring system with input from the National Ash Management Advisory Board. Using this
system, Duke Energy evaluated and scored the options using an options evaluation framework designed
to identify the option that balances environmental protection, cost, schedule and local community
impacts. It is noted that internal working draft versions of these 2015-2016 Options Analyses for Allen,
Belews Creek, Cliffside, Marshall, Mayo, and Roxboro were provided to the North Carolina Department
of Environmental Quality (NCDEQ) at its request in May and June 2018.
The 2016 internal working draft Options Analyses identified Closure-in-Place as the preferred solution
for the Cliffside Active Ash Basin that is protective of the environment, safely closes the ash basin,
reduces the other associated risks, and was the least cost to customers. A permit-level design was
developed for that option in 2016. Duke Energy then paused that work, pending determination that the
site would meet the requirements for a low-risk impoundment classification pursuant to the North
Carolina Coal Ash Management Act (CAMA), as amended by House Bill 630. Duke Energy has completed
those requirements at the Cliffside Active Ash Basin site for a low-risk classification and now has
updated this analysis.
SITE BACKGROUND
Duke Energy owns and operates the coal-fired Rogers Energy Complex, located in Mooresboro, in
Rutherford and Cleveland Counties, North Carolina. The Station is located on the Broad River
approximately 55 miles west of Charlotte and about 1.5 miles south of the town of Cliffside, North
Carolina. The power plant is situated on the south side of the Broad River and straddles the
Cleveland/Rutherford County line. The project location is illustrated on Figure 1. The Station began
construction and initial operations in 1939 and 1940 with Units 1-4. Unit 5 began operations in 1972,
followed by Unit 6 in 2012. Units 1-4 were retired from service in 2011 as part of the Station
decommissioning and demolition program, and the Units 1-4 building was imploded in October 2015.
Summary – Page 2
Currently, only Units 5 and 6 continue to operate with a combined capacity of approximately 1,387
megawatts.
The Rogers Energy Complex ash management facilities include the Unit 5 Inactive Ash Basin, the Active
Ash Basin which includes an ash stack area, Ash Storage Area 1, and the on-site landfill. The ash in the
Units 1-4 Ash Basin has been excavated and placed in the on-site landfill, and this area has been
repurposed for stormwater and plant process water basins. Discharge from the Active Ash Basin is
permitted by the NCDEQ Division of Water Resources under the National Pollutant Discharge
Elimination System Permit NC0005088. The plant location and layout of ash management facilities are
shown on Figure 1.
The Active Ash Basin is located on the eastern portion of the site, east and southeast of Unit 5 and Unit
6.The basin was formed by construction of two earthen embankments across Suck Creek, bracketing a
5600 ft long reach of the former stream valley. At the upstream dam (State ID CLEVE-050), Suck Creek
was diverted through a canal to the Broad River. The upstream dam has a crest length of 890 feet. The
downstream dam (State ID CLEVE-049), located near the original confluence of Suck Creek with the
Broad River, has a crest length of 876 feet.
The Active Ash Basin was constructed in two phases. The first phase consisted of excavation of the Suck
Creek diversion canal and construction of the upstream dam to elevation 745 feet and the downstream
dam to elevation 725 feet. This first phase began in 1974 and was completed in 1975. The second phase
consisted primarily of raising both dams to elevation 775 feet. The downstream dam was raised in two
stages, with the first stage involving construction of the dam to a temporary elevation of 737 feet in late
1979. The second stage of construction was completed in 1980 when it was expanded outward to its
current footprint. The Active Ash Basin began receiving sluiced ash from Unit 5 in 1975 and continued to
receive sluiced bottom ash and fly ash from Unit 5 until this year when a conversion was completed to
enable dry handling of ash. The Active Ash Basin also receives stormwater and other wastewaters from
the Station.
Summary – Page 3
Figure 1. Active Ash Basin and Related Site Features
CLOSURE OPTIONS
For the Active Ash Basin, under the direction of Duke Energy, Wood Environment & Infrastructure
Solutions, Inc. (Wood) developed the following conceptual closure options that remain under
evaluation:
•Option 1: Closure-in-Place
•Option 2: Closure-by-Removal
•Option 3: Hybrid Closure-in-Place
Option 1 consists of closing the ash basin area by grading the ash deposits for proper drainageand then
closing it with an infiltration barrier/cap system meeting the requirements of the Federal Coal
Combustion Residuals (CCR) Rule and N.C. Coal Ash Management Act (CAMA). This option is
represented by the attached Figure A1.

Summary – Page 4
Option 2 consists of closing the ash basin area by removing all the ash to the onsite CCP Landfill. The
existing landfill would be expanded with a base liner system and an infiltration barrier/cap system
meeting the requirements of the Federal CCR Rule and CAMA to provide the necessary capacity. The
scope also includes removal and disposal of one foot of residual soil/sediment material within the Active
Ash Basin footprint. This option is represented by the attached Figure A2.
Option 3 consists of consolidating ash into a smaller footprint and grading for proper drainage,
constructing a stability feature, and then capping the area with an infiltration barrier/cap system
meeting the requirements of the Federal Coal Combustion Residuals (CCR) Rule and CAMA. This option
is represented by the attached Figure A3.
Tables 1, 2, and 3 of this report present a tabulated summary of each evaluated closure option,
estimated quantities of ash and soil materials associated with each closure option, and a more detailed
overview of each closure option presented.
Attachment A of this report includes figures to support conceptual review and scope development for
each closure option as follows:
• Figure A1 - Option 1 Closure-in-Place
• Figure A2 – Option 2 Closure-by-Removal
• Figure A3 – Option 3 Hybrid Closure-in-Place
Attachment B includes rough order of magnitude (ROM) cost estimates for each closure option.
Attachment C contains the scoring matrix which summarizes the composite scores of the various closure
options, the assumptions of which are outlined in Table 3 for each particular option.
METHODOLOGY
A scoring matrix was prepared to consistently evaluate closure options for each of the various site
locations. This scoring evaluation matrix is included in Attachment C and considers the following
primary criteria:
• Environmental Protection and Impacts
• Cost
• Schedule
• Regional Factors
• Constructability
Rough Order of Magnitude Costs
ROM Class 5 cost estimates were prepared for each of the closure options, based on information and
quantities developed during the conceptual design activities. The estimated costs include construction,
permitting, engineering design, post-construction operations and maintenance, and groundwater
monitoring. A tabulated summary of the preliminary closure cost estimates for the options considered
is presented below:

Summary – Page 5

Summary of Current ROM Cost Estimates
Closure Option Option Description
Total
Estimated
Cost
Estimated
Post-Closure
Maintenance
Cost
Option 1 Closure-in-Place $75,490,186 $32,942,670
Option 2 Closure-by-Removal $148,929,040 $4,170,960
Option 3 Hybrid Closure-in-Place $88,004,258 $31,463,670

As indicated by the cost estimate summary, Option 1: Closure in-Place has the lowest total estimated
cost, which is primarily attributed to the additional cost for dewatering, ash excavation, and ash hauling
required for Closure-by-Removal and Hybrid Closure-in-Place. In addition, the Closure-by-Removal
Option has additional costs of landfill development. Detailed, tabulated ROM cost estimates are
included in Attachment B.
Schedule
Within the scoring evaluation, estimates of the length of time required to initiate closure activities and
the anticipated construction duration are considered for each option. Thirty-six months of effort is
anticipated for site preparation and dewatering activities for all options based on the large free water
area.
Option 1 - Close-in-Place is estimated to take 74 months or 6.2 years. Option 2 - Closure-by-Removal is
estimated to take 111 months or 9.3 years. Option 3 – Hybrid Closure-in-Place is estimated to take 93
months, or 7.8 years.
A major driver in the estimated construction durations is the assumed material excavation/movement of
1,000,000 CY/year; therefore, the Closure-By-Removal option has a longer construction duration, due to
the requirement to move all ash materials, compared to the Hybrid and Closure-In-Place options where
material movement quantities are less. Another driver is the assumed capping rate of 50 acres/year for
completing the closure system for the Hybrid and Closure-In-Place options.

Evaluation Criteria
This Options Analysis was developed as a decision-making tool in selection of closure options when
multiple methods are allowed under applicable regulations. The intent was to develop a decision
framework that used weighting factors to balance environmental factors, cost, and the safety of workers
and the public. The Options Analysis incorporates Duke Energy’s obligation as a public utility to ensure
that its closure decisions are protective of the environment and communities, while also being prudent
from a cost-effectiveness perspective.
The analysis considered multiple aspects within each criterion, including surface water impacts,
groundwater impacts, air emissions, greenfield disturbance, construction duration, imported soil needs,
transportation and noise impacts, stormwater management, long-term maintenance needs and post-
closure monitoring.
These elements were combined to calculate a weighted sum for each criterion using the following
weights: environmental considerations (30%), cost (35%), schedule (15%), regional/community factors
(15%) and constructability (5%). Duke Energy placed primary emphasis on environmental factors and
cost, which were approximately equal in weight. When considering all of the criteria and associated
weightings, the environmental considerations have a slightly higher weight than cost with the inclusion
of certain regional/community factors (transportation impact, noise impact, view impact) which are
effectively environmental considerations.
The scoring matrix, provided in Attachment C, scores each option on a scale of 0 (least favorable) to 10
(most favorable) for each of the specified criteria. The scores for each option are then summed based
on specified criterion weighting, resulting in an overall weighted score for each option. The results of
the scoring evaluation for the Active Ash Basin closure options are summarized in the following table:
Summary of Closure Options Evaluation Scoring
Criterion Option
1 Closure-in-
Place
2 Closure-by-
Removal
3 Hybrid
Closure-in-Place
Environmental Protection and Impacts 2.6 2.7 2.7
Cost 2.8 0.7 2.4
Schedule 1.5 0.5 1.0
Regional Factors 1.4 1.3 1.4
Constructability 0.5 0.2 0.3
Total Score 8.8 5.3 7.6
DISCUSSION
The Options Analysis finds relatively similar rankings for environmental protection and impacts which
considers groundwater impacts, surface water impacts, air emissions based on miles driven, and
avoidance of greenfield disturbance. The most effective step to improve groundwater is to safely decant
the free water from the ash basin, which will occur in any closure approach.
In terms of the duration of work and closure time, the Closure-In-Place scenario is expected to be
completed in 6.2 years, compared to the Closure-By-Removal option which is expected to take 9.3 years.
The Closure-In-Place Hybrid scenario is expected to take 7.8 years. Unless work is initiated in early 2020,
Summary – Page 6
Summary – Page 7
Option 2 – Closure-by-Removal would not likely be completed by the CAMA deadline of 2029.
Other aspects the company considered are regional impacts to the surrounding community related to
traffic and noise generated by each of the options. Traffic to and from the site will occur through the
duration for each option noted above. That will include workers, trucks for deliveries or movement of
soil, topsoil, stone, geosynthetics. For the Closure-In-Place option (#1) and Hybrid option (#3) traffic will
be mingled with typical traffic on the main roads leading to Cliffside. At the Cliffside site, the active on-
site landfill is located within the Station limits so access using a public highway is not required for the
Closure-By-Removal option. The noise generated for each the options would be similar to someone
near the site, but the duration of the work and the exposure to that noise varies directly with the time
required for each option and would be longer for Closure-by-Removal. Along with increased duration
and truck trips comes higher levels of emissions for the Closure-by-Removal option as well.
The Closure-By-Removal is almost double the estimated capital cost of the Closure-In-Place option, and
causes other unnecessary community impacts with little compelling environmental benefit.
Long-term modeling indicates a quicker reduction in the boron plume within the immediate vicinity of
the basin footprint for the Closure-By-Removal scenario compared to the Closure-in-Place and Hybrid
scenarios. Predicted future boron concentrations at a downstream point beyond the current
compliance boundary vary for each scenario. At the modeled point, boron is predicted to exceed the 2L
standard for approximately 100 years in the Closure-By-Removal scenario, approximately 500 years in
the Closure-in-Place scenario, and approximately 400 years for the Hybrid scenario. This difference in
modeled plume size within the immediate vicinity of the basin footprint is not enough to justify the cost
of the Closure-by-Removal scenario, particularly when the impact and improvement do not materially
affect neighbors or other potential receptors.
CONCLUSION
Based on the conceptual designs for the selected closure options and evaluation of the criteria
established (environmental protection/impacts, cost, schedule, regional factors and constructability),
Option #1: Closure-In-Place or Option #3: Hybrid were identified as the preferred options that best
balance the various considerations associated with basin closure.
ATTACHMENTS
•Table 1 – Closure Option Summary (Identification of Options)
•Table 2 – Estimated Quantity Summary
•Table 3 – Closure Options Detail Descriptions
•Attachment A – Figures and Reference Drawings
•Attachment B - Rough Order of Magnitude (ROM) Cost Estimates
•Attachment C – Closure Options Evaluation Scoring Matrix
Table 1 – Active Ash Basin Closure Options Summary
Ash Basin Closure Options Evaluation
Rogers Energy Complex – Cliffside Steam Station
Duke Energy
1
Option Description
1. Closure In-Place
Option 1 consists of leaving the ash material within the Active Ash Basin, which
would be capped with an infiltration barrier/cap system meeting the
requirements of the Federal Coal Combustion Residuals (CCR) Rule and N.C.
Coal Ash Management Act (CAMA). The scope also includes modification of
the downstream dam for stormwater discharge, removal of the material in the
Ash Storage Area 1 and regrading into the Active Ash Basin area.
2. Closure by
Removal Option 2 consists of excavating all ash material and a 1-ft thick soil layer within
the limits of the Active Ash Basin and placing the material in the existing on-site
permitted industrial landfill located south of the Unit 5 Inactive Ash Basin. This
industrial landfill would be expanded and constructed with a base liner system
and an infiltration barrier/cap system meeting the requirements of the Federal
CCR Rule and CAMA. This option also includes removal of the material in the
Ash Storage Area 1 and disposal into the landfill.
3. Closure In-
Place (Hybrid)Option 3 consists of leaving the ash material within the Active Ash Basin but
consolidating to a slightly smaller footprint, which would be capped with an
infiltration barrier/cap system meeting the requirements of the Federal Coal
Combustion Residuals (CCR) Rule and CAMA. The scope also includes
modification of the downstream dam for stormwater discharge, removal of the
material in the Ash Storage Area 1 and regrading into the Active Ash Basin
area.
1

Table 2 – Active Ash Basin Quantity Summary
Ash Basin Closure Options Evaluation
Cliffside Station
Duke Energy

Item Volume Units Area
(Acres)
Existing Ash
Ash Basin Area (regulatory boundary) NA 92.0
In Place Ash Volume 4,131,000 CY 92.0
Ash Basin Dam Soil Volume 421,600 CY NA
Ash Storage Area 1 (regulatory boundary) NA 9.2
In Place Ash Volume 170,000 CY 9.2
Ash Storage Area 1 Embankment Soil Volume 248,400 CY NA
Option 1: Closure-in-Place
Ash Volume in Final Closure Footprint 4,301,000 CY 92.0
Ash Excavation Volume (Excavated Area) 170,000 CY 9.2
Over Excavation Volume (1 ft.) 14,843 CY 9
Ash Regrading 1,021,000 CY NA
Dam Soil Cut Volume 248,400 CY NA
Soil Needed (18” Cover Soil) 224,640 CY 92.0
Offsite Topsoil Needed (6” for Final Cover) 81,635 CY 101.2
Option 2: Closure-by-Removal
Ash Excavation Volume (Excavated Area) 4,301,000 CY 101.2
Over Excavation Volume (1 ft.) 163,300 CY 101.2
Dam Soil Cut Volume 670,000 CY NA
Soil Needed (Onsite Landfill: 1.5’ Soil for Closure
Cap) 96,800 CY 40.0
Offsite Topsoil Needed (6” over Closure-by-Removal
Area and Onsite Landfill Closure Cap) 113,900 CY 141.2
Option 3: Hybrid Closure-in-Place
Ash Volume in Final Closure Footprint 4,301,000 CY 63.0
Ash Excavation Volume (Excavated Area) 170,000 CY 38.2
Over Excavation Volume (1 ft.) 61,600 CY 38.2
Ash Regrading 3,395,000 CY NA
Dam Soil Cut Volume 670,000 CY NA
Soil Needed (18” Cover Soil) 152,500 CY 63.0
Offsite Topsoil Needed (6” for Final Cover and 6” for
Closure-by-Removal Area) 81,635 CY 101.2
*Volumes will be determined as part of the final design if the respective option is selected as the closure
option.

Table 3 – Active Closure Option Detail Descriptions
Ash Basin Closure Options Evaluation
Rogers Energy Complex – Cliffside Station
Duke Energy

1

Option Description
1. Closure-In-
Place
Closure-In-Place will be accomplished by grading and covering the ash basin
within its current footprint. This closure option assumes ash will be removed
from within the limits of the Ash Storage Area 1 and permanently placed in the
final Active Ash Basin footprint. The estimated volume of ash moved for
closure is 1,191,000 cy, and the estimated volume of impacted soil moved is
14,843 cy. The Active Ash Basin downstream dam will be breached and the
Ash Storage Area 1 Embankment will be breached/removed to allow
stormwater flow to discharge into the Broad River.
The following reference drawing represents this option:
• Figure A1 – Option 1 – Closure-In-Place
Environmental Protection and Impacts Considerations
• Estimated quantities used for cost estimates are summarized in Table
2.
Cost Considerations
The total estimated construction cost is $75,490,186, and the estimated post-
closure O&M cost (30 years) is $32,942,670.
Schedule Considerations
The total estimated closure duration is estimated at 74 months. Construction
duration is estimated at 38 months, and the time to start ash removal is
estimated at 36 months.
Regional Factors
• Only the Ash Storage Area 1 portion of site could be reused without
consideration of cover system after completion of excavation in that
area (9.2 acres).
• The requirements for imported soil are included in Table 2.
• There are currently no plans for beneficial reuse of ash after closure.
• Noise impact considered lowest for Closure-In-Place due to smallest
amount of material moved.

Table 3 – Active Closure Option Detail Descriptions
Ash Basin Closure Options Evaluation
Rogers Energy Complex – Cliffside Station
Duke Energy

2

Option Description
• View impact considered lowest for Closure-In-Place due to shortest
closure height.
Constructability
• In place closure has highest overall score for constructability followed
by hybrid, then removal option.
• In place closure has a significant constructability and feasibility benefits
utilizing existing embankments for containment and erosion and
sedimentation control and management.

2. Closure-By-
Removal
Closure-By-Removal is based on removing ash from within the limits of the
Active Ash Basin and Ash Storage Area 1 and permanently placing it in an
expansion of the on-site permitted and lined landfill area located at Duke
Energy’s Rogers Energy Complex. The estimated volume of ash
removed/hauled for closure is 4,301,000 cy, and the estimated volume of
residual soil removed/hauled is 163,300 cy. The Active Ash Basin downstream
dam, upstream dam, and the Ash Storage Area 1 Embankment will be
breached/removed to allow stormwater flow to discharge into the Broad River
or Suck Creek.
The following reference drawing represents this option:
• Figure A2 – Option 2 – Closure-By-Removal
Environmental Protection and Impacts Considerations
• Estimated quantities used for cost estimates are summarized in Table
2.
Cost Considerations
The total estimated construction cost is $148,929,040, and the estimate post-
closure O&M cost (30 years) is $4,171,960.
Schedule Considerations
The total estimated closure duration is estimated at 111 months. Construction
duration is estimated at 75 months, and the time to start ash removal is
estimated at 36 months.

Table 3 – Active Closure Option Detail Descriptions
Ash Basin Closure Options Evaluation
Rogers Energy Complex – Cliffside Station
Duke Energy

3

Option Description
Regional Factors
• Ash basin closure area could be reused without consideration of cover
system after completion of closure by removal.
• The requirements for imported soil are included in Table 2.
• There are currently no plans for beneficial reuse of ash after closure.
• Noise impact considered highest for removal and landfill option due to
largest amount of material moved resulting in lowest scoring.
• View impact considered highest for removal and landfill option due to
the height of the landfill and proximity to public roads resulting in lowest
scoring.
Constructability
• Requires development of new landfill space to accommodate all ash
removal.
• Closure-By-Removal has the additional challenge of meeting the CAMA
deadline of 2029 due to longer schedule duration driven by the larger
amount of excavation and transport for removal of ash.
3. Hybrid Closure-
In-Place
The Hybrid Closure-In-Place will be accomplished by consolidating ash within
the Active Ash Basin to a smaller footprint and closing it in place with an
engineered cover system. This closure option assumes ash will be removed
from within the limits of the Ash Storage Area 1 and permanently placed in the
final Active Ash Basin Hybrid Closure footprint. The estimated volume of ash
moved for closure is 3,565,000 cy, and the estimated volume of residual soil
moved is 61,629 cy. The Active Ash Basin downstream dam, upstream dam,
and the Ash Storage Area 1 Embankment will be breached/removed to allow
stormwater flow to discharge into the Broad River or Suck Creek.
The following reference drawing represents this option:
• Figure A3 – Option 3 – Hybrid Closure-In-Place
Environmental Protection and Impacts Considerations

Table 3 – Active Closure Option Detail Descriptions
Ash Basin Closure Options Evaluation
Rogers Energy Complex – Cliffside Station
Duke Energy

4

Option Description
• Estimated quantities used for cost estimates are summarized in Table
2.
Cost Considerations
The total estimated construction cost is $88,004,258, and the estimate post-
closure O&M cost (30 years) is $31,463,670.
Schedule Considerations
The total estimated closure duration is estimated at 93 months. Construction
duration is estimated at 57 months, and the time to start ash removal is
estimated at 36 months.
Regional Factors
• Portion of site could be reused without consideration of cover system
after completion of excavation (38.2 acres).
• The requirements for imported soil are included in Table 2.
• There are currently no plans for beneficial reuse of ash after closure.
• Noise impact considered higher than Closure-In-Place due to larger
amount of material moved but the impact is less than Closure-By-
Removal
• View impact considered higher than Closure-In-Place due to taller
closure height due to smaller footprint but the impact is less than
Closure-By-Removal.
Constructability
• Hybrid option has a significant constructability and feasibility concern
associated with need for dewatering ash and constructing a stabilizing
feature at the leading edge of the ash closed in place resulting in a
score lower than Option 1 – Closure-In-Place.

ATTACHMENTS

Attachment A – Figures and Reference Drawings

CSECSECSECSECSECSECSECSECSE CSECSECSECSECSECSECSECSECSECSECSECSE CSECSECSEC
S
E
C
S
E
CSE CSECSE
CSE
CSE
CSE
CSE
CSE
CSE
C
S
E
CSE CSECSECSECSECSE CSE C
S
E
CSECSECSECSEC
S
ECSE
CSECSECSECSECSECSECSECSECSECS
E
CSECSECSECSECSECSECSECSECSECSECSE780
790
800
810
820
830
840
850860
82
0
83
0
84
0
85
0
86
0
7707807908008108207807908008108207
9
0
80
0 810820830780790800810
820830740750760770780790800780
790
800
8108208
2
0
8
2
0
83083083083
0
83
0
84084084085
0
850850860860860660 670 680 690 700 710 720 730740750760
H062H062670680690700710720730740750 760770780790800CLOSED UNIT 1-4INACTIVEASH BASINBROAD RIVER0+00 2+00 4+00 6+00 8+00 10+00SUCK CREEKASH STORAGE AREA 1(CLOSURE - BY - REMOVAL)4.6
1
%
3.6
2
%3.02%3.35%3.59%
3.1
1
%
4.
8
0%4.83%750770790760770770760780770
790
810
830 COVER SYSTEM EXTENTS (TYP.)FINAL COVER SYSTEM (TYP.)EXISTING GROUTED ANDABANDONED IN PLACE OUTFALL PIPECOVER SYSTEM GEOCOMPOSITE PERIMETER OUTLET (TYP.)I062M063M063I062L062N063N063J062J062K062K0621.0702.070L062APPROXIMATE LIMITS OFCCR BOUNDARYAPPROXIMATE LIMITS OF ASHBASIN UNIT BOUNDARYCBR: VERIFICATION AREA FOR THEPRESENCE OF CCR. (SEE NOTE 2)CBR: VERIFICATION AREA FOR THEPRESENCE OF CCR. (SEE NOTE 2)A SOIL STABILIZATION PLANWILL BE DEVELOPED PRIORTO CONSTRUCTIONASH STORAGE AREA 1 DAMADDITIONAL IMPROVEMENTSTO CHANNELS TO BEEVALUATED PRIOR TOCONSTRUCTIONACTIVE ASH BASINUPSTREAM DAM(CLEVE-050)ACTIVE ASH BASINDOWNSTREAM DAM(CLEVE-049)STRUCTURAL DESIGN OFSPILLWAY TO BE DEVELOPEDPRIOR TO CONSTRUCTION0
+
0
0
2
+
0
0
4
+
0
0
6
+
0
0
8
+
0
0
10+00
12+00
14+00
16+00
18+00
20+00
22+00
24+00
26+00
28+00
30+00
32+00
34+000+002+004+006+006+760+00
2+00
4+00
6+00
8+00
10+0
0
12+0
0
14+0
0
16+
0
0
17+0
00+002+004+006+008+0010+0012+0014+0016+0018+0020+0022+0022+320
+
0
0
1
+
0
0
2
+
0
0
3
+
0
0
4
+
0
0
5
+
0
0
6
+
0
0
0+001+002+003+00720720730730730730740740740740750 750750760760760770770770780CBR: VERIFICATION AREA FOR THEPRESENCE OF CCR. (SEE NOTE 2)ACTIVEASH BASINNDWG SIZEREVISIONFORDRAWING NO.TITLEFILENAME:DWG TYPE:JOB NO:DATE:SCALE:DES:DFTR:CHKD:ENGR:APPD:AFEDCB234578645789106AFCB22"x34"ANSI DSEALREVDATEJOB NO.PROJECT TYPE DES DFTR CHKD ENGR APPDDESCRIPTIONDMSDMSKKKKKK.DWG6057792411-16-2018AS NOTED032N.C. ENGINEERING LICENSE NO.F-0342OPTION 1 - CLOSURE-IN-PLACEACTIVE ASH BASIN CLOSURE PLANROGERS ENERGY COMPLEX - CLIFFSIDE STEAM STATIONFOR REVIEW ONLY - NOT ISSUED FOR CONSTRUCTIONCLS.C901.002.042.DWGFIGURE A100FIGURE A1FIGURE A1LEGENDAPPROXIMATE LIMITS OF ASH BASIN UNIT BOUNDARYAPPROXIMATE LIMITS OF CCR BOUNDARYDUKE ENERGY PROPERTY BOUNDARYCOVER SYSTEM EXTENTSCLOSURE-BY-REMOVAL AREACSENOTE:1. CLOSURE-IN-PLACE IS PROPOSED WITHIN THE FINAL COVER LIMITS (COVER SYSTEM EXTENTS).2. CLOSURE-BY-REMOVAL AREA BETWEEN COVER SYSTEM EXTENTS AND APPROXIMATE LIMITS OF ASH BASINUNIT BOUNDARY IS CONSIDERED TO BE AN AREA WHERE SPOIL AND SOIL FILL WAS PLACED BASED ON PLANTOPERATIONAL INFORMATION FROM DUKE ENERGY. THE HISTORICAL PRE-DEVELOPMENT BASE GRADEELEVATIONS OF THESE AREAS ARE GENERALLY ABOVE THE HISTORICAL MAXIMUM ELEVATION OF THE STOPLOG OF THE RISER STRUCTURE AND THE DAM ELEVATION. DUKE ENERGY BELIEVES THERE IS NO CCR IN THISAREA. THEREFORE, AECOM IS PROPOSING A SOIL SAMPLING PLAN USING DRILLING TO EVALUATE THEPRESENCE OF ASH BELOW THE FILL, CONSISTENT WITH THE EXCAVATION SOIL SAMPLING PLAN PREPARED BYDUKE ENERGY FOR CLOSURE-BY-REMOVAL AREAS AND INCLUDED AS APPENDIX E TO THE CLOSURE PLAN. IFVISIBLE ASH IS NOT DISCOVERED, THEN THE COVER SYSTEM WILL REMAIN AS SHOWN. IF THE PRESENCE OFASH IS DISCOVERED, THE ASH WILL BE EXCAVATED AND PLACED WITHIN THE PROPOSED COVER SYSTEMEXTENTS AND FILL TO THE DESIGNED GRADES USING CLEAN SOIL, ESPECIALLY IN LOCATIONS WHERE ASH MAYBE PRESENT AT SHALLOW DEPTHS ONLY.3.THE “APPROXIMATE LIMITS OF ASH BASIN UNIT BOUNDARY” AND THE “APPROXIMATE LIMITS OF CCR BOUNDARY”WERE DEVELOPED BY AMEC AND ADOPTED BY AECOM. THESE BOUNDARIES ARE BASED ON AERIALPHOTOGRAPHY, TOPOGRAPHIC MAPPING, AND OTHER HISTORICAL DRAWINGS AND INFORMATION AND SHOULDBE CONSIDERED APPROXIMATE. THE “APPROXIMATE LIMITS OF ASH BASIN UNIT BOUNDARY” INCLUDES THECONTAINMENT DAMS AND DIKES WHILE THE “APPROXIMATE LIMITS OF CCR BOUNDARY” EXCLUDES THOSESTRUCTURES AND IS BASED ON UPDATED TOPOGRAPHIC MAPPING, REPORTED OPERATIONAL LEVELS, ANDSUBSURFACE DATA COLLECTED WITHIN THE BASIN. IT SHOULD BE NOTED THAT THE DETERMINATION OF THEACTUAL LATERAL EXTENT OF THE CCR MATERIALS WILL TAKE PLACE PRIOR TO, AND/OR DURING,IMPLEMENTATION.4. THE PROPOSED 5(H):1(V) SLOPES FOR EXCAVATIONS IN SATURATED SLUICED ASH IS THE MAXIMUM SLOPEALLOWABLE BASED ON THE CURRENT LEVEL OF DESIGN. THIS DESIGN ELEMENT WILL BE FURTHER REFINEDDURING THE FINAL CONSTRUCTION-LEVEL DESIGN TO EVALUATE CONSTRUCTION SEQUENCE/PHASING,DURATION THE EXCAVATION AREA MAY REMAIN OPEN, DEWATERING REQUIREMENTS, INSTRUMENTATION ANDMONITORING APPROACHES, ACTUAL CONDITIONS OF SLUICED ASH AT THE LOCATION OF THE EXCAVATION,AND OTHER RELATED STABILITY AND SAFETY CONSIDERATIONS. THE CONSTRUCTION CONTRACTOR WILL BEREQUIRED TO PROVIDE A DEWATERING AND MONITORING PLAN PRIOR TO EXCAVATION TO VERIFY THAT THEPROPOSED EXCAVATION MEETS THE MINIMUM FACTORS OF SAFETY FOR THE CONDITIONS MODELED.5. ASH FILL AND STACK AREAS WILL BE COMPACTED TO 90% OF THE MAXIMUM DRY DENSITY OR GREATER.6. FINAL COVER GEOMEMBRANE AND COVER SYSTEM GRADES MUST BE INSTALLED WITH AN ADEQUATESEPARATION BETWEEN THE MEMBRANE AND GROUNDWATER SUCH THAT DEVELOPMENT OF GROUNDWATERPRESSURE UNDERNEATH THE COVER SYSTEM IS MITIGATED. AN UNDERDRAIN SYSTEM IS BEING MODELED BYOTHERS FOR DUKE ENERGY AND A DETAIL DESIGN WILL BE DEVELOPED PRIOR TO CONSTRUCTION.REFERENCES:1. EXISTING TOPOGRAPHIC INFORMATION WAS PRODUCED FROM PHOTOGRAMMETRIC METHODS FROM AERIALPHOTOGRAPHY OBTAINED ON JULY 31, 2015 BY WSP.2. APPROXIMATE LIMITS OF CCR BOUNDARY EXTRACTED FROM INTERPRETED BOTTOM OF ASH AUTOCAD CIVIL 3DSURFACE BY AMEC. INTERPRETED BOTTOM OF ASH CONTOURS TAKEN FROM AMEC FOSTER WHEELER, WASTESTRATEGY ANALYSIS, CLIFFSIDE STEAM STATION, APRIL 17, 2015.
2.5:12.5:1720730740750760710670
680 690
700
730 740 750760
7407507606706806907007107207307407507
1
0
71072072
0
730
730740
74
0
750
750760
760770700710720730740
750
7607706906706706806806907006907007106806907007107207407607707507307
1
0
700710720 730740750760 770780
790
800810780790800810820800
810
820
83
0
840
850860
810820830840850860
780790800810820830840850860780
790
800
810
820
790800810820
830
840
8507807908008107
7
0
780
790
800 780790800810820760760760770780 660670680690700710720 770780790800810820
8
3
0
750760770780 730740750760770770670680690700710720 660670680S-3S-10S-11S-13S-12S-4S-9S-5S-6S-22S-7S-14S-15S-21S-16GWA-10IB-1GWA-11IB-2IB-3IB-4GWA-14GWA-13GWA-12GWA-29AS-2GWA-33GWA-20AB-2AS-7AS-1AS-5AS-6AS-4AS-3GWA-28AB-1AB-3GWA-27MW-7AB-4GWA-26AB-6BG-1GWA-25AB-5MW-22GWA-24GWA-23MW-21GWA-21GWA-22C-5C-4C-3C-2C-1C-7C-6U-1U-2RUTHE-050-P100U-3RUTHE-050-P101U-5U-6U-4D-1D-2D-3D-4D-6D-5U-10U-8U-7A-1U-9680720 740770790750760770
780 700730690
7
0
0
710
720730700700710720730730740750UNIT 1-4INACTIVEASH BASINACTIVEASH BASINBROAD RIVERSUCK CREEKASHSTORAGEAREA 1ASSUMED CLOSURE BYREMOVAL LIMITS SHOWNASSUMED CLOSURE BYREMOVAL LIMITS SHOWNASSUMED CLOSURE BYREMOVAL LIMITS SHOWNNNC GEOLOGY: C-247NC ENG: F-1253LICENSURE:FAX: [phone]TEL: [phone]CHARLOTTE, NC 28208SUITE 1002801 YORKMONT ROAD11/7/20187810150346DWGAS SHOWNKRDJMBJMBDLJCNBActive Basin - Closure Option 2 Concept Plan.dwg000FIGURE A2FIGURE A2FIGURE A2NOT RELEASED FOR CONSTRUCTION OPTION 2 - CLOSURE BY REMOVAL11/7/20180NOT RELEASED FOR CONSTRUCTIONKRDJMBJMBDLJCNBCIVIL DESIGN PLAN7810150346REFERENCES:1. BOTTOM OF ASH CONTOURS TAKEN FROM AMEC FOSTER WHEELER, WASTE STRATEGY ANALYSIS, CLIFFSIDE STEAM STATION, APRIL 17, 2015.2. BORING LOCATIONS, PIEZOMETER LOCATIONS, AND SEEP LOCATIONS TAKEN FROM HDR, COMPREHENSIVE SITE ASSESSMENT REPORT, CLIFFSIDE STEAM STATION ASH BASIN,AUGUST 2015 AND PHASE 2 RECONSTITUTION OF ASH POND DESIGNS FINAL REPORT, REV 1, FEBRUARY 19, 2016.3. EXISTING TOPOGRAPHIC INFORMATION WAS PRODUCED FROM PHOTOGRAMMETRIC METHODS FROM AERIAL PHOTOGRAPHY OBTAINED ON JULY 31, 2015 BY WSP.102030TENTHSINCHES123DWG SIZEREVISIONFORDRAWING NO.TITLEFILENAME:DWG TYPE:JOB NO:DATE:SCALE:DES:DFTR:CHKD:ENGR:APPD:AFEDCB234578645789106AFCB22"x34"ANSI DSEALREVDATEJOB NO.PROJECT TYPE DES DFTR CHKD ENGR APPDDESCRIPTIONABSAT ISSUE #DATEDESIGNEnvironment & InfrastructureSolutions2801 YORKMONT ROAD, SUITE 100CHARLOTTE, NC 28208TEL: [phone] FAX: [phone]LICENSURE: NC ENG: F-1253 NC GEOLOGY: C-247
5
:
1 5:15:1
5:1
5:15
:
1
3
.
8
1%
3
.
06%
4.46%4.64%51+000+005+0010+0015+0020+0025+0030+00 35+004
0
+
0
0
45+00
50+00A D M Y DESCENG. APPR.B D M Y DESCENG. APPR.C D M Y DESCENG. APPR.D D M Y DESCENG. APPR.E D M Y DESCENG. APPR.F D M Y DESCENG. APPR.G D M Y DESCENG. APPR.AS NOTEDISSUE/REVISION DESCRIPTIONYREV D MENG. APPR.CLIENT LOGO:REVIEWED BY:SCALE:DATUM:PROJECTION:TITLE:PROJECT:DATE:FIGURE NO.REVISION NO.PROJECT NO.:DRAWN BY:CLIENT:2801 YORKMONT ROAD, SUITE 100CHARLOTTE, NC 28208TEL: [phone] FAX: [phone]LICENSURE: NC ENG: F-1253 NC GEOLOGY: C-247Amec Foster Wheeler Environment & Infrastructure, Inc.DATUMPROJECTIONDRAWNREVN0200'100'OPTION 3 - HYBRID CLOSURE-IN-PLACEFIGURE A3781005034608/18/15CLIFFSIDE STEAM STATIONACTIVE ASH BASINEXCAVATION TO HISTORICAL GRADESDUKE ENERGY CAROLINAS, LLCEXCAVATION TO HISTORICAL GRADESEXCAVATION TO HISTORICAL GRADESEXCAVATION TO HISTORICAL GRADES

ATTACHMENTS

Attachment B - Rough Order of Magnitude (ROM) Cost
Estimates

Item Description Quantity Unit Unit Cost Total Cost
Mobilization/Demobilization 1 LS $1,475,859 1,475,859$
1,475,859$
Abandon Outlet Structures/Piping 1 Pond $30,000 30,000$
Field Surveying and Utility Location1 1 LS $454,334 454,334$
484,334$
Erosion/Sediment Control and Storm Water Management 101.2 Acres $14,000.00 1,416,800$
Surface Water Diversions/Ditches/Swales 27,638 LF $100.00 2,763,840$
Permanent Stabilization Measures 101.2 Acres $3,787 383,244$
Armor Embankment 59,825 SF $15 897,375$
5,461,259$
Removal and Filtration Free Water (Ash Basin)2 Mo $416,667.00 833,334$
Remvoal and Treatment of Pore Water (Ash Basin)60 Mo $583,333 34,999,980$
35,833,314$
Construction Entrance 50 LF $65 3,250$
Clearing and Grubbing 9.2 Acres $5,000 46,000$
Topsoil Stripping 6.2 Acres $4,000 24,729$
Earthwork Cut to Fill2 248,400 CY $6.87 1,706,508$
Excavation of Residual Adjacent and Subsurface Soils and Loading in Trucks 14,843 CY $10.00 148,427$
Hauling, Placement, and Compaction of Material (soil, pond ash, rock) to another area of Ash Pond 1,205,843 CY $5.00 6,029,213$
7,958,127$
Final Cover System - Subgrade Preparation 92 Acres $5,000 460,000$
40-mil Textured LLDPE Geomembrane 4,007,520 SF $0.42 1,683,158$
Geocomposite Drainage Layer3 4,007,520 SF $0.60 2,404,512$
Final Cover System - Vegetative/Protective Soil Material (18-inch thick un-compacted fill from on-site, 6inch topsoil from off-site4) 296,853 CY $16.00 4,749,653$
9,297,324$
60,510,217$
Closure Design/Engineering/Permitting (5% of Final Cover System Construction Costs excluding Mob/Demob)1 LS 2,951,718$ 2,951,718$
Construction Quality Assurance (CQA) (5% of Final Closure Construction Costs excluding Mob/Demob)1 LS 2,951,718$ 2,951,718$
5,903,436$
Maintenance 30 YR 156,400$ 4,692,000$
Monitoring 30 YR 941,689$ 28,250,670$
32,942,670$
Additional Costs
Contingency (15% of Final Closure System Construction Costs)1 LS 9,076,533$ 9,076,533$
9,076,533$
Total Capital Costs 75,490,186$
Total OMM Costs 32,942,670$
108,432,856$
1,178,618$
Notes:
1. Includes construction stakeout, intermediate field survey, and project record drawings.
2. Regrading of embankment by grading into the former pond area following grading of the ash.
3. Geocomposite to have geotextile fabric heat-bonded to each side.
4. Sources of earthwork material is clarified as on- or off-site sources per line item.
Subtotal - PCC Costs
Earthwork
Subtotal - Earthwork
Cover System with Geosynthetics
Subtotal - Additional Costs
Subtotal - Cover System with Geosynthetic
Subtotal - Final Closure Cover System Construction Costs
Design, Permitting and CQA
Subtotal - Design, Permitting and CQA
Post Closure Operations and Maintenance Costs
Subtotal - Ash Pond Dewatering, Treatment, and Disposal
Total Opinion of Probable Closure Costs
Opinion of Probable Closure Cost Per Acre
Active Basin Option 1 Overview: Close in Place
Closure Opinion of Probable Cost
Duke Energy - Rogers Energy Complex - Cliffside Steam Station
Mooresboro, North Carolina
Acquisition
Subtotal - Acquisition
General
Subtotal - General
Erosion/Sediment Control and Storm Water Management
Subtotal - Erosion/Sediment Control and Storm Water Management
Ash Pond Dewatering, and Treatment
Item Description Quantity Unit Unit Cost Total Cost
Mobilization/Demobilization 1 LS 2,911,371 2,911,371$
2,911,371$
Abandon Outlet Structures/Piping 1 LS $200,000 200,000$
Field Surveying and Utility Location1 101.2 Acres $2,000 202,400$
402,400$
Erosion/Sediment Control and Storm Water Management 101.2 Acres $14,000.00 1,416,800$
Permanent Stabilization Measures 101.2 Acres $3,787 383,244$
1,800,044$
Construction Entrance 50 LF $65 3,250$
Clearing and Grubbing 9.2 Acres $5,000 46,000$
Breaching Main Dam 1.0 LS $1,000,000 1,000,000$
Earthwork Cut to Fill2 670,000 CY $6.87 4,602,900$
Topsoil Stripping 5.5 Acres $4,000 21,974$
Topsoil Material; if required (6-inch thick un-compacted fill, source material off-site4) 74,213 CY $10.78 800,020$
6,474,144$
Landfill Construction 40 Acres $400,000.00 16,000,000$
Landfill Closure 40 Acres $150,000.00 6,000,000$
22,000,000$
Temporary Dewatering (Ash Basin) Free Water 2 Mo $416,667.00 833,334$
Temporary Dewatering (Ash Basin) Construction Water 54 Mo $583,333 31,249,867$
Haul Road Construction 500 LF $60 30,000$
Excavation of Pond Ash and Loading in Trucks 4,301,000 CY $8.43 36,257,430$
Excavation of Residual Adjacent and Subsurface Soils and Loading in Trucks 163,269 CY $10.00 1,632,693$
Hauling, Placement, and Compaction of Pond Ash and Residual Soils to Cliffside CCP Landfill 3 4,464,269 CY $3.50 15,624,943$
Truck Wash 1 LS $150,000 150,000$
85,778,267$
119,366,227$
Closure Design/Engineering/Permitting (5% of Final Closure Construction Costs excluding Mob/Demob)1 LS 5,822,743$ 5,822,743$
Construction Quality Assurance (CQA) (5% of Final Closure Construction Costs excluding Mob/Demob)1 LS 5,822,743$ 5,822,743$
11,645,486$
Landfill Area Maintenance 30 YR 139,032$ 4,170,960$
Landfill Area Monitoring 0 YR -$
4,170,960$
Additional Costs
Contingency (15% of Final Closure Construction Costs)1 LS 17,904,934$ 17,904,934$
17,904,934$
Total Capital Costs 148,929,040$
Total OMM Costs 4,170,960$
153,100,000$
3,827,500$
Notes:
1. Includes construction stakeout, intermediate field survey, project record drawings and utility location.
2. Remove existing embankment by grading into the former pond area following removal of the ash and impacted adjacent and subsurface material.
3. Excavated pond ash to be hauled and placed in onsite ash landfill.
4. Sources of earthwork material is clarified as on- or off-site sources per line item.
Total Opinion of Probable Closure Costs
Opinion of Probable Closure Cost Per Acre
Subtotal - Final Closure Construction Costs
Design and Permitting
Subtotal - Design and Permitting
Post Closure Operations and Maintenance Costs
Subtotal - Post Closure Costs
Subtotal - Additional Costs
ONSITE DISPOSAL COSTS
Subtotal - Acquisition
General
Subtotal - General
Erosion/Sediment Control and Storm Water Management
Subtotal - Erosion/Sediment Control and Storm Water Management
Earthwork
Subtotal - Earthwork
Landfill
Subtotal - Landfill
Ash Pond Dewatering, Loading, Hauling, and Placement
Onsite Landfill Subtotal - Ash Pond Dewatering, Loading, Hauling, and Placement
Acquisition
Active Basin Option 2 Overview: Removal
Closure Opinion of Probable Cost
Duke Energy - Rogers Energy Complex - Cliffside Steam Station
Mooresboro, North Carolina
Item Description Quantity Unit Unit Cost Total Cost
Mobilization/Demobilization 1 LS 1,247,771 1,247,771$
1,247,771$
Abandon Outlet Structures/Piping 1 Pond $30,000 30,000$
Utility and Field Surveying1 101.2 Acres $2,000 202,400$
232,400$
Erosion/Sediment Control and Storm Water Management 101.2 Acres $14,000.00 1,416,800$
Surface Water Diversions/Ditches/Swales 12,133 LF $100.00 1,213,280$
Permanent Stabilization 101.2 Acres $3,787 383,244$
Outlet Stabilization 1 LS $500,000 500,000$
3,513,324$
Construction Entrance 50 LF $65 3,250$
Clearing and Grubbing 6.3 Acres $5,000 31,500$
Topsoil Stripping 6.2 Acres $4,000 24,729$
Earthwork Cut to Fill2 670,000 CY $6.87 4,602,900$
Excavation of undercut soil (1ft depth)61,629 CY $10.00 616,293$
Leading Edge Stability Berm (20 ft tall spanning est. 250 ft with overexcavation)30,000 CY $6.87 206,100$
5,484,772$
Final Cover System - Subgrade Preparation 63.0 Acres $5,000 315,000$
40-mil Textured LLDPE Geomembrane 2,744,280 SF $0.42 1,152,598$
Geocomposite Drainage Layer3 2,744,280 SF $0.60 1,646,568$
Final Cover System - Vegetative/Protective Soil Material (18-inch thick un-compacted fill from on-site, 6inch topsoil from off-site5) 203,280 CY $16.00 3,252,480$
6,366,646$
Removal and Filtration Free Water (Ash Basin)2 Mo $416,667.00 833,334$
Remvoal and Treatment of Pore Water (Ash Basin)60 Mo $583,333 34,999,980$
Hauling, Placement, and Compaction of Pond Ash to another area of Ash Pond 3,565,000 CY $5.00 17,825,000$
53,658,314$
70,503,228$
Closure Design/Engineering/Permitting (5% of Final Cover System Construction Costs excluding Mob/Demob)1 LS 3,462,773$ 3,462,773$
Construction Quality Assurance (CQA) (5% of Final Closure Construction Costs excluding Mob/Demob)1 LS 3,462,773$ 3,462,773$
6,925,546$
Maintenance 30 YR 107,100$ 3,213,000$
Monitoring 30 YR 941,689$ 28,250,670$
31,463,670$
Contingency (15% of Final Cover System Construction Costs)1 LS 10,575,484$ 10,575,484$
10,575,484$
Total Capital Costs 88,004,258$
Total OMM Costs 31,463,670$
119,467,928$
1,298,564$
Notes:
1. Includes construction stakeout, intermediate field survey, and project record drawings.
2. Remove existing berm by grading into the former pond area following grading of the ash.
3. Geocomposite to have geotextile fabric heat-bonded to each side.
4. Typically performed using a dozer to move the pond ash material within the pond boundary to the designated location.
5. Sources of earthwork material is clarified as on- or off-site sources per line item.
Additional Costs
Total Opinion of Probable Closure Costs
Opinion of Probable Closure Cost Per Acre
Subtotal - Additional Costs
Subtotal - Post Closure Costs
Earthwork
Subtotal - Earthwork
Cover System with Geosynthetics
Subtotal - Cover System Costs
Ash Pond Dewatering, Loading, Hauling, and Placement
Subtotal - Ash Pond Dewatering, Loading, Hauling, and Placement
Subtotal - Final Cover System Construction Costs
Design, Permitting and CQA
Subtotal - Design, Permitting and CQA
Post Closure Operations and Maintenance Costs
Subtotal - Acquisition
General
Subtotal - General
Erosion/Sediment Control and Storm Water Management4
Subtotal - Erosion/Sediment Control and Storm Water Management
Acquisition
Active Basin Option 3 Overview: Hybrid Closure
Closure Opinion of Probable Cost
Duke Energy - Rogers Energy Complex - Cliffside Steam Station
Mooresboro, North Carolina

ATTACHMENTS

Attachment C - Closure Options Evaluation Scoring
Matrix

Site Name: Rogers Energy Complex ‐ Cliffside Steam Station1= Option‐Specific User Input1 = Calculated ValueOption123Environmental Protection and Impacts Weight: 30%CriterionScoring SystemRequired Input Units Option 1 Option 2 Option 3 Option 1 Option 2 Option 3 Modeled Plume Intersecting Surface WaterRefer to EM Sub‐Scoring Sheet10 10 1024% 7.2%Groundwater Impact Beyond the current Compliance BoundaryRefer to EM Sub‐Scoring Sheet10 10 1024% 7.2%Modeled Off‐site ImpactRefer to EM Sub‐Scoring Sheet10 10 1024% 7.2%Relative rank based on visual interpretation of modeled boron plume Refer to EM Sub‐Scoring Sheet010513% 3.9%Air emissions off‐site (based on miles hauling CCR and CCR contaminated soil )Interpolation. Min value scores 10. Max value scores 0.Truck miles driven Miles0000 1 10 10 10 5% 1.5%Air emissions on‐site (based on gallons of fuel consumed) from closure implementation Interpolation. Min value scores 10. Max value scores 0.Gallons of fuel consumed Gallons1439400 5172000 42175001439400 5172000 10 0 3 5% 1.5%Avoidance of greenfield disturbanceInterpolation. Min value scores 10. Max value scores 0.Disturbed acres of greenfield Acres030 00 30 10 0 10 5% 1.5%2.6 2.7 2.7CostWeight:35%Criterion Scoring System Required Input Units Option 1 Option 2 Option 3 Option 1 Option 2 Option 3Closure Cost Closure Cost USD$75,490,186 $148,929,040 $88,004,25875,490,186.00$           148,929,040.00$            10.0 0.0 8.3 80% 28.0%Operation, Maintenance and Monitoring Cost OM&M Cost USD$32,942,670 $4,170,960 $31,463,6704,170,960.00$             32,942,670.00$              0.0 10.0 0.5 20% 7.0%2.8 0.7 2.4ScheduleWeight:15%Criterion Scoring System Required Input Units Option 1 Option 2 Option 3 Option 1 Option 2 Option 3Initiation TimeTime to move first ashMonths36 36 3636 0 10 10 10 30% 4.5%Construction DurationEstimated durationsMonths38 75 5738 75 10 0 5 70% 10.5%1.5 0.5 1.0Active Ash Basin ClosureInterpolation. Min value scores 10. Max value scores 0.Contribution to Total ScoreValue that Scores 0Closure‐In‐PlaceClosure‐By‐Removal: Existing On‐site LandfillHybrid Closure‐In‐PlaceInterpolation. Min value scores 10. Max value scores 0.User Input Value that Scores 10This Area Not Used For Interpretation of Environmental Modeling ResultsThis Area Not Used For Interpretation of Environmental Modeling ResultsThis Area Not Used For Interpretation of Environmental Modeling ResultsCriterion WeightValue that Scores 0 Calculated or User Selected Score0Calculated or User Selected Score Criterion WeightUser Input Value that Scores 10Calculated or User Selected Score Criterion WeightThis Area Not Used For Interpretation of Environmental Modeling ResultsScoring for Evaluation of Closure OptionsClosure Options Evaluation WorksheetDuke EnergyContribution to Total Score1. Provide continued geotechnical stability meeting appropriate safety factors under applicable loading conditionsThreshold Criteria: All closure options must comply with the following threshold criteria based on Duke Energy Guiding Principals for Ash Basin Closure2. Provide flow capacity and erosion resistance during design storm and flooding conditions3. Effectively mitigate groundwater impacts (in conjunction with GW remediation where present)4. Comply with applicable state and federal regulations (e.g. North Carolina Coal Ash Management Act)Contribution to Total ScoreWeighted Totals (Contribution to Total Score)Weighted Totals (Contribution to Total Score)Value that Scores 10 Value that Scores 0User Input
Site Name: Rogers Energy Complex ‐ Cliffside Steam Station1= Option‐Specific User Input1 = Calculated ValueActive Ash Basin ClosureScoring for Evaluation of Closure OptionsClosure Options Evaluation WorksheetDuke EnergyRegional FactorsWeight:15%Criterion Scoring System Required Input Units Option 1 Option 2 Option 3 Option 1 Option 2 Option 3Plan or potential for beneficial reuse of siteSubjective0005% 0.8%Imported soil needsInterpolation. Min value scores 10. Max value scores 0.Soil ImportedCY0000 1 10 10 10 5% 0.8%Beneficial reuse of CCRInterpolation. Max value scores 10. Zero value scores 0.Fraction UsedNone0.1 0.1 0.10.1 0 10 10 10 15% 2.3%Transportation impact (based on miles driven hauling CCR and CCR contaminated soil off‐site)Interpolation. Min value scores 10. Max value scores 0.Miles DrivenMiles0000 1 10 10 10 65% 9.8%Noise impact due to on‐site activity (based on proximity of neighbors to on‐site work areas)Subjective 0 to 10: 10 is the least noise;0 is the most noise.10 0 25% 0.8%View impact (based on final height of storage facility and land uses within viewshed)Subjective 0 to 10; 10 is the least visual;0 is the most visual.10 0 85% 0.7%1.4 1.3 1.4ConstructabilityWeight:5%Criterion Scoring System Required Input Units Option 1 Option 2 Option 3 Option 1 Option 2 Option 3Consider stormwater management, geotechnical, and dewateringSubjective 0 to 10: 10 is the least commplicated; 0 is the most complicated10 3 5100% 5.0%0.5 0.2 0.38.8 5.3 7.6Total Score For Each Option (On a Scale of 0 to 10)Weighted Totals (Contribution to Total Score)User Input Value that Scores 10 Value that Scores 0 Calculated or User Selected ScoreValue that Scores 10 Value that Scores 0Weighted Totals (Contribution to Total Score)Not Used For Subjective ScoringUser InputCalculated or User Selected ScoreContribution to Total ScoreCriterion WeightNot Used For Subjective ScoringNot Used For Subjective Scoring
Revision GCriteria for Evaluation of Closure OptionsClosure Options Evaluation WorksheetAsh Basin Closure ‐ Master Programmatic DocumentDuke EnergyCategory Criterion Guidance Modeled Plume Intersecting Surface Water Refer to scoring system on Environmental Modeling (EM) Sub‐Scoring worksheet.Groundwater Impact Beyond the current Compliance Boundary Refer to scoring system on  Environmental Modeling (EM) Sub‐Scoring worksheet.Modeled Off‐site Impact Refer to scoring system on  Environmental Modeling (EM) Sub‐Scoring worksheet.Relative rank based on visual interpretation of modeled boron plume  Refer to scoring system on  Environmental Modeling (EM) Sub‐Scoring worksheet.Air emissions off‐site Based on truck miles driven off‐stie for hauling CCR and CCR contaminated soil.Air emissions on‐site from closure implementation Based on total cubic yards of cut and fill on site as a surrogate for gallons of fuel consumed.Avoidance of greenfield disturbance Refer to Scoring System and Required Input columns on scoring sheet.Capital CostOperation, Maintenance and Monitoring CostInitiation TimeConstruction DurationPlan or potential for beneficial reuse of site Refer to Scoring System and Required Input columns on scoring sheet.Imported soil needs Refer to Scoring System and Required Input columns on scoring sheet.Beneficial reuse of CCR Refer to Scoring System and Required Input columns on scoring sheet.Transportation impact Based on truck miles driven off‐site for hauling CCR and CCR contaminated soil.Noise impact due to on‐site activity Based on proximity of neighbors to specific on‐site work areas.View impact Based on final height of storage facility and land uses within viewshed.ConstructabilityConsider stormwater management, geotechnical, and dewatering Subjective and relative comparison to other optionsRegional FactorsFrom rough order‐of‐magnitude cost estimate or detailed cost estimate.Threshold Criteria: All closure options must comply with the following threshold criteria based on Duke Energy Guiding Principals for Ash Basin ClosureFrom preliminary schedule for designing, permitting, bidding and constructing the option.1. Provide continued geotechnical stability under applicable loading conditions and safety factors2. Provide flow capacity and erosion resistance during design storm and flooding conditionsEnvironmental Protection and ImpactsCostSchedule3. Effectively mitigate groundwater impacts4. Comply with applicable state and federal regulations (e.g. North Carolina Coal Ash Management Act)
Environmental Groundwater Sub‐Scoring WorksheetClosure Options Evaluation Duke EnergyScored by: TH, RC, CMCriteria 1.  Modeled Plume Intersecting Surface Water ScoreModeled plume1 does not intersect surface waters after 10 years10Modeled plume1 does not intersect surface waters after 100 years5Modeled plume1 does not intersect surface waters after 200 years0(Option 1) (Option 2) (Option 3)Closure‐In‐Place Closure‐By‐Removal: Existing On‐Site LandfillHybrid Closure‐In‐Place10 10 10Criteria 2.  Groundwater Impact Beyond the current2 Compliance Boundary ScoreModeled plume1 is within current compliance boundary after 10 years10Modeled plume1 is within current compliance boundary after 100 years5Modeled plume1 is within current compliance boundary after 200 years0(Option 1) (Option 2) (Option 3A)(Option 1) (Option 2) (Option 3)Closure‐In‐Place Closure‐By‐Removal: Existing On‐Site LandfillHybrid Closure‐In‐Place10 10 10Criteria 3.  Modeled Off‐site Impact ScoreModeled plume1 does not go off‐site 10Modeled plume1 is predicted to remain off‐site after 100 years5Modeled plume1 is predicted to remain off‐site after 200 years0(Option 1) (Option 2) (Option 3)Closure‐In‐Place Closure‐By‐Removal: Existing On‐Site LandfillHybrid Closure‐In‐Place10 10 10Criteria 4.  Relative rank based on visual interpretation of modeled boron plume ScoreRanked #1 among the three Closure Options based on visual interpretation of modeled boron plume  10Ranked #2 among the three Closure Options based on visual interpretation of modeled boron plume  5Ranked #3 among the three Closure Options based on visual interpretation of modeled boron plume  0(Option 1) (Option 2) (Option 3) Closure‐In‐Place Closure‐By‐Removal: Existing On‐Site LandfillHybrid Closure‐In‐Place0105Note 2: The current compliance boundary is the compliance boundary found in the figure "Ash Basin Waste and Compliance Boundaries" provided to NCDEQ on 3/8/18Station/Plant Name: Rogers Energy Complex ‐ Cliffside Steam StationEvaluation Criteria: Criteria 1 ScoreRogers Energy Complex ‐ Cliffside Steam Station Active Ash Basin Groundwater Sub‐Scoring DocumentNote 1: Based on avaliable data at the time of scoring, the modeled plume considered boron at a concentration of 4,000 ug/l or greater;  4,000 µg/L does not represent a remediation goal, however this concentration does represent the EPA Tap Water Regional Screening Level (RSL) in resident tapwater for boron.Criteria 2 ScoreCriteria 3 ScoreCriteria 4 Score
Environmental Groundwater Sub‐Scoring WorksheetClosure Options Evaluation Duke Energy(Option 1) (Option 2) (Option 3)Justification NotesClosure‐In‐Place Closure‐By‐Removal: Existing On‐Site LandfillHybrid Closure‐In‐Place10 10 10Based on the predictive model for the year 2050, found in the November 2018 Preliminary Updated Groundwater Flow and Transport Modeling Report for Cliffside Steam Station, simulated boron concentrations for the closure‐in‐place scenario did not show boron of 4,000 ppb or greater intersecting a surface water body.Based on the predictive model for the year 2050, found in the November 2018 Preliminary Updated Groundwater Flow and Transport Modeling Report for Cliffside Steam Station, simulated boron concentrations for the closure‐by‐removal scenario did notshow boron of 4,000 ppb or greater intersecting a surface water body.Based on the predictive model for the year 2050, found in the November 2018 Preliminary Updated Groundwater Flow and Transport Modeling Report for Cliffside Steam Station, simulated boron concentrations for the hybrid scenario did not show boron of 4,000 ppb or greater intersecting a surface water body.10 10 10Based on the predictive model for the year 2050, found in the November 2018 Preliminary Updated Groundwater Flow and Transport Modeling Report for Cliffside Steam Station, simulated boron concentrations for the closure‐in‐place scenario did not show boron of 4,000 ppb or greater outside of the current compliance boundary.Based on the predictive model for the year 2050, found in the November 2018 Preliminary Updated Groundwater Flow and Transport Modeling Report for Cliffside Steam Station, simulated boron concentrations for the closure‐by‐removal scenario did notshow boron of 4,000 ppb or greater outside of the current compliance boundary.Based on the predictive model for the year 2050, found in the November 2018 Preliminary Updated Groundwater Flow and Transport Modeling Report for Cliffside Steam Station, simulated boron concentrations for the hybrid scenario did not show boron of 4,000 ppb or greater outside of the current compliance boundary.10 10 10Based on the predictive model for the year 2050, found in the November 2018 Preliminary Updated Groundwater Flow and Transport Modeling Report for Cliffside Steam Station, simulated boron concentrations for the closure‐in‐place scenario did not show boron of 4,000 ppb or greater outside of the current Duke Energy property boundary.Based on the predictive model for the year 2050, found in the November 2018 Preliminary Updated Groundwater Flow and Transport Modeling Report for Cliffside Steam Station, simulated boron concentrations for the closure‐by‐removal scenario did notshow boron of 4,000 ppb or greater outside of the current Duke Energy property boundary.Based on the predictive model for the year 2050, found in the November 2018 Preliminary Updated Groundwater Flow and Transport Modeling Report for Cliffside Steam Station, simulated boron concentrations for the hybrid scenario did not show boron of 4,000 ppb or greater outside of the current Duke Energy property boundary.0105Based on a review of boron concentrations found in the November 2018 Preliminary Updated Groundwater Flow and Transport Modeling Report for Cliffside Steam Station, the closure‐in‐place scenario is not marginally better than Option 2 (closure‐by‐removal) or Option 3 (hybrid). Based on a review of boron concentrations found in the November 2018 Preliminary Updated Groundwater Flow and Transport Modeling Report for Cliffside Steam Station, the closure‐by‐removal scenario is marginally better than Option 1 (closure‐in‐place) and 3 (hybrid). Based on a review of boron concentrations found in the November 2018 Preliminary Updated Groundwater Flow and Transport Modeling Report for Cliffside Steam Station, the hybrid scenario is marginally better than Option 1 (closure‐in‐place).Rogers Energy Complex ‐ Cliffside Steam Station Active Ash Basin Groundwater Sub‐Scoring Document JustificationNotes:1. Based on avaliable data at the time of scoring, the modeled plume considered boron at a concentration of 4,000 ug/l or greater;  4,000 µg/L does not represent a remediation goal, however this concentration does represent the EPA Tap Water Regional Screening Level (RSL) in resident tapwater for boron.2. The current compliance boundary is the compliance boundary found in the figure "Ash Basin Waste and Compliance Boundaries" provided to NCDEQ on 3/8/18.Criteria 1.  Modeled Plume Intersecting Surface WaterCriteria 2.  Groundwater Impact Beyond the Current Compliance Boundary Criteria 3.  Modeled Off‐site Impact Criteria 4.  Relative rank based on visual interpretation of modeled boron plume