NC0003468_2017 Excavation and Soil Sampling Plan_20171205

Dan River Steam Station

Coal Ash Excavation Plan

2017 Update

Table of Contents
I. Statement of Purpose ................................................................................................................... 1
II. General Facility Description ......................................................................................................... 2
III. Project Charter ............................................................................................................................... 3
IV. Critical Milestone Dates................................................................................................................ 6
V. Erosion and Sediment Control Plan ........................................................................................... 6
VI. Dewatering Plan ............................................................................................................................ 7
VII. Location(s) for Removed Ash ...................................................................................................... 7
VIII. Transportation Plan ....................................................................................................................... 7
IX. Environmental and Dam Safety Permitting Plan ...................................................................... 8
X. Contracting Strategy ................................................................................................................... 10
XI. Environmental, Health, and Safety Plan .................................................................................. 10
XII. Communications Plan ................................................................................................................. 10
XIII. Glossary ........................................................................................................................................ 11
XIV. Reference Documents ................................................................................................................ 12

Exhibits
Exhibit A: Excavation Soil Sampling Plan

1: Dan River

I. Statement of Purpose
Duke Energy Carolinas, LLC (Duke Energy or the Company) is required by Part II,
Section 3(b) of the Coal Ash Management Act of 2014 (Session Law 2014-122) (Coal
Ash Act or Act) to close, in accordance with Part II, Section 3(c), the coal combustion
residuals (CCR) surface impoundments located at the Dan River Combined Cycle Plant
(Dan River or Plant), National Pollutant Discharge Elimination System (NPDES) Permit
No. NC0003468, in Rockingham County as soon as practicable, but not later than
August 1, 2019.
This Coal Ash Excavation Plan (Plan) represents activities to satisfy the requirements
outlined in Part II, Sections 3(b) and 3(c), Subparagraphs 1 and 2 of the Act and the
requests set forth in the North Carolina Department of Environmental Quality’s (NC
DEQ) August 13, 2014 letter titled “Request for Coal Ash Excavation Plans for Asheville
Steam Station Electric Generating Plant, Dan River Combined Cycle Station, Riverbend
Steam Station, L.V. Sutton Electric Plant” (NC DEQ Letter).
The NC DEQ Letter was sent by the North Carolina Department of Environment and
Natural Resources, which was renamed the North Carolina Department of
Environmental Quality by Session Bill 2015-241. The NC DEQ Letter specifically
requests that the Plan include 1) soil and sediment erosion control measures, 2)
dewatering, and 3) the proposed location(s) of the removed ash. These requirements
are found in this updated Plan.
This is a revision of the Coal Ash Excavation Plan updated December 21, 2016, which
covered the subsequent phase of ash basin excavation activities, including the initiation
of basin dewatering, site preparation, landfill operation, ash basin preparation, and ash
removal from the basins at Dan River. The Plan will generally be updated and
submitted to NC DEQ annually.
The Plan covers some of the work required by Part II, Sections 3(b) and 3(c) of the Coal
Ash Act. The Act requires the closure of the ash basins as soon as practicable, but no
later than August 1, 2019. However, the Act contains no requirement for the submittal
of an excavation plan of the kind presented here. Thus, while the formulation, submittal,
and review of this Plan will assist in Duke Energy’s work to close the ash basins, its
ultimate approval is an action not specifically required by statutory, regulatory, or other
applicable authority.
The scope of work in excavating the ash basins has been determined by applicable
laws, rules, permits, and approvals that control the activities to be perform ed under the
Plan. There are several external and internal factors that could potentially affect the
precise scope of the work to be performed under the Plan. As a consequence, neither
the submittal of this Plan nor its acknowledgement by NC DEQ should be taken as

2: Dan River

requiring actions different from such applicable requirements. Duke Energy submits this
Plan to NC DEQ based on the understanding that it may be necessary to take actions
that deviate from the Plan in the future, and the Company reserves the right to make
such changes.
II. General Facility Description
The Dan River Steam Station is located in Rockingham County near Eden, NC. It
began operation around 1950 and is currently being decommissioned. The Primary Ash
Basin was constructed in 1956, with an embankment crest elevation of 523.5 feet mean
sea level (msl). In 1968, the basin embankment crests were raised to elevation 530 feet
msl and extended in length approximately 1,200 feet east along the Dan River. An
intermediate dike was constructed in 1976, resulting in two basins, with the Primary Ash
Basin dam crest being raised to elevation 540 feet msl. The east side of the basin was
designated the Secondary Ash Basin. The Primary Ash Basin was periodically dredged
and the material dry-stacked on higher terrain north of the basins (referred to as dry ash
stacks). The dam numbers for the ash basins are (ROCKI-237) and (ROCKI-238.) The
dry ash stacks have been capped with soil.
Duke Energy’s Coal Combustion Residuals Removal Verification Procedure (Removal
Verification Procedure) will be used to verify that primary source ash has been removed
from the basin. Subsequent to removal of the ash pursuant to the Removal Verification
Procedure, Duke Energy will implement its Excavation Soil Sampling Plan (ESSP),
which was developed for the purpose of meeting the applicable performance standard.
Although not required under CAMA, in November 2016, NC DEQ sent Coal Combustion
Residuals Surface Impoundment Closure Guidelines for Protection of Groundwater to
Duke Energy instructing the Company to submit the ESSP to NC DEQ as part of the
site’s excavation plan. In accordance with this directive, a copy of the ESSP is attached
as Exhibit “A” to this Plan.
Primary Ash B asin
The Primary Ash Basin at Dan River consists of a composite dam made up of local
borrow materials, including silty sands and sandy silts with some clay. Portions of the
dam may have been built on, or contain, ash materials. The eastern face of the
embankment is armored with rock up to elevation 512 feet msl. A rock fill berm was
constructed alongside the river, up to elevation 503 feet msl. An intermediate bench
was constructed at approximate elevation of 530 feet msl. The primary basin has an
approximate footprint of 39 acres with a surface water area of 18 acres. The Primary
Ash Basin received sluiced ash from pipes in the southwest corner and outlets into the
Secondary Ash Basin through a decant structure located near the northeast corner of
the Primary Ash Basin. Initially, the Primary Ash Basin contained approximately
1,215,000 tons of CCR material.

3: Dan River

Intermediate Dike (separates the Primary Ash basin and the Secondary Ash basin )
The intermediate dike was constructed in 1976, bisecting the basin into Primary and
Secondary Ash Basins. The dike was constructed on existing ash deposits, with an
upper crest elevation of 540 feet msl adjacent to the Primary Ash Basin and a lower
crest elevation of 530 feet msl adjacent to the Secondary Ash Basin. The dike has a
surface road at the 540 feet msl level. It has a vegetated slope adjacent to the road ,
which extends to a 530 feet msl elevation shelf adjacent to the Secondary Ash Basin.
A rock buttress was constructed below the elevation 530 feet msl crest. The width of
the intermediate dike is approximately 100 feet.
Secondary Ash Basin
The Secondary Ash Basin embankments, including the intermediate dike forming the
southwest boundary, have a crest elevation of 530 feet msl and are constructed of the
same local materials as the Primary Ash Basin. The eastern face of the embankment is
armored with rock up to elevation 512 feet msl. A rock fill berm was constructed
alongside the river, up to elevation 503 feet msl. The basin receives decanted flow from
the Primary Ash Basin in the northwestern corner, and flows exit the basin through a
decant structure near the southeastern corner. Flow from the Secondary Ash Basin is
regulated by NPDES Permit No. NC 0003468. The pool level is controlled by the
decant riser using concrete stop-logs and conveys to the outlet through a 36-inch
diameter reinforced concrete pipe constructed through the embankment dike. Initially,
the Secondary Ash Basin contained approximately 390,000 tons of CCR material.
Ash Stacks
The dry ash stacks are located to the north of the Primary and Secondary Ash Basins.
These ash stacks consist of CCR material dredged from the Primary Ash Basin.
Initially, Ash Stack 1 and Ash Stack 2 contained approximately 950,000 tons and
415,000 tons of CCR material, respectively. For the purposes of stormwater
management, the ash stacks are located within the ash basin system. Stormwater run-
off from the ash stacks is contained within the ash basin system and flows to the
Secondary Ash Basin. The excavation of all CCR from Ash Stack 1 was completed on
July 27, 2017.
III. Project Charter
Dewatering of the ash basins and the removal of ash from the site will be performed
within project phases. As of November 1, 2017, 1.6 million tons of ash have been
excavated. Approximately 1.2 million tons were transported to an off-site landfill.
Approximately 34,000 tons were sent to the Roanoke Cement Company for beneficial
use and the remainder to an on-site landfill. This project has completed Phase I and is
now implementing Phase II.

4: Dan River

The following items in Phase I have been completed or initiated:
1. Developed and installed approved erosion and sediment control measures.
2. Obtained applicable permits for work in Phase I.
3. Completed the work scope and bid event to support ash basin closure.
4. Developed and constructed the infrastructure to remove and transport the ash.
5. Completed rail load out spur for rail transportation.
6. Began bulk dewatering of the Secondary Ash Basin.
7. Initiated and completed the removal of the first 1 million tons of ash from the Dan
River site.
8. Obtained a Permit to Construct the new on-site landfill on October 27, 2016,
following resolution of the environmental justice review.
9. Commenced construction of an on-site landfill.
10. Completed a plan to reroute and eliminate inflows to the ash basins.
11. Validated production rates to meet project requirements.
12. Planned activities for subsequent phase(s), including development of option(s)
for beneficial use or proposed ash disposal location(s).
The Dan River NPDES wastewater permit was issued and became effective on
December 1, 2016. The removal of bulk free water of the Secondary Basin was
completed when the basin water level was lowered to elevation 515 feet msl in 201 6.
Interstitial dewatering of the Secondary Basin is expected to be completed in the
second quarter of 2018 to support excavation of the secondary basin. All leachate and
interstitial dewatering wastewater treatment will be performed by the City of Eden’s
Publically Owned Treatment Works (POTW) in accordance with the Industrial User Pre-
treatment Permit issued to Duke Energy by the City of Eden.
The excavation of Ash Stack 1 began on October 13, 2015, following acknowledgement
of this Plan by NC DEQ and the receipt of final permits. Phase I was completed on
March 23, 2017. Phase II will include completion of the on-site landfill and excavation of
the basins to the on-site landfill. Construction of an on-site landfill began on October
31, 2016, following receipt of the Landfill Permit-to-Construct by NC DEQ.
In accordance with the project plan, during Phase I, the Company removed ash to an
off-site location while simultaneously developing an on-site landfill, which was needed in
order to meet the closure requirements mandated in the Coal Ash Act. The Company
received a Permit-to-Operate (PTO) for the first landfill cell on May 30, 2017, and
promptly began transporting ash to the on-site landfill. The PTO for the second landfill
cell was received on October 2, 2017, and the final remaining PTO for cell 3 is expected
in the second quarter of 2018.

5: Dan River

Project Charter O bjective s
Phase II Objectives
1. Submit and obtain any necessary permits for Phase II activities.
2. Continue to dewater the ash basins.
3. Construct, operate, and close cells for the on-site landfill.
4. Excavate and remove the remaining ash from ash basins and ash stacks.
5. Continue evaluating beneficial use opportunities.
6. Gain knowledge and opportunities for program improvement that can be applied
to the subsequent phase(s).
Project Charter Scope
Phase II Scope
1. Submit and obtain applicable permits
2. Complete construction of the on-site landfill (Cells 1 & 2 complete).
3. Receive PTO's for the on-site landfill cells (PTO's received for Cells 1&2).
4. Excavate and transport the remaining ash from the Dan River Station to the on-
site landfill or for off-site reuse options.
5. Continue dewatering of the Primary and Secondary Ash Basins.
6. Complete closure activities.
7. Operate and close cells for the on-site landfill.

6: Dan River

IV. Critical Milestone Dates
Critical Milestones within the Plan are summarized in the table below.
MILESTONES NO LATER THAN DATE STATUS
Submit Excavation Plan November 15, 2014 Completed
November 13, 2014
Complete Comprehensive
Engineering Review
November 30, 2014 Completed
November 30, 2014
Excavation Plan acknowledgement February 17, 2015 Completed
February 2, 2015
Receive Industrial Stormwater Permit March 18, 2015 Completed
October 1, 2015
Commence work – ash removal
(including ash stack soil overburden)
Final permit approval + 60
Days
Completed
October 13, 2015
Submit Updated Excavation Plan November 15, 2015 Completed November 13,
2015
Submit Updated Excavation Plan December 31, 2016 Completed
December 21, 2016
Receive Permit-to-Construct On-site
Landfill
March 31, 2016 Delayed due to NC DEQ
environmental justice
review; completed
October 27, 2016
Submit Updated Excavation Plan December 31, Annually On track
Receive Permit-to-Operate (PTO)
On-Site Landfill
June 30, 2017 Delayed due to NC DEQ
environmental justice
review. Cell 1 PTO
received May 30, 2017.
Cell 2 PTO received
October 2, 2017.
Eliminate stormwater discharge into
impoundments
December 31, 2018
On track
Impoundments closed pursuant to
Part II, Sections 3(b) and 3(c) of the
Coal Ash Act
August 1, 2019 On track
V. Erosion and Sediment Control Plan
The Erosion and Sediment Control (E&SC) Plan for the excavation of the Ash Stack and
related site activities have been approved. The approval of this plan by NC DEQ meets
the requirement outlined in the referenced NC DEQ Letter. Modifications from E&SC
plans for subsequent phase(s) will be approved by NC DEQ prior to installation and
initiation of subsequent phase work.
The approved contractor will install the E&SC measures indicated in the plan. All
control measures will be maintained throughout the project in accordance with the
E&SC plans. When possible, portions of the E&SC plan will be closed out at the
approval of NC DEQ as areas become stabilized.

7: Dan River

VI. Dewatering Plan
The Dan River ash basins will be dewatered to facilitate the removal of ash and to
mitigate risk. An engineered Stormwater Diversion Plan for Dan River has been
developed and required permit applications were submitted prior to implementing the
plan. An engineered Dewatering Plan for Dan River has been developed and
dewatering will begin once the Stormwater Diversion Plan has been implemented.
Water collected in the Primary Basin will continue to be gravity fed to the Secondary
Basin. All leachate and interstitial dewatering wastewater treatment will be performed
by the City of Eden’s POTW in accordance with the Industrial User Permit issued to
Duke Energy by the City of Eden.
VII. Location(s) for Removed Ash
Ash removed from the site will be transported by the contractor to permitted facilities.
The ash disposal location(s) will be managed and maintained to ensure environmental
compliance with all applicable rules and regulations.
Disposal Site s
The Maplewood Landfill and the on-site landfill at Dan River have been identified as the
primary disposal locations.
Maplewood Landfill
The Maple Landfill is located near Jetersville, VA and is where 1.2 million tons of ash
where shipped by rail during Phase I. The final rail shipment of ash to the Maplewood
Landfill from Dan River occurred on March 23, 2017.
Dan River On-site Landfill
Transportation of ash to the on-site landfill began on May 31, 2017. The project team
utilized lessons learned from Phase I in developing and constructing the on-site landfill,
which provides the improvements below:
 Provide a reliable, long-term, cost-effective, solution for ash designated for
removal
 Support development of a diverse supplier program to drive innovation and
competition
 Establish performance baselines and a system to optimize excavation,
transportation, and disposal of ash
VIII. Transportation Plan
Ash is currently being transported from the basins via off-road articulated dump truck to
the on-site landfill. Truck loading operations will be conducted with a crew working
typically 12 hours per day, five to six days per week. Ash transportation to Roanoke

8: Dan River

Cement Company for beneficiation is by on-road truck. Transportation off-site will be
conducted by approved transporters and will meet Department of Transportation (DOT)
and other applicable federal, state, and local regulations.
IX. Environmental and Dam Safety Permitting Plan
Excavation of ash creates potential for stormwater impacts. The facility holds an
approved E&SC plan and associated Construction Stormwater Permit approval for ash
stack removal. Also, NC DEQ indicated that an NPDES Industrial Stormwater Permit is
required to excavate ash. The Company has received the NPDES Industrial
Stormwater Permit to support ash removal at the site. Pursuant to the requirements of
the NPDES Industrial Stormwater Permit, a stormwater pollution prevention plan
(SPPP) incorporating best management practices has been created and is currently
being implemented. Future modifications to the permit/plan will be managed as
necessary.
On October 27, 2016, Duke Energy received a modified NPDES W astewater Permit,
which included provisions for dewatering activities.
The area between Ash Stack 1 and Ash Stack 2 was determined to be a jurisdictional
wetland and an Individual Permit (IP) will be required to remediate this a rea and
complete stormwater diversion prior to basin closure. W etlands/stream impacts related
to the rail improvements were managed through the United States Army Corps of
Engineers (ACOE) with particular attention paid to the difference between jurisdictional
wetlands/streams under Section 404 and those arising from Section 401 waters. The
Company received approvals from ACOE and NC DEQ for wetlands/stream impacts
related to the rail. The company received approvals from ACOE and NC DEQ for
wetlands/stream impacts related to stormwater diversion in the fourth quarter of 2017.
Dan River ash is a non-hazardous material.
Subsequent phase(s) will include dewatering and continued excavation and removal of
ash from the Primary and Secondary Ash Basins. Subsequent phase(s) also includes
the continued construction of the on-site landfill.
In order to facilitate on-site landfill construction and operation, NC DEQ’s Solid Waste
Section issued a Landfill Permit-to-Construct on October 27, 2016. Following
construction of each cell of the on-site landfill, Construction Quality Assurance Reports
will be submitted to obtain the corresponding PTO. NC DEQ’s Solid Waste Section
issued a Landfill PTO for cell #1 on May 30, 2017 and a Landfill PTO for cell #2 on
October 2, 2017.
All necessary Dam Safety approvals will be or have been obtained to cover activities on
or around jurisdictional dams. Breaching of the dams will require Dam Safety approval.

9: Dan River

Any impacted wells or piezometers will be properly abandoned in accordance with NC
DEQ requirements. Fugitive dust will be managed to mitigate impacts to neighboring
areas.
Other than the agreement with City of Eden regarding development of the on-site
landfill, there are no additional site-specific or local requirements identified.
Permit Matrix
MEDIA PERMIT RECEIVED DATE (R) /
TARGET DATE (T)
COMMENTS
Water
NPDES Industrial
Stormwater
Permit
October 1, 2015 (R) SPPP implementation was
completed March 31, 2016.
NPDES Wastewater
Permit – Major
Modification
October 27, 2016 (R) Became effective on
December 1, 2016.

City of Eden –
Industrial User Permit
June 3, 2016 (R) None
Jurisdictional Wetland
and Stream Impacts /
404 Permitting and
401 WQC
September 14, 2015 (R) Two stream crossings for rail
upgrade
Jurisdictional Wetland
and Stream Impacts /
404 Permitting and
401 WQC
401 Permit
October 9, 2017 (R)

404 Permit
October 24, 2017 (R)
Area between Ash Stack 1 and
Ash Stack 2.
Dam Safety
Dam
Decommissioning
Request Approval
January 31, 2018 (T) Breaching of dike will require
Dam Safety approval.
Waste
Site Suitability Report August 28, 2015 (R) None
Permit-to-Construct
Landfill
October 27, 2016 (R) Target Date was March 31,
2016. Delay was due to NC
DEQ’s environmental justice
review.
Permit-to-Operate
Landfill
Cell # 1
May 30, 2017 (R)

Cell # 2
October 2, 2017 (R)

Cell # 3
Q2 2018 (T)
Cell 1: Target Date was
March 31, 2017. Delay was
due to NC DEQ’s
environmental justice review.

Other
Requirements
Site-Specific
Nuisance/Noise/Odor/
Other Requirements,
including DOT
July 21, 2015 (R) Eden City Council adopted
zoning amendment on July 21,
2015, which allows
construction of Dan River on-
site landfill.

10: Dan River

X. Contracting Strategy
The Ash Management Program strategy is to engage multiple contractors, drive
competition, create system-wide innovation, and develop a collection of best practices.
Duke Energy has engaged contractor(s), who are expe rienced in coal ash excavation,
transportation, and disposal, and continues to evaluate other potential contractors. The
Company provides in-depth oversight, coordination, and monitoring of the contractors to
ensure the work is performed appropriately. Duke Energy’s core values include safety,
quality, and protection of the environment, which are incorporated into our contracts.
The Company continues to evaluate alternate approaches, methods, and contracting
solutions and will adjust its strategy, as necessary.
XI. Environmental, Health, and Safety Plan
Protecting workers, the public, the community , and the environment
The Company is committed to the health, safety, and welfare of employees, contractors,
and the public, and to protecting the environment and natural resources. During all
phases of the project work, the Company and its contractors will follow the Duke Energy
Safe Work Practices Manual, the Environmental, Health, and Safety supplement
document, and any additional requirements. Occupational health and safety
expectations include oversight and continuous improvement throughout the project.
The project includes comprehensive environmental, health, and safety plans
encompassing all aspects of the project work.
In addition to adhering to all applicable environmental, health, and safety rules and
regulations, Duke Energy and its contractors will focus on ensuring the safety of the
public and protection of the environment during each phase of the project.
XII. Communications Plan
The project team is coordinating with Duke Energy’s Corporate Communications
Department to develop a comprehensive external communications plan tailored to the
specific needs of each phase of the project. Many different external stakeholders,
including neighbors, government officials, and media have an interest in this project.
The Company is committed to providing information by proactively communicating
about the project activities to potentially affected parties and responding to inquiries in a
timely manner.

11: Dan River

XIII. Glossary
TERM DEFINITION
Ash Basin Synonymous with Coal Combustion Residual Impoundment. A
topographic depression, excavation, or dammed area that is primarily
formed from earthen materials; without a base liner approved for use by
Article 9 of Chapter 130A of the North Carolina General Statutes or rules
adopted thereunder for a combustion products landfill or coal combustion
residuals landfill, industrial landfill, or municipal solid waste landfill; and
an Area that is designed to hold accumulated coal combustion residuals
in the form of liquid wastes, wastes containing free liquids, or sludge, and
that is not backfilled or otherwise covered during periods of deposition.
Ash Stack Ash storage areas located north of the Primary and Secondary Ash
Basins.
Beneficial Use Projects promoting public health and environmental protection, offering
equivalent success relative to other alternatives, and preserving natural
resources
Bottom Ash The agglomerated, angular ash particles formed in pulverized coal
furnaces that are too large to be carried in the flue gases and collect on
the furnace walls. Bottom ash falls through open grates to an ash hopper
at the bottom of the furnace.
Bulk Water Water above the ash contained in the ash basin. Synonymous with free
water
Coal Ash Excavation
Plan
Plan required by NC DEQ letter dated August 13, 2014, including a
schedule for soil and sediment erosion control measures, dewatering,
and the proposed location of the removed ash
Coal Ash
Management Act of
2014
North Carolina Session Law 2014-122
Coal Combustion
Residuals (CCR)
Residuals, including fly ash, bottom ash, boiler slag, mill rejects, and flue
gas desulfurization residue produced by a coal-fired generating unit
Dewatering The act of removing bulk and entrapped water from the ash basin
Dewatering Plan Engineered plan and the associated process steps necessary to dewater
an ash basin
Duke Energy Safe
Work Practices
Manual
Document detailing the Duke Energy safety guidelines

12: Dan River

TERM DEFINITION
Entrapped Water Flowable water below the ash surface that creates hydrostatic pressure
on the dam
Excavation Activities Tasks and work performed related to the planning, engineering , and
excavation of ash from an ash basin
Excavation Plan Refer to Coal Ash Excavation Plan
Free Water Water above the ash contained in the ash basin. Synonymous with bulk
water
Fly Ash Very fine, powdery material, composed mostly of silica with nearly all
particles spherical in shape, which is a product of burning finely ground
coal in a boiler to produce electricity and is removed from the plant
exhaust gases by air emission control devices
NPDES National Pollutant Discharge Elimination System
NPDES Permit A permit that regulates the direct discharge of wastewater and/or
stormwater to surface waters
Permit Federal, state, county, or local government authorizing document
POTW Publically Owned Treatment Works is typically a municipal water
treatment facility that can be utilized to treat wastewater and/or leachate.

XIV. Reference Documents
REF DOCUMENT DATE
1 NC DEQ Letter to Duke Energy, Request for Excavation Plans August 13,
2014
2 Coal Ash Management Act of 2014 September 20,
2014
3 NC DEQ Letter from Jeff Poupart, Water Quality Permitting Section
Chief, to Duke Energy regarding decant
July 20, 2016

EXCAVATION SOIL SAMPLING PLAN
DAN RIVER STEAM STATION
ASH BASIN SYSTEM
FOR ASH BASIN EXCAVATION
NORTH CAROLINA ASH BASIN CLOSURE

DUKE ENERGY CAROLINAS, LLC.
526 SOUTH CHURCH STREET/EC13K
CHARLOTTE, NORTH CAROLINA 28202

Waste & Groundwater Programs
Revision 1
December 2017
Excavation Soil Sampling Plan December 2017
Dan River Steam Station Ash Basin System Revision 1
Page i
TABLE OF CONTENTS
Section PAGE
1.0 PURPOSE ...............................................................................................................................1
2.0 DOCUMENTATION SUMMARY ................................................................................................1
3.0 SOIL SAMPLING METHODOLOGY ............................................................................................2
3.1 Method Summary ......................................................................................................................... 2
3.1.1 Equipment ............................................................................................................................. 2
3.1.2 Sample Locations .................................................................................................................. 3
3.1.3 Collection of Representative Samples .................................................................................. 3
3.1.4 Sample Preservation, Containers, Handling and Storage ..................................................... 4
3.1.5 Decontamination .................................................................................................................. 4
4.0 VISUAL CONFIRMATION OF ASH REMOVAL .............................................................................5
4.1 Pre-Excavation Documentation .................................................................................................... 5
4.2 Ash Removal Verification Protocol ............................................................................................... 5
4.2.1 Field Documentation ............................................................................................................. 5
4.2.2 Fill Evaluation Criteria ........................................................................................................... 6
4.3 Visual Removal Not Applicable ..................................................................................................... 7
5.0 SOIL SAMPLING AND ANALYSIS ..............................................................................................7
5.1 Soil Sampling ................................................................................................................................. 7
5.1.1 Scenario 1 .............................................................................................................................. 7
5.1.2 Scenario 2 .............................................................................................................................. 8
5.2 Fate and Transport Modeling ....................................................................................................... 8

Excavation Soil Sampling Plan December 2017
Dan River Steam Station Ash Basin System Revision 1
Page 1
1.0 PURPOSE
The purpose of this Excavation Soil Sampling Plan is to provide a standardized method for collecting soil
samples at Duke Energy North Carolina ash basins that are to be closed via excavation. Soil samples are
being collected following all visible ash removal from certain ash basins or other ash management units
referenced in Coal Ash Excavation Plans to support closure activities.
This Excavation Soil Sampling Plan is applicable to the collection of representative soil samples. Analysis
of soil samples may be chemical or physical in nature and may be used to determine the following:
• Extent and magnitude of constituent occurrence
• Input concentrations for groundwater fate and transport model
The methodologies discussed in this Excavation Soil Sampling Plan are applicable to the sampling of soil
in ash basin excavation areas. For the purposes of this plan, soils are those mineral and organic
materials remaining after all visible ash has been excavated.
2.0 DOCUMENTATION SUMMARY

TABLE 1 – Post Ash Excavation Soil Data Collection
Task Description Test Depth
Visual inspection on 100' X 100' grid
node
Visually confirm primary source
removal at nodes (Figure 1) and
document with photographs.
N/A N/A
Visual inspection at 100' X100' grid
node
Collect representative samples at
nodes (Figure 1) the appropriate
depths.
PLM 0 - 6 inches1
2' - 2.5'
Soil Sample Analysis on an acre grid
system2
Collect representative samples at the
appropriate depths.
Total Metals
SPLP
0 - 6 inches1
2' - 2.5'
7' - 7.5'
12' - 12.5'
17' - 17.5'
Notes:
1If a certain six-inch sample interval does not yield sufficient soil volume to fill five 8-ounce sample bottles, the
sample interval may be expanded two twelve inches to allow for sufficient soil sample volume. The revised sample
interval should be appropriately documented.
2Excavation is complete once confirmed by visual inspection and PLM analysis per Section 4.0.

Excavation Soil Sampling Plan December 2017
Dan River Steam Station Ash Basin System Revision 1
Page 2
3.0 SOIL SAMPLING METHODOLOGY
3.1 Method Summary
This Excavation Soil Sampling Plan has been adapted from Environmental Protection Agency (EPA)
Standard Operating Procedures (SOPs) #2012 and #2006 and North Carolina Department of
Environmental Quality (NC DEQ) Attachment 1 Coal Combustion Residuals Surface Impoundment
Closure Guidelines for Protection of Groundwater, November 4, 2016.

Soil samples are collected directly using stainless steel or plastic trowel, spade, shovel, or scoops.
Following collection, soil is transferred from the sampling device to a stainless steel or plastic bowl to be
homogenized. Once homogenized, the soil is transferred into Duke Energy Laboratory supplied sample
bottles.
Soil samples will be submitted under chain of custody for the following analyses: total metals and
Synthetic Precipitation Leaching Procedure (SPLP) metals. Analytical methods for total metals and SPLP
metals are described in Table 2. Ash presence is quantitatively determined by polarized light
microscopy (PLM) by RJ Lee Laboratory (or other approved vendor). PLM analysis passes visible light
through a pair of polarizing filters to create optical effects used in identifying unknown materials. This
method is commonly used in asbestos and coal ash identification.
3.1.1 Equipment
• Stainless steel or plastic trowel, scoop, spade or shovel – Used for collecting soil samples
from surface locations.
• Sample containers – To be supplied by Duke Energy Laboratory with appropriate
cooler(s). Estimated that five 8-ounce sample bottles with Teflon-lined lids will be
required for each sample location and sample depth. For return of cooler to the lab, ice
will be required.
• Gloves – Used for personal protection and to prevent cross-contamination of samples –
nitrile, disposable, powderless.
• Field clothing and Personal Protective Equipment – Used as specified in the site Health
and Safety Plan.
• Sampling flags – Used for identifying soil sampling locations.
• Field notebook – A bound book used to record progress of sampling effort and record
any problems and field observations during sampling.
• Three-ring binder book – Used to store necessary forms and record and track samples
collected at the site.
• Permanent marking pen – Used to label sample containers, document field logbooks,
data sheets and chain of custody.
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• Stainless steel or plastic spoon – Used for homogenizing soil samples within a stainless
steel or plastic bowl.
• Stainless steel or plastic bowl – Used for homogenizing soil samples, when applicable.
• Camera – Used for photo-documentation of sample locations and samples.
• GPS – Device used to obtain elevation, latitude and longitude of sample location.
• Trash bag – Used to dispose of gloves and any other non-hazardous waste generated
during sampling.
• Decontamination supplies and equipment.
3.1.2 Sample Locations
General locations for soil sampling are determined by the soil scientist in the field at a rate of
one soil sample for every 1 acre of ash basin area excavated. Actual sampling locations on site
may vary to account for site conditions and to allow collection of representative samples.
Representative samples reflect areas where all ash has been visually excavated and natural soil
is observed.
3.1.3 Collection of Representative Samples
For the purpose of this plan, surface soil is considered to range from 0 to 6 inches in depth,
while deeper samples will be collected at a range of 2 to 2.5 feet below ground surface (bgs), 7
to 7.5 feet bgs, 12 to 12.5 feet bgs, and 17 to 17.5 feet bgs (Table 1) unless bedrock, refusal, or
the water table are encountered. A surface soil sample and deeper samples will be collected at
each location for every 1 acre of ash basin excavated. A new pair of nitrile gloves is worn at
each sampling location and each depth. Each sampling location is recorded on the site map
prior to collecting the sample if location is not already noted on the map. The GPS location of
each sampling location (i.e. elevation, latitude and longitude), sample descriptions, and area
photographs are also recorded. All sampling equipment is decontaminated prior to use
irrespective of depth. The following procedure will be used to collect representative soil
samples with a scoop, shovel, trowel, geoprobe or excavator:
• Locate general sampling locations.
• Determine suitability of sampling location for a representative sample.
• If sampling location appears to reflect representative conditions that would allow
collection of a representative sample, proceed with sampling procedure. If
location is not indicative of conditions that would allow collection of a
representative sample, notify the project manager so an alternate location can
be identified.
• Using a decontaminated sampling instrument, remove the desired thickness and
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volume of soil from the sampling area. The sampler must obtain enough soil to
fill five 8-ounce sample bottles. If a certain six-inch sample interval does not
yield sufficient soil volume to fill five 8-ounce sample bottles, the sample interval
may be expanded to allow for sufficient soil sample volume. The revised sample
interval should be appropriately documented.
• Transfer the sample into an appropriate sample or homogenization bowl. Non-
dedicated containers should be adequately decontaminated. Stir for
approximately one minute until there appears to be a uniform color and
consistency.
• Transfer homogenized sample to a labeled container(s) of appropriate size and
construction for the analyses requested.
• Secure sample container tightly.
3.1.4 Sample Preservation, Containers, Handling and Storage
Chemical preservation of soils is generally not recommended. Cooling to 4oC on wet ice is
usually the best approach, supplemented by the appropriate holding time for the analyses
requested.
The Duke Energy Laboratory will supply the appropriate sample bottles for the collected soil
samples. The sample volume is a function of the analytical requirements and the Duke Energy
Laboratory will ensure the appropriate number of bottles are supplied. Ensure chain of custody
is completed for sample bottle return to the Duke Energy Laboratory.
Table 2 contains a list of parameters to be analyzed with corresponding reporting units and
analytical methods. If a parameter or group of parameters is not included in Table 2, the
laboratory performing the analysis should be contacted to determine the appropriate sample
bottles, volumes, and preservatives.
All non-dedicated sampling devices should be decontaminated and wrapped in plastic. The
sampling device should remain in this wrapping until it is needed. Each sampling device should
be used for only one sample and then decontaminated or disposed of. Non-dedicated sampling
devices should be cleaned in the field using the decontamination procedure described below.
3.1.5 Decontamination
Decontamination procedures can be time consuming; having a sufficient quantity of sampling
tools available is recommended. All non-dedicated sampling equipment must be
decontaminated prior to reuse. Equipment decontamination consists of:
1. Detergent wash and brush cleaning
2. Tap water rinse
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3. De-ionized water rinse
4. Air dry
5. Wrap sampling tools with plastic
4.0 VISUAL CONFIRMATION OF ASH REMOVAL
4.1 Pre-Excavation Documentation
Closure by removal is defined herein as removing the primary source (primary source of potential
constituents of interest) to the point that ash is not visible to the unaided eye at the ground surface.
Primary source ash is the main body of ash that was deposited in the basin. This method is intended
solely to verify and document primary source ash removal and is not intended to validate environmental
quality standards of the subsurface (considered the secondary source of potential constituents of
interest). Pre-excavation documentation would consist of:

• Review topographic mapping, aerial photography, construction drawings, and boring logs to
estimate the pre-ash placement topography and/or ash/soil interface

• Preparation of an ash basin figure illustrating a grid spacing of 100-feet (Figure 1). Each grid
point (node) will be assigned a unique identifier. Each node of the grid spacing (grid point) will
represent a visual verification location.

4.2 Ash Removal Verification Protocol
Ash excavation will be considered complete based on visual confirmation that all ash has been removed.
Ash removal will be based on sampling of the ash/soil interface and analysis by PLM. Soil samples will
be examined utilizing methods outlined in American Society for Testing and Materials (ASTM) D2488,
Standard Practice for Description and Identification of Soils (Visual-Manual Procedure). Vertical and
horizontal excavation of ash can terminate when the remaining material can be documented using PLM
to contain less than 50% ash.

Project will excavate ash until a visible change in color or texture confirms removal. This location shall
be referred to as the ash/soil interface. If visual evaluation is inconclusive, then request additional
evaluation to confirm ash removal.

4.2.1 Field Documentation
Evaluate the excavated surface elevation relative to the pre-ash placement topography.
Periodically check bottom elevation to evaluate if fill is present above historic bottom elevation.
Visual confirmation will be performed on a 100-foot grid system (Figure 1) unless conditions
prevent such confirmation, as described in Section 4.3. Soil sampling will be performed on an
100-foot grid system and will be analyzed using PLM.

• Personnel will locate each node by GPS or survey control, determine elevation, and
evaluate whether that point is above or below the historic bottom elevation.

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• Personnel will then observe the surface area represented by the node, to note if visible
ash is present at the surface. If present, the location should be documented and
excavation will need to continue. If the evaluation indicates the surface soils are
residuum or bedrock, then hand auger to two feet below surface (or refusal) and
perform visual-manual classification of the soils at the surface and depth according to
ASTM method D2488. Submit sample from surface and depth (or shallower if refusal)
for PLM analysis. The conditions shall be documented by taking photographs.

• The classification indicator for fly ash will be grey to black silt-sized particles with no
plasticity. The classification indicator for bottom ash will be grey to black sand to gravel
sized particles and porous. If the material cannot be positively identified as soil, submit
a sample for PLM analysis.

• If the node point elevation is near the historic bottom elevation and either (1) residuum
is indicated by observation or (2) soil is confirmed by visual manual classification (ASTM
D2488) and PLM analysis is less than 50%, then personnel can conclude the primary
source is removed.

4.2.2 Fill Evaluation Criteria
The following procedure provides an approach that can be used to ascertain if the fill can remain
in place. The procedure specified is based on the fill material and depth.

• If the elevation is less than eight feet above the historic bottom elevation and residuum
is not observed, then test pits may be excavated to historic bottom elevation or until
residuum or bedrock is encountered, but no more than eight feet below the surface.
o Personnel will evaluate existing information to determine if the test pits are
necessary. If necessary personnel may recommend excavating test pits at a
frequency no tighter than 100 feet by 100 feet.
o If visible ash is not discovered based on information defined above, then the
primary source removal may be confirmed.
o If visible ash is discovered, then continue excavation.

• If the elevation is more than eight feet above historic bottom elevation and residuum is
not observed, discuss with CCP Closure Personnel.
o CCP Closure Personnel will confirm historic information and recommend a
drilling and sampling program at a frequency no tighter than 100 feet by 100
feet to evaluate the presence of ash below the fill in accordance with the
information defined above. If unusual features are revealed by the drilling, CCP
Closure Engineering may request/recommend additional borings. Exploration is
to be performed by continuous sampling during drilling.
o If visible ash is not discovered based on information defined above, then the
primary source removal may be confirmed.
o If visible ash is discovered, then continue excavation.

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4.3 Visual Removal Not Applicable
If possible, excavation of ash should continue even if groundwater is encountered. Visual
documentation cannot be completed where ash is under the water table. If Duke Energy cannot
complete visual removal because of site conditions or other restricting factors, documentation shall be
presented to NC DEQ.

Duke Energy anticipates that in locations where visual documentation cannot be completed, additional
ash characterization along with groundwater fate and transport modeling will be completed. Ash
characterization may consist of SPLP and/or other testing with results imputed into an updated site wide
groundwater fate and transport model. Details will be provided to DEQ for review and concurrence.

5.0 SOIL SAMPLING AND ANALYSIS
5.1 Soil Sampling
Soil sampling of the remaining soils (less than 50% ash per PLM analysis) will be necessary to evaluate
the extent of potential secondary source impacts depending on the depth of the water table and any
proposed institutional or engineering controls that may be used in the area of excavation. Soil sampling
will not be required if refusal or the top of bedrock are encountered, or the remaining soils are below
the water table. Soil samples for laboratory analysis must be collected in a manner that will ensure a
relatively uniform distribution of particles throughout the six inch sample.
The systematic approach and design for soil sampling an analysis is dependent upon two scenarios:
• Scenario 1: Remaining soil (containing less than 50% ash per PLM analysis) is located above the
seasonal high water table and final constructed institutional and/or engineering controls will
restrict infiltration from the surface reaching the water table (e.g. installation of a liner system).

• Scenario 2: Remaining soil (containing less than 50% ash per PLM analysis) is located above the
seasonal high water table and infiltration from the surface would continue to reach the water
table.

5.1.1 Scenario 1
Confirmation sampling will include discrete surface samples collected from the first six inches of
the soil. Sampling will be performed on an acre grid system. This sample collection
methodology shall be sufficient to characterize the horizontal extent of any remaining potential
secondary source impacts for comparison with the NC DEQ Preliminary Soil Remediation Goals
(PSRG). The samples shall be analyzed by a North Carolina certified laboratory for total
concentrations for the following parameters: antimony, aluminum, arsenic, barium, beryllium,
boron, cadmium, calcium, chloride, chromium (total and hexavalent), cobalt, copper, iron, lead,
magnesium, manganese, mercury, molybdenum, nickel, nitrate as nitrogen, pH, potassium,
selenium, silver, sodium, strontium, sulfate, thallium, vanadium, and zinc. No SPLP testing is
required.

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5.1.2 Scenario 2
Confirmation sampling will include collection of both discrete surface and subsurface soil
samples performed on an acre grid system. Discrete surface samples will be collected from the
first six inches of the soil and a subsurface soil sample will be collected at 2 to 2.5 feet below
ground surface (bgs), 7 to 7.5 feet bgs, 12 to 12.5 feet bgs, and 17 to 17.5 feet bgs, unless
refusal, bedrock or the water table are encountered. The use of a geoprobe or excavator is
anticipated. This sample collection methodology shall be sufficient to characterize both the
horizontal and vertical extent of any remaining potential secondary source impacts for
comparison with the DEQ PSRGs and/or input into the soil leachate model. The samples shall be
analyzed by a North Carolina certified laboratory for both total concentrations and SPLP for the
following parameters: antimony, aluminum, arsenic, barium, beryllium, boron, cadmium,
calcium, chloride, chromium (total and hexavalent), cobalt, copper, iron, lead, magnesium,
manganese, mercury, molybdenum, nickel, nitrate as nitrogen, pH, potassium, selenium, silver,
sodium, strontium, sulfate, thallium, vanadium, and zinc.

5.2 Fate and Transport Modeling
Contingency for stabilization of remaining amounts of potential secondary source impacts in a manner
that will meet the intent of North Carolina Groundwater 2L Rules and closure requirements shall be
considered as site conditions dictate. Provisions to develop groundwater flow and transport models to
evaluate protection of groundwater criteria if some secondary source impacts are left in place shall be
considered. In addition, the possibility of metals leaching from a potential change in pH and
geochemical conditions related to dewatering and excavation shall be considered along with plans for
groundwater models to assess resulting site conditions.

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TABLE 2 - Soil Parameters and Analytical Methods Totals and SPLP Analysis North Carolina Ash
Basins to be Closed Via Excavation

INORGANIC COMPOUNDS UNITS METHOD1
Aluminum mg/kg or µg/l EPA 6010D
Antimony mg/kg or µg/l EPA 6020B
Arsenic mg/kg or µg/l EPA 6020B
Barium mg/kg or µg/l EPA 6010D
Beryllium mg/kg or µg/l EPA 6020B
Boron mg/kg or µg/l EPA 6010D
Cadmium mg/kg or µg/l EPA 6020B
Calcium mg/kg or µg/l EPA 6010D
Chloride mg/kg or µg/l EPA 9056A
Chromium mg/kg or µg/l EPA 6010D
Cobalt mg/kg or µg/l EPA 6020B
Copper mg/kg or µg/l EPA 6010D
Hexavalent Chromium mg/kg or µg/l EPA Method
7199/218.7
Iron mg/kg or µg/l EPA 6010D
Lead mg/kg or µg/l EPA 6020B
Magnesium mg/kg or µg/l EPA 6010D
Manganese mg/kg or µg/l EPA 6010D
Mercury mg/kg or µg/l EPA Method
7470A/7471B
Molybdenum mg/kg or µg/l EPA 6010D
Nickel mg/kg or µg/l EPA 6010D
Nitrate as Nitrogen mg/kg or µg/l EPA 9056A
pH SU EPA 9045D
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Potassium mg/kg or µg/l EPA 6010D
Selenium mg/kg or µg/l EPA 6020B
Silver mg/kg or µg/l EPA 6020B
Sodium mg/kg or µg/l EPA 6010D
Strontium mg/kg or µg/l EPA 6010D
Sulfate mg/kg or µg/l EPA 9056A
Thallium (low level) (SPLP Extract only) mg/kg or µg/l EPA 6020B
Vanadium mg/kg or µg/l EPA 6020B
Zinc mg/kg or µg/l EPA 6010D
Notes:

1. Soil samples to be analyzed for Total Inorganics using USEPA Methods 6010/6020 and pH
using USEPA Method 9045, as noted above (or similar approved methods). Soil samples will
also be analyzed for leaching potential using SPLP Extraction Method 1312 in conjunction with
USEPA Methods 6010/6020 (or similar approved methods).

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FIGURE 1 - Dan River Steam Station Grid Map