HomeMy WebLinkAboutNC0001422_L.V. Sutton Excavation Plan 2016_20161201
L.V. Sutton Electric Plant
Coal Ash Excavation Plan
2016 Update
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Table of Contents
I. Statement of Purpose ..................................................................................................... 1
II. General Facility Description ............................................................................................ 2
III. Project Charter ............................................................................................................... 3
IV. Critical Milestone Dates .................................................................................................. 5
V. Erosion and Sedimentation Control Plan ........................................................................ 6
VI. Dewatering Plan ............................................................................................................. 7
VII. Proposed Location(s) for Removed Ash ......................................................................... 7
VIII. Transportation Plan ........................................................................................................ 8
IX. Environmental and Dam Safety Permitting Plan ............................................................. 9
X. Contracting Strategy ......................................................................................................11
XI. Environmental, Health, and Safety Plan ........................................................................11
XII. Communications Plan ....................................................................................................12
XIII. Glossary ........................................................................................................................12
XIV. Reference Documents ...................................................................................................14
Exhibits
Exhibit A: Excavation Soil Sampling Plan
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I. Statement of Purpose
Duke Energy Progress, 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 L.V. Sutton Electric Plant (Sutton
or Plant), National Pollutant Discharge Elimination System (NPDES) Permit No.
NC0001422, in New Hanover 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 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 sedimentation erosion control measures, 2)
dewatering, and 3) the proposed location(s) of the removed ash. These requirements
are discussed in this updated Plan.
This is a revision of the Coal Ash Excavation Plan dated November 13, 2015, which
covers the initial phase of ash basin excavation activities, including the initiation of basin
dewatering, site preparation, ash basin preparation, and ash removal from the basins at
Sutton. 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 precise scope of work in excavating the ash basins has been determined by
applicable laws, rules, permits, and approvals that control the activities to be performed
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
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consequence, neither the submittal of this Plan nor its a cknowledgement by NC DEQ
should be taken as 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
Sutton is located in New Hanover County near Wilmington, NC, situated between the
Cape Fear River to the west and the Northeast Cape Fear River to the east. Sutton
was a three-unit, 575 megawatt (MW) coal-fired power plant. The Plant operated from
1954 until retirement of the coal-fired units in November 2013. Upon retirement of the
coal-fired units, a new 625 MW gas-fired unit began operations.
There are two CCR basins—the 1971 and 1984 Basins—and a large Cooling Basin.
Both the 1971 and 1984 Basins contain fly ash, bottom ash, boiler slag, stormwater, ash
sluice water, coal pile runoff, and low volume waste water. The Cooling Basin is
accessible to the general public and is used for recreational purposes. The lake was
classified as W aters of the State on November 5, 2014. One other area that contains
CCR material is the Lay of Land Area (LOLA). The LOLA consists mostly of bottom ash
and 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 September 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.
1971 Ash Basin
The 1971 Basin was operated from 1971 to 1985. It was opened again in 2011 for
temporary use during repair work and ash removal activities. The 1971 Basin is unlined
and was initially constructed with a crest elevation of 18 feet mean sea level (msl),
which was raised in 1983 to 26 msl. The 1971 Basin initially contained approximately
3.8 million tons of CCR material. The southern basin dikes of the 1971 Basin contain
ash and will be excavated as part of final closure.
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1984 Ash Basin
The 1984 Basin was operated from 1984 to 2013. The 1984 Basin was constructed
with a 12-inch thick clay liner at the basin bottom, which extends along the side slopes
where it is protected by a 2-foot thick sand layer. The 1984 Basin crest elevation is 34
feet msl. In 2006, an Interior Containment Area (ICA) was constructed within the 1984
Basin with a crest elevation of 42 feet msl. The 1984 Ash Basin initially contained
approximately 2.8 million tons of CCR material.
LOLA
The LOLA is located between the discharge canal and the coal pile. It is believed that
the presence of CCR in this area may have been due to Plant operations between
approximately 1954 and 1972. A small portion adjacent to the coal pile storage area
was used to locate fuel oil storage tanks. The LOLA is on the North Carolina Inactive
Hazardous Waste Sites Priority List. This area contains approximately 686,000 tons of
CCR and soil mixture at depths of 0 to 15 feet.
Current Operating Permit Details
The Cooling Basin, 1971 Basin, and 1984 Basin are operated under NPDES Permit No.
NC0001422 to regulate effluents to the Cape Fear River. Additionally, the dams of the
Cooling Basin, 1971 Basin, and 1984 Basin are listed under the NC DEQ Dam Safety
Program. The dam identification numbers for the Cooling Basin, 1971 Basin, and 1984
Basin are NEWHA-003, NEWHA-004, and NEWHA-005, respectively. The dam
inventory lists the Cooling Basin and 1971 dams as exempt. The 1984 dam is listed as
impounding, hence regulated. In 2014, these dams were re-rated as high hazard by NC
DEQ. The 2006 ICA constructed within the 1984 Basin was permitted and used as a
“basin within a basin,” where an interior dam was constructed on top of the CCR within
the basin; sluiced CCR was excavated from rim ditches, placed within the interior basin,
and compacted to heights that are above the exterior basin dams. This operation was
discontinued before reaching the permitted final grades when the Plant was shut down
in November 2013.
III. Project Charter
Dewatering of the ash basins and the removal of ash from the site is being performed
within project phases. The project has substantially completed Phase I and has been
planning and implementing Phase II. The following items in Phase I have been
completed or initiated:
1. Initiated the removal of ash from the Sutton site
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2. Began dewatering of the ash basins
3. Installation of a waste water treatment system to support dewatering of the ash
basins
4. Development of option(s) for proposed ash disposal or beneficial use locations
5. Complete a work scope and bid event to support ash basin closure
6. Reroute approximately two miles of the Sutton Lake public boat ramp access
road
7. Validate production rates to meet project requirements
8. Develop and construct the infrastructure to remove and transport the ash
9. Initiate the development and complete the permitting of the on-site landfill
10. Obtain permit to construct on-site landfill
The Sutton NPDES waste water permit was issued to Duke Energy in December 2015.
The removal of the bulk free water was completed on January 28, 2016. After the
required waste water treatment was installed and operational, removal and treatment of
the basin interstitial water commenced in June 2016. Based on revisions to the NPDES
permit, the stormwater from the fossil plant has been rerouted and no longer discharges
into the basins. Therefore, rainwater is the only inflow into the basins. Basin
dewatering is currently being implemented on an as-needed basis to maintain the
basins’ clear water ponds as low as reasonably possible.
Under this Plan, the Company began removing ash to an off-site location while
simultaneously developing an on-site landfill in order to meet the closure requirement
mandated in the Coal Ash Act. The Sutton on-site landfill construction permit was
received on September 22, 2016. This date is significantly later than originally
forecasted and combined with the impacts of Hurricane Matthew on the landfill
construction and ash movement, will move the projected completion date beyond the
mandatory closure date of August 1, 2019. Schedule recovery opportunities are and
will continue to be evaluated.
Project Charter O bjective s
Phase II Objectives
1. Continue to dewater the ash basins
2. Submit and obtain any necessary permits for Phase II activities
3. Excavate and transport ash from the 1971 Basin and 1984 Basin
4. Construct and operate cells for the on-site landfill
5. Gain knowledge and opportunities for program improvement that can be applied
to the subsequent phase(s)
Inactive Ash Areas Objectives
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1. Submit and obtain any necessary permits for activities
2. Excavate and transport ash from the LOLA
3. Operate and close cells for the on-site landfill
4. Gain knowledge and opportunities for program improvement
Project Charter Scope
Phase II Scope
1. Submit and obtain applicable permits
2. Install required site haul roads
3. Continue dewatering of the 1984 and 1971 Basins
4. Commence landfill operation
5. Relocate several thousand feet of Piedmont Natural Gas gas line from the LOLA
6. Continue to excavate and transport approximately an additional 3.4 million tons
of ash from the 1984 Basin and the 1971 Basin to an approved landfill, beneficial
use facility, structural fill locations, or on-site landfill
7. Continue infrastructure activities that are required to support the future
excavation of the LOLA
8. Continue infrastructure activities that are required to support the future
excavation of the 1971 Basin southern dikes
9. Dredge and transport approximately 1.3 million tons of material from the 1971
Basin and the 1971 dikes
10. Complete closure activities for the 1971 Ash Basin and the 1984 Ash Basin as
outlined in Part II, Sections 3(b) and 3(c), Subparagraphs 1 and 2 of the Coal
Ash Act
Inactive Ash Areas Scope
1. Excavate and transport the 686,000 tons of material from the LOLA to the on-site
landfill
2. The LOLA will be closed as part of overall site closure, but is not subject to Part
II, Sections 3(b) and 3(c) of the Coal Ash Act
3. Operate and close cells for the on-site landfill
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 November 30, 2014 Completed
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MILESTONES NO LATER THAN DATE STATUS
Engineering Review November 30, 2014
Excavation Plan Acknowledgement February 17, 2015 Completed
February 2, 2015
Submit Updated Excavation Plan November 15, 2015 Completed November 13,
2015
Commence Work – Ash Removal Final permit approval + 14
Days
Completed
October 30, 2015
Receive NPDES Waste water
Permit
December 11, 2015 Completed December 2015
Receive Permit-to-Construct On-
site Landfill
February 29, 2016 Delayed due to
environmental justice
review; Completed
September 2016
Receive Permit-to-Operate On-Site
Landfill
August 31, 2017 Delay due to environmental
justice review; Forecasted
to receive during third
quater 2017
Submit Updated Excavation Plan December 31, 2016 On track
Submit Updated Excavation Plan December 31, Annually On track
Eliminate Stormwater Discharge
into Impoundments
December 31, 2018 Completed July 2016
1971 and 1984 Basins closed
pursuant to Part II, Sections 3.(b)
and 3.(c) of the Coal Ash Act
August 1, 2019 Challenged due to
permitting delay and
Hurricane Matthew
V. Erosion and Sedimentation Control Plan
The project currently has several active Erosion and Sedimentation Control (E&SC)
plans: Rail Road Extension (NEWHA-2016-023), Ash Pond Vegetation Removal
(NEWHA -2016-006), Site Wide Clearing Activities (NEWHA -2016-025), Groundwater
Well Installation (NEWHA -2016-020), and Boat Road Relocation (NEWHA -2016-008).
Additional applications are expected to be submitted during this phase as the project
planning develops. 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 through the project in accordance with the E&SC
plans and permits. When possible, portions of the E&SC plan will be closed out at the
approval of NC DEQ as areas become stabilized.
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VI. Dewatering Plan
The Sutton ash basins will be dewatered to facilitate the removal of ash and to mitigate
risk. Engineering analysis has shown that lowering the water below the level of ash
within each basin does not improve the factor of safety against failure of the associated
dam; therefore, removal of entrapped water is not required.
An engineered Dewatering Plan for Sutton has been developed and dewatering has
been in progress since October 2015. Interstitial basin dewatering will probably be
required throughout the life of the project. The current 1984 Clear Water Pond water
elevation is approximately one foot above the clay bottom. Pumping is managed to
control the water level as low as reasonably possible.
The current plan calls for the removal of ash from the 1971 Basin through different
methods than from the 1984 Basin and the LOLA. Heavy equipment operation directly
on top of the ash in the basin has been deemed impractical due to high groundwater
recharge rates. Therefore, the removal of the ash from the 1971 Basin incorporates
hydraulic dredging and dewatering of the resulting dredged material. The water
generated during ash removal will be directed back to the 1971 Basin.
VII. Location(s) for Removed Ash
Ash removed from the site will be transported by the contractor to permitted facilities.
The ash storage location will be managed and maintained to ensure environmental
compliance with applicable rules and regulations.
Disposal Sites
Brickhaven Structural Fill and the on-site landfill at Sutton have been identified as the
primary disposal locations.
DISPOSAL SITE LOCATION APPROXIMATE
AMOUNT (TONS)
CCR DISPOSAL
Brickhaven
Structural Fill
Moncure, NC 2,000,000 Structural Fill
On-Site Landfill Wilmington, NC (Sutton) 5,300,000 Landfill
Brickhaven Structural Fill
The Brickhaven Structural Fill is located at the Brickhaven Mine near the City of
Moncure in Chatham County, NC. It resides on approximately 299 acres. Ash will be
transported and will be beneficially used as fill material for a structural fill project at the
reclaimed mine.
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Sutton On-Site Landfill
Ash excavated from the basins and LOLA will be disposed of in the proposed on-site
CCR landfill. The project includes the installation of a liner and leachate collection
system for the landfill. The proposed landfill footprint is approximately 100 acres and
will provide approximately 8.3 million cubic yards (approximately 10 million tons,
assuming a density of approximately 1.2 tons/cy) of disposal capacity over a period of
approximately 12 years; however, construction of the cells is expected to be complete
within 10 years. The maximum elevation of the proposed landfill will be approximately
112 feet North American Vertical Datum (NAVD88) with an average top-deck elevation
equal to 108 feet NAVD88.
Contingent Plan: Disposal Sites
Colon Structural Fill
The Colon Structural Fill is located at the Colon Mine in Sanford, NC. Ash would be
transported from Sutton to the Colon Structural Fill to be beneficially used as fill material
for a structural fill project at the reclaimed mine.
The Company continues to develop and evaluate contingency storage locations in the
event this scenario becomes unobtainable. Contingency plans currently being
developed include assessing alternate ash disposal locations and beneficial use.
Subsequent Ph ase(s): Disposal Sites
The project team will utilize lessons learned from Phase I and II to develop an off-site
disposal strategy and/ or alternative beneficial use site(s) that will provide the
improvements below:
Provide a reliable, long-term, cost-effective, solution for ash designated for
removal
Develop a supplier-diverse program to drive innovation and competition
Establish performance baselines and a system to optimize pickup, transport,
drop-off, and beneficial use of ash
VIII. Transportation Plan
Ash will be transported from the site via rail car and truck to the off-site facility.
Transportation of the CCR will be conducted by approved transporters and meet
Department of Transportation (DOT) and other applicable federal, state, and local
regulations.
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Phase I : Transportation
For Phase I, all CCR transported off-site will be transported by rail and truck from Sutton
to the Brickhaven site. Rail car loading operations will be completed with a crew
working typically 12 hours per day, seven days per week. Truck operations are not
currently in progress at Sutton.
Contingent Plan: Transportation
In the event of prolonged rail transportation disruption, truck transportation remains a
contingency option.
Subsequent Phase(s): Transportation
Transportation to the on-site landfill will be by off-road truck.
IX. Environmental and Dam Safety Permitting Plan
Phase I includes the excavation and removal of ash from the 1984 and 1971 Basins to
an off-site location. Implementation for Phase I began once the permitting for Phase I
was obtained in October 2015.
Excavation of ash creates potential for stormwater impacts. Since Sutton has no point
source discharges consisting solely of industrial stormwater, NC DEQ determined that
an individual industrial stormwater permit is not necessary. Instead, NC DEQ has
included internal stormwater outfalls and the requirement to develop a stormwater
pollution prevention plan as a requirement of the NPDES waste water permit. Future
modifications to the permit/plan will be managed as necessary.
NC DEQ has determined that removal of dry ash from the Sutton ash basins can be
regulated via the Construction Stormwater General Permit. Ash removal activities were
permitted when NC DEMLR approved erosion control plan NEWHA-2016-023.
NC DEQ determined that dewatering activities, including free water removal, required a
NPDES waste water permit modification. Based on this requirement, the Company
applied for a permit modification to specifically allow decanting of free water and
dewatering of interstitial water. Application was made in January 2015. The Company
received the modified NPDES permit in October 2016.
There are no jurisdictional wetlands/streams associated with the removal of ash from
the 1984 and 1971 Basins during Phase I and II. The current and future wetland/stream
impacts and jurisdictional determinations will be managed through the United States
Army Corps of Engineers with particular attention paid to the difference between
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jurisdictional wetlands/streams under Section 404 and those arising from Section 401
waters. Any Section 404 individual permitting will require Section 401 Water Quality
Certification by NC DEQ.
Sutton ash is not classified as a DOT hazardous material.
Subsequent phase(s) will include dewatering and continued excavation and removal of
ash from the 1984 and 1971 Basins and the LOLA. Subsequent phase(s) also
include(s) the continued construction of the on-site landfill.
Before shipping ash to a third-party RCRA Subtitle D landfill, waste characterization and
approval will be completed. All necessary Dam Safety approvals will be obtained to
cover activities on or around jurisdictional dams. Breaching of the dams will require
Dam Safety approval. 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.
Permit Matrix
MEDIA PERMIT RECEIVED DATE (R)
/ TARGET DATE (T)
COMMENTS
Water NPDES Waste water
Permit – Major
Modification
October 2015 (R) None
Jurisdictional
Wetland and Stream
Impacts/ 404
Permitting and 401
WQC
September 2016 (R) Four cells in the new Sutton landfill
have identified jurisdictional
wetland/stream impacts in Phase I.
Wetland permits have been received.
Dam Safety Dam
Decommissioning
Request Approval
March 30, 2017 (T) Initial transporting and excavation
activities will not impact a
jurisdictional dam or dike. Breaching
of any dike will require Dam Safety
approval.
Waste Individual Structural
Fill Permit to Operate
October 15, 2015 (R) Mine reclamation Owner/Operator
obtained a structural fill permit as set
forth in Part II, § 130A-309.219 of the
Coal Ash Act.
Site Suitability Report July 2, 2015 (R) Site Suitability obtained for Sutton
landfill and the Brickhaven Mine off-
site structural landfill. Previous date
was March 31, 2015. Change was
related to additional requirements to
complete the report prior to submittal.
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MEDIA PERMIT RECEIVED DATE (R)
/ TARGET DATE (T)
COMMENTS
Permit-to-Construct
Landfill
September 2016 (R) The permit to begin construction and
corresponding E&SC have been
received. Previous Target Date was
February 23, 2016. Construction is
in progress.
Permit-to-Operate
Landfill
August 31, 2017 (T) Previous Target Date was November
23, 2016. Must provide Construction
Quality Assurance Report and then
receive the permit before operation.
Delay is due to environmental justice
review.
Other
Requirements
Site Site-Specific
Nuisance/Noise/Odor
/Other Requirements,
including DOT and
FERC Requirements
N/A None identified.
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 experienced 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.
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The project includes comprehensive environmental, health, and safety plans
encompassing all aspects of the project work, including at the plant, in transit, and at the
final destination, as needed.
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.
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 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 A dry ash storage feature external to the ash basin
Beneficial and
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.
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TERM DEFINITION
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 sedimentation 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
Engineer of
Record
Duke Energy or third-party contracted engineer responsible for final
verification of specific plan actions and documents
Entrapped
Water
Water below the ash surface, which 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
Factor of
Safety
In reference to dam safety, the ratio of the forces or moments resisting
mass movement to the forces or moments tending to produce mass
movement
Free Water Water above the ash contained in the ash basin; synonymous with bulk
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TERM DEFINITION
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.
LOLA Lay of Land Area
NPDES National Pollutant Discharge Elimination System
NPDES Permit A permit that regulates the direct discharge of waste water to surface
waters
Off-Site
Facility
A structural fill or mine reclamation for the long-term storage of coal
combustion residuals
Permitting Federal, state, county, or local government authorizing document
XIV. Reference Documents
REF DOCUMENT DATE
1 Letter to Duke Energy, Request for Excavation Plans August 13, 2014
2 Coal Ash Management Act of 2014 September 20, 2014
Excavation Soil Sampling Plan December 2016
L.V. Sutton Plant 1971 & 1984 Ash Basins Revision 0
EXHIBIT A
EXCAVATION SOIL SAMPLING PLAN
L.V. SUTTON ENERGY COMPLEX
1971 & 1984 ASH BASINS
FOR ASH BASIN EXCAVATION
NORTH CAROLINA ASH BASIN CLOSURE
DUKE ENERGY PROGRESS, LLC.
526 SOUTH CHURCH STREET/EC13K
CHARLOTTE, NORTH CAROLINA 28202
Waste & Groundwater Programs
Revision 0
December 2016
Excavation Soil Sampling Plan December 2016
L.V. Sutton Plant 1971 & 1984 Ash Basins Revision 0
TABLE OF CONTENTS
SECTION PAGE
1.0 Purpose ............................................................................................................................................ 1
2.0 Soil Sampling methodology ............................................................................................................. 1
2.1 Method Summary 1
2.1.1 Equipment 1
2.1.2 Sample Locations 2
2.1.3 Collection of Representative Samples 2
2.1.4 Sample Preservation, Containers, Handling and Storage 3
2.1.5 Decontamination 4
3.0 Visual Confirmation of Ash Removal ............................................................................................... 4
3.1 Pre-Excavation Documentation 4
3.2 Ash Removal Verification Protocol 4
3.2.1 Field Documentation 5
3.2.2 Fill Evaluation Criteria 5
3.3 Visual Removal Not Applicable 6
4.0 Soil Sampling and Analysis ............................................................................................................... 6
4.1 Soil Sampling 6
4.1.1 Scenario 1 7
4.1.2 Scenario 2 7
4.2 Fate and Transport Modeling 7
5.0 Documentation Summary ................................................................................................................ 8
LIST OF TABLE
Table 1 - Soil Parameters and Analytical Methods
LIST OF FIGURE
Figure 1 - L.V. Sutton Plant Ash Basin Sampling Plan
Excavation Soil Sampling Plan December 2016
L.V. Sutton Plant 1971 & 1984 Ash Basins Revision 0
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 Soil Sampling Methodology
2.1 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 (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 1. 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.
2.1.1 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 5-8 ounce samples bottles with Teflon-lined lids will be
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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.
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.
2.1.2 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.
2.1.3 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 (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
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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
volume of soil from the sampling area. The sampler must obtain enough soil to
fill five 8-ounce sample bottles.
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.
2.1.4 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 1 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 1, the
laboratory performing the analysis should be contacted to determine the appropriate sample
bottles, volumes, and preservatives.
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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.
2.1.5 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
3. Deionized water rinse
4. Air dry
5. Wrap sampling tools with plastic
3.0 Visual Confirmation of Ash Removal
3.1 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.
3.2 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.
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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.
3.2.1 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 3.3. Soil sampling will be performed on an
acre 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.
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.
3.2.2 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.
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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.
3.3 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 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.
4.0 Soil Sampling and Analysis
4.1 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 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.
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4.1.1 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 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.
4.1.2 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.
4.2 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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5.0 Documentation Summary
100’ x 100’ Grid Node (Figure 1) Visually confirm primary source removal and document with
photographs
Soil Sample Collection at a Grid Node (1 per Acre)
Depth/Test PLM Total Metals (Table 1) SPLP (Table 1)
0 – 6 inches X X X
2’ – 2.5’ X X X
7’ – 7.5’ N/A X X
12’ – 12.5’ N/A X X
17’ – 17.5’ N/A X X
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Table
Excavation Soil Sampling Plan December 2016
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TABLE 1
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
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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
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).
Excavation Soil Sampling Plan December 2016
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Figure
Excavation Soil Sampling Plan December 2016
L.V. Sutton Plant 1971 & 1984 Ash Basins Revision 0
Figure 1 – L.V. Sutton Plant Ash Basin Sampling Plan