7906_Duke_DanRiver_CoverDemo_DIN27477_20170306

Amec Foster Wheeler Environment & Infrastructure Inc.
14424 Albemarle Point Place, Ste. 115
Chantilly, Virginia 20151
703-488-3700
amecfw.com
Registered in North Carolina
Engineering and Land Surveying License No. F-1253
Geology License No. C-247
February 28, 2017

Ms. Melonie Martin
Duke Energy Carolinas, LLC
Dan River Steam Station
3195 Pine Hall Road
Belews Creek, North Carolina 27009
[e-mail]

Subject: Dan River Landfill (Permit No. 7906-INDUS-2016)
Utilization of 1.06-ft of Sand as Cell 1 Protective Cover
Duke Energy – Dan River Steam Station
Eden, North Carolina
Amec Foster Wheeler Project No. 7810170870

Dear Ms. Martin:
Amec Foster Wheeler is pleased to provide this letter report to Duke Energy Carolinas, LLC
(Duke) describing proposed methods and requirements for utilizing 1.06-ft of sand as protective
cover for Dan River Landfill Cell 1 at Duke’s Dan River Steam Station. This letter has been
prepared by the Dan River Landfill Engineer of Record (EOR, Cedric Ruhl of Amec Foster
Wheeler). We understand that Duke will submit this report to the North Carolina Department of
Environmental Quality (NCDEQ) Solid Waste Section (SWS) for review and concurrence.
Project Information
The Dan River Steam Station was one of four Duke sites identified in the North Carolina Coal
Ash Management Act (CAMA) as a site with high-priority CCR units requiring closure of the CCR
units no later than August 1, 2019. The proposed mechanism for closing the CCR units at the
Dan River Steam Station includes construction of an on-site landfill.
Construction plans for the Dan River Landfill were documented in the “Industrial Landfill Permit
to Construct Application Submittal” developed by Amec Foster Wheeler (December 24, 2015)
and approved by the NCDEQ-SWS on October 26, 2016. Issued for Construction (IFC)
documents were also developed by Amec Foster Wheeler (July 29, 2016). The protective cover
requirements for both permit level and construction level documents were provided in Technical
Specification Section 31 20 20 – Protective Cover. We note that the ground pressure
requirements were modified from permit-level documents to construction-level documents to be
consistent with specifications for previous Duke Energy landfills as follows:
• The minimum cover depth for 5 psi traffic was reduced from 18-inches to 12-inches; and
• The minimum cover depth for 10 psi traffic was reduced from 24-inches to 18-inches.

Utilization of 1.06-ft of Sand as Cell 1 Protective Cover Duke Energy – Dan River Steam Station
Dan River Landfill (Permit No. 7906-INDUS-2016) Eden, North Carolina
2
The permit-level and construction-level Technical Specification Section 31 20 20 – Protective
Cover documents are provided in Attachment 1.
The project intent at the time of design was to utilize CCR material as protective cover for
Landfill Cells 1 through 3 as described in the approved project specifications. Due to the
construction schedule and in order to meet CAMA schedule requirements, CCR material will not
be utilized as protective cover for Landfill Cell 1; however, it is still the intent to utilize CCR as
protective cover for Landfill Cells 2 and 3. Amec Foster Wheeler proposes utilizing 1.06-feet of
sand as protective cover in lieu of 2.12-feet of CCR material for Landfill Cell 1, subject to the
following requirements.
Cell 1 Protective Cover Material – 1.06-ft of Sand
The protective cover material shall meet the requirements of IFC Specification Section 31 20 20
– Protective Cover (Attachment 1). The material shall be classified as SW, SP, SM, S, or ML
according to the Unified Soil Classification System (USCS). Additionally, the material shall be
free of ferrous material, topsoil, roots, stumps, brush, rocks larger than 1-inch, subsoil, debris,
vegetation, calcareous concretions or nodules, and other foreign matter.
In accordance with the specifications, geotechnical laboratory testing will be performed by the
EOR at a frequency of one suite of tests per 3,000 cubic yards of material placed. Each suite of
tests will include the following:
• Water (Moisture) Content (ASTM D2216);
• Liquid Limit, Plastic Limit, and Plasticity Index (ASTM D4318); and
• Grain Size with Hydrometer (ASTM D422).
The general contractor for landfill construction, Trans Ash Inc., identified two potential material
sources and provided information indicating conformance with specifications (Attachment 2).
The EOR proposes waiving the requirement for hydraulic conductivity ratio testing (ASTM
D5567) because the protective cover material has less than 10 percent passing the #200 sieve
(fines).
Cell 1 Protective Cover Placement – 1.06-ft of Sand
The protective cover material shall be placed in accordance with the requirements of IFC
Specification Section 31 20 20 – Protective Cover (Attachment 1) and as follows:
• Protective cover shall be placed to a minimum thickness of 1.06-ft based on a 100-ft by
100-ft grid survey as measured from top of compacted soil liner to top of protective cover;
• Protective cover shall be placed and spread with low ground pressure equipment (5 psi
ground pressure with a minimum cover of 12 inches or 10 psi with a minimum cover of 18
inches);
• Temporary pads/access roads with a minimum thickness of 4-feet can be used to provide
access for heavier equipment (i.e. dump trucks);
• Pads/access roads may remain in place to facilitate future landfill operations
Utilization of 1.06-ft of Sand as Cell 1 Protective Cover Duke Energy – Dan River Steam Station
Dan River Landfill (Permit No. 7906-INDUS-2016) Eden, North Carolina
3
• Material transported with low ground pressure equipment may not be end-dumped on
any areas with less than 1 foot of cover, material transported with standard equipment
may not be end-dumped on any areas with less than 2 feet of cover;
• Maintain low vehicle speeds and avoid sharp turns and sudden starts/stops during
placement and spreading; and
• Upon completion of protective cover placement, the cover material shall be rolled,
tracked-in, or otherwise tamped and smoothed utilizing low ground pressure equipment
(5 psi max).
Protective cover placement will be continuously observed by the Engineer’s on-site
representative to document compliance with placement requirements and observe liner integrity
during placement.
Post-Construction Demonstration of Liner Integrity
Liner integrity will be observed upon completion of protective cover placement by measuring the
quantity of liquids that collect in the leak detection system (LDS) following a rainfall event
(minimum 0.5 inches within a maximum of 24 hours) or by applying water to the cell at an
equivalent rate (about 14,000 gallons per acre). Water application (if selected) must be
performed from the landfill perimeter, minimum 4-ft thick access roads, and/or low ground
pressure equipment (5 psi max). Liner integrity will be assumed to be satisfied if the increase in
volume of liquids present in the LDS at a time of 3 days after completion of the rainfall or wetting
event is less than or equal to 100 gallons per acre per day.
Initial Landfill Operations
Initial landfill operations will consist of methods similar to protective cover placement. Waste
shall be spread in approximate 12-inch lifts utilizing low ground pressure equipment (5 psi within
1-ft of liner, 10 psi within 18-inches of liner). Waste within 4 feet of the liner shall be rolled,
tracked-in, or otherwise tamped utilizing low ground pressure equipment. Material within 2 feet
of the liner system is exempt from density test requirements. Temporary pads/access roads with
a minimum thickness of 4-feet can be used to provide access for heavier equipment (i.e. off-road
trucks). Material transported with low ground pressure equipment may not be end-dumped on
any areas with less than 1 foot of cover, material transported with standard equipment may not
be end-dumped on any areas with less than 2 feet of cover.
A revised Operations Plan including the aforementioned requirements will be submitted as part
of the Landfill Cell 1 Application for Permit to Operate.

Utilization of 1.06-ft of Sand as Cell 1 Protective Cover Duke Energy – Dan River Steam Station
Dan River Landfill (Permit No. 7906-INDUS-2016) Eden, North Carolina
4
Closing
Amec Foster Wheeler appreciates the opportunity to provide this report to Duke. Please contact
us at your convenience with questions.
Sincerely,

Amec Foster Wheeler

Cedric H. Ruhl, P.E. Chris Jordan, E.I.
Senior Engineer Technical Professional

Attachments:
1. Specification Section 31 20 20 – Protective Cover (permit-level and IFC-level)
2. Sand Material Data

ATTACHMENT 1A

Specification Section 31 20 20 – Protective Cover (permit issue)

Dan River Landfill Permit Issue
Amec Foster Wheeler Project No. 7810140065 August 26, 2015
Protective Cover 31 20 20 - 1
SECTION 312020 – PROTECTIVE COVER
PART 1 - GENERAL
1.1 SUMMARY
A. Section includes protective cover for the Dan River Landfill. Protective cover may consist of
coal combustion residual (CCR) material within the limit of waste.
B. Related Requirements:
1. Section 31205 “Trenching.”
2. Section 313220 “Geocomposite Drainage Layer.”
1.2 REFERENCES
A. Construction Quality Assurance (CQA) Plan
B. ASTM International:
1. ASTM D421 - Standard Practices for Dry Preparation of Soil Samples for Particle-Size
Analysis and Determination of Soil Constants.
2. ASTM D422 - Standard Test Method for Particle-Size Analysis of Soils (Grain Size with
Hydrometer)
3. ASTM D2487 - Standard Practices for Classification of Soil for Engineering Purposes
(Unified Soil Classification System)
4. ASTM D4318 - Standard Test Method for Liquid Limit, Plastic Limit, and Plasticity Index
of Soils
1.3 SUBMITTALS
A. Submit record drawings by the Registered Land Surveyor retained by the Contractor before and
after placement of protective cover. The Land Surveyor shall be registered in North Carolina.
1.4 QUALITY ASSURANCE
A. Perform work in accordance with these specifications and the CQA Plan.
B. Conformance Testing - Compacted soil fill.
1. The performance of conformance testing shall be coordinated by the CQA Engineer.
2. Conformance testing will be performed by an independent laboratory at a frequency of at
least 1 test per 3,000 cubic yards, when materials used for protective cover changes, and/or
as directed by the Engineer for the following:
a. Laboratory moisture content (ASTM D2216)
b. Atterberg limits (ASTM D4318)
Dan River Landfill Permit Issue
Amec Foster Wheeler Project No. 7810140065 August 26, 2015
Protective Cover 31 20 20 - 2
c. Grain size with hydrometer (ASTM D422)
d. Other tests as required by the Engineer
C. The maximum percentage passing the No. 200 sieve (ASTM D422) shall be as specified by the
Engineer after hydraulic conductivity ratio (HCR) testing as described in Specification Section
313220.
PART 2 - PRODUCTS
2.1 PROTECTIVE COVER
A. Protective cover within the limit of waste may consist of CCR material or soil. Protective cover
material beyond the limit of waste must consist of soil.
B. Protective cover material consisting of soil shall be classified as SW, SP, SM, SC, or ML soils
according to the Unified Soil Classification System (ASTM D2487).
C. Free of ferrous material, topsoil, roots, stumps, brush, rocks larger than 1-inch, subsoil, debris,
vegetation, calcareous concretions or nodules, and other foreign matter.
PART 3 - EXECUTION
3.1 EXAMINATION
A. Verify installation of geosynthetics and stormwater and leachate conveyance structures has been
inspected, and approved by the Engineer.
3.2 PREPARATION
A. Backfill liner anchor trench prior to placing protective cover on the side slopes in accordance with
Section 312005 Trenching.
B. Ash material may not be used to backfill anchor trenches.
3.3 FILLING
A. Protective cover shall be placed such that the geocomposite drainage layer is not exposed for a
period of 20 days or more. Ensure acceptance of geocomposite drainage layer prior to placement
of protective cover.
B. Protective cover shall be placed to prevent wrinkling or tension of underlying geosynthetics.
Underlying geosynthetics that develop excessive wrinkles, crimp (fold over), or are otherwise
damaged shall be repaired by the Installer at the Contractor’s expense.
1. Protective cover shall not be placed when temperature effects produce excessive wrinkles
or tension in underlying geosynthetics.
Dan River Landfill Permit Issue
Amec Foster Wheeler Project No. 7810140065 August 26, 2015
Protective Cover 31 20 20 - 3
2. Contractor shall modify placement methods if excessive wrinkles develop, or stop placing
protective cover until the underlying geosynthetics cool and wrinkles decrease in size.
3. Wrinkles that exceed approximately 6 inches in height or underlying geosynthetics that
become crimped shall be cut and repaired by the Geosynthetics Installer in a method
approved by the Engineer.
C. Protective cover on the side slopes shall be placed from the toe of slope upward using a small, low
ground pressure dozer, 5 psi or less.
D. Protective cover shall be placed in one continuous lift to a minimum thickness of 2.12 feet.
Compaction of the protective cover shall be performed by a minimum of 3 passes of non-
vibratory smooth drum roller. A pass is defined as one trip of the compacting equipment over
the lift and back to the starting point by a single drum roller or one trip across the lift surface from
one side to the other if the compacting equipment has front and back compacting rollers. This
requirement is to allow thorough remolding of the soil by kneading action.
E. The Contractor shall be responsible for maintaining the protective cover until the final completion
date.
F. General construction traffic shall be limited to areas designated by the Engineer that have been
protected by at least 24 inches of compacted fill material.
G. Any damage to the geosynthetics or stormwater and leachate conveyance structures (e.g., tears,
punctures, creases, folds, strain-yield areas, entrapped air pockets, etc.) shall be brought to the
immediate attention of the Engineer and shall be repaired by the Installer. Any damage resulting
from the Contractor’s activities or negligence shall be repaired at the Contractor’s expense.
3.4 TOLERANCES
A. Top Surface of protective cover: Plus or minus 0.10 feet from required elevations shown on
Drawings.
B. The protective cover must have a minimum thickness of 2.12 feet when measured in the vertical
plane..
3.5 FIELD QUALITY ASSURANCE
A. The CQA Engineer shall observe all aspects of protective cover soil placement.
3.6 PROTECTION OF FINISHED WORK
A. Limit vehicular traffic for protection of liner system below protective cover. Vehicular traffic
shall be limited to 5 psi in areas which have been protected by at least 18 inches of protective
cover above the liner and 10 psi in areas which have been protected by at least 24 inches of
protective cover above the liner. Vehicles shall be prohibited from performing tight turning radii
and rapid braking on the operational cover.
B. Reshape and re-compact fills subjected to vehicular traffic.
Dan River Landfill Permit Issue
Amec Foster Wheeler Project No. 7810140065 August 26, 2015
Protective Cover 31 20 20 - 4
C. Contractor is responsible for making any repairs necessary if any portion of the project is
damaged due to protective cover placement or interior berm placement.
D. Upon achieving protective cover final grades, the Contractor shall apply a stabilizing agent to the
protective cover to prevent erosion. The stabilizing agent shall be approved by the Owner and
Engineer prior to use.

END OF SECTION 312020

ATTACHMENT 1B

Specification Section 31 20 20 – Protective Cover (construction issue)

Dan River Landfill and Stormwater Diversion Issued for Construction
Amec Foster Wheeler Project No. 7810160559 July 29, 2016
Protective Cover 31 20 20 -1
SECTION 312020 –PROTECTIVE COVER
PART 1 -GENERAL
1.1 SUMMARY
A.Section includes protective cover for the Dan River Landfill.Protective cover may consist of
coal combustion residual (CCR) material within the limit of waste.
B.Related Requirements:
1.Section 31205 “Trenching.”
2.Section 313220 “Geocomposite Drainage Layer.”
1.2 REFERENCES
A.Construction Quality Assurance (CQA)Plan
B.ASTM International:
1.ASTM D421 -Standard Practices for Dry Preparation of Soil Samples for Particle-Size
Analysis and Determination of Soil Constants.
2.ASTM D422 -Standard Test Method for Particle-Size Analysis of Soils (Grain Size with
Hydrometer)
3.ASTM D2487 -Standard Practices for Classification of Soil for Engineering Purposes
(Unified Soil Classification System)
4.ASTM D4318 -Standard Test Method for Liquid Limit,Plastic Limit,and Plasticity Index
of Soils
1.3 SUBMITTALS
A.Submit record drawings by the Registered Land Surveyor retained by the Contractor before and
after placement of protective cover.The Land Surveyor shall be registered in North Carolina.
1.4 QUALITY ASSURANCE
A.Perform work in accordance with these specifications and the CQA Plan.
B.Conformance Testing –Protective Cover.
1.The performance of conformance testing shall be coordinated by the CQA Engineer.
2.Conformance testing will be performed by an independent laboratory at a frequency of at
least 1 test per 3,000 cubic yards, when materials used for protective cover changes, and/or
as directed by the Engineer for the following:
a.Laboratory moisture content (ASTM D2216)
b.Atterberg limits (ASTM D4318)
Dan River Landfill and Stormwater Diversion Issued for Construction
Amec Foster Wheeler Project No. 7810160559 July 29, 2016
Protective Cover 31 20 20 -2
c.Grain size with hydrometer (ASTM D422)
d.Other tests as required by the Engineer
C.The maximum percentage passing the No. 200 sieve (ASTM D422) shall be as specified by the
Engineer after hydraulic conductivity ratio (HCR) testing as described in Specification Section
313220.
PART 2 -PRODUCTS
2.1 PROTECTIVE COVER
A.Protective cover within the limit of waste may consist of CCR material or soil. Protective cover
material beyond the limit of waste must consist of soil.
B.Protective cover material consisting of soil shall be classified as SW,SP,SM,SC,or ML soils
according to the Unified Soil Classification System (ASTM D2487).
C.Free of ferrous material,topsoil,roots,stumps,brush,rocks larger than 1-inch,subsoil,debris,
vegetation,calcareous concretions or nodules,and other foreign matter.
PART 3 -EXECUTION
3.1 EXAMINATION
A.Verify installation of geosynthetics and stormwater and leachate conveyance structures has been
inspected,and approved by the Engineer.
3.2 PREPARATION
A.Backfill liner anchor trench prior to placing protective cover on the side slopes in accordance with
Section 312005 Trenching.
B.CCR material may not be used to backfill anchor trenches.
3.3 FILLING
A.Protective cover shall be placed such that the geocomposite drainage layer is not exposed for a
period of 20 days or more. Ensure acceptance of geocomposite drainage layer prior to placement
of protective cover.
B.Protective cover shall be placed to prevent wrinkling or tension of underlying geosynthetics.
Underlying geosynthetics that develop excessive wrinkles,crimp (fold over),or are otherwise
damaged shall be repaired by the Installer at the Contractor’s expense.
1.Protective cover shall not be placed when temperature effects produce excessive wrinkles
or tension in underlying geosynthetics.
Dan River Landfill and Stormwater Diversion Issued for Construction
Amec Foster Wheeler Project No. 7810160559 July 29, 2016
Protective Cover 31 20 20 -3
2.Contractor shall modify placement methods if excessive wrinkles develop,or stop placing
protective cover until the underlying geosynthetics cool and wrinkles decrease in size.
3.Wrinkles that exceed approximately 6 inches in height or underlying geosynthetics that
become crimped shall be cut and repaired by the Geosynthetics Installer in a method
approved by the Engineer.
C.Protective cover on the side slopes shall be placed from the toe of slope upward using a small,low
ground pressure dozer,5 psi or less.
D.Protective cover shall be placed in one continuous lift to a minimum thickness of 2.12 feet.
Compaction of the protective cover along the cell floor shall be performed by a minimum of
3 passes of non-vibratory smooth drum roller.Compaction of the protective cover along the
side slopes shall be approved by the Engineer based on a field demonstration.A pass is defined
as one trip of the compacting equipment over the lift and back to the starting point by a single
drum roller or one trip across the lift surface from one side to the other if the compacting equipment
has front and back compacting rollers.
E.The Contractor shall be responsible for maintaining the protective cover until the final completion
date.
F.General construction traffic on the liner system shall be limited to areas designated by the
Engineer that have been protected by at least 24 inches of compacted protective cover material.
G.Any damage to the geosynthetics or stormwater and leachate conveyance structures (e.g.,tears,
punctures,creases,folds,strain-yield areas,entrapped air pockets,etc.)shall be brought to the
immediate attention of the Engineer and shall be repaired by the Installer.Any damage resulting
from the Contractor’s activities or negligence shall be repaired at the Contractor’s expense.
3.4 TOLERANCES
A.Top Surface of protective cover: Plus or minus 0.10 feet from required elevations shown on
Drawings.
B.The protective cover must have a minimum thickness of 2.12 feet when measured in the vertical
plane.
3.5 FIELD QUALITY ASSURANCE
A.The CQA Engineer shall observe all aspects of protective cover soil placement.
3.6 PROTECTION OF FINISHED WORK
A.Limit vehicular traffic for protection of liner system below protective cover.Vehicular traffic
shall be limited to 5 psi in areas which have been protected by at least 12 inches of protective
cover above the liner and 10 psi in areas which have been protected by at least 18 inches of
protective cover above the liner.General construction traffic shall be limited to areas designated
by the Engineer that have been protected by at least 24 inches of compacted fill material.
Dan River Landfill and Stormwater Diversion Issued for Construction
Amec Foster Wheeler Project No. 7810160559 July 29, 2016
Protective Cover 31 20 20 -4
Vehicles shall be prohibited from performing tight turning radii and rapid braking on the
operational cover.
B.Reshape and re-compact fills subjected to vehicular traffic.
C.Contractor is responsible for making any repairs necessary if any portion of the project is
damaged due to protective cover placement or interior berm placement.
D.Upon achieving protective cover final grades, the Contractor shall apply a stabilizing agent to the
protective cover to prevent erosion. The stabilizing agent shall be approved by the Owner and
Engineer prior to use.
END OF SECTION 312020

ATTACHMENT 2

Sand Material Data

Piedmont District
413 South Chimney Rock Rd.
Greensboro, N.C. 27409 Telephone: [phone]
Fax: [phone]

February 16, 2017
Ryan Jamison
Trans Ash Inc.
Re: Material Certification

Dear Ryan,
This letter is to certify that the 2ms material to be furnished by Martin Marietta’s Salem
Stone Quarry will meet the standards set forth by ASTM C-33. The aggregate is a non-
calcareous granite material and also complies with all requirements of NCDOT’s Standard
Specifications for Roads and Structures for aggregate. Thank you for the opportunity to meet your aggregate needs.

Sincerely,

Shawn K. Norton

Shawn K. Norton
Quality Control Manager Martin Marietta Materials Inc.
Piedmont District

Martin Marietta Materials is providing these test results for information purposes only. There are a variety of tests that can be used in connection with determining suitability of aggregates in specific applications and a variety of methods to mitigate potential degradation and deterioration depending upon the end use of the product and other circumstances. Nothing in this letter or report represents or warrants (1) the reliability of the tests used herein (2) whether other tests would be more appropriate or reliable, and/or
(3) whether any mitigation factors referenced in this letter or report are effective or the most appropriate, all of which you would determine based on the end use and other factors. MARTIN MARIETTA MATERIALS AND ITS AFFILIATES HEREBY EXCLUDES ANY AND ALL WARRANTIES OF MERCHANTABILITY AND ALL WARRANTIES OF FITNESS FOR ANY PARTICULAR PURPOSE, AND ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, AS TO THE PERFORMANCE OF ITS AGGREGATES.
Plant 44318-Salem Stone
Basic Quality Statistical Summary Report
Sieve/Test SpecificationAverageSt DevTests
Product 0955-2MS Sand
Target
Specification 2MS Sand
Period 01/27/2017 - 01/28/2017
3/8" (9.5mm)100.0 100-1001
#4 (4.75mm)99.7 95-1001
#8 (2.36mm)80.3 80-1001
#16 (1.18mm)62.3 45-951
#30 (0.6mm)48.8 25-751
#50 (0.3mm)31.7 8-351
#100 (0.15mm)18.0 0.5-201
#200 (75µm)4.46 0-81
Pan 0.001
FM 2.591
Query Query Selections
Date Created 02/02/2017
Date Range 01/27/2017 - 01/28/2017
Plant Salem Stone
Sample Type Quality Monitoring
1Page:of 1Martin Marietta, Inc.StonemontQC 02/02/2017