1812_DukeMarshall_PLMReport_FID_20220525

May 19, 2022
Duke Energy Marshall Steam Station
EHS Groundwater & Waste Programs
8320 NC Highway 150
Terrell, North Carolina 28682
Attention: Ms. Ashley Healy, P.G.
Reference: Clean Closure Verification - Visual Confirmation and PLM Results
Duke Energy Marshall Steam Station
Confirmatory Soil Sampling — Marshall Steam Station Bottom Ash Roads - Gypsum Pad Area
S&ME Project No. 212013, Ph. 06
Ms. Healy:
S&ME, Inc. (S&ME) is submitting the enclosed summary of results supporting the removal of Coal Combustion
Residual (CCR) material by visual verification and Polarized Light Microscopy (PLM) analysis results within the
bottom ash roads adjacent to the Gypsum Pad at Duke Energy's Marshall Steam Station, located in Catawba
County, North Carolina.
This summary letter is provided so that the North Carolina Department of Environmental Quality Solid Waste
Section (NCDEQ — SWS) may review PLM analytical results prior to our formal report documenting our full clean
closure verification field activities as outlined in the June 17, 2020 Excavation Soil Sampling Plan for Bottom Ash
Road Excavation dated June 17, 2020, approved by NCDEQ-SWS on July 8, 2020 (FID 1418126).
We have attached Table 1 — PLM Sample Results and Soil Sampling Summary to this letter which includes soil
sample descriptions, including visual verification that CCR material has been removed, and supporting PLM
analysis results for samples collected by S&ME personnel during sampling events conducted May 11, 2022. A
corresponding map, Figure 1— Gypsum Pad Bottom Ash Road Clean Closure Sampling Location Summary is
enclosed as well, depicting sample locations at the bottom ash road adjacent to the Gypsum Pad that have been
sampled and analyzed using the PLM method for CCR material.
Please note that samples collected in the bottom ash road May 11, 2022 contained 21% or less CCR material. The
clean closure benchmark value for CCR material in soil samples is 50%.
S&ME thanks you for your receipt of these records. Should you have any questions or need additional
information, please do not hesitate to contact us at [phone].
S&ME, Inc. 12016 Ayrsley Town Blvd., Suite 2-A I Charlotte, NC 282731 p 704.523.4726 1 www.smeinc.com

EHS Groundwater & Waste Programs
Respectfully Submitted,
5&ME, Inc.
Skyler Schmal, GIT Erin Kinsey, P.E.
Staff Professional Geologist Project Engineer
Senior Reviewed By: Julie P. Robertson, P.G. (Registration No. 1995)
May 19, 2022
Page 2
Enclosures: Table 1 — PLM Results and Soil Sampling Summary
Figure 1 — Gypsum Pad Area Bottom Ash Road Clean Closure Sampling Location Summary
cc: James Malloy, Project Manager, Duke Energy Marshall Steam Station
S&ME, Inc.

Table 1: PLM Sample Results and Soil Sampling Summary
Bottom Ash Road - Gypsum Pad Area
Duke Energy Marshall Steam Station
S&ME Project Number: 212013, Ph. 06 111
E
Sample
ID
Proposed
I
Date
Duke Energy
ProposedS&ME
Sample
Sample
DescriptionCollected
Sample ID
Actual
Depth
Column
Row
Sample
Northing
East2in
Northing
Easting
Yes
No Date Received
Results
Depth'
Sand with some silt (SM) - Brown, fine, non -plastic fines,
5/11/2022
2022012790
Q
75
0" - 6"
0" - 6"
679403.06
1413346.68
679415.63
1413335.08
X
5/18/2022
21%
some organics and gravel present [RES]; Refusal at 6" bgs
Sand with some clay (SC) - Reddish brown, fine to medium,
5/11/2022
2022012791
R
75
0" - 6"
0" - 6"
679400.16
1413445.30
679412.73
1413430.80
X
5/18/2022
2%
low -plastic fines [RES]
Clayey sand (SC) - Reddish brown, fine, low- to medium -
5/11/2022
2022012792
R
75
2' - 2.5'
2' - 2.5'
679400.16
1413445.30
679412.73
1413430.80
X
5/18/2022
1%
plastic fines, micaceous [RES]
Clayey sand (SC) - Brown, reddish brown, fine to medium,
5/11/2022
2022012793
S
75
0" - 6"
0" - 6"
679392.42
1413553.59
679398.22
1413526.52
X
5/18/2022
1%
low -plastic fines, some gravel and organics [RES]
Sandy silt (ML) - Reddish brown, fine, non -plastic fines,
5/11/2022
2022012794
S
75
2' - 2.5'
2' - 2.5'
679392.42
1413553.59
679398.22
1413526.52
X
5/18/2022
ND
micaceous [RES]
Notes:
(1) For the purposes of PLM method, Fly Ash is defined as any particle consistent with Coal Combustion Residual (CCR) material.
(2) ND = Not Detected. The PLM Method Reporting Level is 1%; samples with less than 1% CCR are considered ND.
'Actual sample depths may vary due to sampling method and volume of soil needed for laboratory testing.
2CCR = Coal Combustion Residuals
3Residual Material (RES): Residuum and saprolitic material that is a product of weathered bedrock.
4United Soil Classification System descriptions are provided for each sample description and are denoted with a two letter abbreviation following the soil type.
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