NC0001422_Coal Pile Assessment Final_20180904

TECHNICAL MEMORANDUM

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Coal Pile\Work Plan\Sutton - Coal Pile Assessment Final.docx
Date: August 31, 2018 File: 1026.108
To: John Toepfer
Cc: Kathy Webb (SynTerra)
From: Perry Waldrep, North Carolina P.G. #2453
Subject: L.V. Sutton Energy Complex FADA & Former Coal Storage Assessment Work
Plan
Duke Energy Carolinas, LLC (Duke Energy) owns and operates the L.V. Sutton Energy
Complex (Site) in Wilmington, New Hanover County, North Carolina. The Site
encompasses approximately 3,300 acres. Groundwater and soil assessment activities
proposed for the former ash disposal area (FADA) and the adjacent former coal storage
area (coal storage) are described herein.
Regulatory Background
In 2014, The North Carolina General Assembly passed the Coal Ash Management Act
(CAMA). CAMA required owners of a coal combustion residuals (CCR) surface
impoundment to conduct a detailed assessment of site groundwater within and around
the CCR surface impoundments.
Primary sources of CCR-related constituents identified during the Comprehensive Site
Assessment (CSA) for CAMA were the 1971 and 1984 ash basins. Groundwater
monitoring wells were installed in the FADA during the CSA; ABMW-02S, (screened
within the ash) and ABMW-02D, screened at the bottom of the surficial aquifer. Wells
existed in the FADA prior to the CSA, including shallow and deep surficial well clusters
at MW-13, MW-14, MW-15, MW-16 and MW-20. Two temporary wells (TW-L024 and
TW-L098) were installed in the FADA in 2017. The temporary wells were screened in
the upper surficial zone below the ash. The temporary wells were closed after samples
were collected.
Data from the CSA indicated the presence of boron as well as other metals that are
attributed to CCR. Groundwater flow and transport modeling indicates flow from the
1971 ash basin beneath the discharge canal to the FADA, therefore some of these
concentrations could be attributed to the 1971 ash basin. The purpose of the assessment
of the FADA will be to determine if constituents are migrating from the 1971 basin and
also to delineate the contaminants of interest (COIs) downgradient (south) of the
FADA.
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The former coal storage area soil and underlying groundwater may also be a potential
additional primary and secondary source of inorganic constituents to be assessed.
Station Description
The Site started operations in 1954 with three coal-fired boilers that primarily used
bituminous coal as fuel to produce steam to generate electricity. Ash generated from
coal combustion was originally stored on-site in the FADA, also known as the ‘lay of
land area’, then in the 1971 ash basin (old ash basin), and finally the 1984 ash basin (new
ash basin) (Figure 1). These ash storage areas are referred to as the ash management
area. The Site ceased burning coal in November 2013 and switched to natural gas for
electricity generation, thus the facility no longer generates coal ash.
The FADA is located south of the ash basins, on the south side of the cooling water
discharge canal. It is believed that ash may have been placed in this area from
approximately 1954 to 1972. The FADA contains approximately 840,000 tons of ash
which appears to vary in thickness from a few feet up to 14 feet below ground surface.
The ash in the FADA extends to the groundwater table in some areas.
Historical aerial photographs indicate coal was stored in the area west of the plant
between the Cape Fear River and the power plant. The former coal storage area
consists of approximately 14 acres bounded to the north by the FADA, to the east by
vacant land formerly containing plant buildings (now razed) and parking areas, and to
the south and west by the cooling water pond (Sutton Lake) and intake canal. Coal was
delivered to the Site by rail or off-loaded from vessels on the Cape Fear River and
transported by conveyor to the coal storage area. Coal storage at the plant ended when
coal-burning operations ceased in 2013. A storm water retention basin has been
installed in the former coal storage area and is partially submerged with surface water
runoff. The CSA did not include sediment, soil or groundwater data from this area. No
other coal storage areas are indicated on historical photographs.
Groundwater elevation maps generated during the CSA indicate groundwater in the
FADA/coal storage area flows southwest toward the intake canal and the Cape Fear
River beyond.
FADA Assessment Objectives
Objectives of the FADA area assessment include the following:
• Characterize inorganic constituent concentrations in soil and groundwater at
the FADA perimeter
• Determine if there is COI migration underneath the discharge canal from the
1971 ash basin to the FADA in the upper and lower surficial flow zones
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• Compare inorganic constituent concentrations in the FADA to Site
background concentrations.
FADA Soil Assessment
Soil samples are proposed to be collected from the FADA perimeter and analyzed for
inorganic parameters to determine if it is a secondary source with the potential to
impact underlying groundwater. Unsaturated soil samples will be collected at
proposed monitoring well locations (MW-13R, MW-15R, MW-45, MW-46, MW-47, MW-
48 & MW-49), during well installation activities (Figure 1). Soil samples will be
collected at approximately 2-foot intervals to the top of the groundwater table
(approximately 6 to 8 feet below ground surface). An additional soil sample will be
collected below the water table within the new well screen intervals for groundwater
modeling purposes. Soil samples will be analyzed for inorganic parameters listed on
Table 1. Select soil samples from the well screen intervals will also be submitted for
hydrous ferric oxides and hydrous aluminum oxides (HFO/HAO) analyses to support
the geochemical modeling effort.
FADA Groundwater Assessment
Fourteen assessment groundwater monitoring wells are proposed to be installed to
characterize groundwater in the upper and lower surficial zones at the perimeter of the
FADA. The upper surficial zone at the Site extends to approximately 25 feet below
ground surface (bgs). The lower surficial zone underlies the upper zone and extends to
the top of the Pee Dee formation, generally 45 to 50 feet bgs at the Site. Seven upper
surficial wells (MW-13R, MW-15R, MW-45B, MW-46B, MW-47B, MW-48B and MW-
49B) and seven lower surficial wells, (MW-13R-D, MW-15R-D, MW-45C, MW-46C,
MW-47C, MW-48C and MW-49C) will be installed as well pairs. The MW-45 well pair
will be installed on the west side of the intake canal (opposite the FADA) to assess
potential migration of COIs beyond the canal. Proposed FADA well installation
locations are shown on Figure 1 and proposed well details are provided as Table 2.
Specific well locations may be shifted depending upon access and field conditions at the
time of installation. Existing monitor wells MW-20 (upper surficial), MW-20D (lower
surficial), MW-16 (upper surficial) and MW-16D (lower surficial) are also proposed to
be sampled as part of the assessment. Groundwater samples will be analyzed for
inorganic constituents listed on Table 3.
Former Coal Storage Area Assessment Objectives
Objectives of the former coal storage area assessment include the following:
• Characterize inorganic constituent concentrations in soil and groundwater
along the former coal storage area perimeter
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• Compare inorganic constituent concentrations in the former coal storage area
to Site background concentrations
Former Coal Storage Soil Assessment
Former coal storage area unsaturated soils are proposed to be sampled and analyzed for
inorganic parameters to determine if it is a secondary source of coal constituents with
potential to impact underlying groundwater. Due to the recent modifications of the
former coal storage area into a retention basin, soil samples cannot be collected from
within the footprint of the former coal storage. Soil samples can be collected at
proposed monitoring well locations at the perimeter of the former coal storage area
(MW-43, MW-44, MW-46, and MW-50) during well installation activities (Figure 1).
Soil samples will be collected at approximately 2-foot intervals to the top of the
groundwater table (approximately 6 - 8 feet below ground surface). An additional soil
sample will be collected below the water table within the new well screened intervals
for HFO/HAO analyses. Soil samples will be analyzed for inorganic parameters listed
on Table 1.
Former Coal Storage Groundwater Assessment
Existing well pair MW-20/MW-20D and proposed FADA well pair MW-46B/MW46C
are proposed to be included in the former coal storage groundwater assessment. Three
additional well pairs (MW-43B/C, MW-44B/C and MW-50B/C) are proposed for
assessment of the former coal assessment. As with the FADA wells, the well pairs will
consist of wells screened in the upper and lower surficial zones at approximate depths
of 25 and 50 feet bgs, respectively. Proposed well installation locations are shown on
Figure 1 and proposed well details are provided as Table 2. Specific well locations may
be shifted depending upon access and field conditions at the time of installation.
Groundwater samples will be analyzed for inorganic constituents listed on Table 3.
Assessment Report
An assessment report is anticipated to include the soil and at least two groundwater
analytical data sets. The report for both areas would include the following components:
1) Site History and Source Characterization
2) Site Geology and Hydrogeology
3) Sampling Results
4) Site Conceptual Model
5) Conclusions and Recommendations

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ATTACHMENTS:
Table 1: Soil Analytical Methods
Table 2: Proposed Coal Storage Assessment Soil Samples and Monitoring Wells
Table 3: Groundwater Analytical Methods
Figure 1: Proposed FADA and Former Coal Storage Assessment Sample Locations
FADA & Coal Storage Assessment Work Plan August 31, 2018
L.V. Sutton Energy Complex

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ATTACHMENTS
TABLE 1
SOIL ANALYTICAL METHODS
L.V. SUTTON ENERGY COMPLEX
DUKE ENERGY PROGRESS, LLC, WILMINGTON, NC
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INORGANIC COMPOUNDS UNITS METHOD
Aluminum mg/kg EPA 6010D
Antimony mg/kg EPA 6020B
Arsenic mg/kg EPA 6020A
Barium mg/kg EPA 6010C
Beryllium mg/kg EPA 6020B
Boron mg/kg EPA 6010C
Cadmium mg/kg EPA 6020A
Calcium mg/kg EPA 6010C
Chloride mg/kg EPA 9056A
Chromium mg/kg EPA 6010C
Chromium (Hexavalent)mg/kg EPA 7199
Cobalt mg/kg EPA 6020A
Copper mg/kg EPA 6010C
Iron mg/kg EPA 6010C
Lead mg/kg EPA 6020A
Magnesium mg/kg EPA 6010C
Manganese mg/kg EPA 6010C
Mercury mg/kg EPA Method 7471B
Molybdenum mg/kg EPA 6010C
Nickel mg/kg EPA 6010C
Nitrate as Nitrogen mg/kg EPA 9056A
pH SU EPA 9045D
Potassium mg/kg EPA 6010C
Selenium mg/kg EPA 6020A
Sodium mg/kg EPA 6010C
Strontium mg/kg EPA 6010C
Sulfate mg/kg EPA 9056A
Synthetic Precipitation Leaching Procedue (SPLP)µg/L EPA 1312
Thallium (low level) (SPLP Extract only)mg/kg EPA 6020A
Total Organic Carbon mg/kg EPA 9060
Vanadium mg/kg EPA 6020A
Zinc mg/kg EPA 6010C
Notes:
1. Soil samples to be analyzed for Total Inorganics using USEPA Methods 6010/6020 and pH using USEPA Method 9045, as noted above.
meq/100g - millequivalents per 100 grams
mg/kg - Milligrams per kilogram
mV - Millivolts
S.U. - Standard Unit
Prepared by: RBI Checked by: PBW
2. Analytical methods and reporting limits as presented were applicable at time of CSA field implementation in 2015. Analytical methods and
reporting limits are updated periodically and applied as appropriate.
TABLE 2
PROPOSED COAL STORAGE ASSESSMENT SOIL SAMPLES AND MONITORING WELLS
L.V. SUTTON ENERGY COMPLEX
DUKE ENERGY PROGRESS, LLC, WILMINGTON, NC
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Tables.xlsx Page 1 of 1
Monitoring
Well ID
Estimated
Well Depth
(feet bgs)
Soil Sample ID
(Estimated Depth
Interval in feet
bgs)*
Comments
----MW-13R (2-3)Unsaturated soil sample
----MW-13R (5-6)Unsaturated soil sample
MW-13R 25 MW-13R (22-23)*Soil sample from upper surficial well screened interval
MW-13R-D 50 MW-13R-D (47-48)*Soil sample from lower surficial well screened interval
----MW-15R (2-3)Unsaturated soil sample
----MW-15R (5-6)Unsaturated soil sample
MW-15R 25 MW-15R (22-23)*Soil sample from upper surficial well screened interval
MW-15R-D 50 MW-15R-D (47-48)*Soil sample from lower surficial well screened interval
----MW-43B (2-3)Unsaturated soil sample
----MW-43B (5-6)Unsaturated soil sample
MW-43B 25 MW-43B (22-23)*Soil sample from upper surficial well screened interval
MW-43C 50 MW-43C (47-48)*Soil sample from lower surficial well screened interval
----MW-44B (2-3)Unsaturated soil sample
----MW-44B (5-6)Unsaturated soil sample
MW-44B 25 MW-44B (22-23)*Soil sample from upper surficial well screened interval
MW-44C 50 MW-44C (47-48)*Soil sample from lower surficial well screened interval
----MW-45B (2-3)Unsaturated soil sample
----MW-45B (5-6)Unsaturated soil sample
MW-45B 25 MW-45B (22-23)*Soil sample from upper surficial well screened interval
MW-45C 50 MW-45C (47-48)*Soil sample from lower surficial well screened interval
----MW-46B (2-3)Unsaturated soil sample
----MW-46B (5-6)Unsaturated soil sample
MW-46B 25 MW-46B (22-23)*Soil sample from upper surficial well screened interval
MW-46C 50 MW-46C (47-48)*Soil sample from lower surficial well screened interval
----MW-47B (2-3)Unsaturated soil sample
----MW-47B (5-6)Unsaturated soil sample
MW-47B 25 MW-47B (22-23)*Soil sample from upper surficial well screened interval
MW-47C 50 MW-47C (47-48)*Soil sample from lower surficial well screened interval
----MW-48B (2-3)Unsaturated soil sample
----MW-48B (5-6)Unsaturated soil sample
MW-48B 25 MW-48B (22-23)*Soil sample from upper surficial well screened interval
MW-48C 50 MW-48C (47-48)*Soil sample from lower surficial well screened interval
----MW-49B (2-3)Unsaturated soil sample
----MW-49B (5-6)Unsaturated soil sample
MW-49B 25 MW-49B (22-23)*Soil sample from upper surficial well screened interval
MW-49C 50 MW-49C (47-48)*Soil sample from lower surficial well screened interval
----MW-50B (2-3)Unsaturated soil sample
----MW-50B (5-6)Unsaturated soil sample
MW-50B 25 MW-50B (22-23)*Soil sample from upper surficial well screened interval
MW-50C 50 MW-50C (47-48)*Soil sample from lower surficial well screened interval
Prepared by: PBW Checked by: WJW
Notes:
bgs = below ground surface
~ = Approximately
* HFO Analyses Only
SynTerra recommends rotosonic drilling methods for boring and well installation.
Continuous cores from sonic drilling provide sufficient material for soil sampling and lithologic description.
SynTerra recommends each well screen be submerged beneath the water table and have a length of at least 10 feet
TABLE 3
GROUNDWATER ANALYTICAL METHODS
L.V. SUTTON ENERGY COMPLEX
DUKE ENERGY PROGRESS, LLC, WILMINGTON, NC
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Tables.xlsx Page 1 of 1
PARAMETER RL UNITS METHOD
pH NA SU Field Water Quality Meter
Specific Conductance NA µS/cm Field Water Quality Meter
Temperature NA ºC Field Water Quality Meter
Dissolved Oxygen NA mg/L Field Water Quality Meter
Oxidation Reduction Potential NA mV Field Water Quality Meter
Eh NA mV Field Water Quality Meter
Turbidity NA NTU Field Water Quality Meter
Aluminum 0.005 mg/L EPA 200.7 or 6010D
Antimony 0.001 mg/L EPA 200.8 or 6020B
Arsenic 0.001 mg/L EPA 200.8 or 6020B
Barium 0.005 mg/L EPA 200.7 or 6010D
Beryllium 0.001 mg/L EPA 200.8 or 6020B
Boron 0.05 mg/L EPA 200.7 or 6010D
Cadmium 0.001 mg/L EPA 200.8 or 6020B
Chromium 0.001 mg/L EPA 200.8 or 6020B
Cobalt 0.001 mg/L EPA 200.8 or 6020B
Copper 0.001 mg/L EPA 200.8 or 6020B
Hexavalent Chromium 0.000025 mg/L EPA 218.7
Iron 0.01 mg/L EPA 200.7 or 6010D
Lithium 1 mg/L EPA 200.7 or 6010D
Lead 0.001 mg/L EPA 200.8 or 6020B
Manganese 0.005 mg/L EPA 200.7 or 6010D
Mercury 0.00005 mg/L EPA 245.1 or 7470A
Molybdenum 0.001 mg/L EPA 200.8 or 6020B
Nickel 0.001 mg/L EPA 200.8 or 6020B
Selenium 0.001 mg/L EPA 200.8 or 6020B
Strontium 0.005 mg/L EPA 200.7 or 6010D
Thallium (low level)0.0002 mg/L EPA 200.8 or 6020B
Vanadium (low level)0.0003 mg/L EPA 200.8 or 6020B
Zinc 0.005 mg/L EPA 200.7 or 6010D
Radium 226 1 pCi/L EPA 903.1 Modified
Radium 228 1 pCi/L EPA 904.0/SW846 9320 Modified
Uranium (233, 234, 236, 238)Varies by isotope µg/mL SW846 3010A/6020B
Total Uranium NA µg/mL Calculated
Alkalinity (as CaCO3)5 mg/L SM 2320B
Bicarbonate 5 mg/L SM 2320B
Calcium 0.01 mg/L EPA 200.7
Carbonate 5 mg/L SM 2320B
Chloride 0.1 mg/L EPA 300.0 or 9056A
Fluoride 0.1 mg/L EPA 300.0 or 9056A
Magnesium 0.005 mg/L EPA 200.7 or 6010D
Potassium 0.1 mg/L EPA 200.7
Sodium 0.05 mg/L EPA 200.7
Sulfate 0.1 mg/L EPA 300.0 or 9056A
Sulfide 0.1 mg/L SM 4500 S2 D
Total Dissolved Solids 25 mg/L SM 2540C
Total Phosphorus 0.05 mg/L EPA 365.1
Total Organic Carbon 0.1 mg/L SM5310C/EPA9060A
Total Suspended Solids 5 mg/L SM 2450D
Prepared by: HHS Checked by: RHJ
Notes:
NA indicates not applicable.
°C - Degrees Celsius
mg/L - Milligrams per liter
mV - Millivolts
NTU - Nephelometric turbidity unit
pCi/L - picocuries per liter
RL = reporting limit
S.U. - Standard Unit
ug/mL - micrograms per milliliter
µS/cm = micro-Siemens per centimeter
Dissolved and total metals analysis
FIELD PARAMETERS
INORGANICS
RADIONUCLIDES
ANIONS/CATIONS/OTHER
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CCR-104B
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CCR-106B
CCR-107B
CCR-108B
MW -43B/C
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MW -15 R/MW -15R-D
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Sourc e: Es ri , Di gital Gl obe, Geo Eye , Earths tar Ge ographic s , CNES/A irbus DS, USDA , USGS,AeroG RID, IGN, and the GIS Us er Community
PROPOSED FADA ANDFORMER COAL STORAGE ASSESSMENTSAMPLE L OCAT IONSL.V. SUT TON ENERGY COM PLEXDUKE ENERGY PROGRESS, LLCDRAWN BY: K . KIN GPROJECT MAN AG ER : P. WALD REPCHECKED BY: B. WY LIE
D AT E: 08 /20/2018
148 RIV ER S TRE ET, S UITE 220GREENVILLE, S OUTH C AROLINA 29601PHONE [phone]www.syn terracorp.com
P:\D u ke E n er g y P ro g re ss .10 2 6 \0 0 GIS B A SE D ATA\S u tto n \M a p _D o c s\M is ce l la neous\Proposed_Monitoring_Well_Locations_FADA_Coal_Pile.mxd
NOTES:EL EVATIO NS A RE REFE RENCED TO THE NORTHAMERICAN VE RTICA L DATUM 88 (NAVD 88)
AE RIAL P HOTOG RAP HY OB TAINED FROM GOOGLEEARTH PRO O N SE P TEMB ER 12, 2017. IMAGECOLLECTED OCTO BER 29, 2016.
DRAW ING HAS B EE N S ET W IT H A PROJECTION OFNORTH CA ROL INA STAT E P L ANE COORDINATE SYSTEM
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IN FEET
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COO LING POND (SUTTON LAKE)
197 1 ASH BASIN
FO R M E R C OA L STORAG E PILE
FO R M E R A ST
MW -22B/C
MW -19
MW -21C
GW PZ-4A/B
ABMW -02/S/D
MW -16/D
MW -20/D
MW -23 B/C/D/EAB-1ABMW -1S/DTW-136TW-132
PZ-1 971
TW-46
MW -18
MW -17
TW-L098
MW -14
TW-L024
MW -15/D
TW-202
MW -13/D
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