NC0000396_Coal Pile Asmt Tech Memo_Final_20180731

TECHNICAL MEMORANDUM

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Date: June 2018 File: 1026.102.52
To: John Toepfer (Duke Energy)
Cc: Kathy Webb (SynTerra)
From: Todd Plating
Subject: Coal Pile Soil and Groundwater Assessment - Asheville Steam Electric Plant
Duke Energy Progress, LLC (Duke Energy) owns and operates the Asheville Steam
Electric Plant (Plant or Site) in the town of Arden in Buncombe County, NC. The Site
encompasses approximately 786 acres. Coal-fired power generation operations began in
1964 with the construction of two coal-fired power generating units. The Plant also has
two combustion turbines that are currently operational. The coal-fired units are
anticipated to be to be replaced by natural gas combined cycle energy production in
2020. Consequently, the coal pile area will be occupied by bituminous coal used by the
coal-fired power generating units until the coal-fired units have been replaced. The coal
is transported onto the Site by rail or tractor-trailer and stored on approximately 7.6
acres immediately south of the power generation units. Groundwater and soil
assessment activities for the coal storage area (coal pile) 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 detailed assessment of site groundwater within and around
the CCR surface impoundment.
As indicated in a letter from the North Carolina Department of Environmental Quality
(DEQ) dated September 8, 2017, it is understood that in addition to CAMA
requirements, Duke Energy is also bound by the rules and requirements of the NC
General Statutes and NC Administrative Code 02L. These provide requirements for the
assessment and abatement of soil and groundwater impacts resulting from site
activities. Therefore, Duke Energy must ultimately address soil and groundwater
impacts resulting from all primary and secondary sources at the coal ash facilities, not
just the CCR surface impoundments. Pursuant to the September 2017 DEQ letter, Duke
Energy understands the former coal pile area soils and underlying groundwater to be a
potential “secondary source” of inorganic constituents that will be assessed apart from
CAMA.
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Site Description
The Asheville Plant is situated on the shore of Lake Julian. Lake Julian provides
cooling water to the plant and was formed by damming the flow of Powell Creek on the
north side of the Plant. A large portion of Lake Julian borders the east side of the Site.
Surface water from the French Broad River is also pumped into Lake Julian as a
supplemental water supply. The water from the French Broad River enters a stilling
area of the lake on the north side of the Plant. Heated water is discharged back into
Lake Julian to the east of the Plant.
The coal pile is centrally located within the Plant operations. The power generating
units are located immediately north of the coal pile. The rail line used to haul coal onto
the Site and a roadway are the only features separating the coal pile from the power
generating units. Smoke stacks and the gypsum processing/storage area are located
adjacent to the coal pile to the west. Immediately to the south of the coal pile are truck
scales, truck wash, and two bulk fuel above ground storage tanks (ASTs). The 1964 and
1982 coal ash basins are located south of the gypsum processing/storage area, truck
scales, truck wash, and two bulk fuel above ground storage tanks (ASTs). The “hot
pond” and Lake Julian are located east of the coal pile.
The land surface of the coal pile and the land surface surrounding the coal pile is
relatively flat and is at an elevation of approximately 2,171 to 2,173 feet North American
Vertical Datum of 1988 (NAVD 88). Surface water runoff from the coal pile and
surrounding areas is directed to the 1964 coal ash basin by ditches and similar
engineered drainage features.
Coal Pile Area Assessment Objectives
Objectives of the coal pile area assessment include the following:
Characterize inorganic constituents associated with coal pile area soils;
Compare inorganic constituent concentrations in coal pile area soils and site
background soils;
Characterize inorganic constituent concentrations in groundwater underlying the
coal pile area and just beyond the coal pile area perimeter; and
Compare inorganic constituent concentrations in coal pile area groundwater and
site background groundwater.

Soil Assessment
Coal pile area soils will be sampled and analyzed for inorganic parameters to determine
if they are a secondary source of coal pile constituents that can leach into underlying
groundwater. Soil samples will be collected at proposed monitoring well locations
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(CPA-1 through CPA-4) as part of well installation activities. One well (CPA-1) is
proposed on the upgradient perimeter of the existing coal pile. The remaining wells
(CPA-2 through CPA-4) are proposed on the down and side-gradient perimeter of the
existing coal pile. The proposed locations of the monitoring wells are included as
Figure 1. Proposed locations are approximate and may vary slightly based on field
observations and locations of underground utilities which will be determined prior to
initiation of boring activities. Soil samples will be collected from the near ground
surface (2 to 3 foot) and at approximately 2-foot intervals to the top of the groundwater
table or bedrock, whichever is encountered first. An additional soil sample will be
collected below the water table within the new well screened intervals. Soil samples
will be analyzed for inorganic parameters consistent with assessment of areas used for
coal and CCR management (Table 1). SPLP samples will be collected at a frequency of 2
per well cluster location from near ground surface (2 to 3 foot) and 2 to 3 feet above the
water table.
Sonic drilling is recommended as the method of installation for the coal pile assessment
wells due to the quality of continuous cores produced for subsurface characterization
purposes. The boreholes will be properly flushed to remove fluids and cuttings prior to
the installation of the monitoring wells. As recommended by NCDEQ, Duke/SynTerra
will consult closely with drillers to use appropriately-sized filter packs and screens.
Centralizers will be used in all wells to provide uniform annulus space for the filter
packs. Continuous soil cores will be collected from the ground surface to the top of
bedrock and will serve three purposes:
Document the underlying stratigraphy;
Identify the depth where the transition zone is encountered, the thickness of the
transition zone, and where the transition zone well will be screened; and
Collect soil samples from a depth corresponding to the middle of the well
screens of transition zone wells.

Groundwater Assessment
A total of 12 coal pile assessment (CPA) groundwater monitoring wells are proposed to
be installed to characterize coal pile area groundwater. Four shallow (“S”), four deep
(“D”), and four bedrock (“BR”) groundwater monitoring wells (CPA-1S/D/BR, CPA-
2S/D/BR, CPA-3S/D/BR, and CPA-4S/D/BR) are planned to be installed as well clusters
at the proposed locations shown on Figure 1. Well installation procedures will be
consistent with ongoing CAMA assessment activities in accordance with the Revised
Groundwater Assessment Work Plan (SynTerra, December 2014). As such, shallow wells
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are proposed to be installed so that the top of the screened interval is positioned
approximately 5 ft below the water table, where practical, to avoid potential issues such
as biofouling and introduction of artificial redox conditions which are common among
monitoring wells with screened intervals that bracket the water table. This approach
for well screen intervals was outlined in a May 18, 2018 email (and subsequent
teleconference) from Duke Energy to NCDEQ. NCDEQ responded via email on May
23, 2018 supporting the proposed technical approach and rationale concerning these
procedures. Proposed well details and anticipated total depths are provided in Table 2.
Groundwater samples will be analyzed for the field parameters (e.g., pH, conductivity,
and turbidity) and inorganic constituents consistent with ongoing CAMA assessment
activities (Table 3).
Coal Pile Assessment Report
A coal pile assessment report will be prepared once soil and groundwater sample
analytical data is received. Components of the report include:
1) Site History and Source Characterization
2) Site Geology and Hydrogeology
3) Sampling Results
4) Site Conceptual Model
5) Conclusions and Recommendations

Attachments: Table 1: Soil Sample Analytical Methods
Table 2: Proposed Coal Pile Assessment Soil Samples and Monitoring Wells
Table 3: Groundwater Analytical Methods
Figure 1: Proposed Monitoring Well & Soil Boring Location Map
Former Coal Pile Assessment Tech Memo June 2018
Asheville Steam Electric Plant

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ATTACHMENTS

TABLE 1
SOIL ANALYTICAL METHODS
ASHEVILLE STEAM ELECTRIC PLANT
DUKE ENERGY PROGRESS, LLC, ARDEN, NC
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
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
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:
meq/100g - millequivalents per 100 grams
mg/kg - Milligrams per kilogram
mV - Millivolts
S.U. - Standard Unit
Prepared by: RBI Checked by: SRW/TCP/VTV
3. 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.
2. Soil samples collected from near ground surface (2 to 3ft) and from just above water table (field determined) in each boring will also
be analyzed for leaching potential using SPLP Extraction Method 1312 in conjunction with USEPA Methods 6010/6020
1. Soil samples to be analyzed for Total Inorganics using USEPA Methods 6010/6020 and pH using USEPA Method 9045, as noted
above.
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Table 1 Asheville Coal Pile Asmt Tech Memo Page 1 of 1
TABLE 2
PROPOSED COAL PILE ASSESSMENT SOIL SAMPLES AND MONITORING WELLS
ASHEVILLE STEAM ELECTRIC PLANT
DUKE ENERGY PROGRESS, LLC, ARDEN, NC
Monitoring
Well ID
Estimated
Well Depth
(feet bgs)
Soil Sample ID
(Estimated Depth
Interval in feet bgs)
Comments
----CPA-SB1 (2-3)Unsaturated soil sample (water table <20 feet bgs); SPLP
----CPA-SB1 (5-6)Unsaturated soil sample
----CPA-SB1 (8-9)Unsaturated soil sample
----CPA-SB1 (11-12)Unsaturated soil sample
----CPA-SB1 (14-15)Unsaturated soil sample; SPLP
CPA-1S 20 CPA-SB1 (17-18)Soil sample from shallow well screened interval
CPA-1D 50 CPA-SB1 (45-47)Soil sample from deep well screened interval
CPA-1BR 80 CPA-SB1 (75-77)Soil sample from bedrock well screened interval
----CPA-SB2 (2-3)Unsaturated soil sample (water table <20 feet bgs); SPLP
----CPA-SB2 (5-6)Unsaturated soil sample
----CPA-SB2 (8-9)Unsaturated soil sample
----CPA-SB2 (11-12)Unsaturated soil sample
----CPA-SB2 (14-15)Unsaturated soil sample; SPLP
CPA-2S 20 CPA-SB2 (17-18)Soil sample from shallow well screened interval
CPA-2D 50 CPA-SB2 (45-47)Soil sample from deep well screened interval
CPA-2BR 80 CPA-SB2 (75-77)Soil sample from bedrock well screened interval
----CPA-SB3 (2-3)Unsaturated soil sample (water table <20 feet bgs); SPLP
----CPA-SB3 (5-6)Unsaturated soil sample
----CPA-SB3 (8-9)Unsaturated soil sample
----CPA-SB3 (11-12)Unsaturated soil sample
----CPA-SB3 (14-15)Unsaturated soil sample; SPLP
CPA-3S 20 CPA-SB3 (17-18)Soil sample from shallow well screened interval
CPA-3D 50 CPA-SB3 (45-47)Soil sample from deep well screened interval
CPA-3BR 80 CPA-SB3 (75-77)Soil sample from bedrock well screened interval
----CPA-SB4 (2-3)Unsaturated soil sample (water table <20 feet bgs); SPLP
----CPA-SB4 (5-6)Unsaturated soil sample
----CPA-SB4 (8-9)Unsaturated soil sample
----CPA-SB4 (11-12)Unsaturated soil sample
----CPA-SB4 (14-15)Unsaturated soil sample; SPLP
CPA-4S 20 CPA-SB4 (17-18)Soil sample from shallow well screened interval
CPA-4D 50 CPA-SB4 (45-47)Soil sample from deep well screened interval
CPA-4BR 80 CPA-SB4 (75-77)Soil sample from bedrock well screened interval
Prepared by: GAB Checked by: TDP
Notes:
bgs = below ground surface
SynTerra recommends rotosonic drilling methods for boring and well installation.
Continuous cores from rotosonic drilling methods provide sufficient material for soil sampling and lithologic description.
Estimated well and soil sample depths based on data from the GW-1 well cluster.
Number of soil samples shown is approximate. A shallower water table will result in fewer samples, and a deeper water table will result in additional samples.
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TABLE 3
GROUNDWATER ANALYTICAL METHODS
ASHEVILLE STEAM ELECTRIC PLANT
DUKE ENERGY PROGRESS LLC, ARDEN NC
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
Turbidity NA NTU Field Water Quality Meter
Ferrous Iron NA mg/L Field Test Kit
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 6020A
Barium 0.005 mg/L EPA 200.7 or 6010C
Beryllium 0.001 mg/L EPA 200.8 or 6020A
Boron 0.05 mg/L EPA 200.7 or 6010C
Cadmium 0.001 mg/L EPA 200.8 or 6020A
Chromium 0.001 mg/L EPA 200.8 or 6010C
Cobalt 0.001 mg/L EPA 200.8 or 6020A
Copper 0.001 mg/L EPA 200.8 or 6020B
Iron 0.01 mg/L EPA 200.7 or 6010C
Lead 0.001 mg/L EPA 200.8 or 6020A
Manganese 0.005 mg/L EPA 200.7 or 6010C
Mercury (low level)0.005 ng/L 1631 ONLY
Molybdenum 0.001 mg/L EPA 200.8 or 6020B
Nickel 0.001 mg/L EPA 200.8 or 6020B
Phosphorus 0.005 mg/L EPA 365.1
Selenium 0.001 mg/L EPA 200.8 or 6020A
Strontium 0.005 mg/L EPA 200.7 or 6010C
Thallium (low level)0.0002 mg/L EPA 200.8 or 6020A
Vanadium (low level)0.0003 mg/L EPA 200.8 or 6020A
Zinc 0.005 mg/L EPA 200.7 or 6010C
Alkalinity (as CaCO3)5 mg/L SM 2320B
Bicarbonate 5 mg/L SM 2320
Calcium 0.01 mg/L EPA 200.7
Carbonate 5 mg/L SM 2320
Chloride 0.1 mg/L EPA 300.0 or 9056A
Magnesium 0.005 mg/L EPA 200.7
Methane 0.01 mg/L RSK 175
Nitrate as Nitrogen 0.01 mg-N/L EPA 353.2
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 SM4500S2-D
Total Dissolved Solids 25 mg/L SM 2540C
Total Organic Carbon 0.1 mg/L SM 5310C/EPA9060A
Total Suspended Solids 2.5 mg/L SM 2450D
Prepared by: RBI Checked by: SRW/TCP
Notes:
ºC - Degrees Celsius
µS/cm = micro-Siemens per centimeter
mg/L - Milligrams per liter
mg - N/L - Milligrams nitrogen per liter
mV - Millivolts
NA - Not analyzed
NTU - Nephelometric turbidity unit
pCi/L - picocuries per liter
RL = reporting limit
S.U. - Standard Unit
ug/mL - micrograms per milliliter
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.
INORGANICS
FIELD PARAMETERS
1. Select constituents will be analyzed for total and dissolved concentrations.
ANIONS/CATIONS
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NOTES:AERIAL PHOTOGRAPHY OBTAINED FROM GOOGLE EARTH PRO ON MAY 24, 2018.IMAGE COLLECTED OCTOBER 18, 2015.
DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANECOORDINATE SYSTEM FIPS 3200 (NAD83).
FIGURE 1PROPOSED COAL PILE ASSESSMENTWELL LOCATIONSASHEVILLE STEAM ELECTRIC PLANTDUKE ENERGY PROGRESS, LLCARDEN, NORTH CAROLINADRAWN BY: B. YOUNGPROJECT MANAGER: T. PLATINGCHECKED BY: G. BARRIER
DATE: 05/24/2018
148 RIVER STREET, SUITE 220GREENVILLE, SOUTH CAROLINA 29601PHONE [phone]www.synterracorp.com
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LEGEND