NC0000396_SOC_20200120

- TRwt r 4nd-
James Wells
faN DUKE Vice President
Environmental, Health and Safety
ENERGY® Programs&Environmental Sciences
526 South Church Street
Charlotte, NC 28202
980-373-9646
January 20, 2020
Via Overnight Mail
Linda Culpepper, Director
I J
Division of Water Resources DIVISION OF WATER RESOURCES
North Carolina Department of Environmental Quality DIRECTOR'S OFFICE _
1617 Mail Services Center .__ ..__r..._
Raleigh, NC 27699-1617
Subject: Report Under Special Order By Consent (SOC) - EMC SOC WQ S17-010
Duke Energy Progress, LLC - Asheville Steam Electric Plant
NPDES Permit NC0000396
Seeps E-01 and F-01 Re-Assessment Report Submittal
Dear Ms. Culpepper:
On behalf of Duke Energy Progress, LLC (DEP), I am submitting the enclosed report
containing the results of a re-assessment of seeps E-01 and F-01 at the Asheville Plant,
as required by Section 2(c)(1) of the Asheville Plant SOC No. S17-010.
Since the issuance of the SOC, and until the fourth quarter of 2019, these seeps have
consistently complied with the SOC's Interim Action Levels (IAL). Following the receipt
of the fourth quarter sampling results for E-01 and F-01, a consultant (SynTerra) was
contracted to conduct the re-assessment. SynTerra conducted a thorough evaluation
including review of groundwater data, surface water data, monitoring of multiple on-site
locations, and previous assessments to understand groundwater hydraulics. This effort
began in November and is continuing as additional data is obtained.
SynTerra's evaluation concluded that there has been an increase in groundwater flow
after rock blasting was conducted in order to construct the combined cycle station. The
results indicate that the source that lowered the pH is not related to the ash basin
operation or coal combustion residual impacts but rather due to either the coal pile and/or
naturally occurring pyrites that have been noted in the bedrock.
The follow-up sample results in December 2019 resulted in a return to compliance with
the IALs for E-01 and F-01. There are several options recommended in the report to
improve the groundwater and prevent recurrence. Duke Energy plans to implement
several of the recommended options in the very near future. The plan to pump out water
from a sediment basin that was determined to contain the lower pH groundwater is ready
to proceed once conditions are sufficiently dry. Also, with the recent closing of the coal

Ms. Culpepper
January 20, 2020
power plant operations the coal pile is scheduled for removal, and subsequent coal yard
cleanup is currently planned to be completed in the second quarter of 2020.
As required by the SOC, I certify under penalty of law that this document and all
attachments were prepared under my direction or supervision in accordance with a
system designed to assure that qualified personnel properly gather and evaluate the
information submitted. Based on my inquiry of the person or persons who manage the
system, or those persons directly responsible for gathering the information, the
information submitted is, to the best of my knowledge and belief, true, accurate, and
complete. I am aware that there are significant penalties for submitting false information,
including the possibility of fine and imprisonment for knowing violations.
Please direct any questions concerning the Asheville Plant NPDES Permit NC0000396
or SOC No. S17-010 to either Robert Wylie at 704 382-4669 or Chris Hallman at 980 373-
7892.
Sincerely,
Jame Wells &I
Vice P sident, Environment, Health and Safety
Programs and Environmental Sciences
Duke Energy
Attachment

synTerra
EMC SOC WQ S17-010 RE-ASSESSMENT
AT
ASHEVILLE STEAM ELECTRIC PLANT
52 NEW ROCKWOOD ROAD
ARDENT NORTH CAROLINA 28704
JANUARY 2020
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress, LLC, Asheville Steam Electric Plant SynTerra
TABLE OF CONTENTS
SECTION PAGE
EXECUTIVE SUMMARY ES-1
1.0 INTRODUCTION 1-1
2.0 RE-ASSESSMENT APPROACH 2-1
3.0 RE-ASSESSMENT ACTIVITIES AND FINDINGS 3-1
3.1 Surface Water Sampling and Data Evaluation 3-1
3.2 Groundwater Sampling and Data Evaluation 3-2
3.3 Precipitation Data 3-4
4.0 INITIAL CONCLUSIONS 4-1
5.0 PROPOSED SHORT-TERM REMEDIAL ACTIONS 5-1
5.1 pH Adjustment 5-1
5.2 pH Adjustment with Supplementary Treatment 5-1
5.3 Groundwater Collection and Treatment 5-2
5.4 Coal Pile Removal 5-2
6.0 REMEDIAL EFFECTIVENESS MONITORING AND REPORTING 6-1
7.0 REFERENCES 7-1
LIST OF TABLES
Table 1-1 Monitored Locations and Interim Action Levels
Table 3-1 Summary of Analytical Monitoring Results
Table 3-2 Low pH Groundwater Wells and Select Constituent Summary
Table 3-3 Asheville Airport Rainfall Data
LIST OF FIGURES
Figure 1-1 Site Layout
Figure 1-2 Water Quality Monitoring Locations
Figure 3-1 SOC Re-Assessment Sampling Location Map
Figure 3-2 Asheville Combined Cycle Station Stormwater System Inspection
Figure 3-3 E-01 and F-01 Time Series Plots- pH, Copper, and Nickel
Figure 3-4 Coal Pile Area
Figure 3-5 E-01 and F-01 Time Series Plots-Boron, Copper, and Nickel
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
EXECUTIVE SUMMARY
Duke Energy Progress, LLC (Duke Energy) and the North Carolina Environmental
Management Commission entered into Special Order By Consent SOC No. S17-010 for
the Asheville Steam Electric Plant(Asheville Plant) which was approved on October 10,
2018. Quarterly monitoring results reported on November 22, 2019 indicated one
analyte (copper) occurred at a concentration 20% greater than the Interim Action Level
(IAL) at one monitoring location (FO1). Nickel concentrations at E-01 and reduced pH
at both E-01 and F-01 were greater than IALs, but less than the 20% threshold that
triggers additional assessment.
Re-assessment of the contributing seep(s) and an evaluation of proposed remedial
actions for treatment and/or control of the seep were promptly initiated upon receipt of
the final analytical laboratory report.
Conclusions from the re-assessment include:
• Increased concentrations of nickel and copper in recently collected surface water
samples from SOC monitoring locations E-01 and F-01 are not related to
migration of groundwater affected by ash basin operations to surface water.
• Reduced pH and increased nickel and copper concentrations are influenced by
the increased groundwater flow that became apparent within the footprint of the
former 1982 ash basin after rock blasting related to construction of the combined
cycle facility.
• Information collected and evaluated to date indicates two possible sources for
reduced pH and elevated nickel and copper concentrations: (1) naturally
occurring low pH induced by weathering processes of the mineral pyrite
contained in bedrock, or (2) downgradient transport of groundwater from an
area near the coal pile that exhibits low pH and elevated inorganic constituents.
• Analytical results from additional compliance monitoring conducted on
December 27, 2019 indicated required monitoring locations identified in the SOC
were in compliance with IALs.
Potential remedial options identified during the evaluation of corrective actions include:
• pH adjustment
• pH adjustment with supplemental treatment
• Groundwater collection and treatment
Page ES-1

SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
• Coal pile removal
Coal power plant operations have recently terminated. Removal of the coal pile is
scheduled to be completed during the second quarter of 2020. After source material
associated with low pH near the coal pile is removed, natural processes should be
effective at mitigating the acidity of the groundwater thereby reducing the mobilization
of metals.
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
1.0 INTRODUCTION
Duke Energy Progress, LLC (Duke Energy) and the North Carolina Environmental
Management Commission entered into Special Order By Consent SOC No. S17-010 for the
Asheville Steam Electric Plant (Asheville Plant) (Figure 1-1), which was approved on
October 10, 2018.
Classified waters of the State receiving flow from non-constructed seeps, found in
Attachment A of the SOC, are actively monitored and analytical results reported as
required at seven (7) seep locations. Interim Action Levels (IALs) were established for
select constituents and pH at the monitoring locations. Two additional sample points in
the French Broad River (upstream and downstream) are also monitored,but no IALs
were established. The constituents that are monitored at each location and IALs are
included in Table 1-1. The monitored locations are shown on Figure 1-2.
As required by the SOC, 2019 fourth quarter monitoring was completed on November
7, 2019 at the seven required seep locations and the French Broad River locations. Both
the Upstream and Downstream French Broad River monitoring locations and seep
locations A-01, B-01, C-01, F-02, and N-01 were in compliance with the IALs established
in the SOC. One sample at F-01 resulted in a concentration greater than 20% of the IAL
(copper, 23.4 µg/L).
Additional IAL exceedances:
• E-01 nickel: 60.8 µg/L (IAL 60 µg/L)
• E-01 pH: 4.1 S.U. (IAL 5-10 S.U.)
• F-01 pH: 4.9 S.U. (IAL 5-10 S.U.)
Per the SOC, sampling events that resulted in constituents detected at concentrations
greater than 20% any interim action level in a single monitoring event, or for two
consecutive monitoring events, Duke Energy shall increase to monthly monitoring and
conduct a re-assessment of the seeps.
This document fulfills the reporting requirement described in section 2. c. Additional
Compliance Measures 1) of the SOC:
If the monitoring of any classified water of the State receiving flow from
seeps regulated by this Special Order indicates exceedance of any interim
action level established by the Special Order, Duke Energy shall increase
monitoring at that location from quarterly to monthly until concentrations
of monitored characteristics return to those observed at the initiation of the
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
Special Order. If any interim action level established by the Special Order
is exceeded by more than 20% in a single sampling event, or exceeded for
two (2) consecutive monitoring events, in addition to paying the
associated stipulated penalty, Duke Energy shall conduct a re-assessment
of the contributing seep(s), including, but not limited to, evaluation of
proposed remedial actions for treatment and/or control of the seep such
that impacts to the receiving waters are quickly mitigated. A report
compiling the findings of the re-assessment, including proposed remedial
actions, shall be provided to the Director of DWR within 60 days of any
applicable exceedance. Following its review, DWR shall notes Duke
Energy of its concurrence or disapproval of Duke Energy's proposed
remedial actions.
The discharge channels identified as Seeps E-01 and F-01 are located in the floodplain of
the French Broad River and convey surface water flows from a wetland/stream complex
west of I-26 and the Asheville Plant. Activities for the re-assessment of E-01 and F-01,
evaluation of interim remedial actions and proposed short- and long-term corrective
actions in pursuit of mitigation are compiled in the remainder of this document.
Information collected and evaluated to date indicates two possible sources for reduced
pH and elevated nickel and copper concentrations:
• Naturally occurring low pH induced by weathering processes of the mineral
pyrite containing bedrock matrix after rock blasting related to CC construction.
• Downgradient transport of groundwater from an area near the coal pile that
exhibits low pH and elevated inorganic constituents.
Groundwater from either source is interacting with the stormwater management
system associated with the CC facility. Both groundwater and stormwater ultimately
flow to the E-01 and F-01 SOC monitoring locations.
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
2.0 RE-ASSESSMENT APPROACH
Planning for the re-assessment of the E-01 and F-01 seeps began on November 22, 2019
after receipt of final laboratory analytical results from the fourth quarter SOC sampling
event. Prior to receipt of the final lab report, field work was conducted to further assess
the low pH identified in the seeps at E-01 and F-01.
The following re-assessment approach was used to evaluate current E-01 and F-01 seep
conditions and develop preliminary remedial options to quickly mitigate affects to
receiving waters, as required by the SOC.
• Conduct site reconnaissance to assess current conditions of the Asheville
combined-cycle stormwater collection system, seepage areas and surface waters
within the wetland complex downgradient of the former 1982 ash basin and west
of Interstate 26 (I-26)
• Perform sampling at seep and surface water locations between the combined-
cycle stormwater conveyance system and the French Broad River
• Review and evaluate historical and current surface water data collected from
seeps E-01 and F-01
• Review and evaluate relevant groundwater analytical data
• Review and evaluate current and historical, local precipitation data
• Develop proposed short- and long-term remedial action strategies to treat and/or
control impacted discharges to the seeps
• Perform stable isotope evaluation of waters within the Asheville combined-cycle
stormwater conveyance system to evaluate water sources within the stormwater
conveyance
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
3.0 RE-ASSESSMENT ACTIVITIES AND FINDINGS
Duke Energy and SynTerra staff completed multiple site visits to evaluate current
conditions affecting the water quality at E-01 and F-01 and to begin development of
remedial options for mitigating the low pH and elevated levels of constituents at the
sample locations. Surface water and groundwater samples were collected, visual
reconnaissance of the streams and wetlands draining to the subject seep locations was
conducted and the newly-constructed, combined-cycle (CC) station's stormwater
collection system was evaluated.
Stormwater collected within the CC stormwater system flows to the head of the stream
channel conveying water to the I-26 culvert. Groundwater emerges at the rip-rap
channel along the eastern boundary of the former 1982 ash basin and near the toe of the
former 1982 ash basin dam contributing to seep flow (Figure 3-1). These upstream
sources of surface water provide the flow at seeps E-01 and F-01.
A dry-weather, visual inspection of the stormwater collection system did not reveal any
non-stormwater flows associated with the CC station or construction activities.
Groundwater infiltration was noted at several manhole locations, identified as MH-021
an
d MH-022 on Figure 3-2, where the stormwater system discharges to the east
stormwater basin (EB) downstream of MH-026. Although identified as a contributing
source of groundwater, the approximate one-half gallons per minute flow was
considered de minimis.
Additional apparent groundwater inputs were identified in two other locations:
• The Upper East Channel (UE Channel) - a perimeter, rip-rap-lined ditch
bordering the eastern extent of combined-cycle project footprint
• Seepage into the EB at a northwestern slope face
Construction personnel for the CC station communicated that following the 2017 rock
drilling and blasting, associated with construction of the combined-cycle station,
groundwater emerged at the surface and was directed to the EB.
3.1 Surface Water Sampling and Data Evaluation
A review of the historical AOW and SOC monitoring data indicates the elevated
concentrations of nickel and copper under discussion and low pH are recent and
isolated. Out of 18 samples collected at E-01 from April 4, 2016 to December 27, 2019,
only one sample resulted in a constituent concentration exceeding an IAL: November 7,
2019 result of 60.8 µg/L nickel (nickel IAL 60 µg/L). At F-01, out of 19 samples collected
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
during the same time period above, only one sample resulted in a concentration of
copper exceeding an IAL: November 7, 2019 result of 23.4 µg/L copper (copper IAL 15
µg/L). Low pH (<5 S.U.) were measured at E-01 and F-01 in April 2016. The cause of
the low pH is unknown. However, it is notable that concentrations of nickel and copper
were not substantially elevated during that event.
Surface water samples were collected at multiple locations within the stormwater
collection system, receiving waters below the former 1982 ash basin, and on the west
side of I-26 upstream of seep locations E-01 and F-01. (Figure 3-1). Field parameters
were collected during each sampling event at each sample location, and from numerous
additional locations to provide data on current conditions of the water features being
investigated. Table 3-1 summarizes field parameters and analytical results and Figure
3-1 includes locations and analytical results.
Surface water analytical results indicate the following:
• Low pH (<5.0) was detected at UE Channel (upstream of the EB) and MH-026
• Elevated copper and nickel concentrations were identified in samples within the
CC stormwater system at the UE Channel, EB Channel, MH-026, and EB Influent
and Effluent
• Low pH (2.9) was detected in the EB
• Low pH (<5.0) and elevated concentrations of copper and nickel were not
detected at the west stormwater basin (WB)
Historical analytical results show trends of increasing nickel and copper concentrations
and lower pH in samples collected from E-01 and F-01 in early 2018 after rock blasting
was completed to construct the new CC generating facility. Time series data to visually
compare the relationship between pH, nickel and copper are provided in Figure 3-3.
3.2 Groundwater Sampling and Data Evaluation
Blasting of bedrock was performed in mid to late 2017 to achieve base grades for the
new facility. During the blasting effort, new groundwater flow to the surface within the
footprint of the former 1982 ash basin was noted and provides a flow path of
groundwater to surface water.
Groundwater sampling has been conducted during re-assessment activities and the
analytical results are included in Table 3-1. Groundwater analytical results from wells
with recent routine low pH (less than 4) are summarized in Table 3-2, and five wells are
identified with recent pH values of less than 4 S.U.
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
These wells include:
• CB-06 (pH: 3.8-3.9 S.U., n=3)
• CPA-04D (pH: 3.3 S.U., n=3)
• CPA-04BR (pH: 3.6-3.7 S.U., n=4)
• MW-03D (pH: 3.9 S.U., n=1)
• MW-05D (pH: 3.6-3.8 S.U., n=5)
Hydraulically all five of these wells are considered upgradient of SOC monitoring
locations E-01 and F-01 with groundwater flow direction from east to west, toward the
French Broad River. However, only the CPA-04D/BR cluster is considered
hydraulically upgradient of the groundwater seepage observed within the CC
stormwater system (Figure 3-4).
Concentrations of nickel and copper measured at the CPA-04 cluster are greater than
those observed at E-01, F-01 and the point where groundwater enters the stormwater
system (UE Channel). Boron concentrations near the coal pile are less than the 02L
standards and generally estimated between 100 and 400 µg/L. Based on hydraulic
information and groundwater geochemistry, migration of inorganic constituents
downgradient through the fractured bedrock flow system is plausible. However, boron
is notably absent from the UE Channel sample and since considered a non-reactive
(conservative) constituent that is mobile, the lack of boron at the UE channel may
indicate natural processes rather than constituent migration are the primary cause of
low pH and elevated constituents.
Concentrations of nickel and copper over time do not correlate with the boron, as
presented on Figure 3-5. Boron is generally accepted as an indicator of ash basin
affected groundwater, and the lack of boron at the UE channel indicates that recently
observed elevated constituent concentrations and low pH are not associated with
groundwater affected by ash basin operation. Boron concentrations at these surface
water locations are decreasing over time with more rapid reduction in concentration
after the completion of the 1982 ash basin excavation (end of 2017).
Correlation analysis between nickel and boron demonstrate no statistical positive
correlation (Spearman correlation—0.6816, n=15; Pearson correlation-0.7345, n=15, P
value=0.0018) indicating migration of groundwater affected by ash basin operations is
not likely causing the recent and isolated increase observed. Statistical analysis for
copper is not possible due to the number of non-detect values in the data set.
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
Evaluation of oxygen and deuterium isotope results indicated a depleted isotopic
signature, similar to the isotopic signature measured in groundwater near the coal pile.
3.3 Precipitation Data
Approximately 4 years of regional and local precipitation data from April 2016 through
December 2019 was reviewed as part of this re-assessment.
Precipitation data collected at the Asheville Regional Airport, approximately 2 miles
from the Asheville Station, was acquired from the North Carolina Climate Office
(http://climate.ncsu.edu/cronos/?station=KAVL) for evaluation. Normal precipitation
records from the National Weather Service (NWS) (https://www.weather.gov/media/
gsp/Climate/AVL/newAVLmonthlyPobs_htm.pdf), were compared to the local data for
the time period being considered and indicated below-normal rainfall for the year 2016
-a 26% decrease. The remaining years experienced above-normal precipitation
amounts, where increases ranged from 17% 73%g in 2017 to in 2018 (Table 3-3). A more
detailed review of daily precipitation event records publishedby the NWS was also
completed, particularly of weeks immediately preceding required SOC sampling
events.
According to data available from the U.S. Drought Monitor
(https://droughtmonitor.unl.edu/Maps/MapArchive.aspx), a product produced by the
National Drought Mitigation Center, National Oceanic and Atmospheric
Administration and United States Department of Agriculture, the Asheville Plant area
was not characterized by drought conditions during the time period under review.
Precipitation can affect constituent concentrations in surface waters, such as the
discharge at E-01 and F-01 through surface runoff and shallow sub-surface flows,
particularly during and immediately after precipitation events, due to dilution. As per
established protocols, the samples collected for SOC compliance and as part of this re-
assessment were collected at times considered representative of normal conditions (e.g.,
normal flows and low turbidity).
Evaluation of sample data and precipitation records did not provide a clear, consistent
correlation between the variability of rainfall and changes in concentrations of copper
and nickel or pH. The November 7, 2019 and December 27, 2019 sampling events were
preceded by similar weekly rain totals:
• October 31, 2019 through November 6, 2019-0.76 inches
• December 20, 2019 through December 26, 2019- 1.05 inches
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
The rain event prior to the November 7 sample collection occurred on day one of the
preceding week and prior to the December 27 sample collection, the rain event occurred
on days three and four of the preceding week. The closer proximity and greater total of
precipitation to the December sample event could have contributed to the
comparatively lower constituent concentrations and slightly increased pH levels to the
November sample.
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
4.0 INITIAL CONCLUSIONS
Based on the information presented in this report, increased concentrations of nickel
and copper and low pH in recently collected surface water samples from SOC
monitoring locations E-01 and F-01 do not appear to be related to migration of
groundwater affected by ash basin operations to surface water. Elevated concentrations
of nickel and copper at E-01 and F-01 are isolated and transient, as indicated by the
historical sampling record at these locations. Most recent sampling results collected on
December 27, 2019 indicate nickel and copper concentrations less than the IALs and pH
values are within an acceptable range.
Information collected and evaluated to date indicates two possible sources for reduced
pH and elevated nickel and copper concentrations:
• Naturally occurring low pH induced by weathering processes of the pyrite
containing bedrock matrix after rock blasting related to CC construction.
• Downgradient transport of groundwater from the coal pile area that exhibits low
pH and elevated inorganic constituents.
Groundwater from either source is interacting with the stormwater management
system associated with the CC facility. Both groundwater and stormwater ultimately
flow to the E-01 and F-01 SOC monitoring locations.
Should pH and constituent concentration levels greater than IALs persist, additional
evaluation of dynamic geochemical conditions through a PHREEQC model is
recommended prior to proceeding with implementation of corrective action strategies.
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
5.0 PROPOSED SHORT-TERM REMEDIAL ACTIONS
Re-assessment activities conducted in accordance with the SOC requirements included
evaluation of options for treatment and/or control of the groundwater that is
discharging to the CC stormwater system affecting constituent concentrations at E-01
and F-01. Should constituent concentration continue to exceed IALs, the options
presented in the following section should be selected and implemented. The following
short-term actions were developed to quickly mitigate possible affects to receiving
waters.
Once the short-term remediation option is selected it will be implemented. Some
options may require agency approval. Upon receipt of this approval the selected
option will then be implemented.
5.1 pH Adjustment
This approach incorporates an in-situ treatment strategy to adjust the pH of the waters
present in the east stormwater basin components of the CC stormwater system.
Limestone, a basic material, would be added as rip-rap to the existing rock in the
conveyance channels (UE Channel and EB Channel) leading to the EB and as#57 gravel
at one rock-baffle location within the stormwater basin. These additions would be
intended to increase the pH to levels between 5 and 9 and precipitate the copper and
nickel as hydroxides, which would settle in the basin.
Use of this method could cause iron to precipitate on the surface of the alkaline material
and reduce its effectiveness, requiring significant, on-going maintenance.
5.2 pH Adjustment with Supplementary Treatment
This approach utilizes the identical option described above with the incorporation of
NC DEQ approved PAM/Flocculant products or other proprietary devices, such as sock
products for stormwater treatment. The subject products have been utilized across
North Carolina, including at Duke Energy sites, to improve stormwater quality. The
sock filter media can capture metals and the PAM can improve flocculation of
suspended particles and assist with settling and potential removal of metals.
Application of these materials can be accomplished by various methods. Additional
evaluation and consultation with vendors will be required to determine the
applicability of the products and, if considered beneficial, to select the specific product
and application method.
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
5.3 Groundwater Collection and Treatment
This approach would utilize either the existing east stormwater basin, a newly
constructed sump, or new impounding structure in the UE Channel and installation of
pumps to capture and treat the targeted groundwater flow to the CC stormwater
system. Options under consideration include:
• EB at or near the outlet structure
o The existing Faircloth skimmer would be deactivated (i.e., placed above
impounded water elevation) to retain normal groundwater base flow in the
EB and an electric pump would be installed to deliver water to a temporary
holding tank.
o Water within the holding tank would periodically be removed and
discharged to the lined retention basin for treatment.
o During rainfall events, the Faircloth skimmer would be reactivated and
pumping would be suspended.
o Once the water level in the EB returned to an operational,base flow level,
pumping, capture and treatment would resume.
• UE Channel above the 60-inch pipe
o Either a sump or impounding structure would be constructed to capture
normal base flow of groundwater and an electric pump would be installed to
deliver water to a temporary holding tank.
o Water within the holding tank would periodically be removed and
discharged to the lined retention basin for treatment.
o During rainfall events, pumping would be suspended and stormflow would
bypass the sump or impounding structure.
o Once conditions returned to base flow, pumping, capture and treatment
would resume.
5.4 Coal Pile Removal
Coal operations are scheduled to terminate by January 31, 2020. Following this date,
the coal pile, which is thought to be one of the probable sources of the acidic
groundwater that mo
bilizes metals, will no longer
g be in use. With the recent closing of
the coal power plant operations the coal pile is scheduled for removal and subsequent
coal yard cleanup is currently planned to be completed in the second quarter of 2020.
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
Coal pile removal should be effective in reducing the acidity of the groundwater in that
area. After pyritic material associated with the coal pile is removed, natural processes
will mitigate the acidity of the groundwater and reduce the mobilization of metals.
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
6.0 REMEDIAL EFFECTIVENESS MONITORING AND REPORTING
Following remedy selection and implementation, remedial effectiveness updates will be
provided to NCDEQ.
Monitoring for effectiveness would vary depending upon the remedy selected. Plans
are for the East Sediment Basin's water will be periodically evaluated in comparison to
the results of the monitoring at E-01 and F-01.
If remedial performance is determined not to be adequate, optimization of existing
components and utilization of additional methods would be considered. Modifications
or additions to treatment would be implemented and reported in a timely manner.
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SOC WQ S17-010 Re-Assessment January 2020
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7.0 REFERENCES
SynTerra (2015). Comprehensive Site Assessment Report—Asheville Steam Electric Pant—
August, 2015. Arden, NC.
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SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
TABLES

TABLE 1-1
MONITORED LOCATIONS AND INTERIM ACTION LEVELS
SOC WQ S17-010 RE-ASSESSMENT
ASHEVILLE PLANT
DUKE ENERGY PROGRESS, LLC, ARDEN, NC
Seep ID Number Interim Action Level
pH 5-10 S.U.
A-01 Mercury 50 ng/L
Selenium 10 pg/L
Mercury 50 ng/L
B-01 Chlorides 600 mg/L
TDS 2100 mg/L
C-01 TDS 1500 mg/L
Nickel 50 pg/L
pH 5-10 S.U.
E-01 Nickel 60 pg/L
TDS 600 mg/L
pH 5-10 S.U.
Copper 15 pg/L
F-01 Mercury 50 ng/L
Nickel 100 pg/L
TDS 1000 mg/L
F-02 pH 5-10 S.U.
N-01 Cadmium 5 pg/L
Mercury 50 ng/L
Upstream and Downstream Monitoring of N/A - 2B Standards Apply
the French Broad River
Prepared by: CBC Checked by: JPC
Notes:
pg/L- micrograms per liter
mg/L- milligrams per liter
ng/L- nanograms per liter
S.U.- Standard units
TDS -Total Dissolved Solids
Page 1 of 1

TABLE 3-1
SUMMARY OF ANALYTICAL MONITORING RESULTS
SOC WQ S17-010 RE-ASSESSMENT
ASHEVILLE PLANT
DUKE ENERGY PROGRESS, LLC, ARDEN, NC
FIELD PARAMETERS SELECTED 40CFR257 APPENDIX III CONSTITUENTS INORGANIC PARAMETERS(TOTAL CONCENTRATION)
Specific Dissolved Oxidation Total
pH Temp Conductance Oxygen Reduction Eh Turbidity Flow Boron Calcium Chloride Sulfate Dissolved Arsenic Barium Cadmium Chromium Copper
Potential
Solids
Reporting Units S.U. Deg C pmhos/cm mg/L mV mV NTUs GPM pg/L mg/L mg/L mg/L mg/L pg/L pg/L pg/L pg/L pg/L
Sample ID Sample
Collection Date Analytical Results Analytical Results
A-01 11/07/2019 6.2 13 229 5.89 200 405 2.3 9 492 17.9 28 42 135 <1 83 <0.1 <1 <1
B-01 11/07/2019 6.4 14 814 5.30 185 390 5.3 1.5 3410 102 120 180 577 <1 63 0.103 <1 <1
C-01 11/07/2019 6.0 13 1151 5.10 223 428 2.2 NM 3260 163 86 420 910 <1 46 0.458 <1 <1
CB-04 01/02/2020 5.0 14 164 NM NM NM NM NM 207 12.3 NA NA NA <2 69 <2 <2 <2
CB-05 01/02/2020 5.1 11 217 NM NM NM NM NM 212 9.51 NA NA NA <2 32 <2 <2 <2
CB-06 01/02/2020 4.6 10 498 NM NM NM NM NM 410 40.6 NA NA NA <2 45 <2 <2 <2
CB-07 01/02/2020 5.9 11 169 NM NM NM NM NM <50 8.04 NA NA NA <2 11 <2 <2 <2
Confluence 11/20/2019 4.0 11 442 5.99 419 624 4.3 89 193 34.7 8 210 277 5.06 47 0.147 <1 4.92
E-01 11/07/2019 4.1 10 392 7.85 274 479 1.2 39 243 38.1 8.8 150 266 1.66 68 0.311 <1 8.37
E-01 12/27/2019 5.0 8 365 NM NM NM NM 12 310 35 15 140 249 <1 49 0.155 <1 1.47
E-01 In Process 01/02/2020 4.2 6 378 9.94 147 352 NM NM 333 31.9 NA NA NA <5 44 <5 <5 <5
1E8 Influent(East Basin) 11/20/2019 3.3 13 679 6.06 568 773 5.6 NM <50 32.1 6.5 280 354 4.92 33 0.179 <1 3.14
EB Channel 12/12/2019 5.8 7 906 NM NM NM NM 5 <50 25.9 NA NA 201 <1 34 <0.1 <1 10.2
EB Effluent 12/12/2019 4.4 8 669 NM NM NM NM NM 76 31.6 NA NA 287 2.79 40 0.111 <1 6.75
EB Effluent 01/02/2020 4.1 7 472 NM NM NM NM NM 107 37.2 NA NA NA <5 39 <5 <5 8.3
EB Seep 01/02/2020 6.0 8 592 NM NM NM NM NM 653 95.8 NA NA NA <5 66 <5 <5 <5
F-01 11/07/2019 4.9 10 367 8.29 221 426 6.3 92 234 35.4 7.2 150 271 6.25 90 0.195 2.35 23.4
F-01 12/27/2019 5.2 8 380 NM NM NM NM NM 323 37.3 11 160 267 2.93 52 0.112 <1 4.39
French Broad Downstream 11/07/2019 6.5 13 47 6.65 185 390 7.0 NM <50 2.91 2.2 2.1 25 <1 14 <0.1 <1 <1
French Broad Upstream 11/07/2019 5.9 11 36 9.00 174 379 7.0 NM <50 2.87 2.2 1.8 31 <1 14 <0.1 <1 <1
1-26 Culvert 11/20/2019 4.7 11 410 6.40 387 592 3.1 90 355 35.3 8.2 190 278 3.92 58 0.143 <1 3.56
MH-026 12/12/2019 4.9 11 873 NM NM NM NM 0.5 <50 25.1 NA NA 308 3.02 40 0.19 <1 4.93
Page 1 of 4

TABLE 3-1
SUMMARY OF ANALYTICAL MONITORING RESULTS
SOC WQ S17-010 RE-ASSESSMENT
ASHEVILLE PLANT
DUKE ENERGY PROGRESS, LLC,ARDEN, NC
INORGANIC PARAMETERS(TOTAL CONCENTRATION) INORGANIC PARAMETERS(DISSOLVED CONCENTRATION WITH FILTER SIZE) OTHER PARAMETERS
Lead Ma Nitrate+ Arsenic Cadmium Chromium Copper Lead Nickel Zinc
gnesium Mercury Nickel Nitrite Selenium Thallium Zinc Bromide Fluoride Hardness
(0.45u) (0.45u) (0.45u) (0.45u) (0.45u) (0.45u) (0.45u)
Reporting Units pg/L mg/L pg/L Pg/L mg-NIL pg/L Pg/L pg/L pg/L pg/L pg/L p9/L pg/L pg/L pg/L pg/L mg/L mg/L
Sample ID Sample
Collection Date Analytical Results
A-Il 11/07/2019 <0.2 7.94 0.00695 <1 0.74 1.43 <0.2 <5 <1 <0.1 <1 <1 <0.2 <1 <5 120 <0.1 77.4
B-Il 11/07/2019 <0.2 30.2 0.00386 4.77 0.33 <1 <0.2 9.78 <1 0.108 <1 <1 <0.2 4.43 8.93 780 <0.5 380
C-01 11/07/2019 <0.2 53 0.00285 23.6 0.44 <1 <0.2 14.4 <1 0.443 <1 <1 <0.2 23.3 13.8 1100 <1 626
CB-04 01/02/2020 <0.4 2.67 NA <2 NA 3.02 <0.4 <10 NA NA NA NA NA NA NA NA NA 41.6
CB-05 01/02/2020 <0.4 5.59 NA <2 NA <2 <0.4 <10 NA NA NA NA NA NA NA NA NA 46.7
CB-06 01/02/2020 <0.4 7.36 NA 12.6 NA <2 <0.4 <10 NA NA NA NA NA NA NA NA NA 132
CB-07 01/02/2020 <0.4 2.13 NA <2 NA 9.07 <0.4 <10 NA NA NA NA NA NA NA NA NA 28.9
Confluence 11/20/2019 1.37 11.8 0.00634 71.3 0.54 <1 <0.2 153 5.07 0.14 <1 5.03 1.27 72 150 130 0.5 135
E-01 11/07/2019 <0.2 11 <0.0005 60.8 0.29 <1 <0.2 146 1.68 0.352 <I 8.67 <0.2 61 147 <100 0.38 141
E-01 12/27/2019 <0.2 10.6 <0.0005 33.6 0.39 <1 <0.2 75.1 <1 0.176 <1 1.46 <0.2 33.5 74.8 <200 0.3 131
E-01 In Process 01/02/2020 <1 10.6 NA 27.5 NA <5 <1 65.8 NA NA NA NA NA NA NA NA NA 123
LB Influent(East Basin) 11/20/2019 2.23 12.7 0.0029 103 0.5 1.15 <0.2 196 5.03 0.157 <1 3.51 2.18 105 200 <100 0.65 132
EB Channel 12/12/2019 <0.2 7.28 NA 31.2 NA <1 <0.2 26.9 NA NA NA NA NA NA NA NA NA 94.6
EB Effluent 12/12/2019 0.991 9.36 NA 67.8 NA <1 <0.2 141 NA NA NA NA NA NA NA NA NA 117
EB Effluent 01/02/2020 1.27 12.4 NA 102 NA <5 <1 188 NA NA NA NA NA NA NA NA NA 144
EB Seep 01/02/2020 1.93 15.3 NA <5 NA <5 <1 32 NA NA NA NA NA NA NA NA NA 302
F-01 11/07/2019 2.92 11.7 0.000973 70.6 0.36 3.15 <0.2 159 3.99 0.214 <1 17.2 0.267 67.9 152 <500 <0.5 137
F-01 12/27/2019 0.266 12.3 0.000804 39.1 0.63 1.19 <0.2 75.4 2.62 0.106 <1 2.58 <0.2 38.3 73.5 <500 <0.5 144
French Broad Downstream 11/07/2019 0.258 0.99 0.00224 <1 0.32 <1 <0.2 <5 <1 <0.1 <1 <1 <0.2 <1 <5 <100 <0.1 11.3
French Broad Upstream 11/07/2019 0.279 0.981 0.00207 <1 0.31 <1 <0.2 <5 <1 <0.1 <1 <1 <0.2 <1 <5 <100 <0.1 11.2
1-26 Culvert 11/20/2019 0.717 12 0.00237 47.9 0.49 <1 <0.2 105 3.1 0.229 <1 3.5 0.51 48.9 104 160 0.35 138
MH-026 12/12/2019 0.713 9.46 NA 98.6 NA <1 <0.2 199 NA NA NA NA NA NA NA NA NA 102
Page 2 of 4

TABLE 3-1
SUMMARY OF ANALYTICAL MONITORING RESULTS
SOC WQ S17-010 RE-ASSESSMENT
ASHEVILLE PLANT
DUKE ENERGY PROGRESS, LLC,ARDEN, NC
FIELD PARAMETERS SELECTED 40CFR25)APPENDIX III CONSTITUENTS INORGANIC PARAMETERS(TOTAL CONCENTRATION)
Oxidation Total
Specific Dissolved
pH Temp Conductance Oxygen Reduction Eh Turbidity Flow Boron Calcium Chloride Sulfate Dissolved Arsenic Barium Cadmium Chromium Copper
Potential Solids
Reporting Units S.U. Deg C pmhos/cm mg/L mV mV NTUs GPM pg/L mg/L mg/L mg/L mg/L pg/L pg/L pg/L pg/L pg/L
Sample ID Sample
Collection Date Analytical Results Analytical Results
MH-026 01/02/2020 3.6 12 770 NM NM NM NM NM <50 36.1 NA NA NA 9.36 37 <5 <5 9.63
N-01 Downstream 11/07/2019 6.8 10 158 7.90 143 348 5.8 75 <50 15.4 5 38 104 <1 27 1.5 <1 <1
Ponded Water F 11/07/2019 6.6 9 222 2.11 200 405 4.8 NM 281 20.3 25 34 160 4 64 0.168 <1 3.02
UE Channel 01/02/2020 2.9 7 1137 NM NM NM NM NM <50 20.3 NA NA NA <5 21 <5 13.3 428
WB Effluent(West Basin) 11/20/2019 8.9 9 198 8.67 228 433 60.1 NM 56 19.4 16 31 92 <1 17 <0.1 2.04 2.21
Notes:
----Not applicable
<-Concentration not detected at or above the adjusted reporting limit.
pg/L-Micrograms per liter
pmhos/cm
pmhos/cm-Mico mhos per centimeter
Deg C-Degrees Celsius
Dup-Duplicate
EB-East Basin
ft-feet
GPM-Gallons per minute
Fig-Mercury
mg/L-milligrams per liter
mg-N/L-milligrams Nitrogen per liter
MH-Manhole
mV-millivolts
NA-Not analyzed
NE-Not established
NM-Not measured
NTUs-Nephelometrlc Turbidity Units
S.U.-Standard units
Temp-temperature
UE-Upper East
Page 3 of 4

TABLE 3-1
SUMMARY OF ANALYTICAL MONITORING RESULTS
SOC WQ S17-010 RE-ASSESSMENT
ASHEVILLE PLANT
DUKE ENERGY PROGRESS, LLC,ARDEN, NC
INORGANIC PARAMETERS(TOTAL CONCENTRATION) INORGANIC PARAMETERS(DISSOLVED CONCENTRATION WITH FILTER SIZE) OTHER PARAMETERS
Nitrate+ Arsenic Cadmium Chromium Copper Lead Nickel Zinc
Lead Magnesium Mercury Nickel Selenium Thallium Zinc Bromide Fluoride Hardness
Nitrite
(0.45u) (0.45u) (0.45u) (0.45u) (0.45u) (0.45u) (0.45u)
Reporting Units pg/L mg/L p9/L pg/L mg-N/L p9/L P9/1 pg/L p9/L p9/I p9/L p9/1 p9/L P9/L p9/L P9/L mg/L mg/L
Sample ID Sample
Collection Date Analytical Results
MH-026 01/02/2020 1.46 19 NA 235 NA <S <1 465 NA NA NA NA NA NA NA NA NA 169
N-01 Downstream 11/07/2019 <0.2 5.85 0.00248 <1 0.33 <1 <0.2 10.5 <1 0.957 <1 <1 <0.2 <1 10.9 <100 <0.1 62.7
Ponded Water F 11/07/2019 <0.2 5.94 <0.005 3.28 0.79 30.2 0.266 13 3.69 0.156 <1 1.96 <0.2 2.98 11.4 <100 <0.1 75
UE Channel 01/02/2020 <1 17 NA 308 NA <5 <1 291 NA NA NA NA NA NA NA NA NA 121
WB Effluent(West Basin) 11/20/2019 0.386 4.34 0.00101 1.23 0.13 <1 <0.2 18.2 <1 <0.1 1.7 1.24 <0.2 <1 <5 120 0.23 66.3
Notes: Prepared by:BER Checked by:1PC
---Not applicable
<-Concentration not detected at or above the adjusted reporting limit.
pg/L-Micrograms per liter
pmhos/col
pmhos/cm-Mico ethos per centimeter
Deg C-Degrees Celsius
Dup-Duplicate
EB-East Basin
ft-feet
GPM-Gallons per minute
Hg-Mercury
mg/L-milligrams per liter
mg-N/L-milligrams Nitrogen per liter
MI1-Manhole
mV-millivolts
NA-Not analyzed
NE-Not established
NM-Not measured
NTUs-Nephelometric Turbidity Units
S.U.-Standard units
Temp-temperature
UE-Upper East
Page 4 of 4

TABLE 3-2
LOW pH GROUNDWATER WELLS AND SELECT CONSTITUENT SUMMARY
SOC WQ S17-010 RE-ASSESSMENT
ASHEVILLE PLANT
DUKE ENERGY PROGRESS, LLC, ARDEN, NC
Analytical Parameter pH Boron Copper Nickel
Reporting Units S.U. pg/L Ng/L pg/L
15A NCAC 02L Standard 6.5-8.5 700 1000 100
Provisional Background(Alluvial Unit) 4.6-5.1 50 5 5
Provisional Background(Saprolite Unit) 4.3-5.8 50 5 10
Provisional Background(Transition Unit) 3.9-7.0 50 2.08 9.825
Provisional Background(Bedrock Unit) 4.1-8.1 50 1 1.77
Sample ID Sample Analytical Results
Collection Date
- 2.721- 3.9 .. ..-.
_- 3.1 �._ .-,
3.4 802 ,_.
3.5
3.6
3.7
- . 3.9 _ .- ,..
3.7 _
3.9 710 -
- . _ 3.8 3 - -
-'.. .
3.7
_ . . _1 3.7 _ __
3.9 741 ._
- ._ -- 3.8 _ _
CB-06 02/08/2018 3.9 444 <1 14
CB-06 04/17/2018 3.8 451 <5 17
CB-06 IMP 04/17/2018 3.8 477 1.2 14
CPA-048R 01/29/2019 3.6 198.76j 378 8580
CP5-04BR. 04/16/2019 3.7 179.061j 211 9720
CPA-0488 07/23/2019 3.7 176.2j 417 8590
CPA-04BR 10/17/2019 3.7 148.786j 325 9800
CPA-040 01/29/2019 3.3 375.946j 921 6000
CPA-04D 04/16/2019 3.3 354.857j 941 6010
CPA-04D 07/23/2019 3.3 370.3 j 1320 7160
_. ._..._ 3.8 ..
3.1
_:-. 3.9
MW-03D CCR 01/24/2019 3.9 346 NA NA
_: _- : _ 3.6
3.8 -. -- _ -
._. _ _-. 3.7 -
,.. _ 3.7 _7 .-
>-- .._.- 3.9 706 _
MW-05D 04/18/2018 3.7 661 12.4 13.7
MW-05D 07/11/2018 3.6 672 9.55 11.3
MW-05D 11/07/2018 3.8 694 5.66 17.2
MW-050 04/17/2019 3.7 602 NA 13.3
MW-05D 07/24/2019 3.6 652 NA 16.9
•
MW-05D 10/18/2019 3.8 670 NA 24.2
- -- • --_. 3.8 __ .-.
Prepared by:CBC Checked by:JPC
Notes:
-Bold highlighted concentration indicates exceedance of the 15A NCAC 02L.0202 Standard or the IMAC.
(Effective date for 15A NCAC 02L.0202 Standard and IMAC is April 1,2013)
<-concentration not detected at or above the adjusted reporting limit.
Pg/L-micrograms per liter
CAMA-Coal Ash Management Act
CCR-Coal combustion residuals
CPA-Coal Pile Area
IMP-Interim Monitoring Program
j-Estimated concentration above the adjusted method detection limit and below the adjusted reporting limit.
NA-not applicable
S.U.-Standard units
SOC-Special Order by Consent
Page 1 of 1

TABLE 3-3
ASHEVILLE AIRPORT RAINFALL DATA
SOC WQ S17-010 RE-ASSESSMENT
ASHEVILLE PLANT
DUKE ENERGY PROGRESS, LLC, ARDEN, NC
Year Total Normal Percentage
Annual Inches Annual Inches Difference
2016 33.45 45.47 -26%
2017 53.20 45.47 17%
2018 78.46 45.47 73%
2019 56.77 45.47 25%
Prepared by: CBC Checked by: JPC
Notes:
0/0 - percent
Sources:
httos://www.weather.gov/QsD/avlcli
htto://climate,ncsu.edu/cronos/?station=KAVL
Page 1 of 1

SOC WQ S17-010 Re-Assessment January 2020
Duke Energy Progress,LLC,Asheville Steam Electric Plant SynTerra
FIGURES

' - LAKE
„t ULIAN
r
ems,.
i .,
e ,
r 7 ^ n r. v,
r , •� 1 r <, ., ,. .
A.
\ ,,,„.. _.,
�� ;� a COAL PILE
\ „. -, .r .., ULIAN
' LAKE
, ~ e ;•":
( :
\ ,, . 1m
mow ^ 4
1':' , 0, qtr.) , .'\
i "�• 11964 ASH BASINS 2 �
1 �+ •"- r I-� ,�*`
!FORMER 1982 ASH BASIN' I...:,.2 ,,z° a
\ . . ,
'ASHEVILLE COMBINED CYCLE STATION;
�t I rx •
1
14
•
. i , ro,,,',-,o, , .
. J ,,
\ t '''' ''''''-''' '''`tIor","*Iotit‘eo, f ' ';''\
WEST STORM WATER BASIN , a , �. x> , ti,
EAST STORM WATER BASIN 1
\ ,
boa V s
::',77,:n , \�p� \ i
,.....„,.... 7
..............
‘‘ ,.---- \ ,
i ,
LEGEND
DUKE ENERGY PROGRESS PROPERTY LINE
SOURCE:
J WETLAND AREAS(APPROXIMATE)
MARCH 6,2019 AERIAL PHOTOGRAPH OBTAINED FROM NC ONE MAP GEOSPATIAL PORTAL ATE' SURFACE WATER FLOW APPROXIMATE
nttp://oata.nconemap.cam/geoponal/catalag/rascer/Eownload.page I ( )
GRAPHIC SCALE
bN DUKE 250 0 250 500
Vf ENERGY IN FEET FIGURE 1-1
PROGRESS DRAWN BY:J.CHASTAIN DATE:1/17/2020 SITE LAYOUT
CHECKED
BY:_ DATE:- ASHEVILLE PLANT
0 CHECKED BY:C.CRANFORDAPPROVED BY:C.CFORD
DATE:1/17/2020
PROJECT MANACERRANPL R1 NG DATE 1/17/2020 ARDEN, NORTH CAROLINA
synTerra www.synterracorp.com

wE RLLK j 1 i
\ - „--uE,
I.
0 FRENCH BROAD-DOWNSTREAM
\ - \\ � )
. ` -i,:- \ 5 I �AKE,UIiAN \
(N.....,..,,,,,, t
, i \ \
yp Y 2-e
6 lam `
\\,._,\
u O
�� \ [1964 ASH BASIN]
' ..
N.
44,911r14.,,..: y ,` ,Icoiln,HevaL co snv�cl `
i. r „'x. . ,.., . A
I cvatsrnilon ...�
p
r
f
c °" 0 FORMI R 1982 ASH BASIN' I
T P
m
�y...'..". I,.....-"-- \
LANE COMn \ �,/ \� \
P
\ /IF.,02.1
\O I1` `
/ i \
I ,
I 1
LEGEND
O of SOC ROUTINE SAMPLE LOCATION
NP N. FRENCH BROAD-FRENCH BROAD RIVER SAMPLE LOCATION(APPROXIMATE)
❑FRENCH BROAD-UPSTREAM � PST=EAM
� DUKE ENERGY PROGRESS PROPERTY LINE
GRAPHIC SCALE
o DUKE 300 0 300 600
GRAP
`V ENERGY an FIGURE 1-2
° § PROURTSs .sE °" ""°'° WATER QUALITY MONITORING LOCATIONS
st .`. ` wE° 0 v 0020 ASHEVILLE PLANT
LASE AL '6 �,A"'"' .N°NE,+° syr�Terra f°rM ARDEN,NORTH CAROLINA
+m°.m,°.�•v .,.vm..am°.a "L - wwwsynterracorp.com

\ \ \
cs
\ \\,./,-"------- - ------4. ,
,. s .
.It
1 !
� .
' if , , ..,
\ ., .
G7d .
'
i
' , 1 . "
MH-026
• -DATE 2019.12.12 .. 4: - .,
! + I I.
p pH=4.9 S.U. ', 4 . ` 4rpy * , .
5 TOTAL COPPER=4.93µgIL '„ ,,-" d...t: , t ,
DACRT 2020-01-02 � TOTAL NICKEL=98.6µg/L g,` °' ,,'`
-7
..\....,„„ii? '
t DATE 2020-01-02 +""c7E .�,+y- ;^!;
pH=5.9 S.U. ,. pH=3.6 S.U. S
TOTAL COPPER=<2pg/L gym ,, '1"t
TOTAL COPPER=9.63µg/L �° .- * "� 7,ss a d,
TOTAL NICKEL=235µg/L "� 3 „;;,
TOTAL NICKEL=<2µg/L SEEP
-DABTE 0 0-01-02 .,..-. ,� ",w... ft� � t
�0�t pH=6AS.U.
• +vp TOTALCOPPER=<Sµg/L d UE CHANNEL
▪ � X TOTAL NICKEL=<5µg1L y* r y `f� � 6` DATE 2020-01 O2
c 1ta ril r R. }.` 1 t `. a# ,d �!/ pH=2.9 S U
° ,- :. afl*47{�.� it
+i' - TOTAL COPPER=428pg..,
% .. a tr t.A,,.N ���al�Y. r.. ' r V:,* C ^` TOTAL NICKEL=308µg/L
WEST BASIN/WB EFFLUENT77;1,EB INFLUENT '° r
CB-6 DATE2019-11-20 �DATE 2019-11-20 - "n DATE 20 0-0.1-0 -3.3 S.U._ H-4.6S.U. PH=6.9 S.U. pH_ . /, ... t°- rP = TOTALCOPPER=2.21µfillTOTAL COPPER=3.14pgIL t;°
E 01 TOTAL COPPER=<2µg/L TOTAL NICKEL=1.23µg1L l TOTAL NICKEL=103µgil { <<
DATE 2019-11-07 TOTAL NICKEL=12.6pglL " '#,�„p
pH=4.1 S.U. A 0 '`�1 'fi r p�x, ..* "��e` ,.'.
TOTAL COPPER=8.37µgIL ,� G /It ` °f t� F G'pi/��Ar4`, '�' s`."
n
' TOTAL NICKEL=60.8µgIL // AAi1 r, ■
■
_� t W' 1t" ■
DATE 2019-12-27 CONFLUENCE tr„ d .l >rg; r , N ■ ... 1
pH=5.0 S.U. a DATE 2019-11-20 P ffir , ', ;.
TOTAL COPPER=1.47µg1L '`. pH=4.0 S.U. ,, t r �:
TOTAL NICKEL=33.6µg/L
,,,
,..,
TOTAL COPPER=4 92µglL: � ,�, '` "�
TOTAL NICKEL 71 3pa/L 4'`.A° " -�,. ; Ai',.,;.
■
\\\
.+
,,,
2�� DEB CHANNEL
•
'p '" , , .
.!DATE 2019-12-12 •°^
�„..
9� ,.' ,. pH=5.8S.U. -
';TOTAL COPPER=10 2ugIL ,,.----...
01 DATE
"
DATE 2019-11-07
pH=4.9 S.U.
TOTAL COPPER=23.4pg/L
TOTAL NICKEL=7D.RIIgn °EAST BASIN/EB EFFLUENT
---- --
TOTAL COPPER DATE 2019-11-20 >fo , a
pH=5.2S.U.DATE 2019-12-27
PH=4.45.U. ''^ ,_
=4.39µgll TOTAL COPPER=6.75pg/L :a n ,..,
TOTAL NICKEL=34.1ug/L
TOTAL NICKEL=67.8µg/L
DATE 2020-01-20
1 4 pH=4.1 S.U.
` TOTAL COPPER=8.3µg/L ,
TOTAL NICKEL=102µg/L «. ., , "' "
'Ott-'�-
CB-4-..---............„ ° 1v\ 1
N. DATE 2020-01-02 /
pH=5.0S.U. ��//
TOTAL COPPER=<2µg/L /
` TOTAL NICKEL=<2µg/L [ LEGEND
N D
l\V .�' i-26 CULVERT '`�.., CVG,V
` / DATE.7 S.U. -20 �+,.,,' WEB CHANNEL' SOC RE-ASSESSMENT SAMPLE LOCATION(APPROXIMATE)
ogee"'
�`�/' , TOTAL COPPER=3.56pg/L �' OF-01 SOC ROUTINE SAMPLE LOCATION
+. TOTAL NICKEL=47.9µg/L ICB-4' MONITORING WELL
���r//�
,, .. 4^, DUKE ENERGY PROGRESS PROPERTY LINE
CB-5 'DATE 2020-01-02 R
' pH=5.1S.u. x I WETLAND AREAS(APPROXIMATE)
TOTAL COPPER=<2µg/L x u
"4 n" ' SURFACE WATER FLOW(APPROXIMATE)
TOTAL NICKEL=<2µgIL - T
f., DUKE GRAPHIC SCALE
200 0 200 300
`CI ENERGY NFEET FIGURE 3-1
PROGRESS DRAWN BY:J.CHASTAIN DATE:1/17/2020 SOC RE-ASSESSMENT SAMPLING DATA
REVISED BY: DATE:-
CHECKEDBV:C.CRANFORD DATE:1/17/2020 ASHEVILLE PLANT
- , - �� APPROVED
CT BY.C.RRT�PLAT PLATING
FORDDATE:1/17/2020 /�RD E N, NORTH C A RO 11�1 A
SOURCE: MR NORTH l�/'1f� L �`IF1
sy■1ena www.synterracorp.com
MARCH 6,2019 AERIAL PHOTOGRAPH OBTAINED FROM NC ONE MAP GEOSPATIAL PORTAL AT
http//clata.nconemap.com/geoporta/catalog/rester/clownIoad.page

Asheville Combined Cycle
L _-"_ i -- - - - -
Stormwater System Inspection '
December 12, 2019 ` w-ot2 ' ���t- MH•015
MH-017 Minimal standing water
se..,yt • Minimal standing water y;a ---____` i • No seepage evident
5 3 • No seepage evident
Hoar DRAIN SEE MOTE 1 rr!-OTS
SEE MOTE N MN.-D 0 !
MH-018
SEE IN--K,,,,,.. ,,
Minlmai standing water
M>F ee © • No seepage evident
.� a II!iOti_00
. E 1l1.00
r
MH-022 MH-020
• Minimal standing water
• Minimal flow through manhole �'vr ao �ttaTPT �'�� g
I • Seepage evident around inlet pipe \\\\ � sEE wtE� ! • No seepage evident
SLL WIC L
may '
MM-et. ---- ROOF MAIN—\\
MH-023 SEE IMA N YaC2! W-0tt fWH-021
• Minimal flow through manhole Minimal flow through manhole
• No seepage evident • Seepage evident around inlet pipe
131-81
l �, MH-024 1
MH-025
j� � Minimal flow through manhole
I • Minimal flow through manhole
j_ No seepage evident I No seepage evident _
♦w Sa m w y. V-C- - I
SEE�07CS ACC00{v�-CV -O4 t-06
____
__ •' Tles were collected for r A
East
' isotopes,metals and TDS(Sample
Stormwater ,� ID:MH-026) /
r /
Basin • pH-d,92SU //
pH-3.315U Temperature-20.8°C //,
• Specific conductance-873 µS/cm • N , 'Z
/:. • Turbidity-5.57 NTU //
M�F ' • Flow-0.5 gpm'(measured via a /
container and stopwatch) /7 N
LEGEND s DUKE DRAWN BY:C.CRANFORD DATE 1/8/2020
C-Degrees Celsius t
ENERGY REVISED BY K.SHECK FIGURE 3-2
CHECKED BY'T.PLATING
pS/cm-micro-Siemens per centimeter ASHEVILLE COMBINED CYCLE STATION
gpm-gallons per minute PROGRESS APPROVED BY- T.PLATING STORMWATER SYSTEM INSPECTION
MH-Manhole PROJECT MANAGER:G.BARRIER
NTU-Nephelometric Turbidity Units SOC WQ S17-010 RE-ASSESSMENT
SU-Standard Units
TDS-TotalDissolvedSolidS J ASHEVILLE PLANT
�/f-1T� ARDEN, NORTH CAROLINA
Source:CBBI Drawing No.ACCOO-CV-C-SO.PL-202 "7' ' www.synterracorp.com

E-01
70 7.0
•
60 •
J
c
50 6.0
0
c 40
a, a
U L
u 30 •
° 5 0 �—Nickel
n3
c ("1 --0—Cop per
a.)
lizi- 20 a pH
vi
c 4.0
0
U
10 :
° 4111111hill 3.0
• TOi� c 2 6Tg �T 'iQ T�� 9i
O4 .pb Tj 0T8 Ty OI OHO
• F-01 .
80
70
7.0
J
i 60
c
050 •
`=
. 411P411111114 C
m 5.0
c 40 0
o —II—Nickel
ro
30 ) —0--Copper
y n pH
20 5.0
0
v
10
° 4.0
T0c9 69, i `/ T,� 9
2d TO T i
i/SO �OT �O 20 209 �0 200TT T9 �TS s j �
LEGEND DUKE DRAWN BY T.PLATING DATE:1/2020
pg/L-micrograms per
liter Cc'�ENERGY, REVISED BY K SHECK FIGURE 3-3
CHECKED BY E-01 AND F-01 TIME SERIES
PROGRESS APPROVED BY PLOTS-pH, COPPER, AND NICKEL
C' PROJECT MANAGER: G BARRIER SOC WQ S17-010 RE-ASSESSMENT
ASHEVILLE PLANT I
synTerra www.synterracorp.com ARDEN, NORTH CAROLINA

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MARCH 6,2019 AERIAL PHOTOGRAPH OBTAINED FROM NC ONE MAP GEOSPAGAI.PORTAL AT , - toptA .F-,==v , d. Op t--4:.5,-• . ,\ .
http//clata...conernap com/geoportal/catelogpaster/downiaad page ',41? ,1,..,.. . ..(V.:' t. 4,,. : . its-
efa., DUKE 200 GRAPHIC SCALE
0 200 400
Ir' ENERGY IN FEET
FIGURE 3-4
PROGRESS DRAWN BY:.I.CHASTAIN DATE:1/17/2020 COAL PILE AREA
REvisED BY- DATE.-
0 CHECKED BY:C.CRANFORD
APPROVED BY C.CRANFORD
PROJECT MANAGER T PLATTING DATE:1/17/2020 1/17/2020
DATE: ASHEVILLE ELECTRIC PLANT
ARD EN, NORTH CAROLINA
i
s y riTe n a www.synterracorp.com

E-01
70 800
60 - 700
on
1
i.
r 600 "LT
''''' '''",,..„,„""\\\
0 tan
50
4t 40 , 500 .o
vo 30 400 U —0—Nickel
v 300 rJ "'♦—Copper
D 111���jjj
20 o Boron
Ln
0 200 Po
v
10
100
0
10 ct, tr, i1 1�p 1� 9,
���r' 8/�O `'O O� /`�O i1�2 �6�1
01S 16 1j 016, 19 0,1.9 O`"O
F-01
80 800 -
70 700
11-1
= 60
600 -
o tann.
i.
50 500 c
4, o
a, 0
o
40 400 --0--Nickel
f •
v u
, 30 300 --*—Copper
`� 0
o ----ilihilH
-Boron
N
20 200 co
o
10 100
0 _ _ 0
�� `,O `00 /vb 1D 1�1
D1s la, 1, 11 19 019 Ov)O
LEGEND f�DUKE DRAWN BY:T PLATING DATE 1/2020
pg/L-micrograms per R i� REVISED BY: K.SHECK FIGURE 3-5
liter ENERGY, CHECKED BY. E-01 AND F-01 TIME SERIES PLOTS—
PROGRESS BORON, COPPER,
APPROVED BY: AND NICKEL
PROJECT MANAGER:G.BARRIER SOC WQ S17-010 RE-ASSESSMENT
ASHEVILLE PLANT
Terra ARDEN, NORTH CAROLINA
www.synterracorp.corn