NC0004961_Appx A - Regulatory Correspondence_20171031

2017 Comprehensive Site Assessment Update October 2017
Riverbend Steam Station SynTerra
APPENDIX A
REGULATORY CORRESPONDENCE
NCDEQ Expectations Document (July 18, 2017)
Completed NCDEQ CSA Update Expectations Check List
NORR Letter
NPDES Wastewater Permit #NC004961
NCDEQ Correspondence -
Revised Interim Monitoring Plan
DEQ Background Location Approvals - July 7, 2017
Zimmerman to Draovitch September 1, 2017
DEQ PBTV Approval Attachments - September 1, 2017

2017 Comprehensive Site Assessment Update October 2017
Riverbend Steam Station
NCDEQ EXPECTATIONS DOCUMENT
()ULY 18, 2017)
SynTerra

DRAFT
Review of Draft Final Updated CSA Table of Contents submitted by Duke Energy July 18, 2017
The Updated Comprehensive Site Assessment Report(CSAs) must meet the requirements of 02L .0106
(g), CAMA, and general guidelines provided in the Notice of Regulatory Requirements letter from DEQ to
Duke on August 13, 2014.
Pursuant to 02L .0106 (g), the CSAs shall:
• Identify the source and cause of contamination,
• Identify imminent hazards and document actions taken to mitigate them,
• Identify all receptors,
• Define the horizontal and vertical extent of contamination,
• Understand all significant factors affecting contaminant transport,
• Understand geological and hydrogeological factors influencing the movement, chemical, and
physical character of the contaminants.
It is the expectation that the CSA report be a stand-alone document that integrates, interprets, and
presents all data/information collected to date. The table of contents submitted on 7/18/17 should be
revised as necessary to ensure that the following comments are reflected in the CSA report.
1. Site history
• Facility description, geographic setting, surrounding land use, permitting history, and
compliance boundaries and permitted sampling, etc.
• ash related history
• history prior to Duke ownership
• history of waste releases unrelated to coal ash
2. Identification of source areas'
3. Identification of potential receptors
• Surface water
o Is the SW used as drinking water supply? if so, what is the distance to intake?
• Supply wells
o Need map and table showing all receptors identified
o Has each identified supply well been abandoned and connected to alternative
permanent water?
' Large ash basins or other waste areas may need to be divided into separate smaller source areas if, for example,
contaminant transport is toward different sets of receptors. Where appropriate, some source areas may be strategically
combined based on geographic proximity (for example, conjoining or overlapping source areas), common source
characteristics and impacts, common receptors, and a shared proposed remedy. The Regional Office should be
consulted when identifying source areas for purposes of CSA and CAP development.
Page 1 of 8

• Evaluation: Are COls in supply wells above 2L/IMAC/background and sourced by ash?
4. Raw data collected to date
• A separate orthophoto base map2 should be provided for each of the following:
o All GW monitoring and supply wells
■ Show screened interval (ft) and most recent concentration of boron and COls
(ug/L) (use different color font for each flow unit)
o All SW, seep, and effluent channel (permitted) sample locations
■ Show most recent results of boron and COls (ug/L)
o All SW locations sampled specifically to determine whether contaminated GW is
causing 2B violations
■ Show most recent results of boron and COls (ug/L); use bold font for values
that exceeded 2B standards (ug/L)
o All solid phase sample locations, to include ash, soil, and sediment locations
■ Show sample depth (ft bls) and corresponding concentration of COls (mg/kg)
o Location, flow unit, screened/open interval (ft bls), and value (ft/d) of hydraulic
conductivity (k) measurements (use different color font for each flow unit)
o Location, depth (ft bls), and flow unit of soil -water pairs (use different color font for
each flow unit)
o Location, depth (ft bls), flow unit, and value of HFO measurements (use different color
font for each flow unit)
o Location, depth (ft bls), and flow unit of sorption coefficient (Kds) measurements (use
different color font for each flow unit)
o Location, flow unit, and value of pH measurements (use different color font for each
flow unit)
o Location, flow unit, and value of Eh measurements (mV) (use different color font for
each flow unit)
o Location of vertical gradient calculations between shallow/TZ unit and BR unit, showing
value (+ is downward gradient, - is upward gradient)
Cross section maps showing ash position, hydrostratigraphy, screen/open intervals, water
level, and groundwater boron and COI concentrations (ug/L)
o inset should show location (in plan view) of the cross section
Summary data tables:
o properties for ash, fill, alluvium, soil/saprolite, deep, and bedrock units, as applicable,
including:
■ Porosity
■ Specific storage
■ Permeability (field, lab, historic)
■ Mineralogy and oxides
■ Physical
Methodology, computations, etc. may be referenced, as applicable
o hydraulic conductivities (k, in ft/d), sorted by flow unit, along with well identifier, flow
unit, and screened/open interval (ft bls)
o sorption coefficients (Kd), sorted by COI then flow unit, along with boring location
identifier, flow unit, and depth (ft bls)
2 All base maps should include2 to 4 foot topographic contours, all surface water features, all jurisdictional
wetlands, all source areas along with waste boundaries and compliance boundaries if applicable, all monitor wells,
and, where scale allows, all supply wells.
Page 2 of 8

• Appendices
o Raw data tables showing chemistry results for:
■ all GW, SW, and seep sample events (appendix and digital excel file)
■ all ash, soil, sediment, and whole rock chemistry results (appendix and digital
excel file)
■ all SPLP samples (appendix and digital excel file)
■ lat/long, flow unit (if applicable), etc. should be included for each sample
location
■ current "master spreadsheet" format may be used
■ lab QC data may be referenced if it has already been provided in a separate
report
o Summary table of monitor well construction details showing well, location (decimal
degree lat/long), screen/open interval, depth to water, date installed, flow unit being
monitored, date abandoned if applicable, etc.
o Water level measurements from all wells and current and historical measurement
events (appendix and digital excel file)
■ List of wells that were dry during sampling or measurement attempts, along
with its flow unit, screened/open interval, and date
o Sorption coefficient testing - methodology, raw data, and computations may be
referenced
o Boring logs and well construction records
■ Include all assessment, historic, CCR, or other wells installed to date
■ Each log should be quality controlled for accuracy and include static WL
information.
o Geophysical logs, rose diagrams, lineament map
o Soil and rock photos
o Most recent pre -ash basin USGS topographic map, with superimposed source areas
o Screening level risk assessment
■ Human health
■ Ecological
o Flow and transport model
o Geochemical model
o GW-SW mixing model, if applicable
5. Site conceptual model
• Overview of the major components, including source(s), hydrologic boundaries, migration
pathway(s), receptors, etc.
• Regional geology and how it is affecting GW flow, GW quality, and contaminant transport at the
site
• Hydrostratigraphy (flow units)
o Flow properties and heterogeneities of each unit
■ Discuss hydraulic conductivities and vertical gradients (refer to maps in 4.
above)
■ Describe where flow units pinch out in each unit, as applicable
■ Discuss fractured bedrock heterogeneities across the site, including ranges of
hydraulic conductivities and porosities
■ Discuss maximum depth of investigation and observed fracture density with
depth; compare this to the depths of proximate supply wells
Page 3 of 8

• Areas of recharge and discharge
• Flow directions
o Potentiometric map (summer) of shallow/TZ unit
o Potentiometric map (winter) of shallow/TZ unit
o Potentiometric map (summer) of bedrock unit
o Potentiometric map (winter) of bedrock unit
■ Potentiometric maps should utilize and show all facility wells, should clearly
show all blue line tributaries, wetlands, and other SWs, and should indicate
areas where a flow unit pinches out as applicable
o Evaluation: Do seasonal or tidal influences effect GW flow or GW chemistry?
6. Background concentrations (PBTVs) of soil and groundwater.
• Piper diagrams for shallow b/g, deep b/g, and bedrock b/g, along with well labels for plotted
points
• List PBTVs for soil
• List PBTVs for groundwater, by flow unit
• Methodology (appendix)
• Description of background wells (why those chosen are appropriate for use) and soil sample
locations (appendix)
• Table of all raw background data showing strikethroughs of unused high pH, high turbidity,
autocorrelated, and outlier data (appendix; digital excel file)
7. Contaminant assessment
For each source area,
• History of ash placement
• Area, depth, and volume of ash (include also the area, depth, and volume of
saturated/submerged ash)
• Status of source removal or control
• Orthophoto base map (large scale, 1 inch — 100 feet) showing waste boundary, compliance
boundary if applicable, 2 to 4 ft topographic contours, all blue line surface water and wetland
features, along with the following:
o subset of supply well and SW receptors from 3. above that are potentially susceptible to
contaminant migration from this particular source area
■ Include inset table with list of supply wells and SW receptors for this source area
o monitor wells, supply wells, and SW, seep, ash, soil, and sediment locations
■ Indicate most recent value (ug/L) for boron and for each COI, and whether its
concentration is increasing, decreasing, stable, or unknown
• Evaluation: Show a vertical gradient isopleth map and discuss vertical gradients and their effect
on GW flow
• List COls (constituents above 02L/IMAC/background) for each flow unit beyond compliance
boundary (or that are within bedrock monitor wells within or beyond compliance boundary if
receptors are potentially at risk)
• List pH and Eh ranges found in: pore water, d/g shallow unit, d/g TZ unit, and d/g BR unit
• Evaluation: Explain the geochemical controls on COls that do not behave as a plume (Fe, Mn,
etc.).
Page 4 of 8

Evaluation: Use the pH, Eh, Kd, and HFO results to discuss the expected capacity of the
subsurface to sorb cationic COls and anionic COls occurring from source to receptor within each
of the flow units.
• Provide the following "data inventory":
o (a) have background concentrations been formally established for all COls in soil and
groundwater?
o (b) for each source area, how many wells within each flow system are located along the
contaminant plume centerline? Along a cross sectional transect that is perpendicular to
the plume centerline?
o (c) how many wells in (b) above are screened across the most contaminated vertical
interval of a given flow unit or are screened across the full thickness of the flow unit?
o (d) is the d/g edge of the plume centerline measured or is this location obstructed by a
major SW or other access issue? If so, is it measured by wells that are screened across
each flow unit?
o (d) what is the length of record and how many valid sample events are available for
wells listed in (b), (c), and (d) above?
o (e) does turbidity, well construction (for example, grout contamination, etc.), or well
"break in" issues preclude the use of data in (b), (c), and (or) (d)?
o (f) for each source area and within each flow unit, how many spatial locations were
sampled for solid phase chemistry and were these locations associated with "end
member" (maximum and minimum) groundwater concentrations for each
contaminantl"? How many of these spatial locations are associated with (b) or (c)
above?
o (g) given that iron hydroxide (HFO) content is a good indicator of retention capacity for
most metal contaminants, how many locations in (f) was HFO measured?
For each COI in this particular source area,
o Evaluation: Were wells properly positioned and screened to measure the horizontal and
vertical extent of the plume? If so, describe the horizontal and vertical plume extent
using plan view and cross sectional maps.
o Has the plume migrated to any supply wells, SW receptors, or GW future use areas?
o Has the plume migrated to any supply wells, SW receptors, or GW future use areas at
concentrations above 2L/IMAC/background?
o Evaluation: Were wells positioned and screened to measure the maximum
concentrations migrating from source to receptor along the longitudinal plume
centerline? If so, describe the plume characteristics is space and time as it flows along
the centerline, through the identified flow units, and discharges into the nearest supply
well or SW receptor.
o Evaluation: Use maps, graphs, statistics, and mass movement or balance equations to
show whether the plume is expanding and whether the plume is moving.
■ Show the COI -distance plot of wells positioned along a plume centerline from
source to farthest d/g location (closest to receptor or future use area.
Ill Measuring the solid phase contaminant concentrations in locations of both low and high groundwater C01
concentrations are important in understanding the sorptive capacity of the system. This is particularly true in the
case of non -linear isotherm adsorption models that describe most metals. That is, a soil has a limited ability to
sorb contaminant mass due, for example, to limited sorption sites, so a soil can become less efficient at removing
mass at higher dissolved concentrations.
Page 5 of 8

■ If applicable, show COI -distance plots at different timepoints to demonstrate
potential plume expansion or migration.
■ If applicable and sufficient sample events are available, use single -well linear
regression or Mann-Kendall/Theil-Sen type trend statistics to show increasing or
decreasing trends at selected d/g monitor wells.
o Describe the soil -water pairs and Kd lab test sample results. Describe where they were
collected, why those locations were selected, and whether those locations are reflective
of high and low COI concentrations in a given flow unit.
o Show concentration isopleths for each COI, including contours of concentrations below
and well above the 2L/IMAC (choose — five contours per COI, from "moderately low" to
"high")
o Show stacked boron -time plots of wells positioned along a plume centerline from source
to farthest d/g location (closest to receptor)
Summary of corrective actions taken to date, if applicable
• Describe preliminary corrective action alternatives for this source area
f:� .. u . •.Cal
• Description of model
• Model construction — domain, layers, boundary conditions, recharge and discharge areas, supply
wells, hydraulic conductivities, stream conductances, etc.
o Layer thicknesses in cross section (show vertical scale in feet)
o Location of supply wells outside model domain
• Calibration method
o List of target wells used in calibration
o List of monitor wells not used in calibration and the rationale for each that was omitted
• Calibration results (where mapped, superimpose on orthophoto base map described above)
o Hydraulic conductivity zones versus measured values for the zone
o List of simulated versus observed heads (include wells and SW features)
o List of simulated versus observed vertical gradients from well pair locations
o List of simulated versus observed discharge to streams
o Potentiometric surface
■ Simulated for each flow layer
■ Observed, shallow
■ Observed, deep
■ Observed, BR
o Flow paths (particle tracks) from each source area
o Reverse flow paths (particle tracks) from SW receptors
o Reverse flow paths (particle tracks) from supply wells (because supply wells are usually
open from casing (at —50 to 75 ft) down to 200 to 500 feet, release particles in all
simulated bedrock layers)
• Quantitative sensitivity analyses to key inputs at various selected d/g locations
• Describe the most significant model limitations
9. Transport model
• Description of model
• Model construction — boundary conditions, time steps, initial conditions, etc.
o Source loading, per layer
o Background concentrations, per layer
Page 6 of 8

o Initial Kds, per layer
o Dispersivities, per layer
o Effective porosities, per layer
• Calibration method
o List of target wells used in calibration
o List of monitor wells not used in calibration and the rationale for each that was omitted
o Calibrated Kds, per layer
• Calibration results (where mapped, superimpose on orthophoto base map described above)
o List of simulated versus observed concentrations in target wells
o List of simulated concentrations in SW discharge locations as shown using particle tracks
released from source areas
o List of simulated versus observed concentrations in selected well pair locations
• Boron isopleth map
■ Simulated for each flow layer
■ Observed, shallow
■ Observed, deep
■ Observed, BR
• For each source area, the time, direction, and distance of contaminant travel must be predicted
under existing conditions and under any other contemplated source control measure (for
example, engineered cap and (or) excavation). For these scenarios, the following figures are
expected:
o (a) a concentration -time plot for each COI corresponding to the following locations: (i)
nearest supply well, (ii) nearest future groundwater use area, and (iii) nearest surface
water.
■ In the plot margin, the following information should be provided: the time it
takes for the COI to reach (i), (ii), and (iii), the time it takes for the COI to reach
(i), (ii), and (iii) at its 2L/IMAC concentration, the time it takes for the COI to
reach (i), (ii), and (iii) at its maximum concentration, and the time it takes for the
COI to reach (i), (ii), and (iii) at a concentration that is back below the 2L/IMAC
concentration.
o (b) a map superimposed on the requested base map showing the maximum predicted
migration distance, at any detectable concentration, of each COI.
o (c) a map superimposed on the requested base map showing the maximum predicted
migration distance, at the 2L/IMAC standard concentration, of each COI.
• Quantitative sensitivity analyses to key inputs at various selected d/g locations and times
• Describe the most significant model limitations
10. Geochemical model for COls controlled primarily by geochemistry
• Conceptual model based on observed site data
o Describe geochemical controls on COI levels in each source area using site data
o Assumptions used in developing the model
o Discuss data used to develop the model
■ For example, how are mineral or adsorption concentrations in fractured media
converted to PHREEQC concentrations representing reaction along the fractures?
■ How were modeled reactive mineral concentrations interpolated between or
extrapolated from the limited number of data collected
Page 7 of 8

o Discuss what the COI concentrations are most sensitive to (pH, Eh, iron/aluminum oxide
content, Kd, distance from source, etc.)
o Describe the most significant limitations of the model
• Numerical model (PHREEQC or PHREEQC 1-D Transport model)
o Description of model
o Purpose of model
o Model construction
o Discuss data used to develop the flow model
o Results with comparison to observed well data (PHREEQC model) or to longitudinal flow
path transect data (PHREEQC 1-D Transport model)
o Sensitivity analysis (to pH, Eh, Kd, COI concentration, total dissolved ion content,
iron/aluminum oxide content, Kd, distance from source, etc.)
o Describe the most significant limitations of the model
11. GW-SW mixing model
• Description of model
• Purpose of model
• Model construction
o Show on map the precise SW locations where model output (simulated SW
concentration) was obtained
o List and discuss data used to construct model
■ Permitted effluent discharge concentrations should be considered in the model
construction
o Assumptions
• Results
• Sensitivity analysis (to GW contaminant concentrations, permitted effluent concentrations,
location where SW output was obtained, stream flow, nearby effluent loading to the SW, etc.)
• Describe the most significant limitations of the model
Page 8 of 8

2017 Comprehensive Site Assessment Update October 2017
Riverbend Steam Station
COMPLETED NCDEQ CSA UPDATE
EXPECTATIONS CHECK LIST
SynTerra

2017 Comprehensive Site Assessment Update - Appendix A October 2017
Riverbend Steam Station SynTerra
NCDEQ CSA Update Expectations — Check List
NCDEQ provided expectations for elements to be included in the CSA Update, in
addition to those provided in the NORR (August 2014) guidance. This guide is
provided to assist locating the requested elements in this CSA Update Report:
Report1 0 NCDEQ Expectations
11. Site History
Facility description, geographic setting, surrounding
land use, permitting history, and compliance Section 2.0
boundaries and permitted sampling, etc.
ash related history
Section 2.0
history prior to Duke ownership
Section 2.1
history of waste releases unrelated to coal ash
Section 2.7
1Large ash basins or other waste areas may need to be
Sections 2.3, 2.4,
divided into separate smaller source areas if, for
and 3.0
example, contaminant transport is toward different sets
of receptors. Where appropriate, some source areas
may be strategically combined based on geographic
proximity (for example, conjoining or overlapping
source areas), common source characteristics and
impacts, common receptors, and a shared proposed
remedy. The Regional Office should be consulted when
identifying source areas for purposes of CSA and CAP
development.
3. Identification
of Potential Receptors
Duke to provide information on where new water lines
Appendix D &
are planned, estimated new water line taps, and
Section 4.0
projected location for filtration systems. Duke and DEQ
will work together to provide most recent analytical
analysis for inclusion in CSA.
Surface water :
Sections 4.0 &
Is the SW used as drinking water supply? if so, what is
4.4
the distance to intake?
Supply wells:
Figure 4-4 &
Need map and table showing all receptors identified
Table 4-1
Has each identified supply well been abandoned and
Section 4.0
connected to alternative permanent water?
Evaluation: Are COIs in supply wells above
Section 14.3
2L/IMAC/back round and sourced b ash?
Page 1 of 13
Tables - Shaded Blue Figures - Shaded Green CAP - Shaded Red

2017 Comprehensive Site Assessment Update - Appendix A October 2017
Riverbend Steam Station SynTerra
NCDEQ CSA Update Expectations - Check List
..
Figures:
• All GW monitoring and supply well locations
Figure 2-4 &
Figure 4-4
• Show screened interval (ft. bgs.) and flow unit (use
Figure 14-51
different color call out box for each flow unit)
• Location, flow unit, and value of pH and Eh
measurements
• Most recent concentration of boron and COIs (ug/L)
• Hydraulic conductivity (k) measurement value (ft/d)
if available for corresponding well screen interval
• All SW, AOW seep and effluent channel (permitted)
Figure 14-52
sample locations
— Show most recent results of boron and COIs
(ug/L)
• All solid phase sample locations, to include ash, soil,
Figure 14-50
and sediment locations
• Show sample depth (ft. bgs.) and flow unit
• Concentration of COIs (mg/kg)
• Location, depth (ft. bgs.) and flow unit of soil -water
pairs shown as blue color font
• Location, depth (ft. bgs.), flow unit for HFO
measurements and value (mg/Kg)
• Location, depth (ft. bgs.), flow unit for sorption
coefficient (Kds) measurements and value (mL/g)
• Location of vertical gradient calculations between
Figure 11-37
shallow/TZ unit and BR unit, showing value (+ is
downward gradient, - is upward gradient)
• Cross section maps showing ash position,
Figures 6-3 to 6-7
hydrostratigraphy, screen/open intervals, water
level, and
• Groundwater boron and COI concentrations (ug/L)
Figures 11-41 to
11-64
• Inset should show location (in plan view) of the
Figures 6-2 to 6-
cross section
7, & 11-41 to 11-
64
Page 2 of 13
Tables - Shaded Blue Figures - Shaded Green CAP - Shaded Red

2017 Comprehensive Site Assessment Update - Appendix A October 2017
Riverbend Steam Station SynTerra
NCDEQ CSA Update Expectations - Check List
Summary
Solid Phase properties for ash, fill, alluvium,
Tables 3-1, 3-2,
data tables:
soil/saprolite, deep, and bedrock units, as applicable,
6-1, 6-2, 6-3, 6-4,
including:
6-5, 6-6, 6-7, 6-
11, 6-12, 6-13, 6-
- Porosity
14, 6-15, 6-17, &
— Specific storage
6-18
— Permeability (field, lab, historic)
— Mineralogy and oxides
— Physical
Methodology, computations, etc. may be referenced, as
applicable
hydraulic conductivities (k, in ft/d), sorted by flow unit,
Table 6-16
along with well identifier, flow unit, and screened/open
interval (ft bls)
sorption coefficients (Kd), sorted by COI then flow unit,
Table 11-1
along with boring location identifier, flow unit, and
depth (ft bls)
Raw data
• all GW, SW, and seep sample events (appendix and
Appendix B
tables showing
digital excel file)
chemistry
• all ash, soil, sediment, and whole rock chemistry
results for:
results (appendix and digital excel file)
• all SPLP samples (appendix and digital excel file)
• lat/long, flow unit (if applicable), etc. should be
included for each sample location
• current "master spreadsheet" format may be used
• lab QC data may be referenced if it has already been
provided in a separate report
Summary table of monitor well construction details
Table 2-1
showing well, location (decimal degree lat/long),
screen/open interval, depth to water, date installed,
flow unit being monitored, date abandoned if applicable,
etc.
• Water level measurements from all wells and current
Table 6-8
and historical measurement events (appendix and
digital excel file)
• List of wells that were dry during sampling or
measurement attempts, along with its flow unit,
screened/open interval, and date
Page 3 of 13
Tables - Shaded Blue Figures - Shaded Green CAP - Shaded Red

2017 Comprehensive Site Assessment Update - Appendix A October 2017
Riverbend Steam Station SynTerra
NCDEQ CSA Update Expectations - Check List
NPV
"W • Expectations
Report
Sorption coefficient testing - methodology, raw data,
Appendix C, G
and computations may be referenced
• Boring logs and well construction records
Appendix F
— Include all assessment, historic, CCR used for
CAMA, or other wells installed to date
— Each log should be quality controlled for accuracy
and include static WL information.
— Combined file Alpha -numeric sorting
Geophysical logs, rose diagrams, lineament map
Figures 6-14 & 6-
15
Soil and rock photos
Appendix F
Most recent pre -ash basin USGS topographic map, with
Figure 1-1 & 2-2
superimposed source areas
Screening level risk assessment
— Human health
Section 12.1
— Ecological
Section 12.2
Flow and transport model
Section 13.1
Geochemical model
Section 13.2
GW-SW mixing model, if applicable
Section 13.3
•.-i
Overview of the major components, including source(s),
Sections 4.0, 6.0,
hydrologic boundaries, migration pathway(s), receptors,
12114
etc.
Regional geology and how it is affecting GW flow, GW
Section 5.0 &
quality, and contaminant transport at the site
14.0
Hydrostratigraphy (flow units)
• Flow properties and heterogeneities of each unit
Section 6.2.1
• Discuss hydraulic conductivities and vertical
Sectiona 6.5 &
gradients (refer to maps in 4. above)
6.4
• Describe where flow units pinch out in each unit, as
Figures 6-3 to 6-7
applicable
• Discuss fractured bedrock heterogeneities across the
Sections 6.5 &
site, including ranges of hydraulic conductivities and
6.9
porosities
• Discuss maximum depth of investigation and
Section 11.1 &
observed fracture density with depth; compare this
14.3
to the depths of proximate supply wells
Page 4 of 13
Tables - Shaded Blue Figures - Shaded Green CAP - Shaded Red

2017 Comprehensive Site Assessment Update - Appendix A October 2017
Riverbend Steam Station SynTerra
NCDEQ CSA Update Expectations - Check List
• Areas of recharge and discharge (Include on vertical
Figure 11-37 &
gradient isocon figure)
Section 6.3
• Flow directions
Figures 6-8 to 6-
- Potentiometric map (summer) of shallow/TZ unit
13
— Potentiometric map (winter) of shallow/TZ unit
— Potentiometric map (summer) of bedrock unit
— Potentiometric map (winter) of bedrock unit
Potentiometric maps should utilize and show all
facility wells, should clearly show all blue line
tributaries, wetlands, and other SWs, and should
indicate areas where a flow unit pinches out as
applicable
Evaluation: Do seasonal or tidal influences affect
Section 14.1
GW flow or GW chemistry?
6. Background
concentrations (PBTVs) of soil and groundwate
Piper diagrams for shallow b/g, deep b/g, and bedrock Figures 10-1 to
b/g, along with well labels for plotted points 10-3
List PBTVs for soil
Table 7-2
List PBTVs for groundwater, by flow unit
Table 10-2
Methodology (appendix)
Appendix H
Description of background wells (why those chosen are
Section 10.1 &
appropriate for use) and soil sample locations
Appendix H
(appendix)
Table of all raw background data showing strikethroughs
Table 10-1 &
of unused high pH, high turbidity, autocorrelated, and
Appendix B, H
outlier data (appendix; digital excel file)
Page 5 of 13
Tables - Shaded Blue Figures - Shaded Green CAP - Shaded Red

2017 Comprehensive Site Assessment Update - Appendix A October 2017
Riverbend Steam Station SynTerra
NCDEQ CSA Update Expectations - Check List
Report
For each source History of ash placement Section 3.0
area
Area, depth, and volume of ash (include also the area,
Section 3.1
depth, and volume of saturated/submerged ash)
Status of source removal or control
Section 2.8
Orthophoto base map (large scale, 1 inch - 100 feet)
Figure 2-1
showing waste boundary, compliance boundary if
applicable, 2 to 4 ft topographic contours, all blue line
surface water and wetland features, along with the
following:
- subset of supply well and SW receptors from 3.
Figures 2-8, 4-3,
above that are potentially susceptible to
4-4, 4-6, & 4-7
contaminant migration from this particular source
area
- Include inset table with list of supply wells and
Table 4-1
SW receptors for this source area
- monitor wells, supply wells, and SW, seep, ash,
Figures 2-1, 2-4,
soil, and sediment locations
4-3, 4-3, 14-50,
14-51, 14-52
- Indicate most recent value (ug/L) for boron and
Figures 14-37 to
for each COI, and whether its concentration is
14-49
increasing, decreasing, stable, or unknown
Evaluation: Show a vertical gradient isopleth map
Figure 11-37,
and discuss vertical gradients and their effect on
Section 11.1, &
GW flow
14-1
List COIs (constituents above 02L/IMAC/background)
Section 10.3
for each flow unit beyond compliance boundary (or that
are within bedrock monitor wells within or beyond
compliance boundary if receptors are potentially at risk)
List pH and Eh ranges found in: pore water, d/g shallow
Figure 14-51
unit, d/g TZ unit, and d/g BR unit
Section 10.2
Evaluation: Explain the geochemical controls on
Sections 13.1 &
COIs that do not behave as a plume (Fe, Mn, etc.).
13.2
Evaluation: Use the pH, Eh, Kd, and HFO results to
Sections 13.1 &
discuss the expected capacity of the subsurface to
13.2
sorb cationic COIs and anionic COIs occurring
from source to receptor within each of the flow
units.
Page 6 of 13
Tables - Shaded Blue Figures - Shaded Green CAP - Shaded Red

2017 Comprehensive Site Assessment Update - Appendix A October 2017
Riverbend Steam Station SynTerra
NCDEQ CSA Update Expectations - Check List
"W I NCDEQ Expectations
Report�
Provide the
(a) have background concentrations been formally
Sections 7.1 and
following "data
established for all COIs in soil and groundwater?
10.1
inventory"
(b) for each source area, how many wells within each
Section 11.1.1
flow system are located along the contaminant plume
centerline? Along a cross sectional transect that is
perpendicular to the plume centerline?
(c) how many wells in (b) above are screened across
Section 11.1 and
the most contaminated vertical interval of a given flow
Figures 11-41 to
unit or are screened across the full thickness of the flow
11-64
unit?
(d) is the d/g edge of the plume centerline measured or
Section 11.1 and
is this location obstructed by a major SW or other
Figures 11-41 to
access issue? If so, is it measured by wells that are
11-64
screened across each flow unit?
(d) what is the length of record and how many valid
Section 10.0 &
sample events are available for wells listed in (b), (c),
Appendix B
and (d) above?
(e) does turbidity, well construction (for example, grout
Section 10.0 &
contamination, etc.), or well "break in" issues preclude
Appendix B
the use of data in (b), (c), and or (d)?
(f) for each source area and within each flow unit, how
Sections 7 & 11,
many spatial locations were sampled for solid phase
Figure 14-50
chemistry and were these locations associated with "end
member" (maximum and minimum) groundwater
Section 11.2
concentrations for each contaminantEll? How many of
these spatial locations are associated with (b) or (c)
above?
[1] Measuring the solid phase contaminant
concentrations in locations of both low and high
groundwater COI concentrations are important in
understanding the sorptive capacity of the system. This
is particularly true in the case of non -linear isotherm
adsorption models that describe most metals. That is, a
soil has a limited ability to sorb contaminant mass due,
for example, to limited sorption sites, so a soil can
become less efficient at removing mass at higher
dissolved concentrations.
(g) given that iron hydroxide (HFO) content is a good
Section 11.2,
indicator of retention capacity for most metal
Figure 14-50
contaminants, how many locations in (f) was HFO
measured?
Page 7 of 13
Tables - Shaded Blue Figures - Shaded Green CAP - Shaded Red

2017 Comprehensive Site Assessment Update - Appendix A October 2017
Riverbend Steam Station SynTerra
NCDEQ CSA Update Expectations - Check List
For each COI in
this particular
source area
Evaluation: Were wells properly positioned and
Section 11.1.1
screened to measure the horizontal and vertical
Figures 11-41 to
extent of the plume? If so, describe the horizontal
11-64
and vertical plume extent using plan view and
cross sectional maps.
Has the plume migrated to any supply wells, SW
Section 13.0
receptors, or GW future use areas?
Has the plume migrated to any supply wells, SW
Sections 13.0 &
receptors, or GW future use areas at concentrations
14.3
above 2L/IMAC/background?
Evaluation: Were wells positioned and screened
Section 11.1
to measure the maximum concentrations
migrating from source to receptor along the
longitudinal plume centerline? If so, describe the
plume characteristics in space and time as it flows
along the centerline, through the identified flow
units, and discharges into the nearest supply well
or SW receptor.
Evaluation: Use maps, graphs, statistics, and
Section 11.1,
mass movement or balance equations to show
13.1, & 15.2
whether the plume is expanding and whether the
plume is moving.
Show the COI -distance plot of wells positioned along a
Figures 6-3 & 11-
plume centerline from source to farthest d/g location
38 to 11-40
(closest to receptor or future use area.
If applicable, show COI -distance plots at different
Section 13.1
timepoints to demonstrate potential plume expansion or
migration.
If applicable and sufficient sample events are available,
NA
use single -well linear regression or Mann-Kendall/Theil-
Sen type trend statistics to show increasing or
decreasing trends at selected d/g monitor wells.
Describe the soil -water pairs and Kd lab test sample
Figure 14-50,
results. Describe where they were collected, why those
Sections 6.7 &
locations were selected, and whether those locations are
13.1.2
reflective of high and low COI concentrations in a given
flow unit.
Page 8 of 13
Tables - Shaded Blue Figures - Shaded Green CAP - Shaded Red

2017 Comprehensive Site Assessment Update - Appendix A October 2017
Riverbend Steam Station SynTerra
NCDEQ CSA Update Expectations - Check List
Show concentration isopleths for each COI, including
Figures 11-1 to
contours of concentrations below and well above the
11-36
2L/IMAC (choose — five contours per COI, from
"moderately low" to "high")
Show stacked boron -time plots of wells positioned along
Figures 11-38 to
a plume centerline from source to farthest d/g location
11-40
(closest to receptor)
Summary of corrective actions taken to date, if
Section 2.8
applicable
Describe preliminary corrective action alternatives for Sections 15.3 &
this source area 15.4
• Description of model
Section 13
(Summary)
• Model construction - domain, layers, boundary
Section 13
conditions, recharge and discharge areas, supply
(Summary)
wells, hydraulic conductivities, stream conductances,
etc.
— Layer thicknesses in cross section (show vertical
scale in feet)
— Location of supply wells outside model domain
• Calibration method
To Be Provided in
CAP
— List of target wells used in calibration
— List of monitor wells not used in calibration and
the rationale for each that was omitted
• Calibration results (where mapped, superimpose on
To Be Provided in
orthophoto base map described above)
CAP
— Hydraulic conductivity zones versus measured
values for the zone
— List of simulated versus observed heads (include
wells and SW features)
— List of simulated versus observed vertical
gradients from well pair locations
— List of simulated versus observed discharge to
streams
— Potentiometric surface
Page 9 of 13
Tables - Shaded Blue Figures - Shaded Green CAP - Shaded Red

2017 Comprehensive Site Assessment Update - Appendix A October 2017
Riverbend Steam Station SynTerra
NCDEQ CSA Update Expectations - Check List
■ Simulated for each flow layer
■ Observed, shallow
■ Observed, deep
■ Observed, BR
— Flow paths (particle tracks) from each source
area
— Reverse flow paths (particle tracks) from SW
receptors
— Reverse flow paths (particle tracks) from supply
wells (because supply wells are usually open
from casing (at —50 to 75 ft) down to 200 to 500
feet, release particles in all simulated bedrock
layers)
• Quantitative sensitivity analyses to key inputs at
To Be Provided in
various selected d/g locations
CAP
• Describe the most significant model limitations
To Be Provided in
CAP
• Description of model
Section 13.1
(Summary)
• Model construction - boundary conditions, time
Section 13.1
steps, initial conditions, etc.
(Summary)
— Source loading, per layer
— Background concentrations, per layer
— Initial Kds, per layer
— Dispersivities, per layer
— Effective porosities, per layer
• Calibration method
Section 13.1
— List of target wells used in calibration
(Summary)
— List of monitor wells not used in calibration and
the rationale for each that was omitted
— Calibrated Kds, per layer
Page 10 of 13
Tables - Shaded Blue Figures - Shaded Green CAP - Shaded Red

2017 Comprehensive Site Assessment Update - Appendix A October 2017
Riverbend Steam Station SynTerra
NCDEQ CSA Update Expectations - Check List
7W
• Calibration results (where mapped, superimpose on
To Be Provided in
orthophoto base map described above)
CAP
— List of simulated versus observed concentrations
in target wells
— List of simulated concentrations in SW discharge
locations as shown using particle tracks released
from source areas
— List of simulated versus observed concentrations
in selected well pair locations
• Boron isopleth map
To Be Provided in
— Simulated for each flow layer
CAP
— Observed, shallow
— Observed, deep
— Observed, BR
• For each source area, the time, direction, and
To Be Provided in
distance of contaminant travel must be predicted
CAP
under existing conditions and under any other
contemplated source control measure (for example,
engineered cap and (or) excavation). For these
scenarios, the following figures are expected:
— (a) a concentration -time plot for each COI
corresponding to the following locations: (i)
nearest supply well, (ii) nearest future
groundwater use area, and (iii) nearest surface
water.
■ In the plot margin, the following information
should be provided: the time it takes for the
COI to reach (i), (ii), and (iii), the time it
takes for the COI to reach (i), (ii), and (iii)
at its 2L/IMAC concentration, the time it
takes for the COI to reach (i), (ii), and (iii)
at its maximum concentration, and the time
it takes for the COI to reach (i), (ii), and (iii)
at a concentration that is back below the
2L/IMAC concentration.
— (b) a map superimposed on the requested base
map showing the maximum predicted migration
distance, at any detectable concentration, of
each COI.
— (c) a map superimposed on the requested base
map showing the maximum predicted migration
distance, at the 2L/IMAC standard concentration,
of each COI.
Page 11 of 13
Tables - Shaded Blue Figures - Shaded Green CAP - Shaded Red

2017 Comprehensive Site Assessment Update - Appendix A October 2017
Riverbend Steam Station SynTerra
NCDEQ CSA Update Expectations - Check List
• Quantitative sensitivity analyses to key inputs at
To Be Provided in
various selected d/g locations and times
CAP
• Describe the most significant model limitations
To Be Provided in
CAP
• Conceptual model based on observed site data
Section 13.2
(Summary)
— Describe geochemical controls on COI levels in
each source area using site data
— Assumptions used in developing the model
— Discuss data used to develop the model
■ For example, how are mineral or adsorption
concentrations in fractured media converted
to PHREEQC concentrations representing
reaction along the fractures?
■ How were modeled reactive mineral
concentrations interpolated between or
extrapolated from the limited number of
data collected
— Discuss what the COI concentrations are most
sensitive to (pH, Eh, iron/aluminum oxide
content, Kd, distance from source, etc.)
— Describe the most significant limitations of the
model
• Numerical model (PHREEQC or PHREEQC 1-D
To Be Provided in
Transport model)
CAP
— Description of model
— Purpose of model
— Model construction
— Discuss data used to develop the flow model
— Results with comparison to observed well data
(PHREEQC model) or to longitudinal flow path
transect data (PHREEQC 1-D Transport model)
— Sensitivity analysis (to pH, Eh, Kd, COI
concentration, total dissolved ion content,
iron/aluminum oxide content, Kd, distance from
source, etc.)
— Describe the most significant limitations of the
model
Page 12 of 13
Tables - Shaded Blue Figures - Shaded Green CAP - Shaded Red

2017 Comprehensive Site Assessment Update - Appendix A October 2017
Riverbend Steam Station SynTerra
NCDEQ CSA Update Expectations - Check List
• Description of model
Section 13.3
(Summary)
• Purpose of model
Section 13.3
(Summary)
• Model construction
To Be Provided in
— Show on map the precise SW locations where
CAP
model output (simulated SW concentration) was
obtained
— List and discuss data used to construct model
■ Permitted effluent discharge concentrations
should be considered in the model
construction
— Assumptions
• Results
To Be Provided in
CAP
• Sensitivity analysis (to GW contaminant
To Be Provided in
concentrations, permitted effluent concentrations,
CAP
location where SW output was obtained, stream
flow, nearby effluent loading to the SW, etc.
• Describe the most significant limitations of the model
To Be Provided in
CAP
Page 13 of 13
Tables - Shaded Blue Figures - Shaded Green CAP - Shaded Red

2017 Comprehensive Site Assessment Update October 2017
Riverbend Steam Station
NORR LETTER
SynTerra

A 4
A=(WA
4AF1
NCDENR
North Carolina Department of Environment and Natural Resources
Pat McCrory John E. Skvarla, III
Governor Secretary
August 13, 2014
CERTIFIED MAIL 7004 2510 0000 3651 1168
RETURN RECEIPT REQUESTED
Paul Newton
Duke Energy
526 South Church Street
Charlotte, NC 28202
Subject: Notice of Regulatory Requirements
Title 15A North Carolina Administrative Code (NCAC) 02L .0106
14 Coal Ash Facilities in North Carolina
Dear Mr. Newton:
Chapter 143, North Carolina General Statutes, authorizes and directs the Environmental
Management Commission of the Department of Environment and Natural Resources to protect
and preserve the water and air resources of the State. The Division of Water Resources (DWR)
has the delegated authority to enforce adopted pollution control rules.
Rule 15A NCAC 02L .0103(d) states that no person shall conduct or cause to be conducted any
activity which causes the concentration of any substance to exceed that specified in 15A NCAC
02L .0202. As of the date of this letter, exceedances of the groundwater quality standards at 15A
NCAC 02L .0200 Classifications and Water Quality Standards Applicable to the Groundwaters
of North Carolina have been reported at each of the subject coal ash facilities owned and
operated by Duke Energy (herein referred to as Duke).
Groundwater Assessment Plans
No later than September, 26 2014 Duke Energy shall submit to the Division of Water Resources
plans establishing proposed site assessment activities and schedules for the implementation,
completion, and submission of a comprehensive site assessment (CSA) report for each of the
following facilities in accordance with 15A NCAC 02L .0106(g):
Asheville Steam Electric Generating Plant
Belews Creek Steam Station
Buck Steam Station
Cape Fear Steam Electric Generating Plant
Cliffside Steam Station
1636 Mail Service Center, Raleigh, North Carolina 27699-1636
Phone: [phone] Internet: www.ncdenr.gov
An Equal Opportunity 1 Affirmative Action Employer— Made in part by recycled paper

Mr. Paul Newton
August 12, 2014
Page 2 of 3
Dan River Combined Cycle Station
H.F. Lee Steam Electric Plant
Marshall Steam Station
Mayo Steam Electric Generating Plant
Plant Allen Steam Station
Riverbend Steam Station
Roxboro Steam Electric Generating Plant
L.V. Sutton Electric Plant
Weatherspoon Steam Electric Plant
The site assessment plans shall include a description of the activities proposed to be completed
by Duke that are necessary to meet the requirements of 15A NCAC 02L .0106(g) and to provide
information concerning the following:
(1) the source and cause of contamination;
(2) any imminent hazards to public health and safety and actions taken to mitigate
them in accordance to 15A NCAC 02L .0106(f);
(3) all receptors, and significant exposure pathways;
(4) the horizontal and vertical extent of soil and groundwater contamination and all
significant factors affecting contaminant transport; and
(5) geological and hydrogeological features influencing the movement,. chemical, and
physical character of the contaminants.
For your convenience, we have attached guidelines detailing the information necessary for the
preparation of a CSA report. The DWR will review the plans and provide Duke with review
comments, either approving the plans or noting any deficiencies to be corrected, and a date by
which a corrected plan is to be submitted for further review and comment or approval. For those
facilities for which Duke has already submitted groundwater assessment plans, please update
your submittals to ensure they meet the requirements stated in this letter and referenced
attachments and submit them with the others.
Receptor Survey
No later than October 14t', 2104 as authorized pursuant to 15A NCAC 02L .0106(g), the DWR is
requesting that Duke perform a receptor survey at each of the subject facilities and submitted to
the DWR. The receptor survey is required by 15A NCAC 02L .0106(g) and shall include
identification of all receptors within a radius of 2,640 feet (one-half mile) from the established
compliance boundary identified in the respective National Pollutant Discharge Elimination
System (NPDES) permits. Receptors shall include, but shall not be limited to, public and private
water supply wells (including irrigation wells and unused or abandoned wells) and surface water
features within one-half mile of the facility compliance boundary. For those facilities for which
Duke has already submitted a receptor survey, please update your submittals to ensure they meet
the requirements stated in this letter and referenced attachments and submit them with the others.
If they do not meet these requirements, you must modify and resubmit the plans.

Mr. Paul Newton
August 12, 2014
Page 3 of 3
The results of the receptor survey shall be presented on a sufficiently scaled map. The map shall
show the coal ash facility location, the facility property boundary, the waste and compliance
boundaries, and all monitoring wells listed in the respective NPDES permits. Any identified
water supply wells shall be located on the map and shall have the well owner's name and
location address listed on a separate table that can be matched to its location on the map.
Failure to comply with the State's rules in the manner and time specified may result in the
assessment of civil penalties and/or the use of other enforcement mechanisms available to the
State.
We appreciate your attention and prompt response in this matter. If you have any questions,
please feel free to contact S. Jay Zimmerman, Water Quality Regional Operations Section Chief,
at [phone].
2hn
ierely,
E. Skvarla, III
Attachment enclosed
cc: Thomas A. Reeder, Director, Division of Water Resources
Regional Offices — WQROS
File Copy

2017 Comprehensive Site Assessment Update October 2017
Riverbend Steam Station
SynTerra
NPDES WASTEWATER PERMIT ##NCOO4961

Water Resources
ENVIRONMENTAL QUALITY
PAT MCCRORY
Govei�ior•
DONALD R. VAN DER VAART
Secrela�
S. JAY ZIMMERMAN
Director•
Febtuaiy 12, 2016
Mt. Hatay Sideris, Senior Vice President
Environmental, Health and Safety
Duke Energy Carolinas, LLC
Mail Code EC13K
P.O. Box 1006
Charlotte, North Carolina 28201-1006
Subject: NPDES Permit Issuance
Permit No. NC0004961
Rivetbend Steam Station
Gaston County
Dear Mr. Sideris:
The Division of Water Resources is forwarding herewith the Final NPDES permit for Riverbend
Steam Station. This permit renewal is issued pursuant to the requirements of North Carolina
General Statute 143-215.1 and the Memorandum of Agreement between North Carolina and the
U.S. Environmental Protection Agency dated October 15, 2007 (or as subsequently amended).
A public hearing was held on Ap44i18, 2015 ul Lincolnton seeking -comments on the Draft
permit. Tlus Final permit incorporates recommendations of the DWR Hearing Officer, EPA, as
well as other changes. Listed below are all changes from the Draft permit:
• The Outfall 010eliminated and the Special Condition A. (16.) was updated to meet
the requirements of The Water QualitjT Standard Regulatory Revisions Final Rule that has
become effective on October 20, 2015.
• Fish tissue monitoring was increased to annually from once every five years to address the
EPA comment. Please see Special Condition A. (12.).
• The Additional Conditions and Definitions Special Condition was added to the permit to
address the EPA comment. Please see Special Condition A. (20.).
• Measurement frequency was changed from "Episodic" to "Per discharge event" (Outfall
002A) to address the EPA comment.
• The Flow limit was added for Outfall 002 (dewatering phase) to address the EPA
comment.
• The automatic pump shutoff requirements for TSS limit exceedance was added for Outfall
002 to address the EPA comment.
• The variance from Monthly Average TSS limit (Outfall 002 and Outfall 011) %vas eliminated
to address the EPA comment.
State of North Carolina I Environmental Quality I Water Resources
1617 Mail service Center � Raleigh, North Carolina 27699-1611
919 707 9000

• Monitoring frequency tot all parameters was increased to Weekly for Outfall 002 to address
the EPA comment.
• The specific date of December 31, 2019 replaced 4.5 years for Outfall 002. This change
was made to address EPA comment. Please see Special Condition A. (2.).
• Clarifying language was added to define the discharge from the ash pond under normal
operating conditions to address the Hearing Officer recommendation and the comment
from the petmittee. Please see Special Condition A. (2).
• The definition of dewatering was added to Special Condition A. (3.). The definition was
added to address the Hearing Office recommendation and the comment from the
permittee.
• The effluent concentration for Whole affluent Toxicity was changed to correct a typo, the
correct concentration is 2.7%. Please see footnote to Special Conditions A. (2.) and A. (3).
• The footnote describing conditions for monitoring Total Copper and Total Iron was
removed (Outfall 011) to correct an error.
• Description of the wastewater sources for Outfall 001 and Outfall 002 was updated to
reflect the current status of the facility.
• Clatif Ting language was added to the Outfall 002 to define the conditions under which the
Emits for Total Copper and Total Iron are applicable. This change was made to address
the Hearing Officer recommendation.
• A distinct outfall was created for each seep with the effluent limits equivalent to the water
quality standards, Technology -Based limits (TSS and Oil & Grease) were also added in
accordance with the 40 CFR 423.
• The monthly seep monitoring was extended to a 12 month period, after which the
monitoring will be reduced to quarterly.
• The following requirements were added to the Condition A. (2). — Outfall 001: flow limit;
use of a floating pump station with free water skimmed from the basin surface using an
adjustable weir; daily monitoring of flow; continuous monitoring of TSS with auto pump
shut-off if TSS concentration (15 minute average) exceeds half the maximum daily TSS limit
(pumping will be allowed to continue if interruption might result in a dam failure or
damage); real time pH monitoring with an auto shut-off if the 15-minute running average
PH falls below 6.1 standard units or rises above 8.9 standard units; drawdown to no less than
three feet above the ash; and monitoring for total chromium, total lead, total cadmium, and
total dissolved solids.
If any parts, measurement frequencies, or sampling requirements contained in this permit are
unacceptable to you, you have the right to an adjudicatoiy hearing upon written request within thirty
(30) days following receipt of this letter. This request must be in the form of a written petition,
conforming to Chapter 150B of the North Carolina General Statutes, and filed with the office of
Administrative Hearings, 6714 Mail Service Center, Raleigh, North Carolina 27699-6714. Unless
such a demand is made, this permit shall be final and binding.
Please take notice that this permit is not transferable except after notice to the Division of Water
Resources. The Division may require modification or revocation and reissuance of the permit. This
permit does not affect the legal requirements to obtain other permits which may be requited by the
Division of Water Resources, the Division of Energy, Mineral, and Land Resources, the Coastal
Area Management Act, or any other federal or local governmental permit.

If you have any questions on this permit, please contact Sergei Chernikov at 919-807-6386.
Sincerely,
S. �Lir�herman, P.G.
Director, Division of Water Resources
Hardcopy: Central Files
NPDES Files
Mooresville Regional Office, SWPS
Email: US EPA, Region N
Aquatic Toxicology Unit
David Merryman, Catawba Riverkeeper, [[e-mail]]

Permit NC0004961
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
In compliance with the provision of North Carolina General Statute 143-215.1, other lawful
standards and regulations promulgated and adopted by the North Carolina Environmental
Management Commission, and the Federal Water Pollution Control Act, as amended,
Duke Energy Carolinas, LLC
is hereby authorized to discharge wastewater from a facility located at the
Riverbend Steam Station
Mount Holly
Gaston County
to receiving waters designated as the Catawba River (Mountain Island Lake) in the
Catawba River Basin
in accordance with effluent limitations, monitoring requirements, and other
applicable conditions set forth in Parts I, II, III, and Appendix A.
This permit shall become effective March 1, 2016.
This permit and authorization to discharge shall expire at midnight on February 29, 2020.
Signed this day February 12, 2016.
S. Jay �;irr� van P, G., Director
Division f er Resources
By Authority of the Environmental Management Commission
Page 1 of 27

Permit NC0004961
SUPPLEMENT TO PERMIT COVER SHEET
All previous NI -DES Permits issued to this facility, whether for operation or discharge are hereby
revoked. As of this permit issuance, any previously issued permit bearing this number is no longer
effective. Therefore, the exclusive authority to operate and discharge from this facility arises under
the permit conditions, requirements, terms, and provisions included herein.
Duke Energy Carolinas, LLC is hereby authorized to:
1. Continue to discharge:
• Water from the plant chiller system (outfall 001).
• Ash basin discharge (outfall 002) consisting of consisting of stormwater
from roof drains and paving, treated groundwater, track hopper sump
(groundwater), coal pile runoff, general plant/trailer sanitary wastewater,
turbine and boiler rooms sumps, vehicle rinse water, and stormwater from
pond areas, upgradient watershed, and miscellaneous stormwater flows.
• Yard sump overflow (outfall 002A).
• 12 potentially contaminated groundwater seeps (outfalls 101-112).
• Wastewater, stormwater and groundwater (outfall 011).
From a facility located at Riverbend Steam Station, Mount Holly in Gaston
County, and
2. Discharge wastewater from said treatment works at the location specified on
the attached map into the Catawba River, which is classified WS-IV and B-CA
waters in the Catawba River Basin,
Page 2 of 27

Permit NC0004961
Part I
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
001) [ 15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge plant chiller system from outfall 001. Such discharges shall be
limited and monitored3 by the Permittee as specified below:
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum
Measurement
Frequenc
Sample Type
I
Sample
Location'
Flow, MGD
Monthly
Pump Logs
Influent or
Effluent
Temperature (OF)
Monthly
Grab
Effluent
Temperature (OF)2
89.6 (320C)
Monthly
Grab
Downstream
Notes:
1. Downstream sampling point: downstream at Mountain Island Lake. If samples are collected
below the water surface, the Permittee will record the sample depth on the DMR form.
2. The ambient temperature shall not exceed 89.60F (32.00C) and is defined as the daily average
downstream water temperature. When the Riverbend Station effluent temperature is recorded
below 89.60F (32.00C), as a daily average, then monitoring and reporting of the downstream water
temperature is not required. In cases where the Permittee experiences equipment problems and
is unable to obtain daily temperatures from the existing temperature monitoring system, the
temperature monitoring must be reestablished within five working days.
3. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.) .
Chlorination of the once through condenser cooling water, discharged through outfall 001, is
not allowed under this permit. Should Duke Energy wish to chlorinate its condenser cooling
water, a Division permission must be requested and received prior to commencing
chlorination.
There shall be no discharge of floating solids or visible foam in other than trace amounts.
Page 3 of 27

Permit NC0004961
A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
002-normal operation) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 002 - Ash Pond Discharge (removing the free
water above the settled ash layer that does not involve mechanical movement of the ash).
Such discharves shall be limited and mnnitorPrl6 by fhP ParmiffaP aQ yr ;f;,l T.o1..r..
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Daily ;
Maximum
Measurement
Frequency
Sample Type
Sample Location
Flow
5.74 MGD
Daily
Pump logs or
estimate
Influent or Effluent
Total Suspended
Solidse
23,0 mg/L
75.0 mg/L
Weekly
Grab
Effluent
Oil and Grease
11.0 mg/L
15.0 mg/L
Weekly
Grab
Effluent
Total Copper'
1.0 mg/L
1.0 mg/L
Weekly
Grab
Effluent
Total Iron'
1.0 mg/L
1.0 mg/L
Weekly
Grab
Effluent
Total Arsenic
52.5 g/L
72.5 lag/L
Weekly
Grab
Effluent
Total Selenium
68.0 g/L
127.5 g/L
Weekly
Grab
Effluent
Nitrate/nitrite as N
0.65 mg/L
0.85 mg/L
Weekly
Grab
Effluent
Total Arsenic
10.5 lag/L7
14.5 lag/L7
Weekly
Grab
Effluent
Total Selenium
13.6 lag/L7
25.5 lag/L7
Weekly
Grab
Effluent
Total Mercury
Nitrate/nitrite as N
47.0 ng/1.5
0.13 mg/L7
47.0 ng/1.5
0.17 mg/L7
Weekly
Weekly
Grab
Grab
Effluent
Effluent
Total Phosphorus,
mg/L
Weekly
Grab
Effluent
Total Nitrogen (NO2 + NO3 + TKN),
mg/L
Weekly
Grab
Effluent
pH2
Weekly
Grab
Effluent
Chronic Toxicity3
Monthly
Grab
Effluent
Turbidity4, NTU
Weekly
Grab
Effluent
Total Chromium,
lag/L
Weekly
Grab
Effluent
Total Cadmium, g/L
Weekly
Grab
Effluent
Total Lead,
g/L
Weekly
Grab
Effluent
TDS, mg/L
MT I
Weekly
Grab
Effluent
ivvLco.
1. The limits for total copper and total iron only apply when chemical metal cleaning wastewaters
are being discharged.
2. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units. The facility
shall conduct a real time pH monitoring with an auto shut-off if the 15-minute running average
pH falls below 6.1 standard units or rises above 8.9 standard units.
3. Whole Effluent Toxicity shall be monitored by chronic toxicity (Ceriodaphnia) P/F at 2.7%. Tests
shall be conducted in January, April, July and October (see Part A.(6.) for details).
4. The discharge from this facility shall not cause turbidity in the receiving stream to exceed 50
NTU. If the instream turbidity exceeds 50 NTU due to natural background conditions, the
discharge cannot cause turbidity to increase in the receiving stream.
NTU - Nephelometric Turbidity Unit.
5. The facility shall use EPA method 1631E.
6. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.).
7. The TBEL limits shall be met no later than December 31, 2019. This time period is provided
in order for the facility to budget, design, and construct the treatment system. Permit might
be re -opened to implement the final EPA Effluent Guidelines and more stringent limits
might be added.
8. The facility shall continuously monitor TSS concentration and the dewatering pump shall be
shutoff automatically when the one half of the Daily Maximum limit (15 minutes average) is
Page 4 of 27

Permit NC0004961
exceeded. Pumping will be allowed to continue if interruption might result in a dam failure or
damage.
The facility is allowed to drawdown the wastewater in the lagoon to no less than three feet
above the ash.
The facility shall use of a floating pump station with free water skimmed from the basin
surface using an adjustable weir.
The metal cleaning waste, coal pile runoff, ash transport water, domestic wastewater,
and low volume waste shall be discharged into the ash settling pond.
No chemicals, cleaners, or other additives may be present in the vehicle wash water
to be discharged from this outfall.
There shall be no discharge of floating solids or visible foam in other than trace
amounts. The level of water in the pond should not be lowered more than 1 ft/week,
unless approved by the DEQ Dam Safety Program,
Page 5 of 27

Permit NC0004961
A. (3.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (outfall
002-dewatering phase) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the commencement date of the dewatering operations and lasting
until expiration,' the Permittee is authorized to discharge from outfall 002 -Ash Pond Discharge
(Dewatering-removing the interstitial water). Such discharges shall be limited and monitored by
the Permittee as specified below;
'EFFLUENT
CHARACTERISTICS
;LIMITS
MONITORING REQUIREMENTS
Monthly:..
Average::
Daily
:Maximum
Measurement
Frequency
Sample Type '
Sample Location
Flow
1.45 MGD
Weekly
Pump logs or
estimate
Influent or Effluent
Total Sus ended Solids
23.0 mglL
75.0 mg/L
Weekl
Grab
Effluent
Oil and Grease
11.0 mg/L
15.0 mg/L
Weekly
Grab
Effluent
Total Copper2
1.0 mg/L
1.0
mglL
Weekly
Grab
Effluent
Total Iron2
1,0 mg/L
1,0 mg/L
Weekly
Grab
Effluent
Total Arsenic
10.5 lag/L
14,5 faglL
Weekly
Grab
Effluent
Total Selenium
13.6 fag/L
25.5 g/L
Weekl
Grab
Effluent
Total Aluminum
3.18 mg/L
3.18 mg/L
Weekl
Grab
Effluent
Total Mercury
47.0 nglLs
47.0 ng/L6
Weekl
Grab
Effluent
Nitrate/nitrate as N
0.13 mg/L
0.17 mg/L
Weekly
Grab
Effluent
Total Phosphorus, mglL
Weekly
Grab
Effluent
Total Nitrogen (NOz + NO3 + TKN),
mg/L
Weekly
Grab
Effluent
Fi3
Weekl
Grab
Effluent
Chronic Toxicity4
Weekl
Grab
Effluent
Turbidity5, NTU
Weekly
Grab
Effluent
Notes:
1. The facility shall continuously monitor TSS concentration and the dewatering pump shall be
shutoff automatically when the limits are exceeded.
2. The limits for total copper and total iron only apply when chemical metal cleaning
wastewaters are being discharged.
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. Whole Effluent Toxicity shall be monitored by chronic toxicity (Ceriodaphnia) P/ F at 2.7%.
Tests shall be conducted in January, April, July and October (see Part A.(6.) for details).
5. The discharge from this facility shall -not cause turbidity in the receiving stream to exceed 50
NTU. If the instream turbidity exceeds 50 NTU due to natural background conditions, the
discharge cannot cause turbidity to increase in the receiving stream.
NTU - Nephelometric Turbidity Unit.
6. The facility shall use EPA method 1631E.
7. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See
Special Condition A. (18.).
The metal cleaning waste, coal pile runoff, ash transport water, domestic wastewater,
and low volume waste shall be discharged into the ash settling pond.
No chemicals, cleaners, or other additives may be present in the vehicle wash water
to be discharged from this outfall. There shall be no discharge of floating solids or
visible foam in other than trace amounts.
The level of water in the pond should not be lowered more than 1 ft/week unless
approved by the DEQ Dam Safety Program.
Page 6 of 27

Permit NC0004961
A. (4.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
002A) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 002A - Yard Sump Overflows. Such discharges
shall be limited and monitored3 by the Permittee as specified below:
EFFLUENT
LIMITS
MONITORING REQUIREMENTS
CHARACTERISTICS
Monthly
Daily
Measurement
Sample Type
Sample Location
Average
Maximum
Frequency
Flow, MGD
Per discharge
Estimate
Effluent
event
Total Suspended Solids
23.0 mg/L
75.0 mg/L
Per discharge
Grab
Effluent
event
Oil and Grease
11.0 mg/L
15.0 mg/L
Per discharge
Grab
Effluent
event
Fecal Coliform, CPU/100 mL
Per discharge
Grab
Effluent
event
Total Copper2
1.0 mg/L
1.0 mg/L
Per discharge
Grab
Effluent
event
Total Iron2
1.0 mg/L
1.0 mg/L
Per discharge
Grab
Effluent
event
pH4
Per discharge
Grab
Effluent
event
ivotes:
1. Effluent samples shall be collected prior to the discharge to the receiving stream.
2. The limits for total copper and total iron only apply when chemical metal cleaning
wastewaters are being discharged.
3. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.).
4. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
ALL FLOWS SHALL BE REPORTED ON MONTHLY DMRS. SHOULD NO FLOW OCCUR DURING A
GIVEN MONTH, THE WORDS "NO FLOW" SHOULD BE CLEARLY WRITEN ON THE FRONT OF
THE DMR, ALL SAMPLES SHALL BE OF A REPRESENTATIVE DISCHARGE.
Page 7 of 27

Permit NC0004961
A. (5.) CHRONIC TOXICITY PASS/FAIL PERMIT LIMIT (QUARTERLY) (Outfall
002) [15A NCAC 02B .0200 et seq.]
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant
mortality to Ceriodaphnia dubia at an effluent concentration of 2.7%.
The permit holder shall perform at a minimum, quarteral monitoring using test procedures outlined
in the "North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised December 2010,
or subsequent versions or "North Carolina Phase If Chronic Whole Effluent Toxicity Test Procedure"
(Revised- December 2010) or subsequent versions. Effluent sampling for this testing must be
obtained during representative effluent discharge and shall be performed at the NPDES permitted
final effluent discharge below all treatment processes.
If the test procedure performed as the first test of any single quarter results in a failure or
ChV below the permit limit, then multiple -concentration testing shall be performed at a
minimum, in each of the two following months as described in "North Carolina Phase II
Chronic Whole Effluent Toxicity Test Procedure" (Revised -December 2010) or subsequent
versions.
All toxicity testing results required as part of this permit condition will be entered on the Effluent
Discharge Monitoring Form (MR-1) for the months in which tests were performed, using the
parameter code TGP3B for the pass/fail results and THP3B for the Chronic Value. Additionally,
DWR Form AT-3 (original) is to be sent to the following address:
Attention: North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicology Branch
1623 Mail Service Center
Raleigh, North Carolina 27699-1623
Completed Aquatic Toxicity Test Forms shall be filed with the Water Sciences Section no later than
30 days after the end of the reporting period for which the report is made.
Test data shall be complete, accurate, include all supporting chemical/physical measurements and
all concentration/response data, and be certified by laboratory supervisor and ORC or approved
designate signature. Total residual chlorine of the effluent toxicity sample must be measured and
reported if chlorine is employed for disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring is
required, the permittee will complete the information located at the top of the aquatic toxicity (AT)
test form indicating the facility name, permit number, pipe number, county, and the month/year of
the report with the notation of "No Flow" in the comment area of the form. The report shall be
submitted to the Water Sciences Section at the address cited above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required,
monitoring will be required during the following month. Assessment of toxicity compliance is based
on the toxicity testing quarter, which is the three month time interval that begins on the first day of
the month in which toxicity testing is required by this permit and continues until the final day of the
third month.
Should any test data from this monitoring requirement or tests performed by the North Carolina
Division of Water Resources indicate potential impacts to the receiving stream, this permit may be
re -opened and modified to include alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum
control organism survival, minimum control organism reproduction, and appropriate environmental
controls, shall constitute an invalid test and will require immediate follow-up testing to be
completed no later than the last day of the month following the month of the initial monitoring.
Page 8 of 27

Permit NC0004961
A. (6.) BIOCIDE CONDITION
The permittee shall not use any biocides except those approved in conjunction with the permit
application. The permittee shall notify the Director in writing not later than ninety (90) days prior to
instituting use of any additional biocide used in cooling systems which may be toxic to aquatic life
other than those previously reported to the Division of Water Resources. Such notification shall
include completion of Biocide Worksheet Form 101 and a map locating the discharge point and
receiving stream. Completion of a Biocide Worksheet 101 is not necessary for the introduction of a
new biocide into an outfall currently being tested for toxicity.
A. (7.) SPECIAL CONDITIONS
The following special conditions are applicable to all outfalls regulated by NC0004961:
• There shall be no discharge of polychlorinated biphenyl compounds.
• Discharge of any product registered under the Federal Insecticide, Fungicide, and Rodenticide Act
to any waste stream which may ultimately be released to lakes, rivers, streams or other waters of
the United States is prohibited unless specifically authorized elsewhere in this permit. Discharge
of chlorine from the use of chlorine gas, sodium hypochlorite, or other similar chlorination
compounds for disinfection in the plant potable and service water systems and in sewage
treatment is authorized. Use of restricted use pesticides for lake management purposes by
applicators licensed by the N.C. Pesticide Board is allowed.
• The Permittee shall report all visible discharges of floating materials, such as an oil sheen, to the
Director when submitting DMRs
A. (S.) PERMIT TERMS
The following are applicable to all outfalls regulated by NC0004961:
• It has been determined from information submitted that the plans and procedures in place at
Riverbend Steam Station are equivalent to that of a BMP.
A. (9.) ASH SETTLING BASIN
Beginning on the effective date of this permit and lasting until expiration, there shall be no discharge
of plant wastewater to the ash pond unless the Permittee provides and maintains at all times a
minimum free water volume (between the top of the sediment level and the minimum discharge
elevation) equivalent to the sum of the maximum 24-hour plant discharges plus all direct rainfall and
all runoff flows to the pond resulting from a 10-year, 24-hour rainfall event, when using a runoff
coefficient of 1.0. During the term of the permit, the Permittee shall remove settled material from the
ponds or otherwise enlarge the available storage capacities in order to maintain the required
minimum volumes at all times. The Permittee shall determine and report to the permit issuing
authority the following on an annual basis:
1) the actual free water volume of the ash pond,
2) physical measurements of the dimensions of the free water volume in sufficient detail to allow
validation of the calculated volume, and
3) a certification that the required volume is available with adequate safety factor to include all
solids expected to be deposited in the pond for the following year.
Present information indicates a needed volume of 86.2 acre-feet in addition to solids that will be
deposited to the ash pond; any change to plant operations affecting such certification shall be
reported to the Director within five days.
NOTE: In the event that adequate volume has been certified to exist for the term of the permit,
periodic certification is not needed.
Page 9 of 27

Permit NC0004961
A.(10.) GROUNDWATER MONITORING WELL CONSTRUCTION AND SAMPLING
The permittee shall conduct groundwater monitoring to determine the compliance of this NPDES
permitted facility with the current groundwater Standards found under 15A NCAC 2L .0200. The
monitoring shall be conducted in accordance with the Sampling Plan approved by the Division.
A$ (11.) STRUCTURAL INTEGRITY INSPECTIONS OF ASH POND DAM
The facility shall meet the dam design and dam safety requirements per 15A NCAC 2K,
A. (12.) FISH TISSUE MONITORING NEAR ASH POND DISCHARGE
The facility shall conduct fish tissue monitoring annually and submit the results with the NPDES
permit renewal application. The objective of the monitoring is to evaluate potential uptake of pollutants
by fish tissue near the Ash Pond discharge. The parameters analyzed in fish tissue shall be arsenic,
selenium, and mercury. The monitoring shall be conducted in accordance with the Sampling Plan
approved by the Division.
A. (13.) INSTREAM MONITORING
The facility shall conduct semiannual instream monitoring (one upstream and one downstream of the
ash pond discharge) for arsenic, selenium, mercury (method 1631E), chromium, lead, cadmium,
copper, zinc, total hardness, and total dissolved solids (TDS). Instream monitoring should be
conducted at the stations that have already been established through the BIP monitoring program: B
(upstream of the Outfall 002) and C (downstream of the Outfall `002). The monitoring results shall be
submitted with the NPDES permit renewal application.
A. (14.) ASH POND CLOSURE
The facility shall prepare an Ash Pond Closure Plan in anticipation of the facility closure. This Plan
shall be submitted to the Division one month prior to the decommissioning of the ponds.
A. (15.) PRIORITY POLLUTANT ANALYSIS
The Permittee shall conduct a priority pollutant analysis (in accordance with 40 CFR Part 136) once
per permit cycle at outfall 002 and submit the results with the application for permit renewal.
A. (16.) SEEP POLLUTANT ANALYSIS
The facility identified 12 unpermitted seeps (all non -engineered) from the ash settling basin, of which
10 of the seeps have been classified as "jurisdictional waters" by the United States Army Corps of
Engineers.
Jurisdictional Water Seeps.
For the jurisdictional water seeps, the facility shall determine within 90 days from the effective date
of the permit if a seep meets the state water quality standards established in 15A NCAC 2B .0200
and submit the results of this determination to the Division. If the standards are not contravened,
the facility shall conduct monitoring for the parameters specified in A. (21.)2 A. (22.), A. (23.), A. (24.),
A. (25.), A. (26.), A. (27.), A. (28.), A. (29.), A. (30.), A. (31.), and A. (32.).
If any of the water quality standards are exceeded (with the exception of the Action Level standards),
the facility shall be considered in violation of the Clean Water Act until one of the options below is
fully implemented. The facility shall,
1) Submit a complete application for 404 Permit (within 30 days after determining that a water
quality standards exceeded) to pump the seep discharge to one of the existing outfalls, install
a pipe to discharge the seep to the Catawba River, or install an in -situ treatment system.
After the 404 Permit is obtained, the facility shall complete the installation of the pump, pipe,
or treatment system within 180 days from the date of the 404 permit receipt and begin
pumping/discharging or treatment.
2) Demonstrate through modeling that the decanting and dewatering of the ash basin will result
in the elimination of the seep and submit the modeling results to the Division within 120 days
from the effective date of the permit. Within 180 days from the completion of the dewatering
Page 10 of 27

Permit NCO004961
the facility shall confirm that the seep flow ceased. If the seep flow continues, the facility
shall choose one of the other options in this Special Condition.
3) Demonstrate that the seep is discharging through the designated "Effluent Channel' and the
water quality standards in the receiving stream are not contravened. This demonstration
should be submitted to the Division no later than 180 days from the effective date of the
permit. The "Effluent Channel' designation should be established by the DEQ Regional Office
personnel prior to the issuance of the permit and appropriate 404 permit shall be obtained.
All effluent limits, including water quality -based effluent limits, remain applicable notwithstanding
any action by the Permittee to address the violation through one of the identified options, so that any
discharge in exceedance of an applicable effluent limit is a violation of the Permit as long as the seep
remains flowing.
If jurisdictional water seeps contravene Action Level Standard, the facility shall conduct a Whole
Effluent Toxicity Test (WET test). If the WET result passes, the facility shall be considered in
compliance with the state water quality standards. If the WET test fails and the Toxicity Identification
Evaluation determines that the parameter contravening the water quality standard is responsible for
the failure the facility shall be considered in violation and, shall implement one of the 3 options
identified above.
Non -Jurisdictional Water Seeps
For the non jurisdictional water seeps the facility shall demonstrate that they will not violate water
quality standards in the receiving stream or that the seep does not discharge to jurisdictional waters
or that the seep does not carry pollutants indicating ash characteristics and submit this
demonstration to the Division within 90 days from the effective date of the permit. If such
demonstration is not possible or not approved by the Division, the facility shall choose one of the 3
options identified above.
New Identified Seeps
If new seeps are identified, the facility shall follow the procedures outlined above for either
I
urisdictional waters or non jurisdictional waters. The deadlines for new seeps shall be calculated
from the date of the seep discovery.
Table 1. List of Identified Seeps
The permittee has identified 12 potentially contaminated seeps in the areas adjacent to the Mountain
Island Lake. The locations of the seeps are identified on the map attached to the permit.
SeeU Coordinates and Assigned Outfall NumhPrc
Seep ID
*
Latitude
Longitude
Outfall number
S-1
35.365
-80.967
101
S-2
35.365
-80.966
102
S-3
36.369
-80.965
103
S-4
35.371
-80.963
104
S-5*
35.370
-80.963
105
S-6
35.367
-80.958
106
S4
35.367
-80.957
107
S-8*
35.365
-80.956
108
S-9
35.371
-80.963
109
S-10
35.369
-80.960
110
5-11
35.369
-80.960
111
5-12
35.368
-80.959
112
1Von jurisdictional seeps
Page 11 of 27

Permit NC0004961
A. (17.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS
(State Enforceable Only) [G.S. 143-215.1(b)]
Proposed federal regulations require electronic submittal of all discharge monitoring reports (DMRs)
and specify that, if a state does not establish a system to receive such submittals, then permittees
must submit DMRs electronically to the Environmental Protection Agency (EPA). The Division
anticipates that these regulations will be adopted and is beginning implementation in late 2013.
NOTE: This special condition supplements or supersedes the following sections within Part II of this
permit (Standard Conditions for NPDES Permits):
• Section B. (11.)
• Section D. (2.)
• Section D. (6.)
• Section E. (5.)
Signatory Requirements
Reporting
Records Retention
Monitoring Reports
1. Reporting fSupersedes Section D. (2.) and Section E (5 L(a)1
Beginning no later than 270 days from the effective date of this permit, the permittee shall begin
reporting discharge monitoring data electronically using the NC DWR's Electronic Discharge
Monitoring Report (eDMR) internet application.
Monitoring results obtained during the previous months) shall be summarized for each month
and submitted electronically using eDMR. The eDMR system allows permitted facilities to enter
monitoring data and submit DMRs electronically using the internet, Until such time that the
state's eDMR application is compliant with EPA's Cross -Media Electronic Reporting Regulation
(CROMERR), permittees will be required to submit all discharge monitoring data to the state
electronically using eDMR and will be required to complete the eDMR submission by printing,
signing, and submitting one signed original and a copy of the computer printed eDMR to the
following address:
NC DENR / DWR /Information Processing Unit
ATTENTION: Central Files /eDMR
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the
facility being physically located in an area where less than 10 percent of the households have
broadband access, then a temporary waiver from the NPDES electronic reporting requirements
may be granted and discharge monitoring data may be submitted on paper DMR forms (MR 1,
1.1, 2, 3) or alternative forms approved by the Director. Duplicate signed copies shall be
submitted to the mailing address above.
Requests for temporary waivers from the NPDES electronic reporting requirements must be
submitted in writing to the Division for written approval at least sixty (60) days prior to the date
the facility would be required under this permit to begin using eDMR. Temporary waivers shall
be valid for twelve (12) months and shall thereupon expire. At such time, DMRs shall be
submitted electronically to the Division unless the permittee re -applies for and is granted a new
temporary waiver by the Division.
Information on eDMR and application for a temporary waiver from the NPDES electronic
reporting requirements is found on the following web page:
http: / /portal.ncdenr.org/web/wq/admin/bogf ipu/edmr
Page 12 of 27

Permit NC0004961
Regardless of the submission method, the first DMR is due on the last day of the month following
the issuance of the permit or in the case of a new facility, on the last day of the month following
the commencement of discharge.
2. six" my Requirements Vaupplements Section B 111 l (b) and supersedes Section B (11.)
ldE
All eDMRs submitted to the permit issuing authority shall be signed by a person described in
Part II, Section B. (11.)(a) or by a duly authorized representative of that person as described in
Part fI, Section B. (11.)(b). A person, and not a position, must be delegated signatory authority
for eDMR reporting purposes.
For eDMR submissions, the person signing and submitting the DMR must obtain an eDMR user
account and login credentials to access the eDMR system. For more information on North
Carolina's eDMR system, registering for eDMR and obtaining an eDMR user account, please visit
the following web page:
http: / /portal. ncdenr. ors J web/ wq/ admin/ bogLpu/ edmr
Certification. Any person submitting an electronic DMR using the state's eDMR system shall
make the following certification [40 CFR 122.22], NO OTHER STATEMENTS OF CERTIFICATION
WILL BE ACCEPTED:
I certify, under penalty of law, that this document and all attachmer2ts 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 fines and imprisonment for knowing violations. "
3. Records Retention Su lements Section
The permittee shall retain records of all Discharge Monitoring Reports, including eDMR
submissions. These records or copies shall be maintained for a period of at least 3 years from
the date of the report. This period may be extended by request of the Director at any time [40
CFR 122.4l].
A. (18.) APPLICABLE STATE LAW (State Enforceable Only)
This facility shall meet the requirements of Senate Bill 729 (Coal Ash Management Act). This permit
may be reopened to include new requirements imposed by Senate Bill 729.
Page 13 of 27

Permit NC0004961
A. (19.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
011) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 011 - Former Stormwater Outfall 1. Such
discharges shall be limited and monitored3 by the Permittee as specified below:
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum
Measurement
Frequency
Sample Type
Sample Location
Flow, MGD
Monthly
Pump logs or
estimate
Influent or Effluent
Total Suspended Solids
23.0 mg/L
75.0 mg/L
MonthlyGrab
Effluent
Oil and Grease
11.0 mg/L
15.0 mg/L
Annually
Grab
Effluent
Total Arsenic, pg/L
Quarterly
Grab
Effluent
Total Selenium,
lug/L
Quarterly
Grab
Effluent
Total Mercury4, ng/L
Quarterly
Grab
Effluent
Nitrate/nitrate as N, mg/L
Quarterly
Grab
Effluent
Total Phosphorus,
mg/L
Semi-annually
Grab
Effluent
Total Nitrogen (NO2 + NO3 + TKN),
mg/L
Semi-annually
Grab
Effluent
pH1
Monthly
Grab
Effluent
Turbidity2, NTU
Monthly
Grab
Effluent
1. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
2. The discharge from this facility shall not cause turbidity in the receiving stream to exceed 50
NTU. If the instream turbidity exceeds 50 NTU due to natural background conditions, the
discharge cannot cause turbidity to increase in the receiving stream.
NTU - Nephelometric Turbidity Unit,
3. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See
Special Condition A. (18.).
4. The facility shall use EPA method 1631E.
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
A. (20.) ADDITIONAL CONDITIONS AND DEFINITIONS
1. EPA methods 200.7 or 200.8 (or the most current versions) shall be used for analyses of all
metals except for total mercury.
2. All effluent samples for all external outfalls shall be taken at the most accessible location after
the final treatment but prior to discharge to waters of the U.S. (40 CFR 1229416))a
3. The term low volume waste sources means wastewater from all sources except those for which
specific limitations are otherwise established in this part (40 CFR 423.11 (b)).
4. The term chemical metal cleaning waste means any wastewater resulting from cleaning any
metal process equipment with chemical compounds, including, but not limited to, boiler tube
cleaning (40 CFR 423.11 (c)).
5. The term metal cleaning waste means any wastewater resulting from cleaning [with or
without chemical cleaning compounds] any metal process equipment including, but not
limited to, boiler tube cleaning, boiler fireside cleaning, and air preheater cleaning (40 CFR
423.11 (d)).
6. For all outfalls where the flow measurement is to be "estimated" the estimate can be done by
using calibrated V-notch weir, stop -watch and graduated cylinder, or other method approved
by the Division.
Page 14 of 27

Permit NC0004961
A. (21.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
101) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 101 - Seep Discharge. Such discharges shall be
limited and monitored' by the Permittee as snecified hPlnwe
EFFLUENT
CHARACTERISTICS
LIMITS '
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum'
Measurement
Frequency
Sample Type
Sample Location
Flow, MGD
Monthly/Quarterly
Estimate
Effluent
H3
Monthly/Quarterly
Grab
Effluent
Fluoride
1.8 mg/L
1.8 mg/L
Month' /Quarter)
Grab
Effluent
Total Mercur 4, ng/L
Monthly/Quarterly
Grab
Effluent
Total Barium
1.0 mg/L
1,0 mg/L
Monthly/Quarterly
Grab
Effluent
Total Iron, mg/L
Monthly/Quarterly
Grab
Effluent
Total Manganese, fag/L
Monthly/Quarterly
Grab
Effluent
Total Zinc, fag/L
Monthly/Quarterly
Grab
Effluent
Total Arsenic
10.0 fag/L
50.0 fag/L
Monthly/Quarterly
Grab
Effluent
Total Cadmium
2.0 fag/L
15.0 fag/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Chromium
50.0 lag/L
1,022.0 fag/L
Month' /Quarterly
Grab
Effluent
Total Copper, g/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Lead, lag/L
25.Opg/L
33.8 fag/L
Monthly/Quarterly
Grab
Effluent
Total Nickel
25.0 fag/L
25.0
fag/L
Monthly/Quarterly
Grab
Effluent
Total Selenium
5.0 fag/L
56.0 fag/L
Monthly/Quarterly
Grab
Effluent
Nitrate as N
10.0 mg/L
10.0 mg/L
Monthly/Quarterly
Grab
Effluent
Sulfates
250.0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
Chlorides
250.0 mg/L
250.0 mg/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
TDS
500.0 mg/L
500.0 mg/L
Month' /Quarterly
Grab
Effluent
Total Hardness, mg/L
100.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
TSS
30.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
Oil and Grease
15.0 mg/L
20.0 mg/L
Monthly/Quarterly
Grab
Effluent
Temperature, OC
Monthly/Quarterly
Grab
Effluent
Specific Conductance, pmho/cm
Monthly/Quarterly
Grab
Effluent
av ores:
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.).
2. The facility shall conduct monthly sampling from the effective date of the permit. After one year
from the effective date of the permit the monitoring will be reduced to quarterly
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall use EPA method 1631E.
If the facility is unable to obtain a seep sample due to the dry or low flow conditions
preventing the facility from obtaining a representative sample, the "no flow" should be
reported on the DMR. This requirement is established in the Section D of the Standard
Conditions and 40 CFR 122.41 (jl.
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Page 15 of 27

Permit NCOOO4961
A. (22.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
102) [15A NCAC 02B .0400 et seq., O2B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 102 - Seep Discharge. Such discharges shall be
limited and monitored) by the Permittee ae Rnecifieri hainxzr
EFFLUENT
CHARACTERISTICS
LIMITS1
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum`
Measurement
Frequency2
; Sample Type
Sample Location
Flow, MGD
Monthly/Quarterly
Estimate
Effluent
pH3
Monthly/Quarterly
Grab
Effluent
Fluoride
1.8 mg/L
1.8 mg/L
Monthly/Quarterly
Grab
Effluent
Total Mercur 4, ng/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Barium
1.0 mg/L
1.0 mg/L
Monthly/Quarterly
Grab
Effluent
Total Iron, mg/L
Monthly/Quarterly
Grab
Effluent
Total Manganese, lag/L
Monthly/Quarterly
Grab
Effluent
Total Zinc, hg/L
Monthly/Quarterly
Grab
Effluent
Total Arsenic
10.0 lag/L
50.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Cadmium
2.0 lag/L
15.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Chromium
50.0 log/L
11022.0 lag/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Copper, lag/L
Monthly/Quarterly
Grab
Effluent
Total Lead, lag/L
25.Opg/L
33.8 lag/L
Monthly/Quarterly
Grab
Effluent
Total Nickel
25,0 lag/L
25.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Selenium
5.0 lag/L
56.0 lag/L
Monthly/Quarterly
Grab
Effluent
Nitrate as N
10.0 mg/L
10.0 mg/L
Monthly/Quarterly
Grab
Effluent
Sulfates
250.0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
Chlorides
250.0 mg/L
250.0 mg/L
Month) /Quarter]
Grab
Effluent
TDS
500.0 mg/L
500,0 mg/L
Monthly/Quarter)Monthly/QuarteqL
Grab
Effluent
Total Hardness, mg/L
100.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
TSS, mg/L
30.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
Oil and Grease
15.0 mg/L
20.0 mg/L
Monthly/Quarterly
Grab
Effluent
Temperature, OC
Monthly/Quarterly
Grab
Effluent
Specific Conductance, lamho/cm
Monthly/Quarterly
Grab
Effluent
1VULCS:
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.).
2. The facility shall conduct monthly sampling from the effective date of the permit. After one year
from the effective date of the permit the monitoring will be reduced to quarterly
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall use EPA method 1631E.
If the facility is unable to obtain a seep sample due to the dry or low flow conditions
preventing the facility from obtaining a representative sample, the "no flow" should be
reported on the DMR. This requirement is established in the Section D of the Standard
Conditions and 40 CFR 122.41 (j).
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Page 16 of 27

Permit NCOOO4961
A. (23.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
103) [15A NCAC O2B .0400 et seq., O2B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 103 - Seep Discharge. Such discharges shall be
limited and monitored' by the Permittee as sbecified below:
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum
Measurement
Frequency2
Sample Type
Sample Location
Flow, MGD
Monthly/Quarterly
Estimate
Effluent
pH3
Month' /Quarterly
Grab
Effluent
Fluoride
1.8 mg/L
1.8 mg/L
Month' /Quarterly
Grab
Effluent
Total Mercury4, ng/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Barium
1,0 mg/L
1,0 mg/L
Monthly/Quarterly
Grab
Effluent
Total Iron, mg/L
Monthly/Quarterly
Grab
Effluent
Total Manganese, fag/L
Monthly/Quarterly
Grab
Effluent
Total Zinc, fag/L
Monthly/Quarterly
Grab
Effluent
Total Arsenic
10.0 fag/L
50.0 fag/L
Monthly/Quarterly
Grab
Effluent
Total Cadmium
2.0 fag/L
15.0
lag/L
Monthly/Quarterly
Grab
Effluent
Total Chromium
50.0 fag/L
1,022.0 lag/L
Month' /Quarterly
Grab
Effluent
Total Copper, lag/L
Monthly/Quarterly
Grab
Effluent
Total Lead, fag/L
25.Ofag/L
33.8 lag/L
Monthly/Quarterly
Grab
Effluent
Total Nickel
25.0 fag/L
25.0 fag/L
Monthly/Quarterly
Grab
Effluent
Total Selenium
5.0 fag/L
56.0 fag/L
Monthly/Quarterly
Grab
Effluent
Nitrate as N
10.0 mg/L
10.0 mg/L
Monthly/Quarterly
Grab
Effluent
Sulfates
250.0 mg/L
250.0 mg/L
Month' /Quarterly
Grab
Effluent
Chlorides
250,0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
TDS
500.0 mg/L
500.0 mg/L
Month' /Qu arterly
Grab
Effluent
Total Hardness, mg/L
100.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
TSS, mg/L
30.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
Oil and Grease
15.0 mg/L
20.0 mg/L
Monthly/Quarterly
Grab
Effluent
Temperature, OC
Monthly/Quarterly
Grab
Effluent
Specific Conductance, prnho/cm
Monthly/Quarterly
Grab
Effluent
Notes:
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.).
2. The facility shall conduct monthly sampling from the effective date of the permit. After one year
from the effective date of the permit the monitoring will be reduced to quarterly
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall use EPA method 1631E.
If the facility is unable to obtain a seep sample due to the dry or low flow conditions
preventing the facility from obtaining a representative sample, the "no flow" should be
reported on the DMR. This requirement is established in the Section D of the Standard
Conditions and 40 CFR 122.41 U).
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Page 17 of 27

Permit NC0004961
A. (24.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
104) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.)
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 104 - Seep Discharge. Such discharges shall be
limited and monitored' by the Permittee »s enerifiPrl hPlnIzr
EFFLUENT
CHARACTERISTICS
LIMITS1
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum
Measurement
Frequei
Sample Type
Sample Location
Flow, MGD
Monthly/Quarterly
Estimate
Effluent
f-13
Monthly/QuarteqL
Grab
Effluent
Fluoride
1.8 mg/L
1.8 mg/L
Monthly/Quarterly
Grab
Effluent
Total Mercury4, ng/L
Monthly/Quarterly
Grab
Effluent
Total Barium
1.0 mg/L
1.0 mg/L
Monthly/Quarterly
Grab
Effluent
Total Iron, mg/L
Monthly/Quarterly
Grab
Effluent
Total Manganese,
lag/L
Monthly/Quarterly
Grab
Effluent
Total Zinc,
lag/L
Monthly/Quarterly
Grab
Effluent
Total Arsenic
10.0 lag/L
50.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Cadmium
2.0 g/L
15.0 g/L
Monthly/Quarterly
Grab
Effluent
Total Chromium
50.0 lag/L
1,022.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Copper,
lag/L
Monthly/Quarterly
Grab
Effluent
Total Lead,
lag/L
25.Olag/L
33.8 lag/L
Monthly/Quarterly
Grab
Effluent
Total Nickel
25.0 lag/L
25.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Selenium
5.0 lag/L
56.0 lag/L
Monthly/Quarterly
Grab
Effluent
Nitrate as N
10.0 mg/L
10.0 mg/L
Monthly/Quarterly
Grab
Effluent
Sulfates
250.0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
Chlorides
250.0 mg/L
250.0 mg/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
TDS
500.0 mg/L
500.0 mg/L
Month' /Quarter)y.
Grab
Effluent
Total Hardness, mg/L
100.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
TSS, mg/L
30.0 mg/L
100.0 mg/L
Monthly/Quarter]y
Grab
Effluent
Oil and Grease
15.0 mg/L
20.0 mg/L
Monthly/Quarterly
Grab
Effluent
Temperature,
0C
Monthly/Quarterly
Grab
Effluent
Specific Conductance, lamho/cm
Monthly/Quarterly
Grab
Effluent
iv v Ica:
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.).
2. The facility shall conduct monthly sampling from the effective date of the permit. After one year
from the effective date of the permit the monitoring will be reduced to quarterly
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall use EPA method 1631E.
If the facility is unable to obtain a seep sample due to the dry or low flow conditions
preventing the facility from obtaining a representative sample, the "no flow" should be
reported on the DMR. This requirement is established in the Section D of the Standard
Conditions and 40 CFR 122.41 (j).
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Page 18 of 27

Permit NC0004961
A. (25.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
105) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 105 - Seep Discharge. Such discharges shall be
limited and monitored' by the Permittee as sbecified below:
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average;
Daily
Maximum"
Measurement
Frequency2
Sample Type
Sample Location
Flow, MGD
Monthly/Quarterly
Estimate
Effluent
pH3
Month' /Quarterly
Grab
Effluent
Fluoride
1.8 mg/L
1.8 mg/L
Monthly/Quarter'Monthly/QuarteqL
Grab
Effluent
Total Mercur 4, ng/L
Month' /Quarter'
Grab
Effluent
Total Barium
1.0 mg/L
1.0 mg/L
Monthly/Quarterly
Grab
Effluent
Total Iron, mg/L
Monthly/Quarterly
Grab
Effluent
Total Manganese, lag/L
Monthly/Quarterly
Grab
Effluent
Total Zinc, lag/L
Monthly/Quarterly
Grab
Effluent
Total Arsenic
10.0 lag/L
50.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Cadmium
2.0 lag/L
15.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Chromium
50.0 g/L
1,022.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Copper, lag/L
Month' /Quarterly
Grab
Effluent
Total Lead, lag/L
25.Opg/L
33.8 lag/L
Monthly/Quarterly
Grab
Effluent
Total Nickel
25.0 lag/L
25.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Selenium
5.0 lag/L
56,0 lag/L
Monthly/Quarterly
Grab
Effluent
Nitrate as N
10.0 mg/L
10.0 mg/L
Monthly/Quarterly
Grab
Effluent
Sulfates
250.0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
Chlorides
250.0 mg/L
250.0 mg/L.
Month ly/Quarterly
Grab
Effluent
TDS
500.0 mg/L
500.0 mg/L
Monthly/Quarterly
Grab
Effluent
Total Hardness, mg/L
100.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
TSS, mg/L
30.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
Oil and Grease
15.0 mg/L
20.0 mg/L
Monthly/Quarterly
Grab
Effluent
Temperature, OC
Monthly/Quarterly
Grab
Effluent
Specific Conductance, prnho/cm
Monthly/Quarterly
Grab
Effluent
Notes:
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.).
2. The facility shall conduct monthly sampling from the effective date of the permit. After one year
from the effective date of the permit the monitoring will be reduced to quarterly
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall use EPA method 1631E.
If the facility is unable to obtain a seep sample due to the dry or low flow conditions
preventing the facility from obtaining a representative sample, the "no flow" should be
reported on the DMR. This requirement is established in the Section D of the Standard
Conditions and 40 CFR 122.41 (j).
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Page 19 of 27

Permit NC0004961
A. (26.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
106) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 106 - Seep Discharge. Such discharges shall be
limited and monitored' by the Permittee ns snpr.ifiPr] hPlnure
EFFLUENT
CHARACTERISTICS
LIMITS]
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum
Measurement
Frequency2
Sample Type
Sample Location
Flow, MGD
Monthly/Quarterly
Estimate
Effluent
pH3
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Fluoride
1.8 mg/L
1.8 mg/L
Monthly/Quarterly
Grab
Effluent
Total Mercury4, ng/L
Monthly/Quarterly
Grab
Effluent
Total Barium
1.0 mg/L
1.0 mg/L
Monthly/Quarterly
Grab
Effluent
Total Iron, mg/L
Monthly/Quarterly
Grab
Effluent
Total Manganese,
pg/L
Monthly/Quarterly
Grab
Effluent
Total Zinc, pg/L
Monthly/Quarterly
Grab
Effluent
Total Arsenic
10.0 pg/L
50.0 pg/L
Monthly/Quarterly
Grab
Effluent
Total Cadmium
2.0 Ng/L
15.0 pg/L
Monthly/Quarterly
Grab
Effluent
Total Chromium
50.0 g/L
1,022.0 pg/L
Month' /Quarterly
Grab
Effluent
Total Copper,
pg/L
Monthly/Quarterly
Grab
Effluent
Total Lead,
pg/L
25.Opg/L
33.8 Ng/L
Monthly/Quarterly
Grab
Effluent
Total Nickel
25.0 pg/L
25.0 Ng/L
Monthly/Quarterly
Grab
Effluent
Total Selenium
5.0 pg/L
56.0 pg/L
Monthly/Quarterly
Grab
Effluent
Nitrate as N
10.0 mg/L
10.0 mg/L
Monthly/Quarterly
Grab
Effluent
Sulfates
250.0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
Chlorides
250.0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
TDS
500.0 mg/L
500,0 mg/L
Month ly/QuarteqK.
Grab
Effluent
Total Hardness, mg/L
100.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
TSS, mg/L
30.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
Oil and Grease
15.0 mg/L
20,0 mg/L
Monthly/Quarterly
Grab
Effluent
Temperature,
OC
Monthly/Quarterly
Grab
Effluent
Specific Conductance, Hmho/cm
Monthly/Quarterly
Grab
Effluent
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.).
2. The facility shall conduct monthly sampling from the effective date of the permit. After one year
from the effective date of the permit the monitoring will be reduced to quarterly
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall use EPA method 1631E.
If the facility is unable to obtain a seep sample due to the dry or low flow conditions
preventing the facility from obtaining a representative sample, the "no flow" should be
reported on the DMR. This requirement is established in the Section D of the Standard
Conditions and 40 CFR 122.41 O).
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Page 20 of 27

Permit NCOOO4961
A. (27.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
107) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 107 - Seep Discharge. Such discharges shall be
limited and monitored' by the Permittee as specified below:
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average;
Daily
Maximum
Measurement
Frequencyz
Sample Type (
Sample Location
Flow, MGD
Monthly/Quarterly
Estimate
Effluent
pH3
Month' /Quarterly
Grab
Effluent
Fluoride
1.8 mg/L
1.8 mg/L
Monthly/Quarterly
Grab
Effluent
Total Mercur 4, ng/L
Monthly/Quarterly
Grab
Effluent
Total Barium
1.0 mg/L
1.0 mg/L
Monthly/Quarterly
Grab
Effluent
Total Iron, mg/L
Monthly/Quarterly
Grab
Effluent
Total Manganese, pg/L
Monthly/Quarterly
Grab
Effluent
Total Zinc, pg/L
Monthly/Quarterly
Grab
Effluent
Total Arsenic
10.0 pg/L
50.0 pg/L
Monthly/Quarterly
Grab
Effluent
Total Cadmium
2.0 pg/L
15.0 pg/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Chromium
50.0 pg/L
1,022.0
pg/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Copper, Ng/L
Month' /Quarterly
Grab
Effluent
Total Lead, pg/L
25.Opg/L
33.8 pg/L
Monthly/Quarterly
Grab
Effluent
Total Nickel
25.0 Ng/L
25.0 pg/L
Monthly/Quarterly
Grab
Effluent
Total Selenium
5.0 pg/L
56.0 pg/L
Monthly/Quarterly
Grab
Effluent
Nitrate as N
10.0 mg/L
10.0 mg/L
Monthly/Quarterly
Grab
Effluent
Sulfates
250.0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
Chlorides
250.0 mg/L
250.0 mg/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
TDS
500.0 mg/L
500.0 mg/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Hardness, mg/L
100.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
TSS, mg/L
30.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
Oil and Grease
15.0 mg/L
20,0 mg/L
Monthly/Quarterly
Grab
Effluent
Temperature, OC
Monthly/Quarterly
Grab
Effluent
Specific Conductance, pmho/cm
Monthly/Quarterly
Grab
Effluent
1Votes:
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.).
2. The facility shall conduct monthly sampling from the effective date of the permit. After one year
from the effective date of the permit the monitoring will be reduced to quarterly
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall use EPA method 1631E.
If the facility is unable to obtain a seep sample due to the dry or low flow conditions
preventing the facility from obtaining a representative sample, the "no flow" should be
reported on the DMR. This requirement is established in the Section D of the Standard
Conditions and 40 CFR 122.41 (j).
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Page 21 of 27

Permit NC0004961
A. '(28.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
108) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 108 Seep Discharge. Such discharges shall be
limited and monitored' by the Permittee as specified below$
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum`
Measurement
Frequency
Sample Type
Sample Location
Flow, MGD
Monthly/Quarterly
Estimate
Effluent
pH3
Month ly/Quarterly
Grab
Effluent
Fluoride
1.8 mg/L.
1.8 mg/L
Monthly/Quarterly
Grab
Effluent
Total Mercur 4, ng/L
Monthly/Quarterly
Grab
Effluent
Total Barium
1.0 mg/L
1.0 mg/L
Monthly/Quarterly
Grab
Effluent
Total Iron, mg/L
Monthly/Quarterly
Grab
Effluent
Total Manganese, lug/L
Monthly/Quarterly
Grab
Effluent
Total Zinc, lug/L
Monthly/Quarterly
Grab
Effluent
Total Arsenic
10.0 pg/L
50.0 pg/L
Monthly/Quarterly
Grab
Effluent
Total Cadmium
2.0 pg/L
15.0 pg/L
Month' /Q arterly
Grab
Effluent
Total Chromium
50.0 Hg/L
1,022.0 fag/L
Month' /Quarterly
Grab
Effluent
Total Copper, pg/L
Month' /Quarter) y
Grab
Effluent
Total Lead, pg/L
25.ONg/L
33.8 pg/L
Monthly/Quarterly
Grab
Effluent
Total Nickel
25.0 Ng/L
25.0 pg/L
Month ly/Qu arterly
Grab
Effluent
Total Selenium
5.0 pg/L
56.0 pg/L
Monthly/Quarterly
Grab
Effluent
Nitrate as N
10.0 mg/L
10.0 mg/L
Monthly/Quarterly
Grab
Effluent
Sulfates
250.0 mg/L
250,0 mg/L
Monthly/Quarterl
Grab
Effluent
Chlorides
250,0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
TDS
500.0 mg/L
500,0 mg/L
Month ly/Quarterly
Grab
Effluent
Total Hardness, mg/L
100.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
TSS, mg/L
30.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
Oil and Grease
15.0 mg/L
20.0 mg/L
Monthly/Quarterly
Grab
Effluent
Temperature, OC
Monthly/Quarterly
Grab
Effluent
Specific Conductance,
Hmho/cm
Monthly/Quarterly
Grab
Effluent
iv ores:
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.).
2. The facility shall conduct monthly sampling from the effective date of the permit. After one year
from the effective date of the permit the monitoring will be reduced to quarterly
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall use EPA method 1631E.
If the facility is unable to obtain a seep sample due to the dry or low flow conditions
preventing the facility from obtaining a representative sample, the "no flow" should be
reported on the DMR. This requirement is established in the Section D of the Standard
Conditions and 40 CFR 122.41 (j).
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Page 22 of 27

Permit NC0004961
A. (29.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
109) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 109 - Seep Discharge. Such discharges shall be
limited and monitored' by the Permittee as sbecified below:
EFFLUENT
CHARACTERISTICS
LIMITS f
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum
Measurement
FrequenC' 2
Sample Type "
Sample Location
Flow, MGD
Monthly/Quarterly
Estimate
Effluent
pH3
Monthly/Quarterly
Grab
Effluent
Fluoride
1.8 mg/L
1.8 mg/L
Monthly/Quarterly
Grab
Effluent
Total Mercury4, ng/L
onthly/Quarterly
Grab
Effluent
Total Barium
1.0 mg/L
1,0 mg/L
Monthly/Quarterly
Grab
Effluent
Total Iron, mg/L
Monthly/Quarterly
Grab
Effluent
Total Manganese, lag/L
Monthly/Quarterly
Grab
Effluent
Total Zinc, lag/L
Monthly/Quarterly
Grab
Effluent
Total Arsenic
10.0 lag/L
50.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Cadmium
2.0 lag/L
15.0
lag/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Chromium
50.0 lag/L
1,022.0 lag/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Copper, lag/L
Monthly/Quarterly
Grab
Effluent
Total Lead, lag/L
2530pg/L
33.8 lag/L
Monthly/Quarterly
Grab
Effluent
Total Nickel
25.0 lag/L
25.0 lag/L
Mont
hly/Quarterly
Grab
Effluent
Total Selenium
5.0 lag/L
56,0
lag/L
Monthly/Quarterly
Grab
Effluent
Nitrate as N
10.0 mg/L
10.0 mg/L
Monthly/Quarterly
Grab
Effluent
Sulfates
250.0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
Chlorides
250.0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
TDS
500.0 mg/L.
500.0 mg/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Hardness, mg/L
100.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
TSS, mg/L
30.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
Oil and Grease
15.0 mg/L
20.0 mg/L
Monthly/Quarterly
Grab
Effluent
Temperature, OC
Monthly/Quarterly
Grab
Effluent
Specific Conductance, lamho/cm
Monthly/Quarterly
Grab
Effluent
ayotes:
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.).
2. The facility shall conduct monthly sampling from the effective date of the permit. After one year
from the effective date of the permit the monitoring will be 4 reduced to quarterly
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall use EPA method 1631E.
If the facility is unable to obtain a seep sample due to the dry or low flow conditions
preventing the facility from obtaining a representative sample, the "no flow" should be
reported on the DMR. This requirement is established in the Section D of the Standard
Conditions and 40 CFR 122.41 (j).
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Page 23 of 27

Permit NC0004961
A. (30.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
110) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 110 - Seep Discharge. Such discharges shall be
limited and monitoredi by the Perm ittep ac gnprrifiari hPInIXTO
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum
Measurement
Frequency2
Sample Type
Sample Location
Flow, MGD
Monthly/Quarterly
Estimate
Effluent
H3
Month ly/Quarterly
Grab
Effluent
Fluoride
1.8 mg/L
1.8 mg/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Mercury4, ng/L
Month/ /Quarterly
Grab
Effluent
Total Barium
1.0 mg/L
1.0 mg/L
Monthly/Quarterly
Grab
Effluent
Total Iron, mg/L
Monthly/Quarterly
Grab
Effluent
Total Manganese, lag/L
Monthly/Quarterly
Grab
Effluent
Total Zinc, lag/L
Monthly/Quarterly
Grab
Effluent
Total Arsenic
10.0 lag/L
50.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Cadmium
2.0 g/L
15.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Chromium
50.0 lag/L
1,022.0 lag/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Copper, g/L
Monthly/Quarterly
Grab
Effluent
Total Lead, lag/L
25.Olag/L
33.8 lag/L
Monthly/Quarterly
Grab
Effluent
Total Nickel
25.0 tag/L
25.0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Selenium
5.0 lag/L
56.0 lag/L
Monthly/Quarterly
Grab
Effluent
Nitrate as N
10.0 mg/L
10.0 mg/L
Monthly/Quarterly
Grab
Effluent
Sulfates
250.0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
Chlorides
250.0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
TDS
500.0 mg/L
500.0 mg/L
Month/ /Quarterly
Grab
Effluent
Total Hardness, mg/L
100.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
TSS, mg/L
30.0 mg/L
100.0 mg/L
Month/ /Quarterly
Grab
Effluent
Oil and Grease
15.0 mg/L
20.0 mg/L
Monthly/Quarterly
Grab
Effluent
Temperature, OC
Monthly/Quarterly
Grab
Effluent
Specific Conductance,
prnho/cm
Monthly/Quarterly
Grab
Effluent
iv u yes:
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.).
2. The facility shall conduct monthly sampling from the effective date of the permit. After one year
from the effective date of the permit the monitoring will be reduced to quarterly
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall use EPA method 1631E.
If the facility is unable to obtain a seep sample due to the dry or low flow conditions
preventing the facility from obtaining a representative sample, the "no flow" should be
reported on the DMR. This requirement is established in the Section D of the Standard
Conditions and 40 CFR 122.41 (j).
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Page 24 of 27

Permit NC0004961
A. (31.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
111) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 111 - Seep Discharge. Such discharges shall be
limited and monitored) by the Permittee ar enPoifiPA }vPln�x.•
EFFLUENT "
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average;
Daily
Maximum
Measurement
Frequen,
Sample Type
Sample Location
Flow, MGD
Monthly/Quarterly
Estimate
Effluent
pH3
Monthly/Quarterly
Grab
Effluent
Fluoride
1.8 mg/L
1.8 mg/L
Monthly/Quarter)
Grab
Effluent
Total Mercur 4, ng/L
Monthly/Quarterly
Grab
Effluent
Total Barium
1.0 mg/L
1.0 mg/L
Monthly/Quarterly
Grab
Effluent
Total Iron, mg/L
Monthly/Quarterly
Grab
Effluent
Total Manganese,
lag/L
Monthly/Quarterly
Grab
Effluent
Total Zinc,
lag/L
Monthly/Quarterly
Grab
Effluent
Total Arsenic
10.0 lag/L
50,0 lag/L
Monthly/Quarterly
Grab
Effluent
Total Cadmium
2.0 Ng/L
15.0 lag/L
Monthly/QuarteqL
Grab
Effluent
Total Chromium
50.0 lag/L
11022.0 g/L
Monthly/Quarterly
FGrab
Effluent
Total Copper, g/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Lead, lag/L
25.Opg/L
33.8 lag/L
Monthly/Quarterly
Grab
Effluent
Total Nickel
25.0 lag/L
25.0 tag/L
Monthly/Quarterly
Grab
Effluent
Total Selenium
5.0 lag/L
56.0 lag/L
Monthly/Quarterly
Grab
Effluent
Nitrate as N
10.0 mg/L
10.0 mg/L
Monthly/Quarterly
Grab
Effluent
Sulfates
250.0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
Chlorides
250.0 mg/L
250.0 mg/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
TDS
500.0 mg/L
500.0 mg/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Hardness, mg/L
100.0 mg/L.
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
TSS, mg/L
30.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
Oil and Grease
15.0 mg/L
20.0 mg/L
Monthly/Quarterly
Grab
Effluent
Temperature,
OC
Month ly/Quarterly
Grab
Effluent
Specific Conductance, famho/cm
AT 1
Monthly/Quarterly
Grab
Effluent
ivvLc�-J.
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.) .
2. The facility shall conduct monthly sampling from the effective date of the permit. After one year
from the effective date of the permit the monitoring will be reduced to quarterly
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall use EPA method 1631E.
If the facility is unable to obtain a seep sample due to the dry or low flow conditions
preventing the facility from obtaining a representative sample, the "no flow" should be
reported on the DMR. This requirement is established in the Section D of the Standard
Conditions and 40 CFR 122.41 (j).
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Page 25 of 27

Permit NC0004961
A. (32.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall
112) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from outfall 112 - Seep Discharge. Such discharges shall be
limited and monitored' by the Permittee as specified below:
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum
Measurement
Frequencyz
Sample Type
Sample Location
Flow, MGD
Monthly/Quarterly
Estimate
Effluent
H3
Month ly/Quarterly
Grab
Effluent
Fluoride
1.8 mg/L
1.8 mg/L
Monthly/Quarterly
Grab
Effluent
Total Mercur 4, ng/L
Monthly/Quarterly
Grab
Effluent
Total Barium
1.0 mg/L
1.0 mg/L
Monthly/Quarterly
Grab
Effluent
Total Iron, mg/L
Monthly/Quarterly
Grab
Effluent
Total Manganese, tag/L
Monthly/Quarterly
Grab
Effluent
Total Zinc, tag/L
Monthly/Quarterly
Grab
Effluent
Total Arsenic
10.0 tag/L
50.0 tag/L
Monthly/Quarterly
Grab
Effluent
Total Cadmium
2.0 tag/L
15.0
tag/L
Monthly/Quarterly
Grab
Effluent
Total Chromium
50.0 g/L
1,022.0 tag/L
Monthly/Quarterly
Grab
Effluent
Total Copper, tag/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Lead, pg/L
25.Opg/L
33.8 tag/L
Monthly/Quarterly
Grab
Effluent
Total Nickel
25.0 tag/L
25.0
tag/L
Monthly/Quarterly
Grab
Effluent
Total Selenium
5.0 pg/L
56.0 tag/L
Monthly/Quarterly
Grab
Effluent
Nitrate as N
10.0 mg1L
10.0 mg/L
Monthly/Quarterly
Grab
Effluent
Sulfates
250.0 mg/L
250.0 mg/L
Monthly/Quarterly
Grab
Effluent
Chlorides
250.0 mg/L
250.0 mg/L
Monthly/Qua terl
Grab
Effluent
TDS
500.0 mg/L
500.0 mg/L
Monthly/QuarterlyMonthly/Quarterly
Grab
Effluent
Total Hardness, mg/L
100.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
TSS, mg/L
30.0 mg/L
100.0 mg/L
Monthly/Quarterly
Grab
Effluent
Oil and Grease
15.0 mg/L
20.0 mg/L
Monthly/Quarterly
Grab
Effluent
Temperature, OC
Monthly/Quarterly
Grab
Effluent
Specific Conductance, pmho/cm
Monthly/Quarterly
Grab
Effluent
Notes:
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (18.).
2. The facility shall conduct monthly sampling from the effective date of the permit. After one year
from the effective date of the permit the monitoring will be reduced to quarterly
3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
4. The facility shall use EPA method 1631E.
If the facility is unable to obtain a seep sample due to the dry or low flow conditions
preventing the facility from obtaining a representative sample, the "no flow" should be
reported on the DMR. This requirement is established in the Section D of the Standard
Conditions and 40 CFR 122.41 (j).
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Page 26 of 27

Permit NC0004961
Appendix A
Plan for Identification of New Discharges (attached).
Page 27 of 27

Duke Energy Corporation
Riverbend Steam Station
State Grid/Ouad: F15SW/Mt. Island Lake, NC
Receiving St reams: Catawba River Sub -Basin: 03-0&33
Stream Class: WS4V & B-CA Permitted Flow: Not limited
Drainage Basin: Catawba River Basin
Latitude (001): 35021' 28" N Longitude (001): 800 58' 12" W
Latitude (002): 35022' 06" N Longitude (002): 80057' 31" W
Latitude (002A): 35021' 51" N Longitude (002A): 800 58' 11" W
Latitude (011): 35021' 38" N Longitude (011): 800 58' 38" W
Map not to scale
Facility
Location
NOY'tj2 NPDES Perinit No. NC0004961
Gaston Coun

2017 Comprehensive Site Assessment Update October 2017
Riverbend Steam Station
NCDEQ CORRESPONDENCE - REVISED
INTERIM MONITORING PLAN
SynTerra

Water Resources
Environmental Quality
October 19, 2017
Paul Draovitch
Senior Vice President
Environmental, Health & Safety
Duke Energy
526 South Church Street
Mail Code EC3XP
Charlotte, North Carolina 28202
Subject: Revised Interim Monitoring Plans for 14 Duke Energy Facilities
Fourth Quarter 2017
Dear Mr. Draovitch:
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. JAY ZIMMERMAN
Director
The North Carolina Department of Environmental Quality (DEQ) is providing the attached revised
Interim Monitoring Plans (IMPs) for the respective coal ash facilities. Per our agreement, the DEQ
will be providing Duke Energy with updated IMPs quarterly until the individual facility Corrective
Action Plans are approved. Also, per our agreement, Duke Energy will include and begin sampling
any newly installed groundwater assessment wells as part of the facility IMP and the DEQ will
formally include it in the subsequent updated quarterly IMP.
The attached IMPs only contain references to groundwater monitoring locations. Sampling at
surface water locations that were identified as part of the May 1, 2017 communication from DEQ
to Duke Energy regarding revised IMPs at the facilities is expected to continue pending further
notice. DEQ may elect to provide Duke Energy with additional surface sampling locations to
incorporate into the revised IMPs at a future time. For clarification, we have also provided the
minimum expected groundwater sampling analyte list.
The attached revised facility IMPs shall be conducted on a quarterly basis commencing the fourth
quarter of calendar year 2017 pursuant to 15A NCAC 02L .0110, until Corrective Action Plans
are accepted for the individual facilities or as directed otherwise by the DEQ. The quarterly
sampling events will be conducted in conjunction with planned compliance monitoring sampling
events for three quarters during the calendar year, supplemented with an additional sampling event
conducted at each facility in order to provide four rounds of monitoring data to evaluate seasonal
fluctuations during a year -long timeframe. If sampling an individual groundwater location is
problematic, please call the Regional Office that manages the facility to discuss issues. Any
changes to IMPs and sampling requirements must be discussed with the respective Regional
Offices and coordinated by official correspondence from the DEQ Central Office.
Since Duke Energy will submit updated Comprehensive Site Assessments in the near future, the
requirement for an annual monitoring report submitted by April 30th for each respective coal
State of North Carolina I Environmental Quality I Division of Water Resources
Water Quality Regional Operations Section
1636 Mail Service Center I Raleigh, North Carolina 27699-1636
919-707-9129

facility as set forth in the May 1, 2017 letter will be extended to a date in 2018 that will be later
defined.
In order to optimize the groundwater monitoring at each facility, DEQ will be removing the
groundwater monitoring condition from the NPDES permits as they are reissued. Duke Energy
shall continue to monitor the compliance wells separately under the individual NPDES permits
until the NPDES permits are reissued with no groundwater monitoring condition. At that time,
the compliance wells shall continue to be monitored per the attached revised IMPs under the
authority of 15A NCAC 02L .0110.
The DEQ is open to consider further optimization of the IMPS following a qualitative and
quantitative review of site -specific data. A thorough analysis of spatial and temporal trends related
to contaminant distribution that include determination of background conditions and identification
of areas impacted by coal ash residuals must be provided as a decision framework to support
improvements to long-term monitoring programs.
If you have any questions, please feel free to contact Steve Lanter at [phone].
Sincerely,
S. Jay Zimmerman, P.G., Director
Division of Water Resources
Attachments: Revised Interim Monitoring Plans for the 14 coal ash facilities
cc: WQROS Regional Offices
WQROS Central File Copy

Revised Riverbend Steam Station Interim Monitoring Plan — Groundwater Only
Wells to be
Sampled
Sample for
Radionuclides
X
Regional Office Notes
AB -ID
Measure pH, if still >10, not sample.
AB -IS
AB-2D
AB-2S
AB-8D
AB-8S
BG-1DA
BG-1 S
BG-2BR
BG-2D
BG-2S
BG-3D
BG-3S
BG-4BR
X
BG-4D
X
BG-4S
X
BG-5BR
BG-5D
C-1BRUA
C-1 S
C-2D
C-2S
GWA-10BRU
Measure pH, if still >10, not sample.
GWA-10S
GWA-11D
GWA-11 S
GWA-12D
X
GWA-12S
X
GWA-13D
GWA-13S
GWA-14D
GWA-14S
GWA-15D
GWA-15S
X
GWA-1BRU
GWA-1 S
GWA-20BR
Measure pH, if still >10, not sample.
Riverbend Steam Station Page I of 3 October 1, 2017

GWA-20DA
GWA-20S
GWA-21BR
GWA-21D
GWA-21 S
GWA-22BR-A
X
GWA-22D
X
GWA-22S
X
GWA-23BR
Measure pH, if still >10, not sample.
GWA-23DA
GWA-23S
GWA-2BR
X
GWA-2BRU
X
Measure pH, if still >10, not sample.
GWA-2S
X
GWA-3BR
GWA-3D
GWA-3S-A
GWA-4BR
Measure pH, if still >10, not sample.
GWA-4D
X
GWA-4S
X
GWA-5D
GWA-5S
GWA-6D
X
Measure pH, if still >10, not sample.
GWA-6S
X
GWA-7BR
GWA-7D
GWA-7S
GWA-8D
X
GWA-8S
X
GWA-9BR
X
GWA-9D
X
GWA-9S
X
MW-10
X
MW-11DR
MW-11 SR
MW-13
MW-14
X
MW-15
MW-15BR
MW-15DA
MW-lD
Riverbend Steam Station Page 2 of 3 October 1, 2017

MW-lS
MW-2D
MW-2S-A
MW-3D
MW-3S
MW-4D
MW-4S
MW-5D
MW-5S
MW-6D
MW-6S
MW-7BRA
X
MW-7D
X
MW-7SR
X
MW-8D
MW-8I
MW-8S
MW-9
X
MW-9BRA
X
MW-9DA
X
Minimum Parameters to be Analyzed
Aluminum
Boron
Copper
Mercury
Selenium
Thallium
Alkalinity
Cadmium
Hexavalent
Molybdenum
Sodium
Total Organic
Chromium
Carbon
Total
Antimony
Calcium
Iron
Nickel
Strontium
Combined
Uranium
Total
Arsenic
Chloride
Lead
Potassium
Sulfate
Suspended
Solids
Barium
Chromium
Magnesium
Radium 226
Sulfide
Vanadium
Total
Beryllium
Cobalt
Manganese
Radium 228
Dissolved
Zinc
Solids
Riverbend Steam Station Page 3 of 3 October 1, 2017

2017 Comprehensive Site Assessment Update October 2017
Riverbend Steam Station
SynTerra
DEQ BACKGROUND LOCATION APPROVALS -
J U LY 7, 2017

Water Resources
Environmental Quality
July 7, 2017
Paul Draovitch
Senior Vice President
Environmental, Health & Safety
Duke Energy
526 South Church Street
Mail Code EC3XP
Charlotte, North Carolina 28202
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. JAY ZIMMERMAN
Director
Subject: Duke Energy Submittal - Background Soil and Groundwater Statistical Methodology for
14 Duke Energy Facilities a -mails submitted May 26, 2017
Dear Mr. Draovitch:
The North Carolina Department of Environmental Quality (DEQ) has received and reviewed the May 26,
2017 a -mails from Duke Energy providing background soil and groundwater datasets. These site -specific
data were compiled following direction provided in an April 28, 2017 letter from DEQ to address technical
concerns related to site assessment and corrective action along with revisions to the Statistical Methods for
Developing Reference Background Concentrations for Groundwater and Soil at Coal Ash Facilities (HDR
Engineering, Inc. and Synterra Corporation, January 2017) technical memorandum (TM).
Attached are reviews of the soil and groundwater datasets for each Duke Energy coal ash facility. These
reviews identify data that are appropriate for inclusion in the statistical analysis to determine background
threshold values for both media following the methodology outlined in the TM. Additional requirements
related to soil and groundwater background determinations are specified for each facility. With approval
of these background datasets, preliminary background determinations for each media are expected to be
completed and provided within 30 days of receipt of this letter for those facilities that will submit
Comprehensive Site Assessments (CSAs) by October 31, 2017. For all other facilities that will submit
CSAs later, preliminary background determinations for each media are due within 60 days of receipt of this
letter.
If you have any questions, please feel free to contact Steve Lanter at [phone].
Sincerely,
S. Jayinlerman, P.G., Director
Division of Water Resources
Attachments: DEQ Background Dataset Reviews for the 14 coal ash facilities
cc: WQROS Regional Offices
WQROS Central File Copy
State of North Carolina I Environmental Quality I Division of Water Resources
Water Quality Regional Operations Section
1636 Mail Service Center I Raleigh, North Carolina 27699-1636
919-707-9129

Allen Steam Station
Groundwater
• The following background wells are appropriate for use:
o BG-lS, BG-2S/D, BG-4S/DBR, GWA-19S, GWA-21SBR, GWA-23S, and
GWA-26S/D
• The following background wells are NOT appropriate for use:
o BG-lD — Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
o BG-2BR — Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included. (Note: while there does
appear to be a topographic divide additional evaluation is needed to determine if
this is just a shallow divide or if it is indeed a divide for all flow layers.)
o AB-4S/DBR — Groundwater elevations below the nearest pond elevation has been
observed in several sampling events since installation of AB-4S/D. Due to the
potential for groundwater flow from the basin toward/through the well cluster this
location should NOT be considered a background location. AB-4BR should also
NOT be considered a background location (potential vertical migration from the
unconsolidated zone). (Note: Duke will evaluate further regarding pond elevation
utilized for assessment.)
o GWA-21D —Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
• All identified sample event dates are appropriate for use.
• The dataset for the shallow flow layer meets the minimum requirement of 10 samples after
excluding samples.
• The dataset for the deep flow layer does NOT meet the minimum requirement of 10
samples after excluding samples. Additional samples are require .
• The dataset for the bedrock flow layer does NOT meet the minimum requirement of 10
samples after excluding samples. Only 4 valid samples, but when additional evaluation
regarding nearest pond elevation used for the AB-4S/DBR locations is provided additional
samples may be available for inclusion.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
• The following background samples are appropriate for use:
o BG-lD (1.0-2.0), BG-lD (9.0-10.5), BG-1D (19.0-20.5), BG-lD (45-50), BG-2D
(1.0-2.5), BG-2D (8.5-10.0), BG-2D (18.0-20.0), BG-3D (1-2.5), BG-3D (13.5-
15), BG-3D (18.5-20), GWA-14D (10.0-12.0), GWA-8D (38.5-40), and GWA-8D
(48.5-50)
• The following background samples are NOT appropriate for use:
o GWA-15D —Sample is at or immediately adjacent to the waste boundary west of
the ash storage area and was also collected in fill material (according to boring log).
Allen Steam Station Pagel of 2

o GWA-5D —Sample is at or immediately adjacent to the waste boundary east of the
ash basin (immediately downgradient) and was also collected in fill material
(according to the boring log).
• The dataset meets minimum requirement of 10 samples after excluding samples.
• The reporting limits for Antimony and Thallium were above the IHSB PSRG Protection of
Groundwater values. Therefore, the number of useable values in the background dataset
is severely limited for these constituents. Additional samples analyzed at a lower detection
limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Allen Steam Station Page 2 of 2

Asheville Steam Electric Plant
Groundwater
• All identified background wells are appropriate for use.
o MW-101 CB-01, CB-09, CB-09SL, NM-24S, CB-011), AMW-03B, and CB-09BR
o Duke Energy recommended adding wells GW-I, GW-1D, and GW-1BR to the
background dataset. Based on a review of the information provided, these wells
may be added to the background dataset. If these wells are added, the new raw
background dataset should be re -submitted to DWR.
• The datasets for each flow layer meets the minimum requirement of at least 10 samples.
• All identified sample event dates are appropriate for use.
• All identified outliers are acceptable and should be removed from the background dataset.
o If GW-1, GW-ID, and GW-1BR are added to the background dataset then re -test
the new dataset for outliers and re -submit to the DWR, including strikethroughs of
outliers and other unusable data (e.g high pH, high turbidity, autocorrelated data.
Soil
• The following background samples are appropriate for use:
o CB-01 SB (7-8), CB-01 SB (30-31), CB-09 SB (1-2), CB-09 SB (25-27), GW-01
SB (1-2), MW-11SB (1.5-2), MW-12 SB (1.5-2), MW-13SB (1.5-2), MW-13SB
(14.5-15), MW-14SB (1.5-2), MW-22 (1-2), MW-23BR (2-3), and NM-24SB (1-
2)
• The following background samples are NOT appropriate for use:
o MW-08 and MW-09 — Samples are at or immediately adjacent to the waste
boundary and should not be used as background locations, even though the samples
were collected above the seasonal high water table.
o CB-08, MW-03, MW-05, and MW-07 — Downgradient of site contamination.
o MW-13SB (22-22.5) — Sample was collected 3-feet below the water table and
should not be used.
• The dataset meets the minimum requirement of at least 10 samples after excluding samples.
• The reporting limits for Antimony, Thallium, and Selenium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the
background dataset is severely limited for these constituents. Additional samples analyzed
at a lower detection limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Asheville Steam Electric Plant Page 1 of 1

Belews Creek Steam Station
Groundwater
• All identified background wells are appropriate for use:
o BG-2S, BG-3S, MW-202S, MW-3, BG-1D, BG-2D, BG-3D, BG-202D, BG-2BR-
A, and MW-202BR
• The datasets for the shallow and deep flow layers meet the minimum requirement of 10
samples.
• The dataset for the bedrock flow layer does NOT meet the minimum requirement of 10
samples. Additional samples are required.
• All identified sample event dates are appropriate for use.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
• All identified background samples are appropriate for use:
o BG-1D (1-2), BG-1D (11), BG-1D (21), BG-lD (31), BG-2D (1-2), BG-2D (10-
12), BG-2D (20-22), BG-2D (30-32), BG-3S (1-2), BG-3S (10-12), BG-3S (20-
22), GWA-3D (34-35.5), GWA 4S (45-47), GWA-12D (10-12), GWA-12D (15-
17), GWA-12D (20-22), and GWA-12D (25-27)
• The dataset meets the minimum requirement of 10 samples.
• The reporting limits for Antimony, Thallium, and Selenium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the
background dataset is severely limited for these constituents. Additional samples analyzed
at a lower detection limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Belews Creek Steam Station Page 1 of 1

Buck Combined Cycle Station
Groundwater
• The following background wells are appropriate for use.
o BG-18, BG-2S/D, BG-3SBRU, NM-6S/D, GWA-lS, MW-613R, and MW-8S/D
• The following background wells are NOT appropriate for use:
o BG-1D/BR— Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
o BG-2BR — Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
o MW-8BR — Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
• All identified sample event dates are appropriate for use.
• The datasets for each flow layer meets the minimum requirement of 10 samples after excluding
samples.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
The following background samples are appropriate for use:
o BG-lD (1-2), BG-1D (9.8-11.2), BG-1D (16.4-17.9), BG-2D (2), BG-2D (10-11.5),
BG-2D (13.5-15), BG-3BRU (1-2), BG-3BRU (10-10.5), BG-3BRU (20-20.5), GWA-
lOD (3.0), and GWA-11D (19-20.5)
The following background samples are NOT appropriate for use:
o GWA-11) — Sample was collected from 0.3-0.6 ft. bgs. Per IHSB Guidance, these
samples were taken too shallow.
o GWA-6BRU — Sample is located downgradient of the Cells 2 and 3 and within 1 foot
of the water table.
o GWA-7D — Sample is located downgradient of the Cells 2 and 3 and within 1 foot of
the water table.
o GWA-91) — Sample is located downgradient of Cell 1, both sample intervals were
collected in fill material (according to boring log) and one sample interval was
collected within 1 foot of the water table.
o GWA-12S —Sample is located downgradient of the ash basin.
o GWA-22D — Sample is located downgradient of Cell 1 and sample interval was
collected in fill material (according to boring log).
• The dataset meets minimum requirement of 10 samples after excluding samples.
• The reporting limits for Antimony, Thallium, and Selenium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the background
dataset is severely limited for these constituents. Additional samples analyzed at a lower
detection limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing fill
should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Buck Combined Cycle Station Page 1 of 1

Cane Fear Steam Electric Plant
Groundwater
• All identified background wells are appropriate for use:
o MW-15SU, MW-15SL, MW-16S, MW-09, MW-9BR, MW-15BR, and MW-16BR
• The datasets for all flow layers meet the minimum requirement of 10 samples.
• The following sample event dates are NOT appropriate for use:
o MW-15BR
■ 3/2/16 — Less than 60 days from previous sample.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
• The following background samples are appropriate for use:
o BG-01(Geosyntec)(2.0-2.5), BG-02(Geosyntec)(2.0-2.5), BG-03(Geosyntec)(2.0-
2.5), MW-09 SB(2-3), MW-09 SB (6-7), and MW-22 SB (3-4)
• The following background samples are NOT appropriate for use:
o MW-05BR SB(0-2), MW-09 SB(0-2), MW-l0BR SB(0-2), MW-12BR SB(0-2),
MW-15 SB(0-2), MW-20 SB(0-2), MW-22 SB(0-2), and MW-23 SB(0-2) — Per
IHSB Guidance, these samples were taken too shallow.
o BG-04(Geosyntec)(2.0-2.5) and BG-05(Geosyntec)(2.0-2.5) — Samples taken
down -gradient of 1985 Ash Pond.
• The dataset does NOT meet the minimum requirement of 10 samples. Additional samples
are required.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Cape Fear Steam Electric Plant Page 1 of I

James E. Rogers Energy Complex
Groundwater
• All identified background wells are appropriate for use.
o BG-1S, CCPMW-1S, MW-305, MW-325, GWA-245, GWA-255, GWA-30S, BG-
1D, MW-24D, MW-32D, GWA-24D, MW-32BR, CCPMW-ID, MW-24DR,
GWA-24BR, GWA-30BR, MW-22BR, and MW-22DR
• The datasets for all flow layers meet the minimum requirement of 10 samples.
• All identified sample event dates are appropriate for use.
• The following outliers are NOT appropriate for use and should be removed from the
background dataset:
Soil
o Total Dissolved Solids — 10,700,000 ug/L (saprolite)
o Total Dissolved Solids — 4,410,000 ug/L (saprolite)
o Total Dissolved Solids—407,000 ug/L (transition zone)
o Total Dissolved Solids—116,000 ug/L (transition zone)
o Iron — 31200 ug/L (transition zone)
o Vanadium — 3 ug/L (transition zone)
The following background samples are appropriate for use:
o BG-ID (3.5-5), BG-ID (8.5-10), BG-2D (3.5-5), BG-2D (8.5-10), BG-2D (18.5-
20), BG-2D (28.5-30), MW-30D (3.5-5.5), MW-30D (8.5-10), MW-30D (18.5-20),
MW-30D (28.5-30), MW-32D (3.5-5), MW-32D (8.5-10), MW-32D (18.5-20),
MW-32S (22.5-24), MW-42D (28.5-30), and GWA-25D (8.5-10)
The following background samples are NOT appropriate for use:
o BG-lS (3.5-5), BG-IS (8.5-10), MW-30S (4-5), MW-30S (9-10), MW-30S (19-
20), and MW-30S (28-29), — Only analyzed for TOC.
o GWA-1 OD — Located at or immediately adjacent to the waste boundary at Units 1-
4 basin.
o GWA-31D (7), GWA-31D (8.7), and GWA-31BR — Located at or immediately
adjacent to and downgradient of the waste boundary at Unit 5 basin and are adjacent
to a road and parking lot.
o MW-38D (33.5-35) — This location is downgradient of the Unit 5 Inactive Ash
Basin and adjacent to the Broad River.
o GWA-3D (48.5-50) — Location is downgradient of the Unit 5 Inactive Ash Basin.
o GWA-12BRU (20-23.5) — Location is immediately downgradient of Units 1-4
Inactive Ash Basin. May be close to water table and is near the Broad River.
o GWA-21BRU (5) — This sample may be immediately above the water table and
more importantly, the location is potentially downgradient of a basin and is situated
adjacent to the Broad River where there a potentially significant fluctuations of
water levels by a discharge point.
o GWA-22S (3-5) — Location is side gradient of the Active Ash Basin and adjacent
to the Broad River. The sample was collected within the screen interval of the well.
James E. Rogers Energy Complex Page 1 of 2

o GWA-27D (13.5-15) and GWA-27D (24.9) — Location is adjacent to and
downgradient of the impoundment. The sample was collected within the screened
interval of the well.
o NM-40BRU (3.5-5) — Location is adjacent to and downgradient of the Unit 5
Inactive Ash Basin and near the Broad River, and the sample was collected from
within the screened interval.
o GWA-61) (28.5-30) — Location is immediately downgradient of Unit 5 Inactive Ash
Basin and may be close to water table and is near the Broad River.
• The dataset meets the minimum requirement of 10 samples after excluding samples.
• The reporting limits for Antimony, Thallium, and Selenium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the
background dataset is severely limited for these constituents. Additional samples for these
three parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• The following outlier is NOT appropriate for use and should be removed from the
background dataset:
o MW-32S (22.5-24)
■ Arsenic — 7.9 mg/kg
James E. Rogers Energy Complex Page 2 of 2

Dan River Combined Cycle Station
Groundwater
• The following background wells are appropriate for use:
o GWA-9S, BG-11), GWA-9D, MW-231), MW-23BR, BG-5S, BG-51), BG-IOS,
BG-101), and BG-10BR
o GWA-9S/D and BG-IOS/D/BR appear to be appropriate for use; however, further
evaluation will be needed to determine whether these wells are truly located up -
gradient of the ash storages.
• The following background wells are NOT appropriate for use:
o GWA-12S/D —It appears that coal ash constituent boron, have been detected in soil
samples taken from this well.
o MW-20S/D — This well could be impacted by groundwater flowing from the
storage 1 area.
• The datasets for the shallow and deep flow layers meet the minimum requirement of 10
samples after excluding samples.
• The dataset for the bedrock flow layer does NOT meet the minimum requirement of 10
samples. Additional samples are required.
• All identified sample event dates are appropriate for use.
o Provisional background threshold value for hexavalent chromium (shallow flow
layer), vanadium (shallow flow layer), and radionuclides (shallow flow layer) are
based on a limited dataset. Additional samples are required.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
The following background samples are appropriate for use:
o BG-513(1-2), GWA-2D(19-20), GWA-9D(20-21.5), GWA-1O1)(9-10), SB-1(1-2),
SB-1(10-11.5), SB-1(15-16.5), SB-1(20-21.5), SB-1(25-26.5), SB-2(1-2), SB-
2(10-11.5), SB-2(20-21.5), SB-2(30-31.25), SB-2(35-36), SB-2(65-65.3), SB-3(1-
2), SB-3(10-11), SB-3(20-21.5), and SB-3(35-36.5)
The following background samples are NOT appropriate for use:
o BG-1D(0-2) — Per IHSB Guidance, this sample was taken too shallow.
o GWA-3D(5-6.5) — Sample taken in close proximity to Ash Storage 1.
o GWA-6S(9-11) — Sample taken down -gradient of Ash Basin Primary Cell
o GWA-10D(19-20) and GWA-10D(25) — Samples taken down -gradient of Ash
Storage 2.
o GWA-1113(10-11.5) — Sample taken down -gradient of Ash Storage 1.
Th dataset meets minimum requirement of 10 samples after excluding samples.
The reporting limits for Antimony, Thallium, and Selenium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the
background dataset is severely limited for these constituents. Additional samples analyzed
at a lower detection limit for these parameters are necessary.
Dan River Combined Cycle Station Page 1 of 2

• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Dan River Combined Cycle Station Page 2 of 2

H. F. Lee Enerev Complex
Groundwater
• The following background wells are appropriate for use:
o AMW-11S, AMW-12S, AMW-13S, AMW-17S, IMW-01S, IMW-03S, AMW-
11BC, AMW-12BC, AMW-13BC, AMW-16BC, IMW-01BC, IMW-02BC, and
IMW-03BC.
o AMW-016BC —The location maybe near the contact with the Black Creek. Please
confirm.
The datasets for the surficial and Cape Fear flow layers meets the minimum requirement
of 10 samples.
The dataset for the Black Creek flow layer does NOT meet the requirement of 10 samples.
Additional samples are required.
The following sample event dates are NOT appropriate for use.
o AMW-12S
■ 3/1/16 — Less than 60 days from previous sample.
o AMW-13S
■ 3/1/16
—Less than 60 days from previous sample.
o AMW-12BC
■ 3/1/16
— Less than 60 days from previous sample.
o AMW-13BC
■ 3/1/16
— Less than 60 days from previous sample.
o IMW-0lBC
■ 3/4/16
— Less than 60 days from previous sample.
o IMW-02BC
• 3/3116 — Less than 60 days from previous sample.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
The following background samples are NOT appropriate for use:
o AMW-12 SB (5-6) — Sample may have been taken within 1 foot of the seasonal
high water table.
o IMW-05 SB (0-2.5) and IMW-05 SB (4-6). This location is in very close proximity
to the southeast corner of Inactive Basin 3 and possibly influenced by the presence
of the ash basin. Per IHSB Guidance, these samples were taken too shallow.
o AMW-18 SB (0-2.5) and AMW-18 SB (3-5). Samples were collected from the
core of the plume migrating from the Active Basin.
o AMW-04 SB (1-2) and AMW-04 SB (4-5). Samples are located at the western end
of the Active Basin, adjacent to the Neuse River.
o AMW-16BC (19-21).
o AMW-11 (0-2), AMW-12 SB (0-2), AMW-13 SB (0-2), and AMW-16BC (0-2) -
Per IHSB Guidance, these samples were taken too shallow.
H. F. Lee Energy Complex Pagel of 2

• The dataset does NOT meet the requirement of 10 samples. Additional samples are
required.
• The reporting limits for Antimony and Thallium were above the IHSB PSRG Protection of
Groundwater values. Therefore, the number of useable values in the background dataset
is severely limited for these constituents. Additional samples analyzed at a lower detection
limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
H. F. Lee Energy Complex Page 2 of 2

Marshall Steam Station
Groundwater
• The following background wells are appropriate for use.
o GWA-4S/D, GWA-5S/D, GWA-6S/D, GWA-8S/D, GWA-12SBR, BG-3BR, MS-
10, MW-4, and MW-4D
• The following background wells are NOT appropriate for use:
o BG-lBR — Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
o GWA-12D — Recently reinstalled due to water quality issues and reevaluation as
background location is necessary before being included.
• The datasets for each flow layer meets the minimum requirement of 10 samples after
excluding samples.
• All identified sample event dates are appropriate for use.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
• The following background samples are appropriate for use:
o BG-3D(1-2), BG-313(10-12), GWA-2DA(3-5), GWA-2DA(8-10), GWA-4D(52-
53), GWA-5D(27.5-29.0), GWA-14S(3-5), and GWA-14S(8-10)
• The following background samples are NOT appropriate for use:
o GWA-1BR — Sample is within the waste boundary downgradient of the ash basin
and coal pile.
o MW-14BR — Sample is located downgradient of the ash basin and Phase I Landfill
(unlined).
• The dataset does NOT meet minimum requirement of 10 samples. Additional background
samples are required.
• The reporting limits for Antimony and Thallium were above the IHSB PSRG Protection of
Groundwater values. Additional samples analyzed at a lower detection limit for these
parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Marshall Steam Station Page 1 of 1

Mayo Steam Electric Plant
Groundwater
• The following background wells are appropriate for use:
o MW-125, BG-02, MW-12D, BG-Ol, MW-13BR, and MW-14BR
• The following background wells are NOT appropriate for use:
o MW-IOBR
• The dataset for the surficial flow layer does NOT meet the minimum requirement of 10
samples. Additional samples are needed.
• The datasets for the transition zone and bedrock flow layers meets the minimum
requirement of 10 samples.
o Provisional background threshold values for radionuclides in the transition zone
flow layer are based on a limited dataset. Additional samples are required.
• The following sample event dates are NOT appropriate for use:
o BG-01
Soil
■ 11/3/2015 —Less than 60 days from previous sample.
■ 1/8/2016 — Less than 60 days from previous sample.
• 9/8/2016 — Less than 60 days from previous sample.
■ 3/28/17 — Less than 60 days from previous sample.
o MW-10BR
■ 1M16 —Less than 60 days from previous sample.
■ 9/7/16 —Less than 60 days from previous sample.
o MW-13BR
■ 1/7/2016 — Less than 60 days from previous sample.
• 9/6/2016 — Less than 60 days from previous sample.
All identified outliers are acceptable and should be removed from the background dataset.
The following background samples are appropriate for use:
o MW-08BR (0.75-1.25), MW-08BR (25.5-26), MW-IOBR (0.75-1.0), MW-12D (1-
2), MW-12D (25-26), SB-01 (1-2), and SB-01 (13.5-14.5)
The following background samples are NOT appropriate for use:
o MW-03BR (0.8-1.25) and MW-15BR (0.5-1) — Samples taken down -gradient of
Ash Basin.
o MW-11BR (0-2) and MW-13BR (0-2) —Per IHSB Guidance, these samples were
taken too shallow.
o SB-02 (0.5-2) and SB-02 (11.0-12.5) — Boring log indicates the presence of coal
ash.
o SB-03 (5-6) and SB-03 (17-18.5) — Boring log indicates the presence of coal ash.
o SB-05 and SB-06. Sample locations were adjacent to the 1981 landfill.
The dataset does NOT meet the minimum requirement of 10 samples. Additional samples
required.
Mayo Steam Electric Plant Page 1 of 2

• The reporting limits for Antimony and Thallium were above the IHSB PSRG Protection of
Groundwater values. Therefore, the number of useable values in the background dataset
is severely limited for these constituents. Additional samples analyzed at a lower detection
limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Mayo Steam Electric Plant Page 2 of 2

Riverbend Steam Station
Groundwater
• The following background wells are appropriate for use:
o BG-lS, MW-7SR, MW-7D, BG-4S, GWA-14S, BG-41), BG-5D, and BG-5BR
o MW-71) was listed under the shallow flow laver. Please re-evaluate.
• The following background wells are NOT appropriate for use:
o GWA-5S — Groundwater water elevations were similar and sometime lower than the
historical water elevation of ash basin. Also, the wells are within compliance boundary
and not far from the waste boundary.
• The datasets for shallow meets the minimum requirement of 10 samples after excluding
samples.
• The datasets for the deep and bedrock flow layers does NOT meet the minimum requirement
of 10 samples. Additional samples are required.
• All identified sample event dates are appropriate for use.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
• The following background samples are appropriate for use:
o BG-lD (5-6), BG-1D (14-15), BG-lD (24-25), BG-2D (3.5-5), BG-2D (48-49), BG-
3D (3-5), BG-31) (18.5-20), BG-3D (23-24), GWA-51) (58.5-60), GWA-6D-1(43.5-
45), GWA-6D-2(48.5-50), GWA-21D(3.5-5), GWA-211)(8.5-10), GWA-21D(18.5-
20), GWA-21D(48.5-50), MW-7BR(43.5-45), and OB-2(38.5-40.0)
• The following background samples are NOT appropriate for use:
o GWA-3D(18.5-19) — Sample taken down -gradient of Ash and Cinder Storage Areas.
o GWA-7S(7.0-8.0) — Sample taken down -gradient of Ash Basins.
o GWA-8D(8.5-10) — Sample taken down -gradient of Ash Basins.
o GWA-9D (1), GWA-10S (8-9), and NM-15D (3.5-5) — Downgradient location and
maybe within the High Seasonal Water Table.
o GWA-20D(40-41.5) — Sample taken in close proximity to Ash Storage Area.
o GWA-22D(38.5-40.0) — Sample taken in close proximity to Ash Storage Area.
o GWA-23D(33.5-35) — Sample taken within the waste boundary of the Ash Storage
Area.
o OB-1(33.5-35.0) — Sample taken inclose proximity to Ash Basin.
• The dataset meets the minimum requirement of 10 samples after excluding samples.
• The reporting limits for Antimony, Thallium, and Selenium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the background
dataset is severely limited for these constituents. Additional samples analyzed at a lower
detection limit for these parameters are necessary
• Please state whether any background sample included fill material. Samples containing fill
should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Riverbend Steam Station Page 1 of 1

Roxboro Steam Electric Plant
Groundwater
• The following background wells are appropriate for use:
o BG-1, MW-15D, MW-18D, BG-01BR MW-IOBR, MW-14BR, MW-15BR, MW-
18BR, and MW-19BRL
• The following background wells are NOT appropriate for use:
o MW-13BR, MW-16BR, and MW-17BR
• The datasets for all flow layers meet the minimum requirement of 10 samples after
excluding samples.
• The following sample event dates are NOT appropriate for use:
o BG-01
■ 9/8/2016 — Less than 60 days from previous sample.
■ 11/16/16 —Less than 60 days from previous sample.
o BG-01BR
■ 7/9/15 — Less than 60 days from previous sample.
o MW-17BR
• 11/10/16 —Less than 60 days from previous sample.
All identified outliers are acceptable and should be removed from the background dataset.
Soil
• The following background samples are appropriate for use:
o MW-08 (14-16), MW-08 (21-23), MW-13BR (22-24), MW-14BR (1-1.25), MW-
14BR (31-31.5), MW-14BR (37.5-38), MW-17 (29-31), MW-18 (31-33), and MW-
18 (37-38)
• The following background samples are NOT appropriate for use:
o MW-07 (0-2), MW-08 (0-2), MW-IOBR (0-2), MW-13BR (0-2), MW-15 (0-2),
MW-16 (0-2), and MW-18 (0-2) — Per IHSB Guidance, these samples were taken
too shallow.
• The dataset does NOT meet the minimum requirement of 10 samples. Additional samples
are required.
• The reporting limits for Antimony and Thallium were above the IHSB PSRG Protection of
Groundwater values. Samples for these two parameters need to be reported below these
values.
• Please state whether any background sample included fill material. Samples containing
fill should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
Roxboro Steam Electric Plant Page 1 of 1

�n

L. V. Sutton Energy Complex
Groundwater
• All identified background wells are appropriate for use:
o MW-05A, MW-0513, MW-3713, MW-0413, MW-05C, MW-08, MW-37C, MW-05CD,
MW-05D, MW-37D, MW-05E, and MW-37E
o Lower Surficial Aquifer — An adequate dataset has been provided for all constituents,
with the exception chromium (VI). Additional samples are planned for collection to
bring the total number of valid chromium (VI) samples to ten by second quarter 2017.
• The datasets for the upper and lower surficial flow layer meet the minimum requirement of 10
samples.
• The dataset for the Upper Peedee flow layer does NOT meet the minimum requirement of 10
samples. Additional samples are planned for collection to bring the total number of valid
samples to ten (second quarter 2017 at the earliest). It was agreed upon to use a pH of less than
or equal to 9.7 S.U. as the upper threshold for these zones in the Peedee aquifer.
• The dataset for the Lower Peedee flow layer does NOT meet the minimum requirement of 10
samples. New and replacement wells have been added to the groundwater monitoring network
(MW-5R-E, MW-8E, MW-41E). Additional samples are planned for collection to bring the
total number of valid samples to 10 (second quarter 2017 at the earliest). It was agreed upon
to use a pH of less than or equal to 9.7 S.U. as the upper threshold for these zones in the Peedee
aquifer.
• All identified sample event dates are appropriate for use.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
• The following background samples are appropriate for use:
o AW-02C (10-11) and MW-37C (4-6)
• The following background sample are NOT appropriate for use:
o AW-01C (0-2), AW-02C (0-2), AW-03C (0-2), AW-04C (0-2), AW-06D (0-2), AW-
07D (0-2), MW-37C (0-2), SMW-01C (0-2), SMW-02C (0-2), SMW-03C (0-2),
SMW-04C (0-2), SMW-05C (0-2), and SMW-06D (0-2) — Per IHSB Guidance, these
samples were taken too shallow.
o AW-05C (4-6) and AW-05C (9-11) —Samples are down -gradient of the ash pond.
• The dataset does NOT meet the minimum requirement of 10 samples. Additional samples are
require .
• The reporting limits for Antimony, Cobalt, and Thallium were above the IHSB PSRG
Protection of Groundwater values. Therefore, the number of useable values in the background
dataset is severely limited for these constituents. Additional samples analyzed at a lower
detection limit for these parameters are necessary.
• Please state whether any background sample included fill material. Samples containing fill
should be omitted from the raw background dataset.
• All identified outliers are acceptable and should be removed from the background dataset.
L. V. Sutton Energy Complex Page 1 of 1

W.H. Weatherspoon Power Plant
Groundwater
• All identified background wells are appropriate for use.
o BW-02S, BW-03S, CCR-101-13G, MW-01, BW-03I, and BW-03D
• The dataset for the surficial flow layer meets the minimum requirement of 10 samples
• The dataset for the Lower Yorktown does NOT meet the minimum requirement of 10
samples. Additional samples are required.
• The dataset for the PeeDee does NOT meet the minimum requirement of 10 samples.
Additional samples are required.
• The following sample event dates are NOT appropriate for use.
o BW-03S
■ 3n116 — Less than 60 days from previous sample.
• All identified outliers are acceptable and should be removed from the background dataset.
Soil
No soil background data was provided. Please coordinate the collection of background
soil data with the DWR Fayetteville Regional Office.
W. H. Weatherspoon Power Plant Page 1 of I

2017 Comprehensive Site Assessment Update October 2017
Riverbend Steam Station
SynTerra
ZIMMERMAN TO DRAOVITCH
SEPTEMBER 1, 2017

Water Resources
Environmental Quality
September 1, 2017
Paul Draovitch
Senior Vice President
Environmental, Health & Safety
Duke Energy
526 South Church Street
Mail Code EC3XP
Charlotte, North Carolina 28202
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. JAY ZINIMERMAN
Director
Subject: Approval of Provisional Background Threshold Values for Riverbend Steam
Station
Dear Mr. Draovitch:
The North Carolina Department of Environmental Quality's Division of Water Resources (DWR)
has reviewed Duke Energy's calculated provisional background threshold values (PBTVs) for soil
and groundwater for the subject facility. DWR calculated PBTVs based on the vetted background
data in the letter to Duke Energy dated July 7, 2017, using the Revised Statistical Methods for
Developing Reference Background Concentrations for Groundwater and Soil at Coal Ash
Facilities dated May 26, 2017. It should be noted that Duke Energy supplied additional data on
August 8, 2017, and September 1, 2017, on which their final calculations were based.
Per 15A NCAC 02L .0202(b)(3), where naturally occurring substances exceed the established
standard, the standard shall be the naturally occurring concentration as determined by the Director.
Therefore, PBTVs that are calculated to be above the 15A NCAC 02L .0202 groundwater
standards or Interim Maximum Allowable Concentrations (IMACs) and accepted by DWR shall
become the enforceable groundwater standard. Otherwise, the enforceable groundwater standards
shall be those listed under 15A NCAC 02L .0202(h) including any effective IMACs.
The attachments document DWR's concurrence/non-concurrence with Duke Energy's calculated
PBTVs for groundwater and soil. For all Duke Energy's calculated PBTVs that DWR finds
acceptable, DWR hereby approves those values. If DWR does not find the Duke Energy's
calculated PBTVs acceptable, justification is provided on the attachments. Duke Energy will be
responsible to provide revised values for DWR to review and approve.
Please note that the approved PBTVs are based on the current data available. DWR recognizes
that, as new data is gathered going forward, the approved PBTVs may be refined. Thus, there will
be need for a periodic review of the data and recalculation of the PBTVs. The timeframes for the
periodic review will established by DWR at a later date and any revised PBTVs will be subject to
approval by the DWR's Director.
State of North Carolina I Environmental Quality I Division of Water Resources
Water Quality Regional Operations Section
1636 Mail Service Center I Raleigh, North Carolina 27699-1636
919-707-9129

Along with the specific comments provided on the attachments, DWR offers the following general
comments with regards to the PBTVs
Outliers are identified with three statistical lines of evidence; Box Plots, Q-Q Plots, and
95% Significance Levels. Based on these lines of evidence, if Duke Energy chooses not
to exclude an outlier, then additional rationale or justifications shall be provided.
The PSRG for Chromium shall be the more conservative value for Chromium (VI) which
is 3.8 mg/kg.
If you have any questions, please contact Shuying Wang (Winston-Salem Regional Office) at
[phone] or Steve Lanter (Central Office) at [phone].
Sincerely,
S. Ja:M' merman, P.G., Director
Division of Water Resources
Attachments
cc: WSRO WQROS Regional Office Supervisor
WQROS Central File Copy

2017 Comprehensive Site Assessment Update October 2017
Riverbend Steam Station
DEQ PBTV APPROVAL ATTACHMENTS -
SEPTEMBER 1, 2017
SynTerra

Riverhead Steam Station - Groundwater Provisional Bac round Threshold Values
Parameter
Reporting Units
Duke lsnergy Calculated PBTVs
Plow Unit
15A NCAC 02L
Standard or
IMAC
DWR Concurrence (Acceptable/Not Acceptable)
Comments
Flow Unit
Shallow
Deep
Bedrock
Shallow
Deep
Bedrock
H
S.U.
4.9 - 7.0
4.9 - 7.0
7.6 - 7.8
6.5-9.5
Acceptable
Acceptable
Acceptable
Not evaluated because the values are below the groundwater standards or no standard is established.
Alkalinity
m L
93.1
139
139
NE
Acceptable
Acceptable
Acce table
Aluminum
µg/L
172.2
_
1204
too
NE
Acceptable
Acceptable
Acceptable
Antimony
µ
1
1.1
2.9
1
Acceptable
Acceptable
Not Acce table
Only four observations ave vailable. Use 21JIMAC until more data are available.
Arsenic
1
1
2.9
10
Acceptable
Acceptable
Acce ble
Not evaluated because the values are below the groundwater standards or no standard is established.
Barium
µ L
561
84.4
135
700
Acceptable
Acceptable
Acce table
Beryllium
ilgli,
I
1
0.1
4
Acceptable
Acceptable
Acceptable
Bicarbonate
mg/L
93 1
147
139
NE
Acceptable
Acceptable
Acceptable
Boron
_
N I)
ND
50
700
Acceptable
Acceptable
Acceptable
Cadmium
_
ND
ND
0.08
2
Acceptable
Acceptable
Acceptable
Calcium
mg/L
_
18.8
32.9
46.7
NE
Acceptable
Acceptable
Acceptable
Carbonate
mg/L
_ND
ND
10.7
5
16
NE
250
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Chloride
mg/L
_
3.242
Chromium VI
_
1.097
0.9
0.16
NA
Acceptable
Acceptable
Acceptable
Chromium
µg/L
14
5
1.5
10
Not Acceptable
Acceptable
Acceptable
Shallow should be 5 (or 2L) because 14 was identified as an outlier.
Cobalt
11.64
0.517
0.088
1
Not Acceptable
Acceptable
Acceptable
Shallow should be 2.3 because 11.3, 9.4, and 8.5 were identified as outliers.
Copper
µg/L
I 5
5
0.5
1000
Acceptable
Acceptable
Acceptable
Not evaluated because the values are below the groundwater standards or no standard is established.
Iron
pgfL
_
I278
56.3
125
300
Not Acceptable
Acceptable
Acceptable
Shallow should be 950 because 1890 was identified as an outlier.
Lead
Magnesimn
p
mg/L
1
3.49
ND
6.81
0.1
7.46
15
NE
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Not evaluated because the values are below the groundwater standards or no standard is established.
Manganese
481
7.9
24.5
50
Acceptable
Acceptable
Acceptable
Memo
ND
ND
0.2
1
Acceptable
Acceptable
Acceptable
Not evaluated because the values are below the groundwater standards or no standard is established.
Methane
pg/L
29.63
6
41.7
NE
Acceptable
Acceptable
Acceptable
Molybdenum
µ
3.9
7.3
10
NE
Acceptable
Acceptable
Acceptable
Nickel
5
5
0.87
100
Acceptable
Acceptable
Acceptable
Nitrate + Nitrite
m -N/L
0,23
0.1
0.02
11*
Acceptable
Acceptable
Acceptable
Potassium
mg/L
5
5
4.57
NE
Acceptable
Acceptable
Acceptable
Selenium
Sodium
µg/L
mg/L
ND
12.8
1.3
17
03
23.7
20
NE
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Strontium
WL
293
697
961
NE
Acceptable
Acceptable
Acceptable
Sulfate
mg/L
2.3
21.9
29
250
Acceptable
Acceptable
Acceptable
Sulfide
mg/L
ND
0.1
2
NE
Acceptable
Acceptable
Acceptable
TDS
mg/L
73
179
223
500
Acce table
Acceptable
Acce table
Thallium
0.2
0.2
0.1
0.2
Acceptable
Acceptable
Acceptable
TOC
mg/L
9
1
NA
NE
Acceptable
Acceptable
Acceptable
Vanadium
2.223
9.74
0.33
0.3
Acceptable
Acceptable
Acceptable
Zinc
18
10
10
1000
Acce table
Acce table
Acce table
Not evaluated because the values are below the groundwater standards or no standard is established.
Radium (Total) I
pCi/L
0.8
NA
0.494
NE
Acceptable
Acceptable
Acceptable
Uranium (Total)
mL
1 0.005
0.009
0.00099
NE
Acceptable
Acceptable
Acceptable
NA - Not Applicable
ND - Not Detected
NE - Not Established
mg/L -milligrams per liter
pCi/L - p¢ocuries per liter
Radium (Total) - Radium-226 and Radium-228 combined
-The ISA NCAC 02L Standard is 10 mg/L for Nitrate and 1 mg/L for Nitrite (added for a total of I I mg/L)
S.U. - Standard Unit
TOC - Total Organic Carbon
TDS - Total Dissolved Solids
µglint, - micrograms per milliliter
µg/L - micrograms per liter
Uranium (Toal) - Cranium-233, Uranium-234, Uranium-236, and Uranium-238 combined

Riverbend Steam Station - Soil Provisional Background Threshold Values
Parameter
Reporting
Units
Duke Energy
Calculated
PB.fvs
PSRG Protection
of Groundwater
DWR Concurrence
(Acceptable/Not
Acceptable)
Comments
H
S.U.
4. 3 - a .7
NE
Acceptable
Aluminum
m
31151
NE
Acceptable
Antimony
mg/kg
O.F,
0.9
Acceptable
Arsenic
mg/kg
3.8
5.8
Acceptable
Barium
my
�kg
190
580
Acceptable
Beryllium
mg/kgmg/kg
1.655
63
Acceptable
Boron
mglkg
2.3
45
Acceptable
Cadmium
mg/kg
0.03
3
Acceptable
Calcium
mg/kg
410
NE
Acceptable
Chloride
mg/kgmg/kg
12
NE
Acceptable
Chromium
mg/kgmg/kg
20
360000- 3.8
Acceptable
Use the PSRG for Chromium (IV) of 3.8 m to be more conservative.
Cobalt
mg/kgmg/kg
5R.61
0.9
Not Acceptable
PBTV for Cobalt should be 46.5 without any identified outliers
Copper
mg/kg
33.09
700
Acceptable
Iron
mg/kg
40150
150
Acceptable
Lead
mg/kgmg/kg
11.29
270
Acceptable
Magnesium
mglkg
760
NE
Acceptable
Manganese
mg/kgmg/kg
1867
65
Acceptable
Mercury
mgkg
0.099
1
Acceptable
Molybdenum
mg/kgmg/kg
1.829
NE
Acceptable
Nickel
mg/kgmg/kg
10.23
130
Acceptable
Nitrate as N)
mg/kgmg/kg
025
NE
Acceptable
Potassium
mg/kg
2440
NE
Acceptable
Selenium
mWkg
1 576
2.1
Acceptable
Sodium
mg/kg
4'7
NE
Acceptable
Strontium
m
Ix. 34
NE
Acceptable
Sulfate
m
12
250
Acceptable
Thallium
mg/kg
0.166
0.28
Acceptable
Vanadium
mglkg
112 t
6
Acceptable
Zinc
mgfkg
_ _ _
60.45
1200
Acceptable
NA - Not applicable (dataset contains zero valid samples)
ND - Non -Detect
NE - Not Established
mg/kg - millittrams per kilobmam
S.U. - Standard Unit