NC0000396_Other_20160503

%> DUKE
ENERGY.
April 28, 2016
Jeffrey O. Poupart
Water Quality Permitting Section Chief
Division of Water Resources
Department of Environmental Quality
State of North Carolina
1617 Mail Service Center
Raleigh, NC 27699-1617
Harry K. Sidens
Senior Vice President
Environmental, Health 8 Safety
526 S Church Street
Mail Code ECUP
Charlotte, NC 28202
[phone]
Subject: March 2, 2016 Insufficiency of Discharge Assessment Plans — Duke Energy Carolinas,
LLC and Duke Energy Progress, LLC
Dear Mr. Poupart:
This responds to your letter of March 2, 2016 to Duke Energy Carolinas, LLC and Duke Energy
Progress, LLC on March 2, 2016 regarding Duke Energy's proposed Discharge Assessment
Plans.
With regard to your letter describing changes in Section 3.2.2 Observation and Sampling:
• The discussion must include a statement noting that jurisdictional determinations regarding
the extent of waters of the United States and their relationship with identified seeps at the
subject facilities will be obtained from the United States Army Corps of Engineers (USA
COE).
Duke Energy does not yet have jurisdictional determinations from the US Army Corps of
Engineers for the relevant areas at all of the twelve sites mentioned in your letter. We submitted
applications for jurisdictional determinations in September, October, and November 2015 and
have since worked with the Corps of Engineers to schedule site visits and provide draft plats for
approval. Nonetheless, the timing of the approved jurisdictional determinations is up to the
Corps and outside of Duke's control. To date, out of these twelve sites, only Buck has an
approved jurisdictional determination, but we do not yet have the signed plats.
We will submit the maps you have requested for each site on a rolling basis, within a reasonable
period after the jurisdictional determinations are complete. In order to address the changes
described in your March 2, 2016 letter, we have added the following text at the start of Section
3.2.2.
Jurisdictional determinations regarding the extent of waters of the United States and
their relationship with identified seeps at the subject facilities will be obtained from the
United States Army Corps of Engineers (USA COE). Until jurisdictional determinations
are finalized by USA COE, preliminary information will be used to evaluate the seeps as
described in the section below.
RECEIVED/NCDEQ/DWR
MAY 0 a Z016
Water Quality
Permitting Section

The second change in Section 3.2.2 described in your letter is as follows.
The schedule for water quality sampling of the seeps and related jurisdictional waters must
be more frequent than the semi-annual basis stated in the proposed DAPs. DWR `
recommends a monthly monitoring schedule, consistent with the conditions described in the
DAPs' general assessment requirements, for all identified seeps that will continue for twelve
(12) months. After that time, monitoring may be reduced to a semi-annual basis until such
monitoring becomes a requirement of the NPDES permit
We do not believe sampling monthly as part of a revised Discharge Assessment Plan is
warranted. For the larger receiving waters, data is available from sampling associated with
NPDES permits that demonstrates the lack of impact on the larger surface waters of the state.
In addition, we are conducting weekly observations of all AOWs on a dam or dike slope,
sampling any new seeps, -and providing the analytical results to DEQ. We recommend the
sampling frequency under the DAPs remain at twice/year with the weekly inspections of dam
slopes for any new seeps with data provided to DEQ. We recommend that we collectively focus
our resources on the completion of all of the NPDES Wastewater Permits for the Duke Energy
sites and implement appropriate sampling frequency for each of the permitted seeps in that
document .
However, in order to address the changes described in your March 2, 2016 letter, we have
added the following text in Section 3.2.2.
In addition to sampling conducted with the semi-annual assessments, additional seep
sampling will be conducted at locations and at a frequency as determined through
discussions with NC DEO personnel.
We would like to work with DEQ to achieve alignment of the various (present and future)
documents involving required seep activities including:
• Discharge Assessment Plans
• Discharge Identification Plans
• NPDES Wastewater Permits
• EPA requirements
Any future legal agreements with either DEQ or EPA
Duke Energy is committed to providing the Department with additional information to facilitate
om r
the Issuance of new NPDES Wastewater permits. The issues are complex and require special
consideration, as illustrated by the time elapsed since the permit applications were submitted.
We look forward to working with you further to resolve the issues identified here on a mutually
acceptable schedule.
Sincerely,
Harry Sideris
Senior Vice President
Environmental, Health and Safety

Asheville Steam Electric Plant Ash Basin
Topographic Map and
Discharge Assessment Plan
NPDES Permit NC0000396
April 29, 2016
10,

Duke Energy Progess, LLC I Discharge Assessment Plan L��
Asheville Steam Electric Plant Ash Basin r
CONTENTS
Contents
Pa4e
Contents......................................................................................................................................i
Figuresand Tables.....................................................................................................................ii
Section1 - Introduction..............................................................................................................
1
Section2 - Site Background.......................................................................................................
3
2.1 Plant Description..................................................................................................3
2.2 Ash Basin Description..........................................................................................3
2.3 Site Geologic/Soil Framework..............................................................................3
2.4 Topographic Map and Identification of Discharges...............................................4
2.4.1 Engineered Drainage System for Earthen Dam........................................5
2.4.2 Non -Engineered Seep Identification.........................................................5
Section 3 - Discharge Assessment Plan.....................................................................................
6
3.1 Purpose of Assessment.......................................................................................6
3.2 Assessment Procedure........................................................................................6
3.2.1 General Assessment Requirements.........................................................6
3.2.2 Observation and Sampling.......................................................................7
3.2.3 Evaluation................................................................................................9
3.2.4 Assessment Reporting.............................................................................9
Section4 — References.............................................................................................................10

Duke Energy Progess, LLC I Discharge Assessment Plan ���
Asheville Steam Electric Plant Ash Basin
FIGURES AND TABLES
Figures and Tables
Figure 1 — Site Location Map
Figure 2 — Topographic Map
Table 1 — Seep and Associated Discharge Locations and Descriptions
Table 2 — Laboratory Analytical Methods
Table 3 — Asheville Steam Electric Plant — Example of Surface Water/Seep Monitoring Flow and
Analysis Results

Duke Energy Progess, LLC I Discharge Assessment Plan -N
Asheville Steam Electric Plant Ash Basin
SECTION 1 - INTRODUCTION
Section 1 - Introduction
The purpose of this document is to address the requirements of North Carolina General Statute
(GS)130A-309.210(a) topographic map and (b) Assessment of Discharges from Coal
Combustion Residuals Surface Impoundments to the Surface Waters of the State, as modified
by North Carolina Senate Bill 729, for the Asheville Steam Electric Plant (Asheville Plant) ash
basin operated under National Pollutant Discharge Elimination System (NPDES) Permit
NC0000396.
The following requirements are contained in General Statute (GS) 130A-309.210(a):
(1) The owner of a coal combustion residuals surface impoundment shall identify all
discharges from the impoundment as provided in this subsection. The requirements for
identifying all discharges from an impoundment set out in this subsection are in addition to
any other requirements for identifying discharges applicable to the owners of coal
combustion residuals surface impoundments.
(2) No later than December 31, 2014, the owner of a coal combustion residuals surface
impoundment shall submit a topographic map that identifies the location of all (i)
outfalls from engineered channels designed or improved for the purpose of collecting
water from the toe of the impoundment and (ii) seeps and weeps discharging from the
impoundment that are not captured by engineered channels designed or improved for
the purpose of collecting water from the toe of the impoundment to the Department.
The topographic map shall comply with all of the following:
a. Be at a scale as required by the Department.
b. Specify the latitude and longitude of each toe drain outfall, seep, and weep.
c. Specify whether the discharge from each toe drain outfall, seep, and weep is
continuous or intermittent.
d. Provide an average flow measurement of the discharge from each toe drain outfall,
seep, and weep including a description of the method used to measure average flow.
- from each toe drain outfall see and
e. Specify whether the dischargep, weep identified
reaches the surface waters of the State. If the discharge from a toe drain outfall, seep,
or weep reaches the surface waters of the State, the map shall specify the latitude and
longitude of where the discharge reaches the surface waters of the State.
f. Include any other information related to the topographic map required by the
Department.
The following requirements are contained in General Statute (GS) 130A-309.210(b):

j
Duke Energy Progess, LLC I Discharge Assessment Plan �)�
r Asheville Steam Electric Plant Ash Basin
SECTION 1 - INTRODUCTION
b) Assessment of Discharges from Coal Combustion Residuals Surface Impoundments
to the' Surface Waters of the State. The owner of a coal combustion residuals surface
impoundment shall conduct an assessment of discharges from the coal combustion
residuals surface impoundment to the surface waters of the State as provided in this
subsection. The requirements for assessment of discharges from the coal combustion
residuals surface impoundment to the surface waters of the State set out in this
- , subsection are in addition to any other requirements for the assessment of discharges
from coal combustion residuals surface impoundments to surface waters of the State
applicable to the owners of coal combustion residuals surface impoundments.
(1) No later than December 31, 2014, the owner of a coal combustion residuals
surface impoundment shall submit a proposed Discharge Assessment Plan to
the Department. The Discharge Assessment Plan shall include information
sufficient to allow the Department to determine whether any discharge, including
a discharge from a toe drain outfall, seep, or weep, has reached the surface
_ waters of the State and has caused a violation of surface water quality standards.
The Discharge Assessment Plan shall include, at a minimum, all of the following:
a. Upstream and downstream sampling locations within all channels that could
potentially carry a discharge.
b. A description of the surface water quality analyses that will be performed.
c. A sampling schedule, including frequency and duration of sampling activities.
d. Reporting requirements.
e. Any other information related to the identification of new discharges required
by the Department.
(2) The Department shall approve the Discharge Assessment Plan if it determines
that the Plan complies with the requirements of this subsection and will be
sufficient to protect public health, safety, and welfare; the environment, and
natural resources.
(3) No later than 30 days from the approval of the Discharge Assessment Plan, the
owner shall begin implementation of the Plan in accordance with the Plan's
schedule.
The North Carolina Senate Bill 729 establishes the submittal date of this topographic map and
Discharge Assessment Plan no later than December 31, 2014.
The topographic map, developed to satisfy the requirements of GS1 30A-309.21 0(a), was
utilized as the basis for developing the assessment procedures presented in this plan, required
by GS1 30A-309.21 0(b).
N

Duke Energy Progess, LLC i Discharge Assessment Plan
Asheville Steam Electric Plant Ash Basin J
SECTION 2 - SITE BACKGROUND
Section 2 - Site Background
2.1 Plant Description
The Asheville Plant is located near Asheville, in Buncombe County, North Carolina. The
Asheville Plant began commercial operation in the 1960s, with additions in the 1990s and
around 2000, and consists of two coal-fired units that primarily use bituminous coal. In addition
to the coal-fired units, the Plant also has two combustion turbines. Coal combustion residues
(CCR) have been managed in the Plant's on -site ash basins and used as beneficial fill at the
nearby Asheville Airport.
Lake Julian was built for cooling water by damming the flow of Powell Creek on the north side of
the plant. A large portion of Lake Julian borders the east side of the plant site. Surface water
from the French Broad River is also pumped into Lake Julian as a supplemental water supply.
The water from the French Broad River enters a stilling area of the lake on the north side of the
plant. Heated water is discharged back into Lake Julian to the east of the plant. The French
Broad River borders the west side of the property and flows south to north. Powell Creek also
flows south to north prior to formation of Lake Julian. Powell Creek flows east to west from the
Lake Julian Dam to the French Broad River.
2.2 Ash Basin Description
The plant and ash basins are located on the east side of 1-26 and the French Broad River where
the ash management system consist of a series of basins. The original 1964 ash basin, built
during plant construction and expanded in the 1970s, is now overlain with wastewater treatment
wetlands. The treatment wetlands basins are lined. The 1964 ash basin was replaced in
approximately 1982 with a second ash basin, built to the south of the 1964 basin. The 1982 ash
basin is now being dewatered, excavated, and transported to the Asheville Airport for structural
fill. New ash, generated daily, is dewatered in concrete -lined basins located on a portion of the
1964 ash basin.
The ash basin system is part of the plant's wastewater treatment system; receiving inflows from
ash transport water, coal pile runoff, storm water runoff, and various low volume wastes. The
treated wastewater is permitted to discharge to the French Broad River permitted Outfall 001. A
500-foot compliance boundary circles the ash management area.
2.3 Site Geologic/Soil Framework
The Asheville Plant is located in the Piedmont Mountain region of North Carolina as described
by LeGrand (2004). In general, the regional geology consists of overburden, also referred to as
regolith, and metamorphic bedrock. In stream valleys, fluvial deposits, also referred to as
alluvium, overlie the bedrock. The metamorphic rock, primarily schist and gneiss, tends to be
exposed on the ground surface along topographic ridges, road cuts, and in stream or river
valleys. Where the metamorphic bedrock has been weathered into unconsolidated material, silt,
sand, and clay are found overlying the bedrock. The regolith tends to be composed of a shallow
soil zone where the relict structure of the original bedrock material is no longer present. The soil

Duke Energy Pragess, LLC I Discharge Assessment Plan ���
Asheville Steam Electric Plant Ash Basin
SECTION 2 - SITE BACKGROUND
zone transitions downward into saprolite, which is still unconsolidated material, but has the
visual texture of the parent bedrock.
The geology across the site varies from mica gneiss and garnet mica schist in the upland areas
(east of 1-26) to alluvium along the French Broad River floodplain (west of 1-26). The mica
gneiss that underlies the majority of the site under the ash management area is described at a
number of locations as containing pyrite, chlorite, and garnets. Mica schist is located in the
vicinity of the compliance boundaries to the south and north of the site.
As discussed by LeGrand (2004), the French Broad River and its tributaries are groundwater
discharge zones for the saprolite and bedrock aquifer at the site. The French Broad River
creates a hydrogeologic boundary to .the west of the plant site. The Powell Creek drainage
feature creates a hydrogeologic boundary to the north side of the site. The unnamed tributary
located along the southern property line creates a hydrogeologic boundary to the south of the
site. Lake Julian is located upgradient of the ash management area and it, along with the Powell
Creek drainage basin, form the eastern hydraulic boundary of the site. The general direction of
groundwater flow in the saprolite aquifer is west, toward the French Broad River, with localized
variations as the water table mirrors surface topography. The saturated saprolite aquifer feeds
the underlying fractures within the upper bedrock aquifer. The direction of groundwater flow in
the upper bedrock aquifer is also generally to the west, toward the French Broad River, with
preferential flow paths toward the small tributaries and exposed outcrops along 1-26 (localize
discharge zones).
2.4 Topographic Map and Identification of Discharges
A topographic map is presented in Figure 2 to meet the requirements of GS 130A-309.210(a) in
the identification of outfalls from engineered channels, as well as seeps and weeps. Seepage is
the movement of wastewater from the ash basin through the ash basin embankment, the
embankment foundation, the embankment abutments, basin rim, through residual material in
areas adjacent to the ash basin. A seep is defined in this document as an expression of
seepage at the ground surface. A weep is understood to have the same meaning as a seep.
Indicators of seepage include areas where water is observed on the ground surface and/or
where vegetation suggests the presence of seepage. Seepage can emerge anywhere on the
downstream face, beyond the toe, or on the downstream abutments at elevations below normal
pool. Seepage may vary in appearance from a "soft," wet area to a flowing "spring." Seepage
may show up first as only an area where the vegetation is lusher and darker green than
surrounding vegetation. Cattails, reeds, mosses, and other marsh vegetation often become
established in a seepage area (NCDENR, 2007). However, in many instances, indicators of
seeps do not necessarily indicate the presence of seeps. Areas of apparent iron staining and/or
excess iron bacteria may also indicate the presence of a seep.
Locations of seepage at the ground surface adjacent to the ash basin have been identified and
are shown in Figure 2. These areas include the earthen embankment(s) which impound the ash
basin as well as adjacent areas where water from the ash basin may have infiltrated into the
underlying residual materials and expressed as seepage.

L .
Duke Energy Progess, LLC I Discharge Assessment Plan F�� Asheville Steam Electric Plant Ash Basin r
SECTION 2 - SITE BACKGROUND
2.4.1 Engineered Drainage System for Earthen Dam
Earth dams are subject to seepage through the embankment, foundation, and abutments.
Seepage control is necessary to prevent excessive uplift pressures, instability of the
downstream slope, piping through the embankment and/or foundation, and erosion of material
by migration into open joints in the foundation and abutments. The control of seepage is
performed by the use of engineered drains such as blanket drains, trench drains, and/or toe
drains. In certain cases horizontal pipes may be installed into the embankment to collect and
control seepage. It is standard engineering practice to collect the seepage and convey seepage
away from the dam.
Drains at the base of the 1964 ash pond collect water into two PVC pipes where flow rates can
be measured. A section of the 1964 dam seeps into a Swale along the dam access road. The
point where the seep is consolidated to flow under the road can be used to measure flow. The
drains at the base of the 1982 ash pond are collected in a weir box. The drainage features, or
outfalls, associated with the ash basin dam are shown as required by GS 130A-309.210(a)(2)(i)
on Figure 2.
2.4.2 Non -Engineered Seep Identification
Topographic maps of the site were reviewed to identify regions of the site where there was a
potential for ash basin related seepage to be present. These regions were determined by
comparing ash basin full pond elevations to adjacent topography with ground surface elevations
lower than the ash basin full pond elevation. Synterra staff performed site observations within
these identified areas as part of NPDES inspections during the reapplication process during
June 2014 and documented locations where seepage was apparent at the time of the site visit.
These seeps are identified as required by GS 130A-309.210(a)(2)(ii) on Figure 2.
5

Duke Energy Progess, LLC I Discharge Assessment Plan L
Asheville Steam Electric Plant Ash Basin rN
SECTION 3 - DISCHARGE ASSESSMENT PLAN
Section 3 - Discharge Assessment Plan
3.1 Purpose of Assessment
The purpose of the assessment is to determine whether existing, known discharges from toe
drain outfalls, seeps, and weeps associated with the coal combustion residuals surface
impoundment (ash basin) have reached the surface waters of the State and have caused a
violation of surface water quality standards as required by North Carolina General Statute 130A-
309.210(b).
Figure 2 and Table 1 present the background and downstream sampling locations to be
considered as part of this Discharge Assessment Plan (DAP). These locations may be
assessed by comparing surface water sampling analytical results of the associated background
location with the corresponding downstream location. For discharges located at the toe of a
dam, an upstream location within the channel may not have been possible to isolate for
comparison given the proximity to the ash basin, which would have the same chemical
composition as the discharge itself. As such, the upstream location was established upstream of
the ash basin and is considered "background." For discharges located a distance from the ash
basin, an identified upstream, or "background" location for sampling may be compared to the
downstream portion of the discharge channel. The background and downstream sampling
locations are shown on Figure 2 with "B" and "D" identifiers, respectively, and the corresponding
Seep locations associated with the sampling locations are indicated on Table 1.
3.2 Assessment Procedure
The assessment procedure associated with the Asheville Plant ash basin is provided within this
section. In addition to the specific requirements for the assessment, Section 3.2 also provides
the general requirements, the frequency of assessment, documentation requirements, and a
description of the surface water quality analyses that will be performed.
3.2.1 General Assessment Requirements
Assessments are to be performed in three phases as follows:
• Observation and sampling (assessment site visit),
• Evaluation, and
• Assessment reporting.
The assessment site visit shall be performed when the background and downstream locations
are accessible and not influenced by weather events. Locations on or adjacent to the ash basin
embankments should be performed within two months after mowing, if possible. In addition, the
assessment site visit should not be performed if the following precipitation amounts have
occurred in the respective time period preceding the planned assessment site visit:
• Precipitation of 0.1 inches or greater within 72 hours or
• Precipitation of 0.5 inches or greater within 96 hours.
The assessments shall be performed under the direction of a qualified Professional Engineer or
Professional Geologist on a semi-annual basis within two nonadjacent quarters. The date of the
6

Duke Energy Progess, LLC I Discharge Assessment Plan
Asheville Steam Electric Plant Ash Basin 01
SECTION 3 - DISCHARGE ASSESSMENT PLAN
initial assessment site visit shall be selected no later than 30 days from the approval of the
Discharge Assessment Plan and should fall within one of the semi-annual timeframes.
Additional seep locations that may have been identified and documented in an Identification of
New Discharge report(s) shall be reviewed prior to performing an assessment site visit, if
available.
3.2.2 Observation and Sampling
Jurisdictional determinations regarding the extent of waters of the United States and their
relationship with identified seeps at the subject facilities will be obtained from the United States
Army Corps of Engineers (USACE). Until jurisdictional determinations are finalized by USACE,
preliminary information will be used to evaluate the seeps as described in the section below.
The initial assessment site visit should be performed to document baseline conditions of the
discharge channel, including location, extent (i.e., dimensions of affected area), and flow of
each discharge. Discharge channel background and downstream locations should be verified
using a Global Positioning System (GPS) device. Photographs should be taken from vantage
points that can be replicated during subsequent semi-annual assessments.
Initial and subsequent assessment site visits shall document a minimum of the following to
respond to the requirements in 130A-309.21 0.1 (b):
• Record the most recent ash basin water surface elevation and compare to the seep and
outfall and associated discharge location surface water elevations.
For each discharge channel, the observer shall note the following as applicable on the
day of the assessment site visit:
o Is the discharge channel flowing at the time of the assessment site visit?
o Does the discharge channel visibly flow into a Water of the U.S. at the time of the
- assessment site visit?
o How far away is the nearest Water of the U.S.?
o Document evidence that flow has or could reach a Water of the U.S. (e.g.,
description of flow, including extent and/or direction) and describe the observed
condition. Evidence that flow could or has reached a Water of the U.S. may be
indicated by an inspection of the adjacent and downstream topographic drainage
features.
o Observe and document the condition of the discharge channel and outfall of the
engineered channel or seep location with photographs. Photographs are to be
taken from similar direction and scale as photographs taken during the initial
assessment site visit.
• Record flow rate within the discharge channel, if measureable, using the following
methods:
7

Duke Energy Progess, LLC I Discharge Assessment Plan L��
Asheville Steam Electric Plant Ash Basin r
SECTION 3 - DISCHARGE ASSESSMENT PLAN
o Timed -volumetric method: Collect a volume of water from the discharge of the PVC
pipe directly into an appropriately sized container. Measure volumes (in mL) in the
field utilizing a graduated container. Record the amount of time (in seconds)
needed to collect the volume of water and calculate the flows (in MGD) for the
timed -volume.
_ o A V-notch weir apparatus will be installed, if necessary, during the initial
assessment site visit to impound seepage at locations with a defined channel.
Once the impounded seep reaches equilibrium discharge, flows will be measured
using the timed -volumetric method described above.
o Area -velocity method: Measure point velocities and water depth at a minimum of
20 stations along a transect setup perpendicular to the direction of flow using a
Swoffer® 3000 flow meter mounted to a standard United States Geologic Survey
(USGS) top -set wading rod. Utilize the average velocity and cross -sectional area of
the wetted channel to calculate flows in MGD.
• Collect water quality samples using the following methods:
o Collect background and downstream samples during a period with minimal
preceding rainfall to minimize potential effects of stormwater runoff. Sampling
procedures should prevent the entrainment of soils and sediment in water samples
that can result in analytical results not being representative of the flow. Because
Areas of Wetness (AOWs)/seeps often have poorly defined flow channels and
minimal channel depth, conventional grab samples collected directly into laboratory
containers or intermediate vessels is not possible without disturbance and
entrainment of soils and sediments. Further, many AOWs are contiguous with low-
lying areas subject to surface water runoff and resulting heavy sediment loading
during storm events or are near surface waters subject to flooding such that
representative samples of the AOW cannot be obtained. If the facility is unable to
obtain an AOW sample due to the dry, low flow or high flow conditions preventing
the facility from obtaining a representative sample, a "no flow" result or "excessive
flow" will be recorded.
o After collection, samples will be preserved and stored according to parameter -
specific methods and delivered to the laboratory under proper Chain -of -Custody
(COC) procedures.
o Analytical parameters for analysis include: Fluoride, Arsenic, Cadmium, Copper,
Chromium, Nickel, Lead, Selenium, and Mercury. This list includes all parameters
previously identified for seep sampling at Duke Energy power plants for which
relevant stream water quality standards are in place. (This list is responsive to the
statutory requirement for the discharge assessment to allow determination whether
discharges from toe drain outfalls, seeps, or weeps have reached surface waters
and caused a violation of surface water quality standards.) Analyses shall be
conducted by Duke Energy's Huntersville Analytical Laboratory (NC Wastewater
Certification #248) and Pace Analytical Laboratories (NC Wastewater Certification

Duke Energy Progess, LLC I Discharge Assessment Plan ���
Asheville Steam Electric Plant Ash Basin
SECTION 3 - DISCHARGE ASSESSMENT PLAN
# 12). Laboratory analytical methods used for each constituent are provided in
Table 2.
o Seep In -situ measurements: In -situ field parameters (temperature and pH) shall be
measured utilizing calibrated field meters either at the discharge of the seep
directly, at the discharge of the flow measurement devices, or in the water pool
created behind the device, if sufficient water depth did not exist at the device
discharge.
o French Broad River and Ash Basin Sample Collection Method: Water quality
samples and in -situ measurements from the French Broad River shall be collected
at a location upstream (French Broad River -Upstream) and downstream (French
Broad River -Downstream) of the ash basin (Figure 2). Additionally, water samples
and in -situ measurements shall be collected from an in -process ash basin location
(Figure 2). The grab samples shall be collected from the river and basin's surface
(0.3 m) directly into appropriate sample bottles.
• In addition to sampling conducted with the semi-annual assessments, additional seep
sampling will be conducted at locations and at a frequency as determined through
discussions with NC DEQ personnel.
3.2.3 Evaluation
Evaluation of the data from the initial assessment site visit will establish baseline conditions and
will serve as the basis for comparison for subsequent assessment site visit results. Evaluation of
observations and sampling results shall include location, extent (i.e., dimensions of affected
area), and flow of each discharge. The analytical results of the upstream and downstream
locations shall be compared to the 15A NCAC 2B standards for surface water quality upon
receipt to identify potential exceedances.
3.2.4 Assessment Reporting
Each assessment site visit shall be documented by the individual performing the assessment,
as described in Section 3.2.2 to meet the requirements in 130A-309.21 0.1 (b). The report should
contain site background, observation and sampling methodology, and a summary of the
observations and descriptions of the discharge channels observed, changes in observations
compared to previous assessment events, estimates of flows quantities, and photographs of
discharges and outfalls of engineered channels designed or improved for collecting water from
the impoundment. Photographs are to be numbered and captioned. The flow and analytical
results shall be recorded and presented in tables similar to the examples provided as Tables 1
and 3. The analytical results shall be compared to the 15A NCAC 2B standards for surface
water quality and exceedances highlighted. This information shall be compiled, reviewed, and
submitted to NC DEQ within 90 days from the Observation and Sampling event.
w

Duke Energy Progess, LLC I Discharge Assessment Plan Lll%n Asheville Steam Electric Plant Ash Basin
SECTION 4 — REFERENCES
Section 4 — References
LeGrand, Harry, Sr. 2004. A Master Conceptual Model for Hydrogeological Site
Characterization in the Piedmont and Mountain Region of North Carolina, North Carolina
Department of Environment and Natural Resources.
North Carolina Department of Environment and Natural Resources. 2007. Dam Operation,
Maintenance, and Inspection Manual, North Carolina Department of Environment and
Natural Resources, Division of Land Resources, Land Quality Division, 1985 (Revised
2007).
10

FIGURES
D
TABLES
t

Table 1 - Asheville Plant Ash Basin -Seep and Associated Discharge Locations and Descriptions
Location Coordinates
i
1
Discharge Location Coordinates
"Seep:/
(NAD83) '
t
Flow Description
Flow Measurement (MGD)
Background
:Discharge Location and Discharge Sampling Location
(NAD 83)
f•
Discharge ID
-
and Method
Location
Latitude
Longitude
-- "
Latitude
Longitude
y `"
I
A-01
35.471253
-82.552914
Continuous
0.00507
2-B
Tributary to the French Broad River
J
-"
timed -volumetric
6-D
A-02
35.471155
-82.552596
Continuous
0.00063
2-B
Tributary to the French Broad River
timed -volumetric
6-D
B-01
35.468595
-82.551418
Continuous
0.07077
26
Tributary to the French Broad River
area -velocity
6-D ,
C-01
35.466042
-82.549701
Continuous
NF
2i-g
Downstream from foSotDbridge;.stagnant pool
C-02
35.466891
-82.548651
Continuous
0.07606
2-B
Flows to C-01
i
area -velocity
5-13
t5oD64EO-3
C-03
35.469383
-82.549293
Continuous
NM
2-B
_Flows
0.04107
Flows into C-01
D-01
35.466013
-82.549584
Continuous
area -velocity
2-B
5-D
0.05170
Near French Broad River; infiltrates ground
E-01
35.465061
-82.549440
Continuous
area -velocity
2-B
5-D
0.12244
Below F-02; slight backflow from French Broad River
F-01
35.463581
-82.548540
Continuous
area -velocity
2-B
4-13
area -velocity
0.00309
At outlet of seep basin; infiltrates ground
35.473439
-82.554425
F-02
35.462533
-82.547499
Continuous
timed -volumetric
2-B
4-D
0.12958
At outlet of ponded seep area; remnants of beaver pond
F-03
35.463114
-82.547177
Continuous
area -velocity
2-B
4-13
0.08175
Confluence of seepage from 1982 dam
K-01
35.463051
-82.545751
Continuous
area -velocity
2-B
2-D
0.00027
Southwest of 1982 dam
K-02
35.463581
-82.544577
Continuous
timed -volumetric
3-D
0.00332
Upstream of 1-26 culvert; downstream of seep convergence point
M-01
35.464266
-82.546712
Continuous
area -velocity
2-1)
0.02208
Upstream of confluence with Powell Creek
N-01
35.474088
-82.551532
Continuous
area -velocity
3-B
7-1)
Upstream in French Broad River
FB-01
35.457527
-82.544846
Continuous
NM
1-B
1-D
Upstream of raw water intake for Lake Julian
FB-02
35.473479
-82.554377
Continuous
NM
3-B
7-D
0.57559
Upstream of 1-26 culvert at southwestern property corner
P-01
35.461850
-82.544625
Continuous
area -velocity
2-B
2-D
Near dry channel
Ponded water F
35.467232
-82.550521
Continuous
NF
6-D

Location Coordinates
Ij Discharge Location Coordinates
Seep / . W
Discharge '-
(Nao ast
Flow.Pescription
Flow Measurement (MGD)
Background
;Discharge Location and Discharge Sampling�Location
1 (MW Ea)
;�
ID
and Method
Location
Latitude
longitude
-
�' Latitude
Longitude
SD-01
35.474121
-82.552079
"J Continuous -
0.00010
3-B
Near Powell Creek
Intermittent
timed -volumetric
7-D
-0 01.462,
Engineered drain from 1964 ash basin; right discharge pipe facing upstream,(east pipe)
-
. - _ _-
64EO-1
35.468319
-82.549104
Continuous
timed -volumetric
v
5-D 1
0.03968
Engineered drain from 1964 ash basin; left discharge pipe facing upstream (west pipe)
64E0-2
35.468319
-82.549104
Continuous
timed -volumetric
5-D 1
i
2� B
Continuous -
0.00002
Engineered drain from 1964 ash basin; at black corrugated culvert; water infiltrates downstream
64EO-3
35.466943
-82.548502
Intermittent
timed -volumetric
C
5-D (
i
r
0.00225
Engineered drain from 1982 ash basin; leftweir facing upstream (west weir)
82EO-1
35.464058
-82.544848
Continuous
timed -volumetric
,
r
`�
3-D
0.01255
Engineered drain from 1982 ash basin; right weir facing upstream (east weir)
82E0-2
35.464058
-82.544848
Continuous
timed -volumetric
3-D
Notes: C
1. Flow description for each seep sample location is based on observation during site visits performed by Synterra in June 2014.
i
C

Table 3 - Asheville Steam Electric Plant - Example of Surface Water/Seep Monitoring Flow and Analysis Results Table
,.
- . - , � •
Parameter,
�. -
``,,Units
''`.A-01,
A-02
B-01:
C-01 �
�
�.` C-02
,D-01
E-01-�, -
F-01�: � '
'�
F-02 '-'
F-0�3 , �
K-01
Fluoride
mg/I
< �.
. 1
<
1
<
1
<
1
<
1
<
1
<
1
<
1
<
1
<
` .1
<
1
Hg -Mercury (71900)
Ng/I
< �_
0.05
<
0.05
<
0.05
<
0.05
<
0.05
<
0.05
<
0.05
<
0.05
`<
--0.65
<
0.05
<
0.05
As - Arsenic (01002)
Ng/I
<
1
<
1
<
- ti-..1 ��
1.38
3.15
<
1
<
1
J 1.21
<
1
<
1
1.50
Cd - Cadmium (01027)
Ng/I
<
1
<
1
<
1
<
1
<
1
<
1
<
1 .
<
1
<
1
<
1
<
1
Cr - Chromium (01034)
Ng/I
< -
1
<
1
<
1 `
<
1
<
1
<
1
<
1
<
1
<
1
<
11
<
1
Cu - Copper (01042)
Ng/I
<._
1
<
1
<
1
;<
1
<
1
1.41
<
1 �
<
1
<
1
<
j1
<
1
Pb - Lead (01051)
Ng/I
< _
1
<
1
<
1
<
1
<
1
2.0
<
1 y
<
1
<
1
<
1
<
1
Ni - Nickel (01067)
Ng/I
< .
1
<
1
1.57
9.3
12.5
3.42
<
11
2.78
<
1
<
i1
1.16
Se - Selenium (01147)
Ng/I
3.63
<
1
<
1
1.95
2.51
<
1
1.64
<
1
<
1
<
1
<
1
pH
S.U.
5.9
5.7
6.1
6.9
6.5
6.2
6.6
l'24
5.9
6.3
6.4
6.2
Temperature
°C
22
25
21
21
19
24
20
21
21
22
Flow
MGD
0.00507
0.00063
0.07077
NF
0.07606
0.04107
0.05170
0.12244
0.00309
0.12958
0.08175
Notes:
1. Flow measurements and analytical samples were collected in June 2014.
c
c
i
}
�s
L
J
(
p
P
�
c
t
1
1

I y.,
Iw
Table 2 — Laboratory Analytical Methods
Parameter
L �_4
Method
Reporting .
Limit
Units
Laboratory
Fluoride (F)
EPA 300.0
1
mg/I
Duke Energy
Mercury (Hg)
EPA 245.1
0.05
Ng/I _
Duke Energy
v.
Arsenic (As)
EPA 200.8
1
Ng/I
Duke Energy
Cadmium (Cd)
EPA 200.8
1
Ng/I
Duke Energy
Chromium (Cr)
EPA 200.8
1
Ng/I
Duke Energy
Copper (Cu)
EPA 200.8
1
Ng/I
Duke Energy
Lead (Pb)
EPA 200.8
1
Ng/I
Duke Energy
Nickel (Ni)
EPA 200.8
1
Ng/I
Duke Energy,
Selenium (Se)
EPA 200.8
1
Ng/I
Duke Energy