Duke Mayo Coal Pile Add Assessment Work Plan_20190924

DUKE
ENERGY
September 24, 2019
North Carolina Department of Environmental Quality
Water Quality Regional Operations
3800 Barrett Drive
1628 Mail Service Center
Raleigh, North Carolina 27699
Attn: Mr. Eric Rice (submitted electronically)
Re: Mayo Steam Electric Plant Coal Storage Pile Area
Additional Groundwater Assessment Work Plan
Mayo Steam Electric Plant
10660 Boston Road
Roxboro, North Carolina 27574
Dear Mr. Rice:
2500 Fairfax Road
Greensboro, North Carolina 27407
336-215-4576
Duke Energy is submitting the attached Additional Assessment Work Plan for the Coal Storage
Pile Area (CSPA) at the Mayo Steam Electric Plant for your review.
The initial assessment Work Plan for the CSPA was submitted on January 23, 2019 (revised
February 10, 2019), approved by the North Carolina Department of Environmental Quality
(NCDEQ) Raleigh Regional Office (RRO) on February 14, 2019. A revised Work Plan was
submitted on February 20, 2019, approved by the RRO March 6, 2019.
Initial assessment efforts indicate the presence of constituents (metals, other inorganics) in
groundwater proximate with the CSPA. Three specific areas require additional investigation to
complete the assessment.
Upon concurrence with this Work Plan, Duke Energy will pursue receipt of necessary permits
for the installation of 24 proposed groundwater monitoring wells, soil investigation, and perform
associated sampling and analysis.
If you need additional information regarding this submittal do not hesitate to call or email, 336-
215-4576 or [e-mail].
Respectfully submitted,
'�4C�z
0-w-
Kimberlee Witt, PE
Environmental Services
Mayo Steam Electric Plant - Page I of 2

Attachments: Work Plan for Additional Assessment — Coal Pile Area, Mayo Steam Electric Plant,
SynTerra September 2019
ecc: Coal Ash War Room - NCDEQ
Rick Bolich - NCDEQ
Eric Smith - NCDEQ
Steve Lanter - NCDEQ
John Toepfer - Duke Energy
Ed Sullivan — Duke Energy
Jerry Wylie - SynTerra
Mayo Steam Electric Plant - Page 2 of 2

161p
synTerra
WORK PLAN FOR ADDITIONAL ASSESSMENT
COAL PILE AREA
MAYO STEAM ELECTRIC PLANT
10660 BOSTON ROAD
ROXBORO, NC 27574
SEPTEMBER 2019
PREPARED FOR
DUKE
ENERGY
PROGRESS
DUKE ENERGY PROGRESS, LLC
Jerry A Wylie, LG 1425
Project Manager
Peggy W. Altman
Project Hydrogeologist

Work Plan for Additional Assessment - Coal Pile Area September 2019
Mayo Steam Electric Plant
TABLE OF CONTENTS
SECTION
PAGE
1.0
INTRODUCTION.........................................................................................................1-1
1.1
Regulatory Background...........................................................................................1-1
1.2
Site Description.........................................................................................................1-2
1.3
Initial Assessment Results.......................................................................................1-3
2.0
COAL PILE ASSESSMENT OBJECTIVES..............................................................2-1
2.1
Soil Assessment.........................................................................................................
2-1
2.2
Groundwater Assessment.......................................................................................
2-2
2.3
Monitoring Well Assessment Procedures.............................................................
2-3
LIST OF FIGURES
Figure 1 Site Location Map
Figure 2 Proposed Additional Monitoring Well and Soil Boring Locations
LIST OF TABLES
Table 1 Soil Sample Analytical Methods
Table 2 Proposed Coal Pile Assessment Soil Samples and Monitoring Wells
Table 3 Groundwater Analytical Methods
Page i

Work Plan for Additional Assessment — Coal Pile Area September 2019
Mayo Steam Electric Plant
1.0 INTRODUCTION
Duke Energy Progress, LLC (Duke Energy) owns and operates the coal-fired Mayo
Steam Electric Plant (Mayo, Plant, or Site) located in a rural area approximately 10 miles
north of the City of Roxboro in Person County, North Carolina (Figure 1). Duke Energy
owns the site property, which is roughly bisected by US Highway 501, encompasses 460
acres, and includes the power plant, ash basin, material storage, industrial landfill and
other operational features associated with coal-fired power generating facilities. Mayo
began operations in 1983 with a single coal-fired unit. Coal is transported to Mayo by
rail and stored on Site.
This work plan describes activities proposed for further assessment of groundwater and
soil around the Mayo coal pile area. Duke Energy submitted a coal pile assessment
Work Plan on January 23, 2019 (revised February 10, 2019) that was approved by the
NCDEQ Raleigh Regional Office (RRO) on February 14, 2019. A revised Work Plan was
submitted on February 20, 2019 and approved by the RRO on March 6, 2019. The initial
assessment effort conducted in the first half of 2019 indicated the presence of
constituents (metals, other inorganics) in groundwater proximate with the coal pile.
Initial assessment data indicate three specific areas around the coal pile to be evaluated
further (Figure 2). The first area, an area represented by low pH in groundwater from
wells CPA-1D, CPA-1BR, and CPA-7D, is located on the northwestern side of the coal
pile. The second area is east of the basin, east of the coal pile, and is represented by well
cluster CPA-5. The third area is southeast of the coal pile and is represented by well
CPA-4D. These areas are described in more detail in Section 1.3.
Initial groundwater assessment indicates that groundwater flow, as anticipated, moves
beneath the coal pile and low pH area, approximately from southeast to northwest;
however, detections of constituents in seemingly upgradient locations (CPA-4; CPA-5
wells) indicate the need for additional assessment of these areas. Proposed groundwater
and soil assessment activities for the coal pile area are described herein.
1.1 Regulatory Background
In 2014, The North Carolina General Assembly passed the Coal Ash Management Act
(CAMA). CAMA required owners of a coal combustion residual (CCR) surface
impoundment to conduct detailed assessment of Site groundwater within and around
the CCR surface impoundment.
Page 1-1

Work Plan for Additional Assessment — Coal Pile Area September 2019
Mayo Steam Electric Plant
As indicated in a letter from the North Carolina Department of Environmental Quality
(DEQ) dated September 8, 2017 (Zimmerman to Sullivan), it is understood that in
addition to CAMA requirements, Duke Energy is also bound by the rules and
requirements of the NC General Statutes and NC Administrative Code 02L. These
provide requirements for the assessment and abatement of soil and groundwater
impacts resulting from Site activities. Therefore, Duke Energy is required to assess soil
and groundwater in areas where there is a potential for groundwater impact, identified
as primary and secondary sources.
1.2 Site Description
Detailed descriptions of the Site operational history, the Site conceptual model, physical
setting and features, geology/hydrogeology, and results of the findings of the
Comprehensive Site Assessment (CSA) and other CAMA-related works are
documented in full in the following documents:
• Comprehensive Site Assessment Report — Mayo Steam Electric Plant (SynTerra,
September 2, 2015)
• Corrective Action Plan Part 1— Mayo Steam Electric Plant (SynTerra, December 1,
2015)
• Corrective Action Plan Part 2— Mayo Steam Electric Plant (SynTerra, February 2,
2016)
• Comprehensive Site Assessment Supplement 1— Mayo Steam Electric Plant (SynTerra,
July 7, 2016)
• Comprehensive Site Assessment Update — Mayo Steam Electric Plant (SynTerra,
October 31, 2017)
The coal pile at Mayo occupies approximately 20 to 30 acres and is located in the south-
central portion of the Plant (Figure 2). The coal pile is bounded to the north and east by
internal Plant access roads and buildings as well as the Plant railroad line. The coal pile
is bounded to the west and south by undeveloped, mostly forested land. The land
surface surrounding the coal pile is generally flat and is at an elevation of
approximately 520 feet North American Vertical Datum of 1988 (NAVD 88). Surface
water runoff from the area was historically directed to the ash basin; however, a coal
pile retention basin and conveyance structures were constructed in 2018 on the western
side of the coal pile area to capture run-off and direct it to new wastewater treatment
facilities.
Page 1-2

Work Plan for Additional Assessment — Coal Pile Area September 2019
Mayo Steam Electric Plant
1.3 Initial Assessment Results
Initial assessment data indicate three specific areas around the coal pile to be evaluated
further (Figure 2).
Low pH Area
The low pH area is an area (represented by CPA-71)) where groundwater pH values are
approximately 4 standard units (S.U.) or less, which is less than S.U.s at other Site areas.
The area is on the northwestern side of the coal pile is represented by wells CPA-11),
CPA-1BR, and CPA-71). Boron is present in concentrations just below the 02L of 700
µg/L at CPA-71).
The source of low groundwater pH conditions has not been identified. However, at
other Duke Energy combustion facilities, similar conditions have been noted associated
with "mill rejects" or "clinkers", rocks that become mixed with coal that was not
combusted as part of the power generation process. Clinkers can be rich in pyrite and
can cause low pH conditions in groundwater. Low pH conditions can cause
metals/inorganics to solubilize and occur at concentrations notably greater than
typically measured. No clinkers or similar material was noted during well installation
activities at Mayo. Other possible reasons for the presence of the low pH groundwater
area continue to be considered.
Groundwater concentrations greater than regulatory comparison criteria are exceeded
for a number of constituents (e.g., sulfate, TDS) in this area and other metals and
inorganics are present. In general - except for iron and manganese - unsaturated soil
concentrations do not exceed NC Preliminary Site Remediation Goals (PSRG) for
Protection of Groundwater (POG) or site -specific Background Threshold Values (BTVs).
CPA-413 Area
The second area is southeast of the coal pile and is represented by well CPA-41).
Elevated concentrations of cobalt, manganese, sulfate, and TDS were noted. Boron was
detected above the background value but well below the 02L. In general - except for
iron and manganese - unsaturated soil concentrations do not exceed POGs or BTVs.
CPA-5 Well Cluster Area
The third area is east of the basin and represented by well cluster CPA-5. Boron is
present above site background values in the surficial well but far below the 02L. Boron
was detected around the analytical reporting limit in the transition zone well and was
undetected in the bedrock well. Elevated cobalt, iron, and manganese concentrations
were noted in wells CPA-5S and SPA-51). In general - except for iron, manganese, and
sporadic chromium detections - soil concentrations do not exceed POGs or BTVs. In
Page 1-3

Work Plan for Additional Assessment — Coal Pile Area September 2019
Mayo Steam Electric Plant
general - except for iron and manganese - unsaturated soil concentrations do not
exceed POGs or BTVs.
Based on initial assessment results, unsaturated soils in/around the coal pile are
unimpacted. This finding indicates that the source of groundwater impact requires
additional investigation.
Page 1-4

Work Plan for Additional Assessment — Coal Pile Area September 2019
Mayo Steam Electric Plant
2.0 COAL PILE ASSESSMENT OBJECTIVES
Objectives of the additional coal pile assessment activities presented in this work plan
include the following:
• Further characterize and delineate constituent concentrations in groundwater in
three areas proximate to the coal pile.
• Refine the understanding of groundwater flow direction in the coal pile area.
• Evaluate the potential need for corrective action for the coal pile area.
2.1 Soil Assessment
Although unsaturated soils do not indicate impact from CCR material, samples will be
collected during assessment activities and for inorganic parameters consistent with
assessment of areas used for coal and CCR management (Table 1).
Coal pile area soils will be sampled and analyzed for metals and inorganic parameters
to determine if they are a source that may leach into underlying groundwater in excess
of NC 02L standards or BTVs. Soil samples will be collected during well drilling and
installation activities. The proposed locations of the monitoring wells are included in
Figure 2. Proposed locations are approximate and may vary slightly based on field
observations and locations of underground utilities, which will be determined prior to
initiation of boring activities.
Soil samples will be collected from the near ground surface (two to three feet) and at
approximately two to five foot intervals to the top of the groundwater table or bedrock,
whichever is encountered first. An additional soil sample will be collected below the
water table within the new well screen intervals. SPLP samples will be collected at a
frequency of two per well cluster location with one unsaturated sample collected from
near ground surface (two to three feet) and a saturated sample collected two to three
feet below the water table (Table 2).
Additional soil borings will be completed around the concrete pad/foundation located
near monitoring well CPA-4D, and soil samples will be collected and analyzed as
detailed above. Only unsaturated soil samples will be collected from these borings and
the borings will terminate either at refusal or when groundwater is encountered.
Exploratory borings will be completed in the area between CPA-1 well cluster and
proposed well cluster CPA-8 on the northwest side of the coal pile area. The area is
approximately 600 feet long and borings are proposed approximately every 50 feet.
Page 2-1

Work Plan for Additional Assessment — Coal Pile Area September 2019
Mayo Steam Electric Plant
Continuous soil sampling will be conducted for visual observation of encountered
soil/material using direct push techniques, rotary sonic drilling, or hollow -stem auger
drilling with split -spoon samplers. The objective of this effort is to attempt to visually
determine the possible presence of clinkers/rejects in the high pH area noted near CPA-
7D. In addition, although previous assessment results indicate no impacts to
unsaturated soils in this area, approximately three to five of the planned borings will be
sampled for laboratory analysis. Sampling depths for unsaturated soil samples will be
similar to those presented for other proposed borings as provided in Table 2.
2.2 Groundwater Assessment
The extent of groundwater impact in three areas identified during initial assessment
activities will be assessed by installing groundwater monitoring wells and
collecting/analyzing representative groundwater samples from newly completed and
existing wells.
Proposed Assessment Locations
A total of eight monitoring well clusters are proposed for installation to further
characterize coal pile area groundwater conditions at the proposed locations shown in
Figure 2. One monitoring well cluster could include one, two, or three individual
monitoring wells depending on Site conditions. If saturated conditions are present, a
well will be installed in the surficial, transition zone, upper bedrock flow zones. Based
on previous drilling operations at Mayo, it is anticipated that surficial groundwater is
not typically encountered. Well locations may be modified slightly based on field
constraints (e.g. underground utility locations, rig stability).
CPA-1, CPA-7 Area
Two monitoring well clusters are proposed for the area along the northwest side of the
coal pile area (locations CPA-8 and CPA-9; Figure 2). The purpose of these proposed
locations is to determine the extent of impact to the northeast (CPA-8) and southwest
(CPA-9) of the low pH/high metals concentration area. In addition, additional
groundwater quality data will inform the need and manner of any potential corrective
action that is deemed necessary or useful in this specific area.
The installation of additional monitoring wells immediately downgradient of the coal
pile - on the northern side - is not possible due to Site infrastructure (haul road,
railroad, leachate lines, steep slope, etc.). The two proposed additional well clusters will
be installed within the current ash basin compliance boundary (CPA-8 and CPA-9).
Page 2-2

Work Plan for Additional Assessment — Coal Pile Area September 2019
Mayo Steam Electric Plant
Proposed Well Cluster CPA-10
One monitoring well cluster (CPA-10) is proposed to provide water level data in the
suspected upgradient direction and to provide a viable background location for the coal
pile area. As indicated in the following subsections, groundwater samples associated
with the areas around CPA-4 and CPA-5 indicated impact in these areas. Therefore, a
new background location for the coal pile area is proposed.
CPA-4 Area
Three well clusters (CPA-11, CPA-12, and CPA-13) are proposed to determine the
extent of impact in this area on the south side of the coal pile area around well CPA-41)
(Figure 2) and to verify groundwater flow direction. This area was initially assumed to
be upgradient of the coal pile area. Detections of metals/inorganics in transition zone
well CPA-41) indicate the need for additional assessment in this area. In addition, a
concrete foundation pad from a previously existing structure is present in this area. The
nature and use of the former structure will be investigated with Duke Energy
personnel. In addition to proposed well CPA-13 located near the structure, three
additional soil borings will be completed around the concrete pad, and unsaturated soil
samples will be collected and analyzed from the borings (Table 1).
During the initial assessment effort, a viable bedrock well could not be installed due to
the lack of encountered water -bearing fractures. Existing location CPA-4BR is an open
borehole; however, the water level in CPA-4BR has still not fully equilibrated after
about five months. This installation will be properly abandoned.
CPA-5 Area
Two well clusters (CPA-14 and CPA-15) are proposed to determine the extent of impact
in this area on the east side of the coal pile area around well cluster CPA-5 (Figure 2)
and to verify groundwater flow direction. This area was initially assumed to be
upgradient of the coal pile area. Detections of boron in shallow well CPA-5S and
transition zone well CPA-51) indicate the presence of low concentrations of boron in
this area.
2.3 Monitoring Well Assessment Procedures
Well installation procedures and well construction materials and lengths will be
consistent with ongoing CAMA assessment activities in accordance with the approved
Proposed Groundwater Assessment Work Plan (Rev. 1) (SynTerra, 2014). During borehole
installations, SynTerra will describe soil and rock cuttings. Those descriptions will
include lithology, color, and the type of soil or rock. The proposed monitoring wells
would be constructed in accordance with NCAC Title 15A, Subchapter 2C, Section .0100
Well Construction Standards. The proposed wells would consist of 2-inch diameter
Page 2-3

Work Plan for Additional Assessment — Coal Pile Area September 2019
Mayo Steam Electric Plant
schedule 40 polyvinyl chloride flush -joint threaded casings and prepacked well screens.
Shallow wells are proposed to be installed so that the top of the screened interval is
positioned approximately five feet below the water table, where practical, to avoid
potential issues such as biofouling and introduction of artificial redox conditions, which
are common among monitoring wells with screened intervals that bracket the water
table.
The primary drilling technology for soil sampling, well drilling, and well installation
will either be rotary sonic drilling or a combination of air rotary and hollow stem auger
drilling. Anticipated well depths are provided in Table 2. After well installation is
complete, monitoring wells will be developed to remove drilling fluids and solids that
might have been introduced into the surrounding formation and sand pack during well
installation. Well development helps establish interaction of the well with surrounding
groundwater. The location and elevation of each newly installed well will be
determined by survey. The newly installed wells will also be slug tested to evaluate
hydraulic properties of the groundwater flow system at each location.
Groundwater samples will be analyzed for field parameters (e.g., pH, conductivity, and
turbidity) and inorganic constituents consistent with ongoing CAMA assessment
activities (Table 3). Groundwater samples will be collected using low -flow sampling
techniques and following procedures outlined in the Low Flow Sampling Plan, Duke
Energy Facilities, Ash Basin Groundwater Assessment Program, North Carolina, June 10, 2015.
To have at least two sampling events and analytical data sets available for evaluation in
the coal pile site assessment report, samples would be collected at a frequency no less
than 60 days between sampling events.
Page 2-4

Work Plan for Additional Assessment — Coal Pile Area September 2019
Mayo Steam Electric Plant
FIGURES

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-..FIGURE
1
COAL PILE AREA ADDITIONAL ASSESSMENT
MAYO STEAM ELECTRIC PLANT
DUKE ENERGY PROGRESS, LLC
synTerra
PERSON COUNTY
. :.-. .- -.
148 RIVER
• ..
ROBINSON•.• , .

• ` G
APPROXIMATE FUTURE
ASH BASIN WASTE BOUNDARY
.!� (SEE NOTE 2)
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synTerra
(' DUKE
ENERGY
PROGRESS
- .rt
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LEGEND
ASH BASIN WASTE BOUNDARY
— - — - — ASH BASIN COMPLIANCE BOUNDARY
k PROPOSED SOIL BORING LOCATION
(APPROXIMATE)
PROPOSED MONITORING WELL LOCATION
(APPROXIMATE)
EXISTING MONITORING WELL AND SOIL
BORING LOCATION
COAL PILE AREA
•
NOTES:
1. COAL PILE DRAINAGE SYSTEM CONSTRUCTION FEATURES PROVIDED BY DUKE
ENERGY PROGRESS.
2. AREA OF INVESTIGATION THAT DETERMINED SETTLED CCR MATERIAL IS NOT
PRESENT IN THIS AREA OF THE ASH BASIN. A FUTURE REPRESENTATIVE ASH BASIN
-
WASTE AND COMPLIANCE BOUNDARY IS INCLUDED IN THE MAYO NPDES PERMIT
NCO038377 PART I, 5.A.(18.) ATTACHMENT FIGURE 1 AND ATTACHMENT B FIGURE 1.1
•
DATED JULY 13, 2018.
■ - •
3. NATURAL RESOURCES TECHNICAL REPORT (NRTR) PREPARED BYAMEC FOSTER
• 1
• —•
••
WHEELER INC., JUNE 17, 2015.
• r =v • '-r - -
4. WSP SURVEY CONDUCTED APRIL 17, 2014.
• _+
5. FLOOD INSURANCE BOUNDARIES PROVIDED BY FEMA, PERSON COUNTY FLOOD
• e
e
INSURANCE STUDY, EFFECTIVE NOVEMBER 17, 2017 ( https://msc.fema.gov/portal).
f �
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_
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'
6. AERIAL PHOTOGRAPHY OBTAINED FROM PERSON COUNTY GIS ON SEPTEMBER 13,
2019. IMAGE COLLECTED IN 2019.
. r —d 1-
7. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE
100 50 0 100 zoo
FIGURE 2
GRAPHIC SCALE IN FEET
COAL PILE AREA ADDITIONAL ASSESSMENT
MAYO STEAM ELECTRIC PLANT
148 RIVER STREET, SUITE 220
CAROLINA 29601
PHONE
DUKE ENERGY PROGRESS LLC
PHONE [phone]
864-421- 9
�
www.suterracoro.com
PERSON COUNTY
ROXBORO NORTH CAROLINA
DRAWNBr.A. ROBINSON DATE09/23/2019
REVISED BY: C. DAVIS DATE: 09/23/2019
CHECKED BY: P. ALTMAN DATE: 09/23/2019
'

Work Plan for Additional Assessment — Coal Pile Area September 2019
Mayo Steam Electric Plant
TABLES

TABLE 1
SOIL SAMPLE ANALYTICAL METHODS
WORK PLAN FOR ADDITIONAL ASSESSMENT COAL PILE AREA
MAYO STEAM ELECTRIC PLANT
DUKE ENERGY PROGRESS LLC, ROXBORO, NC
Inorganic Compounds
Units
Method
Aluminum
mg/kg
EPA 6010D
Antimony
mg/kg
EPA 6020B
Arsenic
mg/kg
EPA 6020B
Barium
mg/kg
EPA 6010D
Beryllium
mg/kg
EPA 6010D
Boron
mg/kg
EPA 6010D
Cadmium
mg/kg
EPA 6020B
Calcium
mg/kg
EPA 6010D
Chloride
mg/kg
EPA 9056A
Chromium
mg/kg
EPA 6010C
Cobalt
mg/kg
EPA 6020A
Copper
mg/kg
EPA 6010C
Iron
mg/kg
EPA 6010C
Lead
mg/kg
EPA 6020B
Magnesium
mg/kg
EPA 6010D
Manganese
mg/kg
EPA 6010C
Mercury
mg/kg
EPA 7471B
Molybdenum
mg/kg
EPA 6010D
Nickel
mg/kg
EPA 6010C
Nitrate as Nitrogen
mg/kg
EPA 9056A
pH
S.U.
EPA 9045D
Potassium
mg/kg
EPA 6010D
Selenium
mg/kg
EPA 6020B
Sodium
mg/kg
EPA 6010D
Strontium
mg/kg
EPA 6010C
Sulfate
mg/kg
EPA 9056A
Thallium
mg/kg
EPA 6020B
Total Organic Carbon
mg/kg
EPA 9060
Vanadium
mg/kg
EPA 6020B
Zinc
mg/kg
EPA 6010C
Prepared by: RBI Checked by: SRW/TCP/VTV
Notes:
1. Soil samples to be analyzed for Total Inorganics using USEPA Methods 6010/6020 and pH using USEPA Method 9045, as noted above.
2. Soil samples collected from near ground surface (2 to 3ft) and from just above water table (field determined) in each boring will also
be analyzed for leaching potential using SPLP Extraction Method 1312 in conjunction with USEPA Methods 6010/6020
3. Analytical methods and reporting limits as presented were developed for CSA field implementation in 2015. Analytical methods and
reporting limits are updated periodically and applied as appropriate.
mg/kg - Milligrams per kilogram
mV - Millivolts
S.U. - Standard Unit
Page 1 of 1

TABLE 2
PROPOSED COAL PILE ASSESSMENT SOIL SAMPLES AND MONITORING WELLS
WORK PLAN FOR ADDITIONAL ASSESSMENT COAL PILE AREA
MAYO STEAM ELECTRIC PLANT
DUKE ENERGY PROGRESSS, LLC, ROXBORO, NC
Monitoring
Well ID
Estimated
Well Depth
(feet bgs)
Soil Sample ID
(Estimated Depth
Interval in feet bgs)
Comments
CPA-S68 2-3
Near -surface unsaturated soil sample (water table —20 feet bgs)
CPA-SBS Various
Continue soil at 5' intervals until the bottom of unconsolidated material is reached (i.e. 7-8', 12-13', 17-18' etc)
CPA-SBS 19-20
Saturated soil sample (may not apply)
CPA-8S
30
CPA-SBS 25-26
Soil sample from shallow well screened interval
CPA-813
50
CPA-SBS 45-46
Soil sample from deep well screened interval
CPA-81311
80
CPA-SB8 75-76
Soil sample from bedrock screened interval
CPA-SB9 2-3
Near -surface unsaturated soil sample (water table —20 feet bgs)
CPA-SB9 Various
Continue soil at 5' intervals until the bottom of unconsolidated material is reached (i.e. 7-8', 12-13', 17-18' etc)
CPA-SB9 19-20
Saturated soil sample (may not apply)
CPA-9S
30
CPA-SB9 25-26
Soil sample from shallow well screened interval
CPA-913
50
CPA-SB9 45-46
Soil sample from deep well screened interval
CPA-91311
80
CPA-SB9 75-76
Soil sample from bedrock screened interval
CPA-S10 2-3
Near -surface unsaturated soil sample (water table —20 feet bgs)
CPA-SB10 Various
Continue soil at 5' intervals until the bottom of unconsolidated material is reached (i.e. 7-8', 12-13', 17-18' etc)
CPA-SB10 19-20
Saturated soil sample (may not apply)
CPA-10S
30
CPA-SB10 25-26
Soil sample from shallow well screened interval
CPA-lOD
50
CPA-SB10 45-46
Soil sample from deep well screened interval
CPA-lOBR
80
CPA-SB10 75-76
Soil sample from bedrock screened interval
CPA-SB11 2-3
Near -surface unsaturated soil sample (water table —20 feet bgs)
CPA-SB11 Various
Continue soil at 5' intervals until the bottom of unconsolidated material is reached (i.e. 7-8', 12-13', 17-18' etc)
CPA-SB11 19-20
Saturated soil sample (may not apply)
CPA-11S
30
CPA-SB11 25-26
Soil sample from shallow well screened interval
CPA-11D
50
CPA-SB11 45-46
Soil sample from deep well screened interval
CPA-11BR
80
CPA-SB11 75-76
Soil sample from bedrock screened interval
CPA-SB12 2-3
Near -surface unsaturated soil sample (water table —20 feet bgs)
CPA-SB12 Various
Continue soil at 5' intervals until the bottom of unconsolidated material is reached (i.e. 7-8', 12-13', 17-18' etc)
CPA-SB12 19-20
Saturated soil sample (may not apply)
CPA-12S
30
CPA-SB12 25-26
Soil sample from shallow well screened interval
CPA-12D
50
CPA-SB12 45-46
Soil sample from deep well screened interval
CPA-12BR
80
CPA-SB12 75-76
Soil sample from bedrock screened interval
CPA-SB13 2-3
Near -surface unsaturated soil sample (water table —20 feet bgs)
CPA-SB13 Various
Continue soil at 5' intervals until the bottom of unconsolidated material is reached (i.e. 7-8', 12-13', 17-18' etc)
CPA-SB13 19-20
Saturated soil sample (may not apply)
CPA-13S
30
CPA-SB13 25-26
Soil sample from shallow well screened interval
CPA-13D
50
CPA-SB13 45-46
Soil sample from deep well screened interval
CPA-13BR
80
CPA-SB13 75-76
Soil sample from bedrock screened interval
CPA-SB14 2-3
Near -surface unsaturated soil sample (water table —20 feet bgs)
CPA-SB14 Various
Continue soil at 5' intervals until the bottom of unconsolidated material is reached (i.e. 7-8', 12-13', 17-18' etc)
CPA-SB14 19-20
Saturated soil sample (may not apply)
CPA-14S
30
CPA-SB14 25-26
Soil sample from shallow well screened interval
CPA-14D
50
CPA-SB14 45-46
Soil sample from deep well screened interval
CPA-14BR
80
CPA-SB14 75-76
Soil sample from bedrock screened interval
CPA-SB15 2-3
Near -surface unsaturated soil sample (water table —20 feet bgs)
CPA-SB15 Various
Continue soil at 5' intervals until the bottom of unconsolidated material is reached (i.e. 7-8', 12-13', 17-18' etc)
CPA-SB15 19-20
Saturated soil sample (may not apply)
CPA-15S
30
CPA-SB15 25-26
Soil sample from shallow well screened interval
CPA-151)
50
CPA-SB15 45-46
Soil sample from deep well screened interval
CPA-15BR
80
CPA-SB15 75-76
Soil sample from bedrock screened interval
CPA-SB100 2-3
Near -surface unsaturated soil sample (water table —20 feet bgs)
CPA-SB100 Various
Continue soil at 5' intervals until the bottom of unconsolidated material is reached (i.e. 7-8', 12-13', 17-18' etc)
CPA-SB100 19-20
Saturated soil sample (may not apply)
CPA-SB100 25-26
Soil sample at top of transition zone
CPA-SB101 2-3
Near -surface unsaturated soil sample (water table —20 feet bgs)
CPA-SB101 Various
Continue soil at 5' intervals until the bottom of unconsolidated material is reached (i.e. 7-8', 12-13', 17-18' etc)
CPA-SB101 19-20
Saturated soil sample (may not apply)
CPA-SB101 25-26
Soil sample at top of transition zone
CPA-SB102 2-3
Near -surface unsaturated soil sample (water table —20 feet bgs)
CPA-SB102 Various
Continue soil at 5' intervals until the bottom of unconsolidated material is reached (i.e. 7-8', 12-13', 17-18' etc)
CPA-56102 19-20
Saturated soil sample (may not apply)
CPA-SB102 25-26
Soil sample at top of transition zone
Prepared by: PWA Checked by: JAW
Notes:
-- : Not applicable
bgs - below ground surface
- Approximately
Estimated well and soil sample depths based on data from the previously installed coal pile assessment wells.
Number of soil samples is approximate. A shallower water table will result in fewer samples, and a deeper water table will result in additional samples.
SynTerra recommends each well screen be submerged beneath the water table and have a length of at least 10 feet.
Saturated soil samples may be conincident with the screened interval of shallow wells. Collect an SPLP sample at the shallow screened interval if this is the case
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TABLE 3
GROUNDWATER ANALYTICAL METHODS
WORK PLAN FOR ADDITIONAL ASSESSMENT COAL PILE AREA
MAYO STEAM ELECTRIC PLANT
DUKE ENERGY PROGRESS LLC, ROXBORO, NC
Parameter
RL
Units
Method
Field Parameters
pH
NA
SU
Field Water Quality Meter
Specific Conductance
NA
PS/CM
Field Water Quality Meter
Temperature
NA
oC
Field Water Quality Meter
Dissolved Oxyqen
NA
mq/L
Field Water Quality Meter
Oxidation Reduction Potential
NA
mV
Field Water Quality Meter
Eh
NA
mV
Field Water Quality Meter
Turbidity
NA
NTU
Field Water Quality Meter
Inorganics
Aluminum
0.005
mq/L
EPA 200.7 or 6010D
Antimony
0.001
mq/L
EPA 200.8 or 602OB
Arsenic
0.001
mq/L
EPA 200.8 or 602OA
Barium
0.005
mq/L
EPA 200.7 or 6010C
Beryllium
0.001
mq/L
EPA 200.8 or 6020A
Boron
0.05
mq/L
EPA 200.7 or 6010C
Cadmium
0.001
mq/L
EPA 200.8 or 602OA
Chromium
0.001
mq/L
EPA 200.8 or 6010C
Cobalt
0.001
mq/L
EPA 200.8 or 6020A
Copper
0.001
mq/L
EPA 200.8 or 6020E
Hexavalent Chromium
0.000025
mq/L
EPA 218.7
Iron
0.01
mq/L
EPA 200.7 or 6010C
Lead
0.001
mq/L
EPA 200.8 or 602OA
Manqanese
0.005
mq/L
EPA 200.7 or 6010C
Mercury
0.000
mq/L
EPA 245.1 or 7470A
Molybdenum
0.001
mq/L
EPA 200.8 or 6020E
Nickel
0.001
mq/L
EPA 200.8 or 6020E
Selenium
0.001
mq/L
EPA 200.8 or 6020A
Strontium
0.005
1 mq/L
I EPA 200.7 or 6010C
Thallium (low level)
0.0002
mq/L
EPA 200.8 or 602OA
Vanadium (low level)
0.0003
mq/L
EPA 200.8 or 602OA
Zinc
0.005
mq/L
EPA 200.7 or 6010C
Radionuclides
Radium 226
1
pCi/L
EPA 903.1 Modified
Radium 228
1
pCi/L
EPA 904.0/SW846 9320 Modified
Uranium 223 234 236 238
Varies by Isotope_
µ /mL
SW846 3010A/6020B
Total Uranium
NA
µg/mL
Calculated
Anions/Cations
Alkalinity (as CaCO3)
5
mq/L
SM 2320B
Bicarbonate
5
mq/L
SM 2320
Calcium
0.01
mq/L
EPA 200.7
Carbonate
5
mq/L
SM 2320
Chloride
0.1
mq/L
EPA 300.0 or 9056A
Maqnesium
0.005
mq/L
EPA 200.7
Potassium
0.1
mq/L
EPA 200.7
Sodium
0.05
mq/L
EPA 200.7
Sulfate
0.1
mq/L
EPA 300.0 or 9056A
Sulfide
0.1
mg/L
SM4500S2D
Total Dissolved Solids
25
mq/L
SM 2540C
Total Orqanic Carbon
0.1
mq/L
SM 5310C/EPA9060A
Total Suspended Solids
2.5
m L
I SM 2450D
Prepared by: RBI Checked by: SRW/TCP
Notes:
1. Select constituents will be analyzed for total and dissolved concentrations.
2. Analytical methods and reporting limits as presented were developed for CSA field implementation in 2015. Analytical methods and reporting limits are updated
periodically and applied as appropriate.
OC - Degrees Celsius
µS/cm - micro -Siemens per centimeter
mg/L - Milligrams per liter
mg - N/L - Milligrams nitrogen per liter
my - Millivolts
NA - Not analyzed
NTU - Nephelometric turbidity unit
pCi/L - picocuries per liter
RL - reporting limit
S.U. - Standard Unit
ug/mL - micrograms per milliliter
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