Belews Creek Background Soil Dataset Evaluation - December 2016

F)2
Technical Memorandum
Date: Tuesday, December 13, 2016
Project: Belews Creek Steam Station
To: Kim Witt and Melonie Martin
From: Jacob Ruffing
Subject: Quantification of Valid Background Soil Samples for Statistical Calculations
The purpose of this memorandum is to provide the basis for evaluation of soil samples proposed for use
in determining site-specific background concentrations using statistical methods. The soil samples
evaluated herein were principally collected during Comprehensive Site Assessment (CSA) fieldwork
conducted between March and May 2015. The locations of soil samples evaluated for use in background
statistical calculations are shown on Figure 1.
Viability of samples for use in statistical calculations was evaluated using the following criteria:
• Soil sample is collected from a location that is not impacted by coal combustion residuals or coal -
associated materials;
• Soil sample is collected from a location that is not impacted by other potential anthropogenic
sources of constituents;
• Soil sample is collected from the unsaturated zone, above the maximum groundwater elevation
measured in shallow wells between July 2015 and September 2016; and
• Soil sample collected from a location not impacted by periodic flooding.
A total of 40 soil samples were collected at BCSS during CSA activities. Of these 40 samples, 17 samples
satisfy the four criteria listed above and are considered viable samples for use in statistical calculations.
These samples were collected from the following locations on-site: BG -1D located beyond the compliance
boundary north/northeast of the active ash basin; BG -2D located beyond the compliance boundary
northeast of the active ash basin; BG -3D located beyond the compliance boundary southwest of the Pine
Hall Road Landfill; GWA-3D located beyond the compliance boundary east of the active ash basin; GWA-
4S located east of the active ash basin and the FGD wastewater treatment system; and GWA-12D
located beyond the compliance boundary south/southeast of the Pine Hall Road Landfill and west of the
Structural Fill area. Note that viable samples collected from borings near the waste boundary or down -
gradient of ash management areas were collected a minimum of one foot above the maximum measured
groundwater elevation and are assumed to have not been impacted by groundwater migrating from ash
sources.
Soil sampling data used in this evaluation, including the range of groundwater elevations for shallow wells
in each well cluster and analytical results per well are provided in Table 1. Note that laboratory reporting
limit for antimony, arsenic, cobalt (three samples), selenium, and thallium exceeded the North Carolina
Protection of Groundwater (POG) Preliminary Soil Remediation Goals, as revised in October 2016.
Revised laboratory reports that will provide the non -detect values and method detection limits are in the
process of being obtained from the lab.

-y
✓ GWA-11D
DUKE ENERGY IF
PROPERTY GWA-11S
w -LOS
ti
GWA-10D
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A
MW -200S
MW -200D
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GWA-ID
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mW -1015 MW -103D
MW -101D
MW -102S
AB -1S MW -102D AB -3S
ap
AV AB -2D AB -3D
AB -ID ti
AB -2S
a
ASH BASIN
DUKE ENERGY
PROPERTY
GWA-2D
ar
GWA-2S
M/DDLETOIV Loop
AS -5D
.5, AS-5SL
AS -5S
AB-4BR
ti AB -4D
AB-6SB
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AB-6SL
AMS
MW -203S "W AB-4SL
MW -203D AB -4S
AB -7D,
AMS AB -7S
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AB -8D
WA -9D
-GWA-9S
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AB-9SB
AMS
AB-9BR
CHEMICAL
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GWA-8S
PINE HALL ROAD ti pp I
ACU LANDFILL I GWA-8D
PERMIT NO. 85-03
000
000
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GWA-12S
BG -3S 1. GWA-12DGWA-12BR
0 IV
BG -3D DUKE ENERGY
PROPERTY
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Ll
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MW -104S
MW -104D
ae
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BG-ISB
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BG-2BR
ti BG-2SB
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DUKE ENERGY
PROPERTY
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GWA-3S
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% GWA-4D
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isa&
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GWA-SBRS
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BELEWS CREEKSTVEA
....,,.STATION
M
BELEWS LAKE
ELEVATION 725 FT
(APPROXIMATE)

Table 1. Analytical Results
General Notes:
Depth -to -Groundwater data was collected in: 7/15, 9/15,11115, 12/15, 4/16,5116, and 9/16
mg/kg - milligrams per kilogram
NA - Not analyzed or not reported by analytical laboratory
Std. Units - pH units
Comparison Criteria:
NS - No applicable standard for this parameter
Shading indicates exceedance of either applicable criteria.
bold - indicates exceedance of NCDEQ Industrial Health Based PSRG
ttallclundedlne- indicates exceedance of NCDEQ Protection of Groundwater PSRG
North Carolina Department of Environmental Quality Division of Waste Management Soil Remediation Goals
Table (October 2016) - Preliminary Industrial Health Based Soil Remediation Goal (PSRG) and Protection of
Groundwater PSRG.
-Note: No PSRG for Total Chromium is currently available, as a surrogate the PSRG for Trivalent Chromium
was used for comparison purposes only.
Qualifier Notes:
U --Not detected above the reporting detection limit.
J -- Estimated Concentration
J+-- Estimated concentration, biased high.
J --Estimated concentration, biased low.
Analyte Aluminum
Antimony
Arsenic
Barium
Boron
Beryllium
Cadmium
Chromium
Cobalt
Copper
Iron
Lead
Manganese
Mercury
Molybdenu
m
Nickel
Selenium
Strontium
Thallium
Vanadium
Zinc
Calcium
Chloride
Magnesium
Nitrate
Potassium
Sodium
Sulfate
pH (field)
Total
Organic
Carbon
CAS RN
7429-90-5
7440-36-0
7440-38-2
7440-39-3
7440-42-8
7440-41-7
7440-43-9
7440-47-3
7440-484
7440-50-8
7439-89-6
7439-92-1
7439-96-5
7439-97-6
7439-98-7
7440-02-0
7782-49-2
7440-24-6
7440-28-0
7440-62-2
7440-66-6
7440-70-2
16887-00-6
7439-954
14797-55-8
7440-09-7
7440-23-5
14808-79-8
PH
TOC
Result Unit
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
m g
g /k
mgIkg
mglkg
mg/kg
mg/kg
mgIkg
mgIkg
mgIkg
mgIkg
mgIkg
mgIkg
mgIkg
mgIkg
mglkg
mgIkg
Std. Unit.
mglkg
NCDEQ Industrial Health PSRG
100000
94
3
44000
46000
460
200
100000
70
9400
100000
800
5200
8
1200
4400
1200
100000
2.4
1200
70000
NS
NS
NS
100000
NS
NS
NS
NS
NS
NCDEQ Protection
of Groundwater PSRG
NS
0.9
5.8
580
45
63
3
360000
0.9
700
150
270
65
1
NS
130
2.1
NS
0.28
6
1200
NS
NS
NS
NS
NS
NS
NS
NS
NS
Sample Name
Sample Date
DTVI min - max (ft bgs)
BG -1 D(1-2)
3/26/2015
38.13 - 41.22
17400
3.1 U
34.6
41.5
15.5 U
0.89
0.37 U
28.7
1.7 J
11.9
38100
21.1
57.6
0.046
3.1 U
1.3 J
3.1 U
1.9 J
3.1 U
54.9
13.2
131 J
305 U
249
30.5 UJ
348
311 U
305 U
4.8 J
13400
BG -1D(11)
3/27/2015
38.13 - 41.22
5490
3.9 U
10.9
26.8
12.2 J
0.68
0.47 U
4.7
28.6 J-
4.5
12200
77.3 J-
1010
0.0063 J
8.9
12
3.9 U
3.9 U
3.9 U
14.2
28.1
195 U
396 U
677
39.6 UJ
540
390 U
396 U
5.7 J
963 U
BG -1 D(21)
3/27/2015
38.13 - 41.22
6210 J+
3.9 U
7.5
50
13.2 J
0.88
0.47 U
2.3
6_8
3.5
12400 J+
25.9
257 J+
0.01 U
3.9 U
2.1
2.2 J
3.9 U
3.9 U
16
31.6
197 U
400 U
836
40 UJ
567
393 U
400 U
5.4 J
967 U
BG -1D(31)
3/27/2015
38.13 - 41.22
12700
3.5 U
30.7
42.3
38.6
2.8
0.42 U
17.1
37.9
9.8
40400
17.1
871
0.01 U
3.5 U
32.8
2.9 J
3.5 U
3.5 U
50.9
85.4
174 U
358 U
3300
35.8 UJ
876
347 U
358 U
5.6 J
871 U
BG -2D(1-2)
3/23/2015
39.83 - 48.34
13800
3.8 U
3.3 J
25.1
18.9 U
0.32 J
0.45 U
8.5
3.8 U
7.6
24100
18.7
53.1
0.064
3.8 U
1.9 U
3.8 U
3.8 U
3.8 U
46.6
10.5
428
363 U
678
36.3 UJ
199 J
378 U
363 U
5.5 J
2590 J
BG -2D(10-12)
3/24/2015
39.83 - 48.34
9670
3.5 U
2.7 J
70.7
34.5 J
0.86
0.42 U
5.3
5.5
8.1
32300
21.7
245
0.015
3.5 UJ
1.7 U
3 J
3.5 UJ
3.5 U
105
14.2
173 UJ
352 U
1060
35.2 UJ
183 J
346 U
352 U
5 J
850 U
BG -2D(20-22)
3/24/2015
39.83 - 48.34
6680
3.7 U
3.7 U
88.9
18.5 U
0.29 J
0.45 U
1.9 UJ
5
4.8
9570
11.3
450
0.01 U
3.7 UJ
1.9 U
3.7 U
3.7 UJ
3.7 U
20
39.1
185 UJ
367 U
1090
36.7 UJ
949
371 U
367 U
5.1 J
903 U
BG -2D(30-32)
3/24/2015
39.83 - 48.34
7530
4 U
4 U
91.9
20.1 U
0.33 J
0.48 U
2 UJ
_5
1.8 J
13000
6.6
680
0.01 U
4 UJ
2 U
4 U
4 UJ
4 U
27
20.1
201 UJ
403 U
1500
40.3 UJ
1240
402 U
403 U
5.2 J
965 U
BG -3S(1 -2)
5/12/2015
27.34 - 31.74
14800
6.4 U
6.4 U
29.9
14 J
0.37
0.77 U
15.9
6.4 U
12.9
27800
26.6
39.6
0.031
3.2 U
4.1
4.8 U
3.2 U
6.4 U
60
8.4
158 J
329 U
238
32.9 UJ
343
320 U
329 U
5.4 J
3410
BG -3S(10-12)
5/12/2015
27.34 - 31.74
10000
7.6 U
7.6 U
32.3
20.9
0.75
0.91 U
21.5
15.6
14.3
44200
6.2 J
513
0.0095 J
3.8 U
4.5
5.7 U
3.8 U
7.6 U
141
21.2
189 U
362 U
647
36.2 UJ
379 U
379 U
362 U
4.9 J
4070
BG -3S(20-22)
5/12/2015
27.34 - 31.74
9280
6.1 U
6.1 U
68.4
16.6
0.76
0.73 U
15.4
8_1
28.5
36800
14.4
216
0.0097 U
3 U
9.8
4.6 U
3 U
6.1 U
55.3
48.5
152 U
308 U
2620
30.8 UJ
2360
304 U
308 U
5 J
1140 J
GWA-3D(10)
5/5/2015
37.80-40.80
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
663U
GWA-3D(34-35.5)
5/4/2015
37.80 - 40.80
7610
7.7 U
7.7 U
108
19.3 U
0.97
0.93 U
1.1 J
7.7 U
2
9110
6.4 J
460
0.012 U
3.9 UJ
1.1 J
7.7 U
11.4
7.7 U
18.4
29.6
1050
366 U
2080
36.6 UJ
1440
386 UJ
366 U
7 J
893 U
GWA 4S(45-47)
3/5/2015
Dry
4830
2.8 U
2.8 U
79.5
5
0.52
0.33 U
1 J+
2.2 J
2.8
7760
15.6
383
0.01 U
0.56 U
1.1
2.8 U
4.3
2.8 U
9.4
20.3
599
284 U
1320
28.4 UJ
1060
49.2 J
284 U
6.4 J
685 U
GWA-12D(10-12)
4/15/2015
48.29 - 52.96
4320
6.2 U
6.2 U
26.6
15.4 U
0.31 U
0.74 U
1.5 UJ
6_5
0.96 J
912
13.2
296
0.0097 UJ
3.1 U
1.5 UJ
6.2 U
3.1 UJ
6.2 UJ
6.2 U
8.5
154 UJ
315 U
287
31.5 UJ
313
308 UJ
315 U
5.6 J
740 U
GWA-12D(15-17)
4/15/2015
48.29 - 52.96
14300
5.6 U
5.6 U
98.6
13.9 U
0.39
0.67 U
1.4 UJ
2.9 J
1.8
7740
19.9
187
0.0092 UJ
2.8 U
1.4 UJ
5.6 U
2.8 UJ
5.6 UJ
5.6 U
64.7
139 UJ
281 U
5180
28.1 UJ
4230
279 UJ
281 U
5.4 J
674 U
GWA-12D(20-22)4/15/2015
48.29 - 52.96
11900
5.8 U
5.8 U
90.7
14.5 U
0.43
0.69 U
0.97 J
3.5 J
9.1
7870
14.7
135
0.009 UJ
2.9 U
0.79 J
5.8 U
2.9 UJ
5.8 UJ
8_2
43.6
145 UJ
285 U
3230
28.5 UJ
2830
289 UJ
285 U
5.3 J
673 U
GWA-12D(25-27)
4/15/2015
48.29 - 52.96
12200
7.9 U
7.9 U
82.5
19.6 U
0.59
0.94 U
4.7
4.5 J
11.3
9790
12.8
247
0.013 UJ
3.9 U
1.1 J
7.9 U
3.9 UJ
7.9 UJ
10.6
43.6
196 UJ
402 U
3070
40.2 UJ
3310
393 UJ
402 U
NA
500 J
Total Number of Viable Soil Samples -1
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
16
18
General Notes:
Depth -to -Groundwater data was collected in: 7/15, 9/15,11115, 12/15, 4/16,5116, and 9/16
mg/kg - milligrams per kilogram
NA - Not analyzed or not reported by analytical laboratory
Std. Units - pH units
Comparison Criteria:
NS - No applicable standard for this parameter
Shading indicates exceedance of either applicable criteria.
bold - indicates exceedance of NCDEQ Industrial Health Based PSRG
ttallclundedlne- indicates exceedance of NCDEQ Protection of Groundwater PSRG
North Carolina Department of Environmental Quality Division of Waste Management Soil Remediation Goals
Table (October 2016) - Preliminary Industrial Health Based Soil Remediation Goal (PSRG) and Protection of
Groundwater PSRG.
-Note: No PSRG for Total Chromium is currently available, as a surrogate the PSRG for Trivalent Chromium
was used for comparison purposes only.
Qualifier Notes:
U --Not detected above the reporting detection limit.
J -- Estimated Concentration
J+-- Estimated concentration, biased high.
J --Estimated concentration, biased low.