Cape Fear BG Soil Tech Memo Dec 2016

TECHNICAL MEMORANDUM
Date: December 15, 2016 File: 1026.103.19
To: John Toepfer (Duke Energy)
Cc: Kathy Webb 45 erra)
From: Chris Sut
Subject: Quantification of Valid Background Soil Samples for Statistics Calculations -
Cane Fear Steam Electric Plant
Proposed Preliminary Background Threshold Values (PPBTVs) for site soils will be calculated
for CAMA assessment constituents. Soil samples used for calculating PPBTVs were collected
from soil borings at the Cape Fear Steam Electric Plant (Site) in 2013 as part of a voluntary
assessment, in 2015 during the Comprehensive Site Assessment (CSA), and in 2016 as part of
CSA data gap assessment. Table 1 provides a summary of the samples (locations and depth
intervals) which are considered for use in statistical calculations to determine concentrations of
naturally occurring (background) inorganic constituents in Site soil. Figure 1 indicates the
location of soil samples to be used for statistical calculations.
Soil samples that meet the following criteria are considered valid for use in the statistic
calculations for background concentrations:
41, Soil sample is collected from a location that is not impacted by coal combustion
residuals or coal associated materials;
47 Soil sample is collected from a location that is not impacted by other potential
anthropogenic sources of constituents; and
47 Soil sample is collected from the unsaturated zone, > 1 ft. above the seasonal high water
table elevation.
Based on the minimum eight sample dataset requirement provided in the Pro UCL guidance
document, no additional background soil samples are projected for the Site.
Antimony, arsenic, cobalt, selenium, and thallium analytical results for samples collected
during CSA activities included in Table 1 had reporting limits greater than the PSRG for
Protection of Groundwater (POG), for some or all samples, as revised in October 2016. Revised
laboratory reports for those samples will provide the non -detect values and method detection
limits are in the process of being obtained from the lab. It is anticipated that once the updated
analytical reports are received, there will be more than eight samples with valid data for each
constituent. Following a review and evaluation of the updated data, a revised Background Soil
Data Summary table will be provided.
The statistical calculation process will include a review of data to determine if outliers exist.
Professional judgment can be used to retain data that does not satisfy one or more of the valid
\ \synterracorp.com \Data\ Proj \Duke Energy Progress.1026\103. Cape Fear Ash Basin GW
Assessment\ 19.EG_CSASUP\Background\Soil\Cape Fear BG Soil Tech Memo revl.docx

Quantification of Valid Background Soil Samples for Statistics Calculations December 15, 2016
Cape Fear Steam Electric Plant
Page 2 of 2
soil sample criteria. Likewise, professional judgement can be used to reject soil sample data that
does satisfy all valid soil sample criteria. However, the decision to retain data that does not
satisfy valid soil sample criteria, and the decision to reject data that satisfy valid soil sample
criteria, must be documented.
ATTACHMENTS: Table 1: Background Soil Data Summary
Figure 1: Background Soil Locations for Statistical Analysis
\ \synterracorp.com\Data\Prof\Duke Energy Progress.1026\103. Cape Fear Ash Basin GW
Assessment\19.EG_CSASUP\Background\Soil\Cape Fear BG Soil Tech Memo revl.docx

TABLE 1
BACKGROUND SOIL DATA SUMMARY
CAPE FEAR STEAM ELECTRIC PLANT
DUKE ENERGY PROGRESS, LLC, MONCURE, NC
Notes:
0 = Concentration or detection limit greater than PSRG Protection of Groundwater Standard
mg/kg = milligrams per kilogram
NE = Not established
S.U. = Standard Units
PSRG Protection of Groundwater = NCDEQ IHSB Preliminary Soil Remediation Soil Remediation Goals Table - October 2016
' = Highest observed water level elevation from either June/July 2015, January 2016, or July 2016 measurements.
= Water level as measured from BGMW-4
= Water level as measured from MW-12BR
< = concentration not detected at or above the adjusted reporting limit.
j = Estimated concentration above the adjusted method detection limit and below the adjusted reporting limit.
NA = Not analyzed
N2 = The lab does not hold accredation for this parameter
D3 = Sample was diluted due to the presence of high levels of non -target analytes or ther matrix interference.
H3 = Sample was received or analysis requested beyond the recognized method holding time.
R1 = Relative Percent Difference value was outside control limits.
M6 = Matrix spike and Matrix spike duplicate recovery not evaluated against control limits due to sample dilution.
Prepared by: BY Checked by: CJS
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Analytical Parameter
pH
Aluminum
Antimony
Arsenic
Barium
Beryllium
Boron
Cadmium
Calcium
Chloride
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Nitrate (as N)
Potassium
Selenium
Sodium
Strontium
Sulfate
Thallium
Vanadium
Zinc
Reporting Units
S.U.
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
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
mg/kg
mg/kg
PSRG Protection of Groundwater
NE
NE
0.9
5.8
580
63
45
3
NE
NE
360000
0.9
700
150
270
NE
65
1
NE
130
NE
NE
2.1
NE
NE
NE
0.28
6
1200
Sample ID
Sample
Collection Date
Sample Depth Water Table
Elevation Elevation
(Feet) (Feet)'
Analytical
Results
BG -01 (Geosyntec) (2.0-2.5)
08/20/2013
175
167'
NA
25600
<0.0992
1.61
NA
NA
5.26j
<0.053
NA
NA
27.2
NA
7.95
NA
19.2
NA
234
0.0387j
NA
4.95
NA
NA
0.414j
NA
NA
NA
0.349
NA
19.8
BG -02 (Geosyntec) (2.0-2.5)
08/20/2013
175
167a
NA
44400
<0.117
3.32
NA
NA
9j
<0.0625
NA
NA
40.4
NA
16.8
NA
16.8
NA
134
0.113j
NA
9.2
NA
NA
0.795j
NA
NA
NA
0.347
NA
33
BG -03 (Geosyntec) (2.0-2.5)
08/20/2013
175
167'
NA
17600
<0.104
2.16
NA
NA
6.54 j
<0.0554
NA
NA
26.9
NA
8.06
NA
12.9
NA
155
0.0536 j
NA
3.44
NA
NA
0.638 j
NA
NA
NA
0.159 j
NA
16.6
BG -04 (Geosyntec)(2.0-2.5)
08/22/2013
165
162'
NA
21100
<0.118
1.83
NA
NA
5.89j
<0.0631
NA
NA
30.8
NA
18.2
NA
15.3
NA
3830
0.0592j
NA
11.2
NA
NA
0.399]
NA
NA
NA
0.224]
NA
47.3
BG -05 (Geosyntec) (2.0-2.5)
08/22/2013
165
162'
NA
21300
<0.108
2.09
NA
NA
5.93j
<0.0579
NA
NA
30.6
NA
19.1
NA
13.6
NA
2330
0.0514j
NA
11.8
NA
NA
0.511]
NA
NA
NA
0.182]
NA47.1
MW-OSBR SB (0-2)
04/23/2015
176
170
S.6
11500
<6.1
<6.1
62.8
0.21j
<15.2
<0.73
1230
<312
24.7
3.7j
8.2
26200
7.4
905
78
0.037
<3
1.3j
<31.2
<304
<6.1
<304
17.5
<312
<6.1
89.6
11.6
MW -09 SB (0-2)
04/25/2015
186
180
4.1
4250
<6.7
<6.7
18.1
<0.33
<16.6
<0.8
<166
<309
4.3
<6.7
4.7
13000
6.3 j
305
19.4
0.011
<3.3
<1.7
<30.9
<333
<6.7
<333
<3.3
<309
<6.7
10.2
9.4
MW -09 SB (2-3)
04/25/2015
185
180
5.6
7720
<5.3
8.1
155
1.2
<13.3
<0.64
979
<265
4.3
31.9
8.8
20000
12.4
2500
324
0.007j
3.3
8.4
<26.5
237j
4.4j
166j
15.1
<265
<5.3
9.7
67.8
MW -09 SB (6-7)
04/25/2015
181
180
6.7
9700
<5.7
<5.7
224
0.73
<14.4
<0.69
2750
<291
5
11.4
17.4
24500
26.1
3420
1140
0.012
<2.9
5.7
<29.1
427
<5.7
338
35.8
<291
<5.7
10.8
154
MW-IOBR SB (0-2)
04/08/2015
169
164
5.0
3300
<5.8
<5.8
33.5
0.21
6.4
<0.7
291
<272
20.6
9.3
7.1
10600
6.9
650
363
0.029
<0.58
2.7
<27.2
114
<5.8
<58.1
3.9
<272
<5.8
31.6
27.2
MW-12BR SB (0-2)
02/24/2015
166
162
5.7
6230
<1.2
0.82j
77.8
0.47
7.8
<0.14
NA
<300
9.4
13.2
8.4
13500
8.7
1520
1510
0.032
<0.58
4.2
<30
68
1.1j
79.2
14
<300
<1.2
30.9
19.3
MW -15 SB (0-2)
04/01/2015
168
167
5.2
9980
<2.9
<5.8
64.9
0.6
18.2
<0.35
1120
<307
15.2
6.4
11.4
24100
8.5
2170
367
0.019
<2.9
8.8
<30.7
<292
<5.8
177 j
15.9
539
<5.8
55.1
32.8
MW -20 SB (0-2)
05/13/2015
166
165
5.1
10100
<6.2
<6.2
75.7
0.39
<15.6
<0.75
1350
<308
16.9
15.2
17.1
18800
9
2470
747
0.0061j
<3.1
5.9
<30.8
<312
<6.2
312
16.8
<308
<6.2
47.3
32.2
MW -22 SB (0-2)
06/10/2016
168
164
5.4
14400
<2.8 N2
1.5
116
0.44
<71.5
<0.17
1030
<301 D3
17.1
17.1
13.7
14900
11.6
1720
490
0.059
<0.72
8.3
<30.1 H3,D3
173
<1.4
158
14.4
<301 D3
<1.4
50
33.9
MW -22 SB (3-4)
06/10/2016
166
164
5.2
15600
<2.8 N2
<1.4
48.4
0.27
<54.7
<0. 17
473
<301 D3
17.8
8.2
14.1
16500
6.1
1890
370
0.014
<0.55
7.8
<30.1 H3,D3
139
<1.4
165
7.3
<301 D3
<1.4
42
28.3
MW -23 SB (0-2)
06/20/2016
171
164
5.6
25400
<2.5 N2,M6,R1
2.3 R1
82.3
0.33
<63
<0.15 R1
837
<297 D3
26.5
5.9 R1
13.7
32200
11.6 R1
1070
73
0.052
<0.63
7.5
<29.7 H3,D3
256
<1.3 R1
<63
14.5
<297 D3
<1.3 R1
77.1
22.5
Total Count of Valid Samples
11
16
5
13
11
11
13
16
SO
11
16
10
16
11
16
11
16
16
11
16
11
11
10
11
it
11
5
11
16
Notes:
0 = Concentration or detection limit greater than PSRG Protection of Groundwater Standard
mg/kg = milligrams per kilogram
NE = Not established
S.U. = Standard Units
PSRG Protection of Groundwater = NCDEQ IHSB Preliminary Soil Remediation Soil Remediation Goals Table - October 2016
' = Highest observed water level elevation from either June/July 2015, January 2016, or July 2016 measurements.
= Water level as measured from BGMW-4
= Water level as measured from MW-12BR
< = concentration not detected at or above the adjusted reporting limit.
j = Estimated concentration above the adjusted method detection limit and below the adjusted reporting limit.
NA = Not analyzed
N2 = The lab does not hold accredation for this parameter
D3 = Sample was diluted due to the presence of high levels of non -target analytes or ther matrix interference.
H3 = Sample was received or analysis requested beyond the recognized method holding time.
R1 = Relative Percent Difference value was outside control limits.
M6 = Matrix spike and Matrix spike duplicate recovery not evaluated against control limits due to sample dilution.
Prepared by: BY Checked by: CJS
P:\Duke Energy Progress. 1026\103. Cape Fear Ash Basin GW Assessment\19.EG_CSASUP\Background\Soil\CapeFear_Background Soil Data Summary 20161213 page 1 of 1