Sutton Background Soil Tech Memo Dec 2016_20161215

TECHNICAL MEMORANDUM
Date: December 15, 2016 File: 1026.108.20
To: John Toepfer (Duke Energy)
Cc: Kathy Webb (SynTerra)
From: Perry Waldre� �% "''i �✓�
Subject: Quantification Of"Valid ckground Soil Samples for Statistics Calculations — L.V.
Sutton Ener�v Complex
Proposed Preliminary Background Threshold Values (PPBTVs) for site soils will be calculated
for CAMA assessment constituents. Soil samples were collected from soil borings during the
Comprehensive Site Assessment (CSA) field activities at the L.V. Sutton Energy Complex (Site)
in 2015. Table 1 provides a summary of the samples collected (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:
�7 Soil sample is collected from a location that is not impacted by coal combustion
residuals or coal associated materials;
�7 Soil sample is collected from a location that is not impacted by other potential
anthropogenic sources of constituents; and
Ei 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.
The analytical results presented in Table 1 for antimony, arsenic, selenium, and thallium
present reporting limits that are greater than the PSRG for Protection of Groundwater (POG),
for some or all samples, 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.
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
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
P: \Duke Energy Progress.1026\108. Sutton Ash Basin GW Assessment Plan\20.EG_CAP\background soil and gw
memos\BG Soil Tech Memo.docx

Quantification of Valid Background Soil Samples for Statistics Calculations December 15, 2016
L.V. Sutton Energy Complex
Page 2 of 2
criteria, must be documented. A revised Background Soil Data Summary table and evaluation
of dataset sample size will be provided following review of updated analytical reports.
ATTACHMENTS: Table 1: Background Soil Data Summary
Figure 1: Background Soil Locations for Statistical Analysis
P: \Duke Energy Progress.1026\ 108. Sutton Ash Basin GW Assessment Plan\20.EG_CAP\background soil and gw
memos \ BG Soil Tech Merno -Final Draft.docx

TABLE 1
BACKGROUND SOIL DATA SUMMARY
L.V. SUTTON ENERGY COMPLEX
DUKE ENERGY PROGRESS, LLC, WILMINGTON, NC
Prepared by: WJW Checked by: PBW
Notes•
0 Concentration or detection limit greater than PSRG Protection of Groundwater Standard
NA =non analyzed
mg/kg =milligrams per kilogram
NE =Not established
j =Estimated concentration above the adjusted method detection limit and below the adjusted reporting limit.
< =concentration not detected at or above the adjusted reporting limit.
* = No detectable concentrations within data set
PSRG Protection of Groundwater = NCDEQ IHSB Preliminary Soil Remediation Soil Remediation Goals Table -October 2016
i =Water table elevations collected during site -wide well gauging event on November 30, 2016.
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
Std. Units
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
Elevation (ft.)
Water Table r
Elevation (ft.)
Analytical Results
AW -01C (0-2)
1/31/2015
15
12.21
4.9
2660
<1
<1
1
<0.12
<2.6
<0.12
<25.9
<266
1.4
<1
0.3
1290
1.8
<25.9
0.9
0.0096
<0.52
0.39
<26.6
<51.8
<1
<S1.S
<0.52
<266
<1
1.5
2.6
AW -02C (0-2)
1/30/2015
26
10.87
4.6
2100
<1.1
<1.1
1.2
<0.13
<2.6
<0.13
<26.5
<260
1.4
<1.1
<0.26
1350
1.5
<26.5
1.3
0.009
<0.53
<0.26
<26
<52.9
<1.1
<52.9
<0.53
<260
<l.l
4.1
<l.l
AW -02C (10-11)
01/30/2015
16
10.87
5.5
584
<1.2
<1.2
1.5
<0.14
<3
<0.14
<29.6
<294
0.67
<1.2
<0.3
445
<1.2
<29.6
10.9
<0.0091
<0.59
<0.3
<29.4
<59.2
<1.2
<59.2
<0.59
<294
<1.2
<1.2
<1.2
AW -03C (0-2)
1/31/2015
16
11.92
4.4
1680
<1
<1
1.5
<0.13
<2.6
<0.13
<26.2
<264
0.85
<1
0.35
824
<1
28.7
0.97
0.0088
<0.52
0.27
<26.4
<52.4
<1
<52.4
<0.52
<264
<1
2.9
<1
AW -04C (0-2)
1/29/2015
16
10.56
6.4
1520
<1
<1
0.91
<0.13
<2.6
<0.13
80.1
<262
0.95
<1
0.28
815
<1
<26.2
1.4
0.0087
<0.52
<0.26
<26.2
<52.3
<1
<52.3
<0.52
<262
<1
2.2
<1
AW-OSC (4-6)
2/2/2015
1S
10.44
5
2430
<l.l
<l.l
1.7
<0.13
<2.6
<0.13
<26.4
<263
1.4
<l.l
0.39
1110
<l.l
35.9
2.1
<O.00Sl
<0.53
0.44
<26.3
<52.9
<l.l
<52.9
<0.53
<263
<l.l
2.5
1.5
AW-OSC (9-11)
02/02/2015
13
10.44
6.4
346
<1.1
<1.1
1
<0.13
<2.8
<0.13
54.3
<278
0.65
<l.l
<0.28
369
<l.l
<27.5
2
<0.0092
<0.56
<0.25
<27.8
<55.7
<1.1
<55.7
<0.56
<278
<l.l
<l.l
<l.l
AW -06D (0-2)
1/29/2015
15
10.83
5.1
542
<1
<1
1.2
<0.12
<2.6
<0.12
66.7
<260
0.39
<1
0.26
562
<1
<25.8
0.75
<0.0082
<0.52
0.44
<26
<51.5
<1
<51.5
<0.52
<260
<1
2.6
<1
AW -07D (0-2)
1/30/2015
13
11.16
4.7
4490
<l.l
<1.1
4.2
<0.13
<2.7
<0.13
<26.6
<263
1.9
<l.l
1.6
1330
3.3
40
1.4
0.0081
<0.53
0.4
<26.3
<53.2
<l.l
<53.2
<0.53
<263
<l.l
2.9
<l.l
MW -37C(0-2)
2/4/2015
19
7.75
6.5
11.6
<l.l
<l.l
<0.54
<0.13
<2.7
<0.13
<26.9
<263
<0.27
<l.l
<0.27
57.9
<l.l
<26.9
0.72
<0.0082
<0.54
<0.27
<26.3
<53.8
<l.l
<53.8
<0.54
<263
<l.l
<l.l
<l.l
MW -37C(4-6)
2/4/2015
15
7.75
5.3
2650
<l.l
<l.l
0.64
<0.13
<2.8
<0.13
<27.9
<275
0.91
<l.l
<0.25
875
2
<27.9
3.9
<0.0088
<0.56
0.33
<27.5
<55.7
<l.l
<55.7
<0.56
<275
<l.l
<l.l
<l.l
SMW-01C (0-2)
4/14/2015
12
10.25
8.4
800
<6.9
<6.9
<3.4
<0.34
<17.2
<0.83
138 j
<336
<1.7
<6.9
<1.7
609
<6.9
<172
2.1
<0.011
<3.4
<1.7
<33.5
<344
<6.9
<344
<3.4
<335
<6.9
<6.9
<6.9
SMW-02C(0-2)
3/24/2015
16
10.14
6.8
702
<3
<3
0.97
<0.059
<3
<0.36
82.7
<300
0.6
<3
0.24j
510
<3
16.7j
0.99
<0.0099
<0.59
0.43
<30
<59.3
<3
<59.3
<0.59
<300
<3
<3
0.76j
SMW-03C(0-2)
3/24/2015
13
9.88
6.8
23.8
<2.5
<2.5
0.36j
<0.05
<2.5
<0.3
43.7
<261
<0.25
<2.5
<0.25
11.3
<2.5
<24.9
<0.25
<O.00S4
<0.5
0.22j
<25.1
<49.7
<2.5
<49.7
<0.5
<261
<2.5
<2.5
<0.99
SMW-04C(0-2)
4/13/2015
11
8.87
5
1800
<7.1
<7.1
1.8j
<0.36
<17.8
<0.85
<178
<337
<1.8
<7.1
<1.8
160
<7.1
<178
<1.S
0.0062]
<3.6
<1.8
<33.7
<355
<7.1
<355
<3.6
<337
<7.1
<7.1
<7.1
SMW-06C (0-2)
4/13/2015
11
10.44
6
39.1
<7.2
<7.2
<3.6
<0.36
<17.9
<0.86
<179
<334
<1.8
<7.2
<1.8
43.8
<7.2
<179
<1.8
<0.012
<3.6
<1.8
<33.4
<358
<7.2
<358
<3.6
<334
<7.2
<7.2
<7.2
SMW-06D (0-2)
4/6/2015
11
10.39
4.6
144
<6.8
<6.8
<3.4
<0.34
<16.9
<0.81
Q69
<323
<1.7
<6.8
<1.7
55.1
<6.8
<169
<1.7
<0.01
<3.4
<1.7
<32.3
<339
<6.8
<339
<3.4
<323
<6.8
<6.8
<6.8
Total Count of Valid Samples
17
17
0*
0*
13
0*
0*
0*
6
0*
it
0*
7
17
4
4
13
7
0*
8
0*
0*
0*
0*
O*
0*
0*
7
3
Prepared by: WJW Checked by: PBW
Notes•
0 Concentration or detection limit greater than PSRG Protection of Groundwater Standard
NA =non analyzed
mg/kg =milligrams per kilogram
NE =Not established
j =Estimated concentration above the adjusted method detection limit and below the adjusted reporting limit.
< =concentration not detected at or above the adjusted reporting limit.
* = No detectable concentrations within data set
PSRG Protection of Groundwater = NCDEQ IHSB Preliminary Soil Remediation Soil Remediation Goals Table -October 2016
i =Water table elevations collected during site -wide well gauging event on November 30, 2016.

�'
�'.
.4
AW -02C
f
1 Ks
AW -03C
1984 ASH �1,"��'�i�.+1/
BASIN �r '� e
(LINED) � �',_,
1971 ASH ��
$�.� BASIN .
, �
�:
�� �.
�` � +`
FORMER ASH
nicoricei �
LEGEND
SOIL SAMPLE LOCATION
CCR SURFACE IMPOUNDMENT
BOUNDARY
■ � .CCR SURFACE IMPOUNDMENT
COMPLIANCE BOUNDARY
■ ■ DUKE ENERGY PROGRESS SUTTON
■ PLANT SITE BOUNDARY
�'
= ,r
^� ��.�
.-a. �"^ `
l'!M +��
i
,•
�AW=06D� ,� 4�
� .•c
NOTES:
AERIAL PHOTOGRAPHY OBTAINED FROM USDA FSANAIP, DATED 05/2312014.
PARCEL BOUNDARY WAS OBTAINED FROM THE NC CENTER FOR GEOGRAPHIC
INFORMATIONANDANALYSIS, AT (http://services.nconemap.gov/)
DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE
PLANE COORDINATE SYSTEM FIPS 3200 (NAD83).
SMW=05C" �•: ,
•� ��ry'..
,� �
SMW-06D '�`
�_'
."�=r
SMW 2C-,�� =�
i � �"' 1
_ SMW-03C�
L1
synTerr�
+���� �
Q�,, 1.1L
1P 1
GRAPHIC SCALE
400 200 0 400 800
IN FEET
148 RIVER STREET, SUITE 220
GREENVILLE, SOUTH CAROLINA 29601
PHONE [phone]
www.svnte rra coro.com
DRAWN BY: A. FEIGL DATE: 12/14/2016
CHECKED BY: P. WA LDREP
PROJECT MANAGER: P. WALD REP
FIGURE 1
SAMPLE LOCATIONS
L.V. SUTTON ENERGY COMPLEX
WILMINGTON, NORTH CAROLINA