Riverbend Background GW Dataset Evaluation - December 2016

F)R
Technical Memorandum
Date: Monday, December 12, 2016
Project: Riverbend Steam Station
To: Kim Witt and Melonie Martin
From: Jacob Ruffing
Subject: Additional Background Monitoring Well Determinations
The purpose of this memorandum is to provide justification for additional monitoring wells that
should be considered as background wells for the Riverbend Steam Station (RBSS) ash basin.
Monitoring wells MW-7D, MW-7SR, MW-713R, BG-1 S, and BG-1 D were previously evaluated
and chosen to represent background groundwater quality as documented in Appendix B of the
RBSS Corrective Action Plan (CAP) Part 1, dated November 16, 2015. Well locations are
shown on Figure 1.
Wells BG-2S, BG-2D, BG-213R, BG-3S, and BG-3D were previously background wells and
should no longer be used to represent background water quality. The results of the evaluation of
these monitoring wells concluded that it was undetermined if the location of these wells
represent background water quality relative to the ash disposal areas at the site and that
subsequent sampling and groundwater measurements would aid in determining the suitability of
these wells for use in determining background concentrations. An additional evaluation of these
monitoring wells is provided on the following pages of this memorandum.
The proposed additional background monitoring wells include BG-4S, BG-4D, BG-413R, BG-5D,
13G-513R, GWA-5S, GWA-14S, and GWA-14D. These wells are being proposed based on
evaluation of the following criteria: groundwater flow direction, groundwater elevation as
compared to the nearest ash basin surface water or porewater elevation, historical analytical
results, and horizontal distance to the ash source area. Distances and elevations pertinent to
the evaluation are provided on Table 1. Additional details are provided for each monitoring well
cluster on the following pages of this memorandum.
Historical analytical data for previously evaluated background wells (CAP Part 1) and the
potential background wells listed above are provided in Table 2. The background wells and
analytical data are separated by groundwater flow layer (shallow, deep and bedrock) and a valid
sample count is provided for each constituent. Samples with field measured turbidity greater
than 10 nephelometric turbidity units (NTU) and/or pH greater than 8.5 standard units (SU) are
denoted with red -colored text and were not included in the valid sample counts.

F)R
BG-2S, BG-2D, and BG-2BR
Monitoring well BG-2S, BG-21D, and BG-2BR were installed as background monitoring wells
during the CSA assessment. June 2015, August 2015, April 2016, and June 2016 groundwater
gauging events have been considered for determining groundwater elevations and flow direction
in this area of the site.
• Monitoring wells BG-2S/D/BR are located approximately 1,450 feet east of the eastern
side of the ash basin waste boundary. The ground surface at the monitoring wells
(approximately 702.5 feet) is 17.5 feet lower than the ash basin waste boundary (720
feet).
• The historical surface water elevation in the ash basin was 713 feet.
• BG-2S is screened from approximately 49.5 feet to 65.5 feet below ground surface (bgs)
in the shallow flow layer (approximately 653 to 637 feet elevation). The lowest
groundwater elevation calculated from gauging events was 648 feet during the
September 2015 event (water elevation in well was 64 feet lower than the historical ash
basin surface water elevation).
• BG-21D is screened from approximately 155 feet to 160 feet bgs (approximately 547 to
542 feet elevation) in the deep flow layer. The lowest groundwater elevation calculated
from gauging events was 648 feet during the July 2015 event (water elevation in well
was 64 feet lower than the historical ash basin surface water elevation).
• BG-2BR is screened from approximately 203 feet to 208 feet bgs (approximately 500 to
495 feet elevation) in the bedrock flow layer. The lowest groundwater elevation
calculated from gauging events was 648 feet during the September 2015 event (water
elevation in well was 64 feet lower than the historical ash basin surface water elevation).
• Based on groundwater flow and groundwater/surface water elevation data, groundwater
in monitoring wells BG-2S/D/BR may originate upgradient and to the west from the ash
basin.
Monitoring wells BG-2S, BG-21D, and BG-2BR may not represent background water quality
relative to the ash disposal areas at the site and have not been included in the valid background
sample counts.
BG-3S and BG-3D
Monitoring well BG-3S and BG-31D were installed as background monitoring wells during the
CSA assessment. June 2015, August 2015, April 2016, and June 2016 groundwater gauging
events have been considered for determining groundwater elevations and flow direction in this
area of the site.
• Monitoring wells BG-3S/D are located approximately 1,350 feet east of the eastern side
of the ash basin waste boundary. The ground surface at the monitoring wells
(approximately 672 feet) is 26 feet lower than the edge of waste at the ash basin waste
boundary (698 feet).
• The historical surface water elevation in the ash basin was 713 feet.

F)R
BG-3S is screened from approximately 21 feet to 37 feet bgs in the shallow flow layer
(approximately 651 to 635 feet elevation). The lowest groundwater elevation calculated
from gauging events was 644 feet during the September 2015 event (water elevation in
well was 69 feet lower than the historical ash basin surface water elevation).
BG-31D is screened from approximately 100 feet to 105 feet bgs (approximately 572 to
567 feet elevation) in the deep flow layer. The lowest groundwater elevation calculated
from gauging events was 642 feet during the September 2015 event (water elevation in
well was 71 feet lower than the historical ash basin surface water elevation).
Based on groundwater flow and groundwater/surface water elevation data, groundwater
in monitoring wells BG-3D/BR may originate upgradient and to the west from the ash
basin.
Monitoring wells BG-3S and BG-3D may not represent background water quality relative to the
ash disposal areas at the site and have not been included in the valid background sample
counts.
BG-4S, BG-4D, and BG-4BR
Monitoring wells BG-4S, BG-4D, and BG-4BR were installed as background monitoring wells
during the installation of the additional assessment wells. The June and September 2016
groundwater gauging events have been considered for determining groundwater elevations and
flow direction in this area of the site.
• Monitoring wells BG-4S/D/BR are located approximately 920 feet southwest of the ash
storage area waste boundary. The ground surface at the monitoring wells (approximately
705 feet) is 25 feet higher than the edge of the ash storage area waste boundary (680
feet).
• The historical full pond elevation in the primary cell of the ash basin was 713 feet.
• BG-4S is screened from approximately 50 feet to 65 feet bgs in the shallow flow layer
(approximately 655 to 640 feet elevation). The lowest groundwater elevation calculated
from gauging events was 664 feet during the September 2016 event (water elevation in
well was 49 feet lower than the historical ash basin surface water elevation).
• BG-41D is screened from approximately 127 feet to 137 feet bgs (approximately 578 to
568 feet elevation) in the deep flow layer. The lowest groundwater elevation calculated
from gauging events was 664 feet during the September 2016 event (water elevation in
well was 49 feet lower than the historical ash basin surface water elevation).
• BG-4BR is screened from approximately 164 feet to 169 feet bgs (approximately 541 to
535 feet elevation) in the bedrock flow layer. The lowest groundwater elevation
calculated from gauging events was 538 feet during the June 2016 event (water
elevation in well was 175 feet lower than the historical ash basin surface water
elevation).
• Although the water level in the wells is lower than the historical ash basin water
elevation, based on the slope aquifer system groundwater at the wells would originate to
the northwest of the monitoring wells along Horseshoe Bend Beach Road, and not from
the ash disposal areas on the site.

F)R
• Boron was not reported in any of these wells at concentrations which equal or exceed
the laboratory method reporting limit. Sulfate reported at one to two orders of magnitude
less than the 2L Standard. Chloride reported at approximately two orders of magnitude
less than the 2L Standard. BG-4BR had a TDS exceedance reported; however, the pH
and turbidity values were not recorded an may have had an effect on the results of this
sample.
Based on analytical data, groundwater flow, and groundwater/surface water elevation
data, groundwater in monitoring wells BG-4S/D/BR originates northwest of well locations
at Horseshoe Bend Beach Road and is not impacted by ash disposal areas.
Based on the justification provided above and analytical data included in Table 2, monitoring
wells BG-4S, BG-41D, and BG-4BR represent background water quality relative to the ash
disposal areas at the site and have been included in the valid background sample counts.
BG-5D and BG-5BR
Monitoring wells BG-51D and BG-5BR were installed as background monitoring wells during the
installation of the additional assessment wells. The June and September 2016 groundwater
gauging events have been considered for determining groundwater elevations and flow direction
in this area of the site.
• Monitoring wells BG-5D/BR are located approximately 2,875 feet southwest of the ash
storage and cinder storage area waste boundaries. The ground surface at the monitoring
wells (approximately 716 feet) is 36 feet higher than the edge of the ash storage area
waste boundary (680 feet).
• The historical full pond elevation in the primary cell of the ash basin was 713 feet.
• BG-51D is screened from approximately 97.5 feet to 102.5 feet bgs in the deep flow layer
(approximately 618.5 to 613.5 feet elevation). The lowest groundwater elevation
calculated from gauging events was 684 feet during the September 2016 event (water
elevation in well was 29 feet lower than the historical ash basin surface water elevation).
• BG-5BR is screened from approximately 127.5 feet to 132.5 feett bgs (approximately
588.5 to 583.5 feet elevation) in the bedrock flow layer. The lowest groundwater
elevation calculated from gauging events was 678 feet during the June 2016 event
(water elevation in well was 35 feet lower than the historical ash basin surface water
elevation).
• Although the water level in the wells is lower than the historical ash basin water
elevation, based on the slope aquifer system groundwater at the wells would originate to
the west of the monitoring wells to the east of State Route 1911, and not from the ash
disposal areas on the site.
• Boron was not reported in either of these wells at concentrations which equal or exceed
the laboratory method reporting limit. Sulfate and chloride reported at one order of
magnitude less than the 2L Standard.
4

F)R
Based on analytical data, groundwater flow, and groundwater/surface water elevation
data, groundwater in monitoring wells BG-5D and BG-5BR originates upgradient and
west of the well locations and is not impacted by ash disposal areas.
Based on the justification provided above and analytical data included in Table 2, monitoring
wells BG-5D and BG-5BR represent background water quality relative to the ash disposal areas
at the site and have been included in the valid background sample counts.
GWA-5S and GWA-5D
Monitoring wells GWA-5S and GWA-51D were installed as an upgradient monitoring well during
the CSA assessment. June 2015, August 2015, April 2016, and June 2016 groundwater
gauging events have been considered for determining groundwater elevations and flow direction
in this area of the site.
• Monitoring wells GWA-5S/D are located approximately 225 feet southeast of the ash
storage area waste boundary. The ground surface at the monitoring wells (approximately
785 feet) is 25 feet higher than the edge of waste at the ash storage area waste
boundary (760 feet).
• The historical full pond elevation in the primary cell of the ash basin was 713 feet.
• GWA-5S is screened from approximately 60 feet to 75 feet bgs in the shallow flow layer
(approximately 725 to 710 feet elevation). The lowest groundwater elevation calculated
from gauging events was 710 feet during the November 2015 event (water elevation in
well was 3 feet lower than the historical ash basin surface water elevation).
• GWA-51D is screened from approximately 212.5 feet to 217.5 feet bgs in the deep flow
layer (approximately 572.5 to 567.5 feet elevation). The lowest groundwater elevation
calculated from gauging events was 716 during the September 2015 event (water
elevation in well was 3 feet higher than the historical ash basin surface water elevation).
• Boron was not reported in any of these wells at concentrations which equal or exceed
the laboratory method reporting limit. Sulfate and chloride reported at one to two orders
of magnitude less than the 2L Standard.
• Based on analytical data, groundwater flow, and groundwater/surface water elevation
data, groundwater in monitoring wells GWA-5S/D originates upgradient and south of the
well location and the ash basin and is not impacted by ash disposal areas.
Based on the justification provided above and analytical data included in Table 2, monitoring
wells GWA-5S and GWA-51D represent background water quality relative to the ash disposal
areas at the site and have been included in the valid background sample counts. Monitoring well
GWA-51D appears to be grout contaminated and the historical results from this well will not be
utilized. The well is scheduled for re -development. If the pH in the well is lowered to within the
acceptable range following re -development the future results will be considered for incorporation
of background concentration determinations.

F)R
GWA-14S and GWA-14D
Monitoring wells GWA-14S and GWA-14D were installed as upgradient wells during the
installation of the additional assessment wells. The June and September 2016 groundwater
gauging event has been considered for determining groundwater elevations and flow direction in
this area of the site.
• Monitoring wells GWA-14S/D are located approximately 540 feet southeast of the ash
basin waste boundary. The ground surface at the monitoring wells (approximately 776
feet) is 46 feet higher than the edge of the ash basin waste boundary (730 feet).
• The historical full pond elevation in the primary cell of the ash basin was 713 feet.
• GWA-14S is screened from approximately 65 feet to 80 feet bgs in the shallow flow layer
(approximately 711 to 696 feet elevation). The lowest groundwater elevation calculated
from gauging events was 713 feet during the September 2016 event (water elevation in
well equal to the historical ash basin surface water elevation).
• GWA-14D is screened from approximately 202.5 feet to 207.5 feet bgs (approximately
573.5 to 568.5 feet elevation) in the deep flow layer. The lowest groundwater elevation
calculated from gauging events was 712 feet during the September 2016 event (water
elevation in well was 1 feet lower than the historical ash basin surface water elevation).
• Boron was not reported in GWA-14S at a concentration which equals or exceeds the
laboratory method reporting limit. Sulfate and chloride were reported at two orders of
magnitude less than the 2L Standard in monitoring well GWA-14S.
• The pH of monitoring well GWA-14D was reported at 9.6 and 10 SU. The well is grout
contaminated and the data has not been included in the valid background sample
counts.
• Based on groundwater flow and groundwater/surface water elevation data, groundwater
in monitoring wells GWA-14S/D originates upgradient and south of the well location and
the ash basin and is not impacted by ash disposal areas.
Based on the justification provided above and analytical data included in Table 2, monitoring
well GWA-14S represents background water quality relative to the ash disposal areas at the site
and has been included in the valid background sample counts. The pH measured in GWA-14D
indicates that this well is grout contaminated and it has not been included in the valid
background sample counts.
6

LEGEND
Ie
CAMAASSESSMENT
GROUNDWATER MONITORING WELL
NPDES COMPLIANCE
GROUNDWATER MONITORING WELL
NPDES VOLUNTARY
GROUNDWATER MONITORING WELL
CAMAASSESSMENT
GROUNDWATER OBSERVATION
WELL
ASH BASIN WASTE BOUNDARY
ASH BASIN COMPLIANCE
BOUNDARY
ASH BASIN COMPLIANCE
BOUNDARY COINCIDENT WITH
DUKE ENERGY PROPERTY
BOUNDARY
ASH STORAGE
DUKE ENERGY PROPERTY
BOUNDARY
0
-
HYDROGRAPHY
IL
COUNTY LINE
NOTES:
1. WASTE BOUNDARY AND ASH STORAGE AREA BOUNDARIES ARE APPROXIMATE
2. THE COMPLIANCE BOUNDARY IS ESTABLISHED ACCORDING TO THE DEFINITION
FOUND IN 15A NCAC 02L .0107 (a)
3. AERIAL IMAGERY IS FROM A WSP AERIAL SURVEY (2014)
4. HYDROGRAPHY WAS DIGITIZED FROM USGS 1:24,000 SCALE TOPOGRAPHICAL MAPS
5. AS -BUILT CAMA ASSESMENT AND NPDES SERIES WELLS HAVE BEEN PROVIDED BY WSP
AND DUKE ENERGY
e
J
SCALE (FEET)
500 0 500 1,000
k
G ID
D
;A'� S�H�BASIN
SECONDARY
CELL
f9fif Y
FEZ
GWA 22
GWA-23'S
GWA-20D GWA-23D
GWA-20BR GWA-23BR
Jpl
WELL LOCATION MAP
DUKE ENERGY CAROLINAS, LLC
RIVERBEND STEAM STATION ASH BASIN
GASTON COUNTY, NORTH CAROLINA
N
CV.
DATE
DECEMBER 2016
FIGURE
1

Table 1. Monitoring Well Information
Distance and
Closest
Direction from
Ground-
Ground
Elevation of
Lowest
Ash Basin
Well ID
Source Area
water
Surface
Screened
Elevation of
Water
Groundwater Elevation Gauging Events
(Primary/Secondary
Flow
Elevation
Interval
Groundwater
Elevation
Cells, Ash Storage
Direction
(feet)
(feet)
(feet)
to Well
Area
feet
CAP 1 Evaluated Monitoring Wells
MW-7SR
380 feet SE
NE
763
696-716
710.15
713
2015 - July, September
2016 — June, September
MW-7D
380 feet SE
NE
763
660-665
710.12
713
2015 - July, September, November, December
2016 — March, June, September
MW-7BR
380 feet SE
NE
763
561-566
709.76
713
2015 - July, September, December
2016 — March, June, September
BG-1S
1,600 feet ESE
N
701
656-671
669.2
713
2015 - July, September, November, December
2016 — March, June, September
BG-1D
1,600 feet ESE
N
701
502-507
667.01
713
2015 - July, September, November, December
2016 — March, June, September
BG-2S
1,450 feet E
N
702.5
637-653
648.95
713
2015 - July, September, November, December
2016 — March, June, September
BG-2D
1,450 feet E
NE
702.5
542-547
647.96
713
2015 - July, September, November, December
2016 — March, June, September
BG-2BR
1,450 feet E
N
702.5
495-500
647.58
713
2015 - July, September, November, December
2016 — March, June, September
BG-3S
1,350 feet E
N
672
635-651
643.79
713
2015 - July, September, November, December
2016 — March, June, September
BG-3D
1,350 feet E
N
672
567-572
641.83
713
2015 - July, September, November, December
2016 — March, June, September

Table 1. Monitoring Well Information
Distance and
Ground-
Closest
Direction from
water
Ground
Elevation of
Lowest
Ash Basin
Well ID
Source Area
Flow
Surface
Screened
Elevation of
Water
Groundwater Elevation Gauging Events
(Primary/Secondary
Directio
Elevation
Interval
Groundwater
Elevation
Cells, Ash Storage
(feet)
(feet)
(feet)
to Well
Area
n
feet
Proposed Monitoring Wells for Background Evaluation
BG-4S
920 feet SW
SE*
705
655-640
664.05
713
2016 — June, September
BG-4D
920 feet SW
SE*
705
578-568
664.41
713
2016 — June, September
BG-4BR
920 feet SW
SE*
705
541-536
538.39
713
2016 — June, September
GWA-5S
225 feet SE
N
785
725-710
709.95
713
2015 - July, September, November
2016 — June, September
GWA-5D
225 feet SE
N
785
572.5-567.5
715.57
713
2015 - July, September, November
2016 — June, September
BG-5D
2,875 feet SW
NE*
716
618.5-613.5
683.85
713
2016 — June, September
BG-5BR
2,875 feet SW
NE*
716
588.5-583.5
677.99
713
2016 — March, June, September
GWA-14S
540 feet SE
N
776
711-696
713.184
713
2016 — March, June, September
GWA-14D
540 feet SE
N
776
573.5-568.5
711.938
713
Round 6, Round 7
Notes:
1. Elevations presented in North American Vertical Datum (NAVD) 88.
2. The groundwater elevations presented are the lowest groundwater elevations reported over the period of monitoring.
3. Ash basin surface water elevations surveyed during the June 2016 gauging event.
* = Groundwater direction estimated based on topography and slope -aquifer system.

Table 2. Analytical Results
Oxidation
Dissolved
Specific
Carbonate
Bicarbonate
Total
Total
Total
Constituent:
pH
Eh
Reduction
Oxygen
Conductance
Turbidity
Temperature
Alkalinity
Alkalinity
Alkalinity
Methane
Sulfide
Organic
Suspended
Boron
Calcium
Chloride
Strontium
Sulfate
Dissolved
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Potential
Carbon
Solids
Solids
15A NCAC 02L, DHHS, IMAC:
6.5 - 8.5
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
700
NS
250000
NS
250000
500000
NS
1
10
700
4
2
10
Reporting Units:
SU
my
ma/I
us/cm
NTU
Deo C
uo/1
ug/I
ug/I
ug/I
ug/1
ug/1
ug/I
ug/l
ug/1
uo/l
ug/1
uo/l
uo/1
ug/l
uo/I
uo/l
ug/1
uo/l
uo/I
uo/I
Ni-, 1
BG-1S
7 6 2015
5.75
488
288
5.45
33.3
13.71
21.2
10200
< 5000 U
10200
2.6 J+
< 100 U
< 1000 U
20600
< 50 U
1460
1900
16
5801
< 25000 U
1600
0.433
0.213
42
0.0761
0.0343
5.2
BG-1S
9/17/2015
5.6
214
14
0.1
24.2
9.5
23.4
10100 J+
< 5000 U
10100 J+
2.3 J+
< 100 U
8700
9500
< 50 U
2170
1600
15
< 1000 U
< 25000 U
150
< 0.5 U
< 0.5 U
20
< 0.2 U
< 0.08 U
0.79 J+
BG-IS
11 9 2015
5.3
460.7
260.7
5.87
20.6
7.48
14.7
6800
< 5000 U
6800
2.1 J+
< 100 U
< 1000 U
120000
< 50 U
760
--
8.9
< 1000 U
< 25000 U
400
0.3 J
0.15 J
24
< 0.2 U
< 0.08 U
0.74 J+
BG-IS
12/9/2015
5.7
450.4
250.4
5
30.4
5.6
15.2
8800
< 5000 U
8800
2.2 J+
< 100 U
< 1000 U
7300
< 50 U
1150
2000
12 J+
< 1000 U
< 25000 U
< 100 U
< 0.5 U
< 0.5 U
23 J+
< 0.2 U
< 0.08 U
0.21 J+
BG-IS
3 14 2016
5.5
391.1
191.1
6.9
20.8
1
15.7
5500
< 5000 U
5500
2 J+
< 100 U
< 1000 U
< 2500 U
< 50 U
588
1400
8
760 J
< 25000 U
< 100 U
< 0.5 U
< 0.1 U
17.2
0.099 J+
< 0.08 U
0.33 J+
BG-1S
6/27/2016
--
--
--
--
--
--
--
3800 J+
< 5000 U
3800 J+
< 10.0 U
< 100 U
--
< 2500 U
< 50.0 U
406 J+
1900
7.1
5101
< 25000 U
< 100 U
< 0.50 U
< 0.10 U
18.3
0.011 J+
< 0.080 U
0.11 J+
BG-IS
9/28/2016
5.3
368.9
168.9
5.8
20.3
1.2
22.6
5500
< 5000 U
5500
< 10 U
< 100 U
< 5000 U
< 50 U
327
1500
7
< 1000 U
36000 J+
< 100 U
< 0.5 U
< 0.1 U
16.9
0.022 J
< 0.08 U
0.32 J+
MW-7SR
12/6/2010
5.48
--
--
--
29
2.76
13.21
--
--
--
--
--
--
< 50 U
--
--
--
970
120000
--
< 1 U
< 1 U
29
--
< 1 U
< 5 U
MW-7SR
2 2 2011
5.33
23.4
2.84
15.36
< 50 U
220
< 50000 U
< 1 U
< 1 U
20
< 1 U
< 5 U
MW-7SR
6/6/2011
5.34
24
6.25
16.69
< 50 U
170
22000
< 1 U
< 1 U
21
< 1 U
< 5 U
MW-75R
10 4 2011
5.37
28
4.39
15.31
< 50 U
170
< 10000 U
< 1 U
< 1 U
18
< 1 U
< 5 U
MW-7SR
2/22/2012
5.13
574
374
6.69
21
1.8
15.32
< 50 U
< 1000 U
24000
< 1 U
< 1 U
16
< 1 U
< 5 U
MW-7SR
6 5 2012
5.19
549
349
3.86
22
0.8
16.01
< 50 U
130
32000
< 1 U
< 1 U
15
< 1 U
< 5 U
MW-7SR
10/3/2012
5.24
582
382
5.8
22
1.28
16.78
< 50 U
190
10000
< 1 U
< 1 U
15
< 1 U
< 5 U
MW-7SR
2 4 2013
5.12
568
368
5.69
20
1.34
15.17
7200
< 50 U
312
210
15000
< 1 U
< 1 U
14
< 1 U
< 5 U
MW-7SR
6/3/2013
4.96
566
366
5.86
20
0.81
16.24
< 100 U
< 50 U
291
150
< 25000 U
< 1 U
< 1 U
14
< 1 U
< 5 U
MW-7SR
10 14 2013
5.29
548
348
6.81
22
9.17
16.52
6500
< 50 U
295
160
< 25000 U
< 1 U
< 1 U
14
< 1 U
< 5 U
MW-7SR
2/5/2014
5.06
603
403
7.1
19
3.02
14.55
7700
< 50 U
250
160
< 25000 U
< 1 U
< i U
12
< 1 U
< 5 U
MW-7SR
6 2 2014
5.05
615
415
6.87
20
5.66
17.38
< 5000 U
< 50 U
268
120
< 25000 U
< 1 U
< 1 U
14
< 1 U
< 5 U
MW-7SR
10/6/2014
5.1
584
384
6.4
20
3.19
15.92
< 5000 U
< 50 U
260
140
< 25000 U
< 1 U
< 1 U
13
< 1 U
< 5 U
MW-7SR
2 2 2015
5.05
583
383
6.04
20
4.65
15.62
< 5000 U
< 50 U
262
170
< 25000 U
< 1 U
< 1 U
14
< 1 U
< 5 U
MW-7SR
6/1/2015
5.03
618
418
5.99
19
8.8
16.15
< 5000 U
< 5000 U
< 5000 U
--
--
47000
< 50 U
246
180
< 25000 U
498
< 1 U
< 1 U
30
< 1 U
< 1 U
14
MW-7SR
9 16 2015
5.37
332
132
4.8
26
427
19.8
7200 J+
< 5000 U
7200 J+
11.1 J+
< 100 U
5303
214000
< 50 U
400
2000
5.8
< 1000 U
< 25000 U
3200
< 0.5 U
0.383
30
0.073
< 0.08 U
3.1
MW-7SR
12/10/2015
5.3
380.7
180.7
4.4
24
7.3
17.6
5100
< 5000 U
5100
7.6 J+
< 100 U
< 1000 U
12100
< 50 U
344
2100
2.5 J
< 1000 U
< 25000 U
140
< 0.5 U
< 0.5 U
15
< 0.2 U
< 0.08 U
0.88 J+
MW-7SR
9/27/2016
5.2
517.1
317.1
5.7
21.3
0.01
23.5
5000 J
< 5000 U
5000 J
20.3
< 100 U
--
< 5000 U
< 50 U
301
1800
3.1 J
510 J
< 25000 U
< 100 U
< 0.5 U
< 0.1 U
14
< 0.1 U
< 0.08 U
1.8 J+
MW-7D
12/6/2010
5.79
--
--
--
37
0.74
13.31
--
--
--
--
--
--
< 50 U
--
--
--
220
< 50000 U
--
< 1 U
< 1 U
25
--
< 1 U
< 5 U
MW-7D
222011
5.61
32.9
8.82
15.7
<50U
210
<50000U
< 1 U
<1U
25
< 1 U
< 5 U
MW-7D
6/6/2011
5.79
33
0.59
17.15
< 50 U
210
45000
< 1 U
< 1 U
26
< 1 U
< 5 U
MW-7D
10 4 2011
5.8
38
0.44
15.45
< 50 U
220
27000
< 1 U
< 1 U
26
< 1 U
< 5 U
MW-7D
2/22/2012
5.56
603
403
8.31
36
1.48
15.47
< 50 U
< 1000 U
47000
< 1 U
< 1 U
26
< 1 U
< 5 U
MW-7D
6 5 2012
5.68
559
359
3.73
36
1.2
15.88
< 50 U
190
40000
< 1 U
< 1 U
26
< 1 U
< 5 U
MW-7D
10/3/2012
5.68
569
369
8.31
37
0.29
16.47
< 50 U
200
30000
< 1 U
< 1 U
27
< 1 U
< 5 U
MW-7D
2 4 2013
5.51
595
395
8.16
37
0.89
15.57
17000
< 50 U
2430
250
39000
< 1 U
< 1 U
27
< 1 U
< 5 U
MW-7D
6/3/2013
5.5
572
372
7.92
37
0.42
15.93
15000
< 50 U
2530
180
32000
< 1 U
< 1 U
27
< 1 U
< 5 U
MW-7D
10 14 2013
5.69
571
371
7.88
37
3
15.92
16000
< 50 U
2490
200
42000
1.04
< 1 U
27
< 1 U
< 5 U
MW-7D
2/5/2014
5.62
601
401
8.09
37
2.05
15.43
16000
< 50 U
2440
180
42000
< 1 U
< 1 U
26
< 1 U
< 5 U
MW-7D
6 2 2014
5.48
594
394
8.03
37
4.73
15.82
11000
< 50 U
2510
150
41000
< 1 U
< 1 U
27
< 1 U
< 5 U
MW-7D
10/6/2014
5.61
569
369
8.05
38
3.25
15.76
11000
< 50 U
2450
160
34000
< 1 U
< 1 U
26
< 1 U
< 5 U
MW-7D
2 2 2015
5.56
574
374
7.97
37
6.5
15.64
14000
< 50 U
2500
160
29000
< 1 U
< 1 U
27
< 1 U
< 5 U
MW-7D
6/1/2015
5.47
626
426
8.14
35
3.04
15.82
16500
< 5000 U
16500
--
--
--
< 5000 U
< 50 U
2450
140
47000
22
< 1 U
< 1 U
28
< 1 U
< 1 U
< 5 U
MW-7D
9 16 2015
5.67
421
221
6.6
38
1.3
16.9
15600
< 5000 U
15600
1.8 J+
< 100 U
< 1000 U
< 2500 U
< 50 U
2550
1100 J+
41
< 1000 U
49000
< 100 U
< 0.5 U
< 0.5 U
26
< 0.2 U
< 0.08 U
0.75 J+
MW-7D
12/9/2015
5.9
252.7
52.7
6.1
40.3
1
17.8
18000
< 5000 U
18000
1.3 J+
< 100 U
< 1000 U
< 5000 U
< 50 U
3060
1400
47
< 1000 U
43000
< 100 U
< 0.5 U
< 0.5 U
28
< 0.2 U
< 0.08 U
0.87 J+
MW-7D
3 23 2016
5.4
454
254
3.5
45
0.8
22.4
17500
< 5000 U
17500
1.4 J+
< 100 U
< 1000 U
< 2500 U
< 50 U
2620
1400
48.9
< 1000 U
32000
< 100 U
< 0.5 U
< 0.1 U
29.3
< 0.1 U
< 0.08
1.3 J+
MW-7D
6/28/2016
5.8
528.2
328.2
6
38.7
5.5
17
16800
< 5000 U
16800
< IOU
< 100 U
--
5700
< 50 U
2700
950 J
46.1
< 1000 U
33000
96.6 J
< 0.5 U
< 0.1 U
30
0.013
< 0.08
tlffj
MW-7D
9/27/2016
5.8
303.5
103.5
4.7
39.6
1.8
21.5
17200
< 5000 U
17200
< 10 U
< 100 U
< 2500 U
< 50 U
2530
1000
44.6
580 J
30000
50.1 J
<0.5U
< 0.1 U
28.9
< 0.1 U
< 0.08
Valid Sample Count 42 42 42 28 14 14 12 12 8 14 42 28 11 12 42 42 14 42 42 42 14 42 42
... Fi- I....
BG-1D
7/11/2015
12.14
37.6
-162.4
6.65
1687
32.1
19.82
412000
401000
< 5000 U
2.9 J+
< 100 U
7300
237000
27 J
83300
6100 J-
3300
48400 J+
555000
1400
3.3
2
370
< 0.2 U
< 0.08 U
32.3
BG-1D
9 18 2015
11.7
122.4
-77.6
0.1
1582
2.3
16.6
298000
256000
42400
4.3 J+
< 100 U
2900
124000
< 50 U
40800
3500
2600
25800
504000
2700
1.7
0.96
240
< 0.2 U
< 0.08 U
13.7
BG-ID
11/9/2015
12.1
-265.3
-465.3
3.1
1748
5.1
15
357000
148000
< 5000 U
2.93
< 100 U
5900
9400
< 50 U
56000
--
3100
29800
< 250000 U
540
0.8
0.54
330
< 0.2 U
< 0.08 U
3.7
BG-ID
12/9/2015
12
0.8
-199.2
0.2
1786
2.9
15.3
357000
288000
69800
4.4 J+
< 100 U
4600
4800
< 50 U
58900
3100
3200
30000 J+
508000
510 J+
1.1
0.81
320
< 0.2 U
< 0.08 U
2.5
BG-ID
3/14/2016
12.2
-9.4
-209.4
0.2
1492
2.5
16.5
324000
216000
< 5000 U
3.8 J+
< 100 U
5600
< 2500 U
< 50 U
47500
2700
3020
31700
414000
455
0.98
0.48
283
0.042 J+
< 0.08 U
1.2 J+
BG-ID
6 28 2016
11.8
-154.6
-354.6
0.4
1457
9.5
16.5
306000
237000
< 5000 U
< IOU
< 100 U
--
3500
< 50 U
45300
2700
3000
27200
305000
428
0.95
0.49
334
< 0.1 U
< 0.08 U
2.6
BG-1D
9/28/2016
11.4
190.1
-9.9
3.7
1456
0.3
24.2
288000
253000
35000
< 10 U
< 100 U
< 2500 U
< 50 U
42500
3100
3030
28400
838000
462
1.2 3+
0.64
310
< 0.1 U
< 0.08 U
1 0.56 J+
Valid Sample Count 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Bedrock Flow Layer
MW-7BR
7 10 2015
12.76
102.7
-97.3
4.04
6304
7.95
18.67
1080000
657000
< 5000 U
1.6 J+
< 100 U
1300
7000
< 50 U
537000
4900
1600
7200
1180000
760
0.86
0.23 J
340
< 0.2 U
< 0.08 U
24.7
MW-76R
9/15/2015
12.26
-6
-206
3.85
5381
6.4
18.5
1850000
103000
< 5000 U
2 J+
< 100 U
7703
14500
< 50 U
587000
4400
3200
14300
1590000
680
1.6
0.28 J
550
< 0.2 U
< 0.08 U
20.9
MW-7BR
12/9/2015
12.57
-15.3
-215.3
1.68
5577
4.31
15.5
1190000
479000
< 5000 U
2.2 J+
< 100 U
7803
5000
< 50 U
491000
4300
1900
< 1000 U
1340000
330
2.5
< 0.5 U
400
< 0.2 U
< 0.08 U
18.6
MW-7BR
3/28/2016
12.6
194.5
-5.5
1.62
4343
9.97
21.4
1210000
251000
< 5000 U
5 J+
< 100 U
1400
7100
< 50 U
483000
4600
2020
5500 J+
1320000
506
6.53
< 2 U
440
< 2 U
< 1.6 U
20.1
MW-7BR
6 21 2016
12.66
-20
-220
1.21
553
8.76
20.12
1180000
820000
358000
< 10 U
< 100 U
--
5800
< 50 U
525000
4400
1830
3400
1040000
342
7.4
< 1 U
426
< 1 U
< 0.8 U
20.1
MW-7BR
9/27/2016
12.3
56.3
-143.7
2.3
51.11
6.9
25.2
1330000
304000
< 5000 U
< IOU
< 100 U
--
6400
67.8 J+
470000
5300
1940
3700
1150000
366
1.3
0.1
416
0.012 J+
< 0.08 U
15.8
Valid Sample Count 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
1 of 4 Riverbend Steam Station

Table 2. Analytical Results
Constituent:
15A NCAC 02L, DHHS, IMAC:
Reporting Units:
INORGANIC
PARAMETERS
(TOTALS)
RADIONUCLIDES
Chromium
(VI)
0.07
ug/I
Cobalt
1
ug/I
Copper
1000
ug/I
Iron
300
ug/I
Lead
15
ug/I
Magnesium
NS
ug/I
Manganese
50
ug/I
Mercury
1
ug/I
Molybdenum
NS
ug/I
Nickel
100
ug/I
Nitrogen,
N N2O plus
NS
ug/I
Potassium
NS
ug/I
Selenium
20
ug/I
Sodium
NS
ug/I
Thallium
0.2
ug/I
Vanadium
0.3
ug/I
Zinc
1000
ug/I
Radium-
226
NS
pCi/L
Radium-
228
NS
pCi/L
Uranium,
Natural
NS
ug/I
Uranium-
233
NS
ug/I
Uranium-
234
NS
ug/I
Uranium -
236
NS
ug/I
Well/Sample ID ICollection Date
Shallow Flow Layer
b6 i5
7 6 2015
3
2.4
2200
0.61
1330
300
< 0.2 U
0.21
4.4
40
< 5000 U
< 0.5 U
< 5000 U
0.0323
5.9
19
1.01 J+
< 3 U
0.331
< 0.05 U
< 0.05 U
< 0.05 U
BG-1S
9/17/2015
--
1.3
2.5
190
0.0893
1130
96
< 0.2 U
0.223
0.92
99
< 5000 U
< 0.5 U
< 5000 U
0.0173
0.633
26 J+
--
--
--
--
--
--
BG-1S
11 9 2015
< 0.03 U
0.93
1.5 J+
520
0.0733
1090
95
< 0.2 U
< 0.5 U
1.7 J+
70
< 5000 U
< 0.5 U
< 5000 U
0.0293
0.3 J
30 J+
BG-1S
12/9/2015
0.018 J
0.68
1.3
64 J+
< 0.1 U
1310
62 3+
< 0.2 U
< 0.5 U
0.98
100
< 5000 U
< 0.5 U
< 5000 U
< 0.1 U
< i U
9.8 J+
BG-1S
3 14 2016
< 0.03 U
0.42
0.443
< 50 U
< 0.1 U
1080
38.7
< 0.2 U
< 0.5 U
0.6
100
< 5000 U
< 0.5 U
< 5000 U
< 0.1 U
< 0.3 U
7.43
0
0.0262
< 0.5 U
BG-1S
6/27/2016
0.022 J+
0.39 J+
0.49 J+
30.5 J+
< 0.10 U
1000
39.8 J+
< 0.20 U
< 0.50 U
0.54 J+
96
< 5000 U
< 0.50 U
11803
< 0.10 U
< 0.30 U
4.53
0
0.78
< 0.50 U
BG-1S
9/28/2016
0.11 3+
0.26
< 0.5 U
< 50 U
< 0.1 U
1000
29.8
< 0.2 U
< 0.5 U
0.58
120
< 5000 U
< 0.5 U
11203
0.025 J+
< 0.3 U
5.93
--
--
< 5 U
MW-7SR
12/6/2010
--
--
< 5 U
125
< 1 U
--
256
< 0.05 U
--
7
--
--
< 1 U
--
--
--
6
--
MW-7SR
222011
< 5 U
790
< 1 U
413
<0.05U
< 5 U
< 1 U
< 5 U
MW-7SR
6/6/2011
< 5 U
495
< 1 U
304
< 0.05 U
< 5 U
< 1 U
< 5 U
MW-7SR
1042011
< 5 U
532
< 1 U
167
<0.05U
< 5 U
< 1 U
< 5 U
MW-7SR
2/22/2012
< 5 U
285
< 1 U
113
< 0.05 U
< 5 U
< 1 U
< 5 U
MW-7SR
652012
< 5 U
520
< 1 U
122
<0.05U
< 5 U
< 1 U
<5
MW-7SR
10/3/2012
< 5 U
221
< 1 U
67
< 0.05 U
< 5 U
< 1 U
< 5 U
MW-7SR
242013
< 5 U
158
< 1 U
1070
43
<0.05U
< 5 U
776
< 1 U
1110
< 5 U
MW-7SR
6/3/2013
< 5 U
155
< 1 U
1020
38
< 0.05 U
< 5 U
777
< 1 U
1210
< 5 U
MW-7SR
10 14 2013
< 5 U
445
< 1 U
1050
68
< 0.05 U
< 5 U
799
< 1 U
1050
< 5 U
MW-7SR
2/5/2014
< 5 U
166
< 1 U
959
40
< 0.05 U
< 5 U
737
< 1 U
1120
< 5 U
MW-7SR
622014
< 5 U
117
< 1 U
963
33
<0.05U
< 5 U
737
< 1 U
1180
< 5 U
MW-7SR
10/6/2014
< 5 U
110
< 1 U
1000
31
< 0.05 U
< 5 U
746
< 1 U
1180
< 5 U
MW-7SR
222015
< 5 U
154
< 1 U
991
40
<0.05U
< 5 U
767
< 1 U
1210
7
MW-7SR
6/1/2015
--
< 1 U
13
558
< 1 U
1050
54
< 0.05 U
< 1 U
14
814
< 1 U
1240
18
MW-7SR
9 16 2015
< 0.02 UJ
2.2
2.3
6500
1.4
929
110
< 0.2 U
0.163
1.8
33
< 5000 U
0.273
< 5000 U
0.024 J+
7.4
11 J+
MW-7SR
12/10/2015
0.25
1.4
0.341
420
0.11
985
81
< 0.2 U
< 0.5 U
1.3
59 J+
< 5000 U
< 0.5 U
< 5000 U
< 0.1 U
0.571
3.73
MW-7SR
9/27/2016
0.89
0.18
0.173
29.1 J+
< 0.1 U
904
16.6
< 0.2 U
< 0.5 U
1.6
34
< 5000 U
< 0.5 U
12203
0.0163
< 0.3 U
4.1 J+
MW-71D
12/6/2010
--
--
< 5 U
< 10 U
< 1 U
--
< 5 U
< 0.05 U
--
< 5 U
--
--
< 1 U
--
--
--
< 5
MW-71D
222011
< 5 U
<10U
< 1 U
< 5 U
<0.05U
< 5 U
< 1 U
< 5 U
MW-71)
6/6/2011
< 5 U
<10U
< 1 U
< 5 U
<0.05U
< 5 U
< 1 U
< 5 U
MW-71D
1042011
< 5 U
<10U
< 1 U
< 5 U
<0.05U
< 5 U
< 1 U
< 5 U
MW-71D
2/22/2012
< 5 U
<10U
< 1 U
< 5 U
<0.05U
< 5 U
< 1 U
< 5 U
MW-71D
652012
< 5 U
<10U
< 1 U
< 5 U
<0.05U
< 5 U
< 1 U
< 5 U
MW-7D
10/3/2012
< 5 U
<10U
< 1 U
< 5 U
<0.05U
< 5 U
< 1 U
< 5 U
MW-7D
242013
< 5 U
<10U
< 1 U
898
< 5 U
<0.05U
< 5 U
949
< 1 U
3330
<5
MW-71)
6/3/2013
< 5 U
<10U
< 1 U
919
< 5 U
<0.05U
< 5 U
975
< 1 U
3510
< 5 U
MW-7D
10142013
< 5 U
<10U
< 1 U
923
< 5 U
<0.05U
< 5 U
960
< 1 U
3370
< 5 U
MW-71)
2/5/2014
< 5 U
< 10 U
< 1 U
927
< 5 U
< 0.05 U
< 5 U
960
< 1 U
3280
6
MW-71D
622014
< 5 U
<10U
< 1 U
906
< 5 U
<0.05U
< 5 U
940
< 1 U
3470
6
MW-7D
10/6/2014
< 5 U
26
< 1 U
900
< 5 U
< 0.05 U
< 5 U
938
< 1 U
3340
< 5 U
MW-71D
222015
< 5 U
<10U
< 1 U
901
< 5 U
<0.05U
< 5 U
961
< 1 U
3370
7
MW-71)
6/1/2015
--
<1U
< 5 U
20
< 1 U
929
< 5 U
<0.05U
<I
< 5 U
958
< 1 U
3480
< 5 U
MW-7D
9162015
0.583
<0.5U
0.443+
<50U
<0.1U
871
< 5 U
<0.2U
<O.5U
0.223
193
<5000U
<0.5U
31203
<0.1U
< 1 U
3.33
MW-71)
12/9/2015
0.87
< 0.5 U
0.423
< 50 U
< 0.1 U
1010
< 5 U
< 0.2 U
I < 0.5 U
0.183
25
< 5000 U
< 0.5 U
36803
0.0213
< 1 U
9.63
MW-71D
3232016
1.2
0.023
0.331
<50U
<0.1U
944
< 5 U
<0.2U
<0.5U
0.56
<20U
<5000U
<0.5U
3570]
<0.1U
0.173
6.63
MW-71)
6/28/2016
0.68
0.0911
0.51
82.5
< 0.1 U
1000
4.53
< 0.2 U
< 0.5 U
< 0.5 U
< 20 U
< 5000 U
< 0.5 U
35703
< 0.1 U
0.293
3.23
MW-71D
9/27/2016
0.74
0.0381
0.67
56.3 J+
0.7
876
2.61
< 0.2 U
< 0.5 U
< 0.5 U
27
< 5000 U
< 0.5 U
32403
0.0253
0.12 J+
6.7 J+
Valid Sample Count 42 11 14 42 42 42 28 42 42 14 42 12 28 42 28 12 12 42 1 1 2 0 0 0
Deep Flow Layer
BG-1D
7/11/2015
--
1.3
2.8
1500
0.24
112
27
0.12 J+
9.4
6.7
30
130000
2.1
75600
< 0.1 U
22
< 10 U
0.652 J+
3.18 J+
0.112 J
< 0.05 U
< 0.05 U
< 0.05 U
BG-1D
9 18 2015
--
1.8
4.9
3600
0.39 J+
360
72
< 0.2 U
13.2
2.9
20
96900
0.96
54600
< 0.1 U
21.7
7.63
--
--
--
--
-
--
BG-1D
11/9/2015
1.5
0.75
1.1
150
< 0.1 U
< 100 U
2.83
< 0.2 U
9.8
0.86
< 20 U
98000
0.78
61300
< 0.1 U
10.6
< 10 U
BG-1D
12/9/2015
0.025 J
0.86
1.2
100 J+
0.0473
< 100 U
< 5 U
< 0.2 U
12.4
1
< 20 U
87900
0.65
76100
< 0.1 U
9.9
< 10 U
BG-1D
3/14/2016
0.018 J-
0.61
0.81
35.5 J
< 0.1 U
< 100 U
< 5 U
< 0.2 U
13
0.7
< 20 U
86900
0.43 J
51900
< 0.1 U
2.2
< 10 U
1.5
0.79
< 0.5 U
BG-1D
6 28 2016
1 49
0.81
1.3
84.3
< 0.1 U
< 100 U
< 5 U
< 0.2 U
13.7
0.64
< 20 U
83700
0.413
53200
< 0.1 U
1.4
< 10 U
2.74
1.22
< 5 U
BG-1D
9/28/2016
< 0.03 U
0.51
< 0.5 U
< 50 U
< 0.1 U
< 100 U
< 5 U
< 0.2 U
17.9
0.7
< 20 U
78600
0.37 J
49600
< 0.1 U
1
< 10 U
--
< 0.5 U
Valid Sample Count 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Bedrock Flow Layer
MW-7BR
7 10 2015
--
< 0.5 U
1.5
< 50 U
0.21
< 100 U
< 5 U
< 0.2 U
13.3
0.291
193
17800
0.51
25300
0.064 J+
2.1
< 10 U
--
--
--
--
--
--
MW-7BR
9/15/2015
--
< 0.5 U
1.8 J+
53
0.27
< 100 U
< 5 U
< 0.2 U
8.5
0.84
16 J
19600
0.381
21100
0.0393
1.2
5.2 J+
MW-7BR
12/9/2015
22.6
< 0.5 U
1.4
< 50 U
0.21
< 100 U
< 5 U
< 0.2 U
9.7
0.193
27
23700
0.35 J
40300
0.0373
0.913
12
MW-7BR
3/28/2016
18.5]+
0.22J
2.2J
<50U
< 2 U
<100U
< 5 U
<0.2U
10.8
<10U
151
16200
<10U
28700
< 2 U
1.83
3.3J
4.13
1.28
<0.5U
MW-7BR
6 21 2016
18.7
< 1 U
5.7
< 50 U
< 1 U
< 100 U
< 5 U
0.0741
10.6
< 5 U
360
14900
< 5 U
30300
< 1 U
1.43
9.43
--
--
--
MW-7BR
9/27/2016
11.6
0.17
4.5
62.2 J+
0.42
< 100 U
< 5 U
0.0971
9.1
3.4
20
12800
< 0.5 U
30200
0.13
0.67 3+
9.93
--
--
< 0.5 U
Valid Sample Count 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2 of 4 Riverbend Steam Station

Table 2. Analytical Results
Constituent:
15A NCAC 02L, DHHS, IMAC:
Reporting Units:
FIELD
PARAMETERS
WATER QUALITY
PARAMETERS
SELECTED
40CFR257
APPENDIX
III
CONSTITUENTS
pH
6.5 - 8.5
SU
Eh
NS
Oxidation
Reduction
Potential
NS
mV
Dissolved
Oxygen
NS
mg/I
Specific
Conductance
NS
PS/cm
Turbidity
NS
NTU
Temperature
NS
Deg C
Alkalinity
NS
ug/I
Carbonate
Alkalinity
NS
ug/I
Bicarbonate
Alkalinity
NS
ug/I
Methane
NS
ug/I
Sulfide
NS
ug/I
Total
Organic
Carbon
NS
ug/I
Total
Suspended
Solids
NS
ug/I
Boron
700
ug/I
Calcium
NS
ug/I
Chloride
250000
ug/I
Strontium
NS
ug/I
Sulfate
250000
ug/I
Total
Dissolved
Solids
500000
ug/I
Aluminum
NS
ug/I
Antimony
1
ug/I
Arsenic
10
ug/I
Barium
700
ug/I
Beryllium
4
ug/I
Cadmium
2
ug/I
Chromium
10
ug/I
Well/Sample ID ICollection Date
POTENTIAL BACKGROUND WELLS TO BE ADDED - JUSTIFICATION ATTACHED
Shallow Flow Layer
BG-4S
9/27/2016
6.98
361.9
161.9
0.77
159.3
7.59
18.6
91000
< 5000 U
91000
11.3
< 100 U
--
< 2600 U
< 50 U
19400
2700
277
2300
138000
130
0.161
0.35
59.9
0.013
< 0.08 U
0.63 J+
GWA-5S
6 18 2015
3.56
204.2
4.2
5.98
184
1.92
18.6
27003
< 5000 U
2700 J
2.4 J+
< 100 U
< 1000 U
< 2500 U
< 50 U
915
980 J
9.7
< 1000 U
< 25000 U
< 100 U
< 0.5 U
< 0.5 U
17
< 0.2 U
< 0.08 U
0.57 J+
GWA-5S
6/23/2016
5.09
424
224
6.73
12
5.2
23.78
11003
< 5000 U
11001
< 10 U
< 100 U
< 5000 U
< 50 U
326
710 J
5.7
7701
5000
80.81
< 0.5 U
0.044 J
8.6
< 0.1 U
< 0.08 U
1.8
GWA-14S
3 1 2016
5.8
377.3
177.3
7.5
27.6
1.9
16.6
--
< 5000 U
5500
2 J+
< 100 U
39000
< 2500 U
< 50 U
1310
2800
12
2100 J+
39000 J+
< 100 U
0.483
0.12
15
0.13 J+
< 0.08 U
0.36 J+
GWA-14S
6/28/2016
7.1
125
-75
4
120.2
5.8
21
48500
< 5000 U
48500
< 10 U
< 100 U
--
3300
< 50 U
18800
1000
208
< 1000 U
1 59000
64.21
0.11 J
0.43
42.1
< 0.1 U
< 0.08 U
0.63
Valid Sample Count 47 47 47 32 19 19 17 17 10 19 47 33 16 17 47 47 19 47 47 47 19 47 47
(Including BG-4S, GWA-
SS, and GWA-14S
Deep Flow Layer
BG-41)
7.19
396.4
196.4
4.3
195
8.94
17
94700
< 5000 U
94700
< 10 U
< 100 U
4700
< 50 U
27400
6000
217
14400
179000
< 100 U
0.383
0.61
18.2
< 0.1 U
< 0.08 U
17.3
BG-5D
"26
--
--
--
--
141000
< 5000 U
141000
< 10 U
< 100 U
4600
< 50 U
46600
10800
712
24800
255000 J+
169
0.8 J+
0.49
105
< 0.1 U
< 0.08 U
1.8 J+
GWA-14D
9.59
286
86
0
201
4.56
18.14
95400
37700
57800
< 10 U
< 100 U
11800
< 50 U
27700
2000
158
9600
144000
298
0.19J
1.4
31.8
0.016 ]
< 0.08 U
6.5
GWA-14D
10
68
-132
2
176.4
13.4
20.1
72300
32400
39900
< 10 U
< 100 U
--
31300
65.7 J+
19900
2400
154
7900
149000
795
0.261
1.5
60.7
0.063 J+
< 0.08 U
7.2
Valid Sample Count 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1
(Including BG-4D, BG-
SD, and GWA-14D
Bedrock Flow Layer
BG-4BR
6 16 2016
2710000
490000
< 5000 U
< 10 U
< 100 U
45900
< 50 U
473000
4700
7370
7400
4060000
2300
0.291
0.65
1260
0.056 J
< 0.08 U
21.2
7G-5BR
4/22/2016
7.9
101.2
-98.8
0.2
204.8
5.4
18.1
119000
< 5000 U
119000
< 10 U
< 100 U
< 1000 U
< 2500 U
< 50 U
39700
14500
892
26400
197000
83.3 J
1.4
0.37
145
< 0.1 U
< 0.08 U
1.2 J+
BG-513R
6/8/2016
7.75
153
-47
1.03
378
1.26
21.06
132000
< 5000 U
132000
< 10 U
< 100 U
< 5000 U
< 50 U
46700
14500
908
29000
223000
52.93
0.421
1.1
128
0.034 J
< 0.08 U
1.5
Valid Sample Count 2 2 2 2 2 2 2 2 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2
(Including BG-4BR and
BG-5BR)
Notes:
Red text indicates samples that will not be used in determining proposed provisional background threshold values (PPBTVs) due to pH > 8.5 or turbidity >10 NTU.
- Bold highlighted concentration indicates exceedance of the 15A NCAC 02L Standard or IMAC, Appendix 2, April 1, 2013.
pm = micron
pg/L = micrograms per liter
pS/cm = microsiemens per centimeter
ft = feet
mg/L = milligrams per liter
Eh values were calculated by adding 200 mV to the field -measured ORP value. Depending on the field meter used, Eh values calculated using this formula can vary by +/- 5 mV
mV = millivolts
NTU - nephelometric turbidity units
pCi/L = picocuries per liter
SU = standard unit
J = laboratory estimated concentration
J- = estimated concentration, biased low
J+ = estimated concentration, biased high
U = results not detected at concentrations which equal the laboratory's method reporting limit
02L = North Carolina groundwater standards as specified in T15A NCAC 02L
D = dissolved
Deg C = degree Celsius
DHHS = North Carolina Department of Health and Human Services
DO = dissolved oxygen
GW = groundwater
GWQS = groundwater quality standard
IMAC = Interim Maximum Allow Concentration
3of4
Riverbend Steam Station

Table 2. Analytical Results
Constituent:
15A NCAC 02L, DHHS, IMAC:
Reporting Units:
INORGANIC
PARAMETERS
(TOTALS)
RADIONUCLIDES
Chromium
(VI)
0.07
ug/I
Cobalt
1
ug/I
Copper
1000
ug/I
Iron
300
ug/I
Lead
15
ug/I
Magnesium
NS
ug/I
Manganese
50
ug/I
Mercury
1
ug/I
Molybdenum
NS
ug/I
Nickel
100
ug/I
Nitrogen,
N N2O3us
NS
ug/I
Potassium
NS
ug/I
Selenium
20
ug/I
Sodium
NS
ug/I
Thallium
0.2
ug/I
Vanadium
0.3
ug/I
Zinc
1000
ug/I
Radium-
226
NS
pCi/L
Radium-
228
NS
pCi/L
Uranium,
Natural
NS
ug/I
Uranium-
233
NS
ug/I
Uranium-
234
NS
ug/I
Uranium -
236
NS
ug/I
Well/Sample ID ICollection Date
Shallow Flow Layer
BG-4S
9/27/2016
1.1
0.33 J+
293
< 0.1 U
3690
732
< 0.2 U
3.8
1.2
180
< 5000 U
< 0.5 U
12700
< 0.1 U
1 1.9
3.1 J
0.0951
GWA-5S
6 18 2015
4.5
2.6 J+
44 J+
< 0.1 U
278
190
0.11 J+
0.193
3.7
< 20 U
< 5000 U
< 0.5 U
< 5000 U
< 0.1 U
< 1 U
14 J+
--
GWA-5S
6/23/2016
0.038
2.7
50.5
85.8
0.0923
92.13
63.7
< 0.2 U
0.77
0.93
< 20 U
< 5000 U
< 0.5 U
7471
< 0.1 U
0.76
9.43
GWA-14S
3 1 2016
< 0.03 U
2
13.2
453
< 0.1 U
398
84
< 0.2 U
< 0.5 U
1.3
< 20 U
< 5000 U
< 0.5 U
30203
< 0.1 U
0.0913
33
--
GWA-14S
6/28/2016
< 0.03 U
8.5
0.73
1890
< 0.1 U
688
1280
< 0.2 U
0.433
1.4
< 20 U
< 5000 U
< 0.5 U
14103
< 0.1 U
0.213
33
0.0641
Valid Sample Count 47 14 19 47 47 47 33 47 47 19 47 17 33 47 33 17 17 47 1 1 4 0 0 0
(Including BG-4S, GWA-
SS, and GWA-14S
Deep Flow Layer
BG-4D
9/27/2016
0.92
0.28
0.66 J+
137
< 0.1 U
4370
9
< 0.2 U
2.6
9.2
150
4280 J
0.39 J
12200
< 0.1 U
6.4
2.53
0.88
BG-5D
9/28/2016
0.76
0.38
< 0.5 U
142
0.12
7230
47.6
< 0.2 U
7.2
1
2000
7360
1.7
16600
< 0.1 U
2.6
9.23
0.85
GWA-14D
6 14 2016
4
0.48
0.423
104
0.14
2160
< 5 U
< 0.2 U
2.5
2.2
28
< 5000 U
< 0.5 U
16200
< 0.1 U
12.5
< 10 U
0.2
0.511
0.52
GWA-14D
9/27/2016
0.59
0.27
0.84
461 J+
1
1380
12.4
< 0.2 U
2.4
3.1
21
< 5000 U
0.481
17700
0.0293
10.4
3.6 J
0.787
0.266
0.9
Valid Sample Count 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 1 0 0 0
(Including BG-4D, BG-
SO, and GWA-14D
Bedrock Flow Layer
BG-4BR
6 16 2016
19.8
0.43
3.6
687
2.1
< 100 U
10.7
< 0.2 U
13.7
5
250
1030000
1.2
307000
< 0.1 U
1.6
15.2
11.6
2.51
0.21
BG-5BR
4/22/2016
0.17
0.09 J
0.43 J+
41.23
< 0.1 U
6600
13.1
< 0.2 U
2.3
0.6
< 20 U
5740
0.57
16200
< 0.1 U
1.2
10.5 J+
BG-5BR
6/8/2016
0.014 J
0.0741
< 0.5 U
108
< 0.1 U
7460
22.2
< 0.2 U
3.2
0.87
< 20 U
3020 J
< 0.5 U
17800
< 0.1 U
0.2 J
< 10 U
0.364
0.13
0.65
Valid Sample Count 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 0 0 0
(Including BG-4BR and
BG-5BR)
Notes:
Red text indicates samples that will not be used i N = normal
- Bold highlighted concentration indicate! NS = no standard
pm = micron PPBC = Proposed Provisional Background Concentrations
pg/L = micrograms per liter T = total
pS/cm = microsiemens per centimeter TDS = total dissolved solids
ft = feet TOC = total organic carbon
mg/L = milligrams per liter *BG-1D and MW-7BR are scheduled for replacement due to potential grout contamination
Eh values were calculated by adding 200 mV to tl
4 of 4 Riverbend Steam Station