NCS000546_Full Permit Renewal Application Uploaded_20200127

Renewal of
Individual NPIDES
Stormwater Permit
Allen Steam Station ,
253 PlantAllen Road
Belmont, NC
NPDES Permit
NCS000546
October 2019
G� Carc�/no`
Shaping the Future

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him, �ku-k
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October 29, 2019
Suzanne McCoy
NCDEMLR Stormwater Program
1612 Mail Service Center
Raleigh, North Carolina 27699-1612
Subject: Duke Energy Carolinas, LLC.
Allen Steam Station
NPDES Stormwater Permit NCS000546
Permit Renewal Application
Dear Ms. McCoy.
Allen Steam Station
2-53
Bebr #, NC 28012
Duke Energy Carolinas, LLC requests the subject permit be renewed and reissued. The subject
permit expires on April 30, 2020. Section III Part S of this permit requires the permit application
for permit renewal to be submitted at least 180 days prior to the expiration date of the permit.
Attached is the renewal application form and duplicate copies of the supplemental information.
Should you have questions or need additional information please contact Robert Wylie at 704
382-4669.
Sincerely,
Terry Tuck
General Manager it
Allen Steam Station
Fossil/Hydro Operations - Carolinas Coal Generation
Attachments:
Renewal Application Form
Supplemental Information
Site Map from the Stormwater Pollution Prevention Plan
Summary of Analytical Monitoring Results
Summary of Visual Monitoring Results
Certification of the Development and Implementation of the SPPP

Permit Coverage
� Renewal Application Form
National pollutant Discharge Elimination System NPDES Permit Number
�C®ENR Stormwater Individual Permit NCS000546
;;ease provide your permit number in box in the upper right hand corner, complete the information in the space provided
below and return the completed renewal form along with the required supplemental information to the address indicated.
Owner Information
Owner / Organization Name
Owner Contact:
Mailing Address:
Phone Number
Fax Number:
E-mail address:
Facilitv Information
Facility Name:
Facility Physical Address
Facility Contact:
Mailing Address:
Phone Number:
Fax Number:
E-mail address:
Permit Information
Permit Contact:
Mailing Address:
..'Phone Number:
�x Number:
E-mail address:
Discharae Information
Receiving Stream:
Stream Class:
Basin:
Sub -Basin:
Number of Outfalls:
* Address to which permit correspondence will be mailed
Duke Energy Carolinas, LLC
Paul Draovitch
526 South Church Street EC3XP
Charlotte NC 28202
980-373-0408
Pau [e-mail]
Allen Steam Station
253 Plant Allen Road
Belmont, NC 28012 Gaston County
Terry Tuck
253 Plant Allen Road
Belmont NC 28012
704-920-2400
[e-mail]
Robert Wylie
Charlotte, NC 28202
704-382-4669
[e-mail]
Catawba River and South Fork River
WS-IV, B (Catawba) WS-V, B (South Fork River)
Catawba River Basin
03-08-34
18 (SW013 includes 9 outfalls under its designation)
Facility/Activity Changes Please describe below any changes to your facility or activities since issuance of your permit. Attached a
separate sheet if necessary.
See Narrative section
CERTIFICATION
I certify that I am familiar with the information contained in the application and that to the best of my knowledge and belief
such information is true, complete and accurate.
Signature'
Terry Tuck
Date
October 29, 2019
General Manager II
Print or type name of person signing above Title
SW Individual Permit Coverage Renewal
Please return this completed application form Stormwater Permitting Program
and requested supplemental information to: 1612 Mail Service Center
Raleigh, North Carolina 27699-1612

Duke Energy Allen Steam
Station I Renewal of
Individual NPDES
Stormwater Permit

Duke Energy Allen Steam
Station I Renewal of
Individual NPDES
Stormwater Permit

Allen Storm Water Outfall SW001
Parameter
ded e�\�o /\°e\�o d\�o L��°�0�
Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
12"CMP to Catawba River (Lake Wylie) -
Draining gravel road, woodland and RR.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
11/2/15
2.88
1 6.48
1 17
1 <0.050
1 0.106
1 <0.001
I <0.001
<0.001
<0.001
0.00228
0.00662
0.00159
1 0.00178
1 <0.001
1 <0.0003
1 <0.0002
1 15.7
1/15/16
1.15
7.82
52
<0.05
0.247
<0.001
<0.001
<0.001
<0.001
0.00261
0.00406
0.00530
<0.001
<0.001
<0.0003
<0.0002
23.3
21-1-2016
No Flow
No Flow
1H-2017
No Flow
No Flow
07-2018
No Flow
No Flow
11/2/2018
0.53
7.6
120
<0.05
0.170
<0.001
0.00253
<0.001
<0.001
0.00597
0.00745
0.00198
0.00191
0.00129
<0.0002
<0.0002
13.7
12/20/2018
1.49
8.0
88
<0.05
0.050
<0.001
<0.001
<0.001
<0.001
0.00183
0.00359
0.00145
<0.001
<0.001
<0.0002
<0.0002
13.2
1/2019
No Flow
No Flow
2/2019
No Flow
No Flow
3/2019
No Flow
No Flow
4/2019
No Flow
No Flow
5/2019
No Flow
No Flow
6/2019
No Flow
No Flow
7/2019
No Flow
No Flow
8/2019
No Flow
INo Flow
SU - standard units < - not detected at the following level SA - semi-annual
mg/L - milligrams per liter NA - not applicable SACA Semi-annual during coal or ash transport
ug/L - micrograms per liter NE - not established (monitor only) SA-QCA Semi-annual - Quarterly during coal or ash transport
ng/L - nanograms per liter PCB - polychlorinated biphenyls QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SW001 A
Parameter
Comments / Notes
Qx\
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
12"CMP to Catawba River
(Lake Wylie) - Draining gravel
road, woodland and RR.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
1H-2017
No Flow
2H-2017
No Flow
1H-2018
No Flow
2H-2018
No Flow
1H-2019
No Flow
SU - standard units
mg/L - milligrams per liter
ug/L - micrograms per liter
ng/L - nanograms per liter
< - not detected at the following level
NA - not applicable
NE - not established (monitor only)
PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO02
IN
Parameter
nd
�•�
we
e�
Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
24"CMP to Catawba River (Lake
Wylie) - Draining paved road
and laydown area.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
10/28/15
1.3
1 7.13
1 8
1 0.112
1 0.033
1 <0.001
I <0.001
<0.001
<0.001
I <0.001
1 0.0047
1 <0.001
1 0.00128
1 0.0024
1 <0.0003
<0.0002
3.085
1/15/16
1.15
8.00
61
<0.05
0.034
<0.001
<0.001
<0.001
<0.001
0.0015
0.00506
<0.001
0.00175
<0.001
<0.0003
<0.0002
5.1
1H-2018
No Flow
No Flow
12/20/2018
1 1.49
7.9
55
<0.05
0.029
<0.001
0.00209
<0.001
<0.001
0.00174
0.00526
0.00209
0.00144
<0.001
<0.0002
<0.0002
12.6
1H-2019
I
No Flow
I No Flow
SU - standard units
mg/L - milligrams per liter
ug/L - micrograms per liter
ng/L - nanograms per liter
< - not detected at the following level
NA - not applicable
NE - not established (monitor only)
PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO03
Parameter
Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
18"CPP to Catawba River (Lake
Wylie) - Draining RR lines.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
11/2/15
2.88
7.24
14
0.14
0.011
<0.001
1 0.00126
<0.001
<0.001
<0.001
1 0.00318
1 0.001
<0.001
0.00297
<0.0003
<0.0002
4.49
1/15/16
1.15
7.99
41
<0.05
0.0100
<0.001
0.00202
<0.001
<0.001
<0.001
1 0.00208
1 <0.001
<0.001
<0.001
<0.0003
<0.0002
5.1
1H-2017
No Flow
No Flow
2H-2017
No Flow
No Flow
1H-2018
No Flow
No Flow
12/20/2018
1.49
8.4
160
<0.05
0.0990
<0.001
0.00122
<0.001
<0.001
1 0.00296
1 0.00684
1 0.00214
1 0.00182
1 <0.001
<0.0002
1 <0.0002
11.0
1H-2019
No Flow
No Flow
SU - standard units < - not detected at the following level SA - semi-annual
mg/L - milligrams per liter NA - not applicable SACA Semi-annual during coal or ash transport
ug/L - micrograms per liter NE - not established (monitor only) SA-QCA Semi-annual - Quarterly during coal or ash transport
ng/L - nanograms per liter PCB - polychlorinated biphenyls QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO05
Parameter
Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
12"CMP to Catawba River (Lake
Wylie) - Draining gravel laydown
yard, paved roadway and
vegetated slopes.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
12/17/15
1.25
8.6
1 17
1 <0.05
1 0.061
1 <0.001
1 0.00108
1 <0.001
I <0.001
I <0.001
1 0.00392
1 <0.001
1 0.00101
1 0.00107
<0.0003
1 <0.0002
1 3.86
1H-2018
No Flow
No Flow
11/2/2018
0.53
8.1
6.6
<0.05
1 0.082
1 <0.001
I <0.001
I <0.001
I <0.001
I <0.001
1 0.00322
1 <0.001
I <0.001
I <0.001
<0.0002
1 <0.0002
1.96
1H-2019
I
No Flow
No Flow
SU - standard units
mg/L - milligrams per liter
ug/L - micrograms per liter
ng/L - nanograms per liter
< - not detected at the following level
NA - not applicable
NE - not established (monitor only)
PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO07
101\°�a
�`-1
o,�e � o,�e o,�o `moo �,�� she e� Q 0 '�, P �` Comments / Notes Parameter
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
18"CMP to Catawba River (Lake Wylie) -
Draining gravel roadway, Ls conveyor and
RR lines.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
12/17/15
1.25
1 9.43
1 220
1 <0.05
1 0.409
1 <0.001
1 0.0026
<0.001
<0.001
1 0.00298
0.00469
1 0.0023
0.00207
<0.001
1 <0.0003
<0.0002
7.94
3/1/2017
No Flow
No Flow
4/3/2017
0.36
7.47
260
<0.05
0.66500
<0.001
0.002
<0.001
<0.001
0.00262
0.00916
0.00243
0.00283
<0.001
<0.0003
<0.0002
4.4
12/20/2017
0.4
7.33
160
<0.05
0.691
<0.001
0.00190
<0.001
<0.001
0.00243
0.00521
0.00191
0.00212
<0.001
<0.0003
<0.0002
4.74
8/2018
No Flow
No Flow
9/2018
No Flow
No Flow
10/10/2018
0.80
8.0
62
<0.05
0.241
<0.001
0.00121
<0.001
<0.001
<0.001
0.00326
<0.001
<0.001
0.0117
<0.0002
<0.0002
2.02
11/2/2018
0.53
8.0
19
<0.05
0.072
<0.001
0.00166
<0.001
<0.001
<0.001
0.00323
<0.001
<0.001
<0.001
<0.0002
<0.0002
2.48
12/20/2018
1.49
8.0
130
<0.05
0.415
<0.001
0.00124
<0.001
<0.001
0.00162
0.00345
0.00137
0.00125
<0.001
<0.0002
<0.0002
3.2
1/2019
No Flow
No Flow
2/2019
No Flow
No Flow
3/2019
No Flow
No Flow
4/2019
No Flow
No Flow
5/2019
No Flow
No Flow
6/7/2019
1.06
8.0
<5
<0.05
0.153
<0.001
<0.001
<0.001
<0.001
<0.001
0.00750
<0.001
0.00103
0.00106
<0.0002
<0.0002
3.53
7/2019
No Flow
No Flow
8/2019
No Flow
INo Flow
SU - standard units < - not detected at the following level SA - semi-annual
mg/L - milligrams per liter NA - not applicable SACA Semi-annual during coal or ash transport
ug/L - micrograms per liter NE - not established (monitor only) SA-QCA Semi-annual - Quarterly during coal or ash transport
ng/L - nanograms per liter PCB - polychlorinated biphenyls QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO08
\
�o`
owe
�
\�
0e\
Ld
��'
\�
o`
�°
e\
13
Parameter
�n
�e
Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
24"CMP to Catawba River
(Lake Wylie) - Draining gravel
roadway & Ls conveyor.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
10/27/2015
0.5
6.8
29
<0.05
0.039
<0.001
0.00116
<0.001
<0.001
0.00138
0.00478
0.00107
0.00228
0.0016
<0.0003
1 <0.0002
1 3.44
1/15/16
1.15
7.82
17
<0.05
0.032
<0.001
<0.001
<0.001
<0.001
0.0011
0.00286
0.00115
0.00137
<0.001
<0.0003
<0.0002
1 3.04
1/1/2017
Outfall could not be sampled due to being inaccessible because of construction activities
involving the building of permanent sampling platforms.
1H-2018
No Flow
No Flow
2H-2018
No Flow
INo Flow
6/7/19
1.06
8.4
1 25
1 <0.05
1 0.062
1 <0.001
1 0.00140
1 <0.001
I <0.001
1 0.00104
1 0.00975
1 <0.001
1 0.00182
1 0.00160
1 <0.0002
<0.0002
1 4.39
SU - standard units
mg/L - milligrams per liter
ug/L - micrograms per liter
ng/L - nanograms per liter
< - not detected at the following level
NA - not applicable
NE - not established (monitor only)
PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO09
\
ed� �\\�o� \,`o
�o'`
Parameter Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
Concrete ditch to Catawba River (Lake
Wylie) - Draining RR.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
Units
inches
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
10/27/15
0.5
6.9
5
<0.05
0.178
<0.001
0.00152
<0.001
<0.001
<0.001
0.00359
<0.001
0.00111
0.00825
<0.0003
<0.0002
2.455
1/15/16
1.15
7.9
7
<0.05
0.0350
<0.001
0.00211
<0.001
<0.001
0.00112
0.00288
0.00101
0.00103
0.00253
<0.0003
<0.0002
2.6
12/20/2017
0.4
7.2
6
<0.05
0.214
<0.001
<0.001
<0.001
<0.001
<0.001
0.00505
<0.001
<0.001
<0.001
<0.0003
<0.0002
3.02
12/20/2018
1.49
8.2
15
<0.05
0.119
<0.001
0.00130
<0.001
<0.001
0.00101
0.00311
0.00146
<0.001
0.00178
<0.0002
<0.0002
3.39
01/03/2019
No Flow
No Flow
2/2019
No Flow
No Flow
3/2019
No Flow
No Flow
4/2019
No Flow
No Flow
5/2019
No Flow
No Flow
6/7/2019
1.06
8.1
<5
<0.05
0.173
<0.001
0.00163
<0.001
<0.001
<0.001
0.00533
<0.001
0.00111
0.0133
<0.0002
<0.0002
2.76
7/2019
No Flow
INo Flow
8/2019
No Flow
INo Flow
SU - standard units
mg/L - milligrams per liter
ug/L - micrograms per liter
ng/L - nanograms per liter
< - not detected at the following level
NA - not applicable
NE - not established (monitor only)
PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SW010
,10
fie\
a�� �hQ \�\\� o°J `\Q ��\ ��\ \�c�•\�'� Q`p\� \�� ��\ QUO �� �A\�
e 9 ec
Parameter oaew
5 -,I-Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
24"CMP to Catawba River (Lake Wylie) - Draining RR.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
8/19/2015
0.52
6.8
38
0.059
0.110
<0.001
0.006
<0.001
<0.001
0.003
0.011
1 0.003
0.004
0.018
<0.0003
<0.001
9.15
11/30/15
1.79
1 6.6
36
<0.05
0.052
<0.001
0.0024
<0.001
I <0.001
1 0.002421
0.0076
1 0.00157
1 0.0024
1 0.0059
<0.0003
<0.0002
6.27
1/2017
Outfall could not be sampled due to being inaccessible because of construction activities involving the building of permanent sampling platforms.
12/20/2017
0.4
7.0
220
<0.05
0.118
<0.001
0.0100
<0.001
<0.001
0.0149
0.02720
0.01190
0.0171
0.00860
<0.0003
<0.0002
17.7
10/10/2018
0.80
8.3
6.2
<0.05
0.037
<0.001
0.00501
<0.001
<0.001
0.00108
0.00543
<0.001
<0.001
0.0168
<0.0002
<0.0002
2.78
11/2/2018
0.53
7.9
410
<0.05
0.171
<0.001
0.00717
<0.001
<0.001
0.0171
0.0427
0.0130
0.0158
0.0106
<0.0002
0.000347
21.1
12/20/2018
1.49
8.0
700
<0.05
0.164
<0.001
0.0105
<0.001
<0.001
0.0205
0.0491
0.0169
0.0202
0.00391
<0.0002
0.000363
60.9
1/2019
No Flow
No Flow
2/2019
No Flow
No Flow
3/2019
No Flow
No Flow
4/2019
No Flow
No Flow
5/2019
No Flow
No Flow
6/7/2019
1.06
1 8.3
1 8.2
1 <0.05
1 0.043
1 <0.001
1 0.00223
1 <0.001
I <0.001
1 0.00133
1 0.00815
1 <0.001
1 0.00134
1 0.0117
1 <0.0002
<0.0002
4.88
7/2019
No Flow
No Flow
8/2019
No Flow
No Flow
SU - standard units < - not detected at the following level SA - semi-annual
mg/L - milligrams per liter NA - not applicable SACA Semi-annual during coal or ash transport
ug/L - micrograms per liter NE - not established (monitor only) SA-QCA Semi-annual - Quarterly during coal or ash transport
ng/L - nanograms per liter PCB - polychlorinated biphenyls QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO13-7
�\�o
P��o��
e\�o
d\�o
�'\�
�o�e
�e\
Parameter
Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
Fifteen 10"CMPs to Catawba River
(Lake Wylie) - Draining soil borrow
area and gravel/dirt roadways.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
1H-2017
No Flow
No Flow
2H-2017
No Flow
No Flow
1H-2018
No Flow
No Flow
2H-2018
No Flow
No Flow
1H-2019
I
No Flow
INo Flow
SU - standard units
mg/L - milligrams per liter
ug/L - micrograms per liter
ng/L - nanograms per liter
< - not detected at the following level
NA - not applicable
NE - not established (monitor only)
PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO13-8
/\o
'\�
�o,�e
'`�\
•\�o��\
\/\o
Parameter
610
nd
�•�
we
Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
Fifteen 10"CM Ps to Catawba River
(Lake Wylie) - Draining soil borrow
area and gravel/dirt roadways.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
12/17/15
1.251
81
221
<0.051
0.07
<0.0011
0.00121
<0.001
<0.0011
0.001281
0.005181
0.001111
0.00339
<0.001
<0.0003
<0.00021
7.69
1H-2017
No Flow
No Flow
2H-2017
No Flow
No Flow
1H-2018
No Flow
No Flow
2H-2018
No Flow
No Flow
1H-2019
No Flow
No Flow
SU - standard units
mg/L - milligrams per liter
ug/L - micrograms per liter
ng/L - nanograms per liter
< - not detected at the following level
NA - not applicable
NE - not established (monitor only)
PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO13-9
o
..���\\
Qe�ded '�°��\
�°��\
���\�o
P��o��
��e\�o
��d\�o
.���'\�
��\�o,�e
'�°'`�\
•\�o��\
��e\�o
\�o'`�\
��\�o�
���
Parameter
nd
�•�
we
e�
Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
Fifteen 10"CM Ps to Catawba River
(Lake Wylie) - Draining soil borrow
area and gravel/dirt roadways.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
11/30/15
1.791
6.071
<51
0.1151
0.034
<0.001
<0.001
<0.001
<0.001
<0.001
0.00253
<0.0011
0.00569
<0.001
<0.0003
<0.0002
2.7
1H-2017
No Flow
No Flow
2H-2017
No Flow
No Flow
1H-2018
No Flow
No Flow
2H-2018
No Flow
No Flow
1H-2019
No Flow
No Flow
SU - standard units
mg/L - milligrams per liter
ug/L - micrograms per liter
ng/L - nanograms per liter
< - not detected at the following level
NA - not applicable
NE - not established (monitor only)
PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO13-10
o
..���\\
Qe�ded '�°��\
�°��\
���\�o
P��o��
��e\�o
��d\�o
.���'\�
��\�o,�e
'�°'`�\
•\�o��\
��e\�o
\�o'`�\
��\�o�
���
Parameter
nd
�•�
we
e�
Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
Fifteen 10"CM Ps to Catawba River
(Lake Wylie) - Draining soil borrow
area and gravel/dirt roadways.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
12/17/15
1.25
8.7
40
<0.05
0.01
<0.001
<0.001
<0.001
<0.001
0.001531
0.0537
0.00111
0.00172
<0.001
<0.0003
<0.00021
8.98
1H-2017
No Flow
No Flow
2H-2017
No Flow
No Flow
1H-2018
No Flow
No Flow
2H-2018
No Flow
j No Flow
1H-2019
No Flow
No Flow
SU - standard units
mg/L - milligrams per liter
ug/L - micrograms per liter
ng/L - nanograms per liter
< - not detected at the following level
NA - not applicable
NE - not established (monitor only)
PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO13-11
o
..���\\
Qe�ded
'�°��\
�°��\
���\�o
P��o��
��e\�o
��d\�o
.���'\�
��\�o,�e
'�°'`�\
•\�o��\
��e\�o
\�o'`�\
��\�o�
���
Parameter
Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
Fifteen 10"CMPs to Catawba River
(Lake Wylie) - Draining soil borrow
area and gravel/dirt roadways.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
1H-2017
No Flow
No Flow
2H-2017
No Flow
No Flow
1H-2018
No Flow
No Flow
2H-2018
No Flow
No Flow
1H-2019
No Flow
INo Flow
SU - standard units < - not detected at the following level SA - semi-annual
mg/L - milligrams per liter NA - not applicable SACA Semi-annual during coal or ash transport
ug/L - micrograms per liter NE - not established (monitor only) SA-QCA Semi-annual - Quarterly during coal or ash transport
ng/L - nanograms per liter PCB - polychlorinated biphenyls QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO13-12
o
..���\\
Qe�ded
'�°��\
�°��\
���\�o
P��o��
��e\�o
��d\�o
.���'\�
��\�o,�e
'�°'`�\
•\�o��\
��e\�o
\�o'`�\
��\�o�
���
Parameter
nd �•�
we
4e
Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
Fifteen 10"CM Ps to Catawba River
(Lake Wylie) - Draining soil borrow
area and gravel/dirt roadways.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
1H-2017
No Flow
No Flow
2H-2017
No Flow
No Flow
1H-2018
No Flow
No Flow
2H-2018
No Flow
No Flow
1H-2019
No Flow
No Flow
SU - standard units
mg/L - milligrams per liter
ug/L - micrograms per liter
ng/L - nanograms per liter
< - not detected at the following level
NA - not applicable
NE - not established (monitor only)
PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO13-13
o
..���\\
Qe�ded '�°��\
�°��\
���\�o
P��o��
��e\�o
��d\�o
.���'\�
��\�o,�e
'�°'`�\
•\�o��\
��e\�o
\�o'`�\
��\�o�
���
Parameter
o�
Q
oo�° �
0 '�,
�'`�
P
she
P
e��
0
ed�
L
r�°
L
o��
L
end
�,
�•�
ewe
r"�
e�
�`
Comments /Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
Fifteen 10"CM Ps to Catawba River
(Lake Wylie) - Draining soil borrow
area and gravel/dirt roadways.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
1H-2017
No Flow
No Flow
2H-2017
No Flow
No Flow
1H-2018
No Flow
No Flow
2H-2018
No Flow
No Flow
1H-2019
No Flow
No Flow
SU - standard units
mg/L - milligrams per liter
ug/L - micrograms per liter
ng/L - nanograms per liter
< - not detected at the following level
NA - not applicable
NE - not established (monitor only)
PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO13-14
o
o
��d\�o
.���'\�
��\�o,�e
'�°'`�\
•\�o��\
��e\�o
\�o'`�\
��\�o�
���
Parameter
Phe
Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
Fifteen 10"CMPs to Catawba River
(Lake Wylie) - Draining soil borrow
area and gravel/dirt roadways.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
1H-2017
No Flow
No Flow
2H-2017
No Flow
No Flow
1H-2018
No Flow
No Flow
2H-2018
No Flow
No Flow
1H-2019
No Flow
INo Flow
SU - standard units < - not detected at the following level SA - semi-annual
mg/L - milligrams per liter NA - not applicable SACA Semi-annual during coal or ash transport
ug/L - micrograms per liter NE - not established (monitor only) SA-QCA Semi-annual - Quarterly during coal or ash transport
ng/L - nanograms per liter PCB - polychlorinated biphenyls QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO13-15
�
'\°��\°��\�o
`�\
Parameter
Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
Fifteen 10"CMPs to Catawba River
(Lake Wylie) - Draining soil borrow area
and gravel/dirt roadways.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
1H-2017
No Flow
No Flow
2H-2017
No Flow
No Flow
1H-2018
No Flow
No Flow
2H-2018
No Flow
No Flow
1H-2019
No Flow
INo Flow
SU - standard units
mg/L - milligrams per liter
ug/L - micrograms per liter
ng/L - nanograms per liter
< - not detected at the following level
NA - not applicable
NE - not established (monitor only)
PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO15
o'`� � oono .�° �'`� she e�� ed� r�o o�� end �•� ewe ��e r"� e�
Parameter Q 0 '�, Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
36"RCP to Catawba River (Lake
Wylie) - Draining soil borrow area,
ash fill, and gravel/dirt roads.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
10/27/15
0.5
6.81
<5
0.572
0.014
<0.001
0.00759
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.0003
<0.0002
1.033
SWO15 REMOVED FROM PERMIT ON 9/9/2016 AS IT WILL BE INCLUDED IN THE WASTEWATER PERMIT
SWO15 RETURNED TO PERMIT ON 3/7/2019
1H-2019
No Flow
No Flow
SU - standard units < - not detected at the following level SA - semi-annual
mg/L - milligrams per liter NA - not applicable SACA Semi-annual during coal or ash transport
ug/L - micrograms per liter NE - not established (monitor only) SA-QCA Semi-annual - Quarterly during coal or ash transport
ng/L - nanograms per liter PCB - polychlorinated biphenyls QCA Quarterly during coal or ash transport

Allen Storm Water Outfall SWO16
` ` fo ` `\ he e,Parameter �\\ e� Comments Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
36"CMP to discharge canal to South Fork Catawba
River - Draining paved/gravel/dirt roads, and ash haul
road.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
Frequency
SA-QCA
QCA
SA-QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
QCA
Date
11/2/15
2.88
6.6
28
<0.05
0.022
<0.001
0.00153
<0.001
<0.001
0.00173
0.00368
<0.001
0.00154
<0.001
<0.0003
<0.0002
8.87
1/15/16
1.15
8.2
360
<0.05
0.091
<0.001
0.00782
<0.001
<0.001
0.0154
0.02140
0.00863
0.0112
0.00188
<0.0003
0.000226
17.7
5/17/16
0.77
7.0
240
<0.05
0.061
<0.001
0.00463
<0.001
<0.001
0.00946
0.01480
0.00489
0.0072
0.00127
<0.0003
<0.0002
8.2
6/15/2016
0.43
7.9
230
0.103
0.084
<0.001
0.0075
<0.001
<0.001
0.0083
0.0163
0.00423
0.00727
0.00348
<0.0003
0.00028
20.3
7/21/2016
0.24
1 7.0
1 48
1 0.139
1 0.049
1 <0.001
1 0.00636
<0.001
<0.001
1 0.00294
0.00768
1 0.0014
0.00244
0.00305
<0.0003
1 <0.0002
1 12.05
9/1/2016
1.25
1 8.1
1 100
1 <0.05
1 0.047
1 <0.005
1 0.00184
<0.001
<0.001
1 0.00403
0.00705
1 0.0029
0.00254
<0.005
<0.0003
1 <0.0002
13.5
2/1/2017
No sample collected at this outfall
during the month of
Feb. 2017. This outfall was not accessible to sample due to ongoing construction of permanent sampling
platforms.
3/1/2017
No sample collected at this outfall during the month of March 2017. This outfall was not accessible to sample due to ongoing construction of permanent sampling platforms.
4/3/2017
0.36
No sample collected at this outfall during the month of April 2017. This outfall was not accessible to sample due to ongoing construction of permanent sampling platforms.
12/20/2017
0.4
7.4
360
<0.05
0.161
<0.001
0.00256
<0.001
<0.001
0.0155
0.0223
0.00819
0.00977
<0.001
<0.0003
<0.0002
23.45avg
1/2018
No Flow
No Flow
2/2018
No Flow
No Flow
3/6/2018
0.51
8.9
1100
<0.05
0.200
<0.001
0.00661
<0.001
<0.001
0.0307
0.0564
0.0183
0.0240
0.00175
<0.0003
0.000457
70.8
4/23/2018
1.96
No sample collected at this outfall during the month of April 2018. This outfall was not accessible to sample due construction activity.
Not Accessible
5/2018
No Flow
No Flow
6/2018
No Flow
No Flow
7/2018
No Flow
No Flow
8/2018
No Flow
No Flow
9/2018
No Flow
No Flow
10/10/2018
0.80
7.9
86
<0.05
0.091
<0.001
0.00184
<0.001
<0.001
0.00324
0.00838
0.0162
0.00246
<0.001
<0.0002
<0.0002
10.5
11/2/2018
0.53
7.0
68
<0.05
0.252
<0.001
0.00113
<0.001
<0.001
0.00756
0.00949
0.00206
0.00326
<0.001
<0.0002
<0.0002
5.53
12/20/2018
1.49
5.9
<5
<0.05
0.145
<0.001
<0.001
<0.001
<0.001
0.00257
<0.001
<0.001
<0.001
<0.001
<0.0002
<0.0002
1.1
1/2019
No Flow
No Flow
2/2019
No Flow
No Flow
3/2019
No Flow
No Flow
4/2/2019
0.11
7.6
<5
<0.05
0.072
<0.001
<0.001
<0.001
<0.001
<0.001
0.00117
<0.001
<0.001
<0.001
<0.0002
<0.0002
<0.5
5/2018
No Flow
No Flow
6/7/2019
1.06
7.3
180
<0.05
0.350
<0.001
0.00330
<0.001
<0.001
0.00628
0.0102
0.00373
0.00392
<0.001
<0.0002
<0.0002
7.03
7/2019
No Flow
No Flow
8/2019
No Flow
No Flow
SU - standard units
mg/L - milligrams per liter
ug/L - micrograms per liter
ng/L - nanograms per liter
< - not detected at the following level
NA - not applicable
NE - not established (monitor only)
PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport
avg - average of primary and duplicate.

Allen Storm Water Outfall SWO18
�o
e�11
\�o�a°��\
�a �a c° ° �• 5e cJ c° QQ a� � �e� ,ec a��` eto 0'y 0'y 0,• 0'y 0'y 0'y 0'y �4}
Parameter �o �� �o �° '(>�` Qc� Qc 0e La Lr Oo �e �� Se �� �r �` QO QO QO QO QO QO QO O� Comments / Notes
Units
inches
SU
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ng/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
mg/L
48"CMP to discharge canal to South Fork Catawba
River - Draining paved roads, ash haul road, sluce
piping and switchyard.
Benchmark
NA
6.0-9.0
100
NE
0.126
0.09
0.34
0.065
0.003
0.9
0.010
0.075
0.335
0.056
0.0003
NE
NE
<-Detect->
15
Frequency
SA
SA
SA
SACA
SACA
SACA
SACA
SACA
SACA
SACA
SACA
SACA
SACA
SACA
SACA
SACA
SACA
SA
SA
SA
SA
SA
SA
SA
SA
Date
11/2/15
2.88
6.42
120
1 <0.05
0.0140
<0.001
<0.001
<0.001
<0.001
0.004341
0.00959
0.00191
0.0031
0.00184
<0.0003
<0.0002
11.85
<0.4
<0.4
<0.4
<0.4
<0.4
<0.4
<0.4
<4
1/15/16
1.15
7.87
830
<0.05
0.0740
<0.001
0.00165
<0.001
<0.001
0.0271
0.03380
0.00940
0.0156
<0.001
<0.0003
<0.0002
28.2
<0.4
<0.4
<0.4
<0.4
<0.4
<0.4
<0.4
6.3
5/17/16
0.77
6.78
170
<0.05
0.0230
<0.001
<0.001
<0.001
<0.001
0.00593
0.00807
0.00807
0.0027
<0.001
<0.0003
<0.0002
12.3
<0.4
<0.4
<0.4
<0.4
1 <0.4
<0.4
<0.4
<4
6/15/2016
0.43
7.35
63
<0.05
0.0110
<0.001
<0.001
<0.001
<0.001
0.00137
0.00925
<0.001
<0.001
<0.001
<0.0003
<0.0002
2.9
Not Collected
PCB & O&G not collected
9/1/2016
1.25
8.25
200
<0.05
0.0270
<0.005
<0.001
<0.001
<0.001
0.00982
0.0150
10.003811
0.0055
1 <0.005
<0.0003
<0.0002
16.6
<0.4
<0.4
<0.4
<0.4
1 <0.4
<0.4
<0.4
<4.8
2/1/2017
No sample collected from this outfall
during the month of February 2017 due to the river level being so high into the outfall pipe that any storm water effluent would be comingled with it.
Comingled
3/1/2017
No sample collected from this outfall during the month of March 2017 due to the river level being so high into the outfall pipe that any storm water effluent would be comingled with it.
Comingled
4/3/2017
0.36
1 7.18
1 29
1 <0.05
1 0.02
1 <0.001
I <0.001
I <0.001
I <0.001
10.00115
10.00233
1 <0.001
I <0.001
I <0.001
1 <0.0003
1<0.00021
2.56
Discontinued
<4
2H-2017
No Flow
No Flow
1/2018
No Flow
No Flow
2/2018
No Flow
No Flow
3/6/2018
0.51
8.26
1 110
1 <0.05
1 0.012
1 <0.001
I <0.001
I <0.001
I <0.001
0.00358
10.00648
10.001611
0.00206
1 <0.001
1 <0.0003
1<0.00021
6.83
1 Discontinued
<4.2
4/23/2018
1.96
No sample collected at this outfall during the month of April 2018. This outfall was not accessible to sample due construction activity.
Not Accessible
5/2018
No Flow
No Flow
6/2018
No Flow
No Flow
8/2018
No Flow
No Flow
9/2018
No Flow
No Flow
10/10/2018
0.80
8.1
280
<0.05
0.028
<0.001
<0.001
<0.001
<0.001
0.00500
0.0115
0.00217
0.00324
<0.001
<0.0002
<0.0002
7.67a g
Discontinued
<4.4
11/2/2018
0.53
7.5
<5
<0.05
<0.005
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.0002
<0.0002
0.938
Discontinued
<4.3
12/20/2018
1.49
7.4
<5
<0.05
<0.005
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.0002
<0.0002
1.31a g
Discontinued
<5.1
1/2019
No Flow
No Flow
2/2019
No Flow
No Flow
3/2019
No Flow
No Flow
4/2/2019
0.11
7.7
<5
<0.05
<0.005
<0.001
<0.001
<0.001
<0.001
<0.001
I <0.001
<0.001
I <0.001
<0.001
1 <0.0002
<0.0002 0.507a g
Discontinued
NRS
5/2019
No Flow
No Flow
6/7/2019
1.06
7.3
190
<0.05
0.017
<0.001
<0.001
<0.001
<0.001
0.00425
1 0.00784
0.00249
1 0.00228
<0.001
1 <0.0002
<0.0002
8.65a g
1 Discontinued
<5.0
7/2019
No Flow
No Flow
8/2019
No Flow
No Flow
SU - standard units < - not detected at the following level
mg/L - milligrams per liter NA - not applicable
ug/L - micrograms per liter NE - not established (monitor only)
ng/L - nanograms per liter PCB - polychlorinated biphenyls
SA - semi-annual
SACA Semi-annual during coal or ash transport
SA-QCA Semi-annual - Quarterly during coal or ash transport
QCA Quarterly during coal or ash transport

Parameter
Units
Benchmark
Frequency
Date
10/27/15
1/15/16
5/17/16
6/15/16
7/21/2016
9/1/2016
2/1/2017
3/1/2017
4/3/2017
1/11/2018
3/6/2018
4/23/18
5/2018
6/2018
7/2018
9/2018
10/10/18
11/2/18
12/20/18
1/2019
2/2019
3/2019
4/2019
5/2019
6/2019
7/2019
8/2019
Allen Storm Water Outfall SW020
inches
SU
NA
6.0-9.0
SA-QCA
QCA
5
�o
�o ties
mg/L
mg/L
mg/L
100
NE
0.126
SA-QCA
QCA
QCA
a�
'o
P�
mg/L
0.09
QCA
�0\
0
Pth 0
mg/L mg/L
0.34 0.065
QCA QCA
etJ
e\(J
�cc
mg/L mg/L
0.003 0.9
QCA QCA
a�
cc�
o Q
�o
mg/L
0.010
QCA
1�1
�01�
mg/L mg/L mg/L mg/L mg/L ng/L
Comments / Notes
0.075 1 0.335 0.056 0.0003 NE NE 48"CMP to discharge canal to South Fork Catawba River - Draining
QCA I QCA QCA QCA QCA QCA paved roads, gravel storage const. parking area.
0.5 150
1.15 8.09 230 <0.05 0.125 <0.001 <0.001 <0.001 <0.001 0.00648 0.0234 0.00254 0.00668 <0.001 <0.0003 <0.0002
0.77 6.76 42 <0.05 0.079 <0.001 <0.001 <0.001 <0.001 <0.001' 0.00478 <0.001 0.00135 <0.001 <0.0003 <0.0002
0.43 8.30 17 <0.05 0.139 <0.001 <0.001 <0.001 <0.001 <0.001 0.00847 <0.001 0.00244 <0.001 <0.0003 <0.0002
0.24 6.78 12 1 <0.05 1 0.162 1 <0.001 I <0.001 I <0.001 <0.001 I <0.001 1 0.00584 1 <0.001 0.00244 <0.001 1 <0.0003 1 <0.0002
1.25 8.36 630 1 <0.05 1 0.180 1 <0.005 1 <0.001 1 0.0011 1 <0.001 1 0.0131 1 0.0525 1 0.00646 0.0136 1 <0.005 1 <0.0003 11 <0.0002
No sample collected at this outfall during the month of February 2017. This outfall was not accessible to sample due to ongoing construction of permanent sampling platforms.
No sample collected at this outfall during the month of March 2017. This outfall was not accessible to sample due to ongoing construction of permanent sampling platforms.
0.36 1 No sample collected at this outfall during the month of April 2017. This outfall was not accessible to sample due to ongoing construction of permanent sampling platforms.
No Flow
0.51 8.46 1 470 <0.05 1 0.113 1 <0.001 1 0.00103 1 <0.001 I <0.001 1 0.0123 1 0.0275 1 0.00651 1 0.00841 1 <0.001 1 <0.0002 1 <0.0002
1.96 1 Not accessible due to construction activitv.
No Flow
No Flow
No Flow
No Flow
0.80 8.3 14 <0.05 0.044 <0.001 <0.001 <0.001 <0.001
0.53 7.8 360 <0.05 0.084 <0.001 <0.001 <0.001 <0.001
1.49 7.7 1 86 <0.05 0.037 <0.001 <0.001 <0.001 <0.001
No Flow
No Flow
No Flow
No Flow
No Flow
No Flow
No Flow
No Flow
12.5
4.4
7.7
11.9
18.4
19.9
<0.001
0.00401
<0.001
<0.001
<0.001
<0.0002
<0.0002
3.17
0.00695
0.0179
0.00373
0.00563
<0.001
<0.0002
<0.0002
11.0a�
0.00263
0.00778
0.00134
0.00193
<0.001
<0.0002
<0.0002
14.6
SU - standard units < - not detected at the following level SA - semi-annual
mg/L - milligrams per liter NA - not applicable SACA Semi-annual during coal or ash transport
ug/L - micrograms per liter NE - not established (monitor only) SA-QCA Semi-annual - Quarterly during coal or ash transport
ng/L - nanograms per liter PCB - polychlorinated biphenyls QCA Quarterly during coal or ash transport
Semi annual
Not Accessible
Not Accessible
Not Accessible
No Flow
Not Accessible
No Flow
No Flow
No Flow
No Flow
No Flow
No Flow
No Flow
No Flow
No Flow
No Flow
No Flow
No Flow

Duke Energy Allen Steam
Station I Renewal of
Individual NPDES
Stormwater Permit

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW001
11-7ardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring
Reports
Date:
Discharge
Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
11/2/2015
Medium Orange
None
4
1
3
None
None
Yes
2.88
1/15/2016
Brown/medium
tint
None
3
1
2
None
None
Yes
0.75
12/20/2017
Brownish Red
None
3
3
3
None
None
None
0.9
11/2/2018
Clear
None
1
1
1
None
None
None
0.53
12/14/2018
Clear
None
1
1
1
None
None
None
0.78
12/20/2018
Clear
None
1
1
1
None
None
None
1.49
1/2019
No Qualifying Event
2/2019
No Qualifying Event
2/12/2019
No Flow
0.51
3/2019
No Qualifying Event
4/5/2019
Orange
None
3
1
3
1 None
I None
None
0.92
5/2019
No Qualifying Event
6/2019
No Qualifying Event
7/2019
No Qualifying Event
8/2019
No Qualifying Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW001A
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
12/14/2018
No Flow
0.78
2/12/2019
No Flow
0.51
3/2019
No Qualifying Event
6/2019
No Qualifying Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SWO02
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge
Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
10/28/2015
Clear
None
1
1
1
None
None
None
1.3
1/15/2016
Lt. Brown
None
3
1
1
None
None
None
0.75
1/21/2017
Lt. Brown
None
2
1
1
None
None
None
0.8
12/14/2018
Clear
None
1
1
1
None
None
None
0.78
12/20/2018
Lt.
Orange
/Brown
None
2
1
2
None
None
None
1.49
2/12/2019
Clear
None
1
1
1
None
I None
None
0.51
3/2019
No Qualifying
Event
4/5/2019
Lt. Tan
None
2
1
2
None
I None
None
0.92
6/2019
No Qualifying Event
7/23/2019
Clear
None
1
1
1
None
I None
None
0.88
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SWO03
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge
Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
11/2/2015
SlightlyNone
Dingy
2
1
1
None
None
None
2.88
1/15/2016
Clear
None
1
1
1
None
None
None
0.75
12/14/2018
No Flow
0.78
12/20/2018
Med.
Orange /
Brown
None
3
1
2
None
None
None
1.49
2/12/2019
No Flow
0.51
3/2019
No Qualifing Event
4/5/2019
Lt.
Orange -
Tan
None
2
1
2
None
None
None
0.92
6/2019
No Qualifying Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW005
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge
Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
12/17/2015
Clear
None
2
1
1
None
None
None
1.25
1/21/2017
Clear
None
1
1
1
None
None
None
0.8
11/2/2018
Clear
None
1
1
1
None
None
None
0.53
2/12/2019
Clear
None
1
1
1
None
None
None
0.51
3/2019
No Qualifying
Event
4/5/2019
Clear -
White
None
1
1
2
None
None
None
0.92
6/2019
No Qualifying Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
,. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW007
G..,^ Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative
Monitoring Reports
Date:
Discharge Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
12/17/2015
Lt. Brown
None
3
1
1
None
None
None
1.25
1/21/2017
Lt. Brown
None
3
1
2
None
None
None
0.8
4/3/2017
Blue / Gray
None
4
1
3
None
None
None
0.65
12/20/2017
Gray
None
2
2
2
None
None
None
0.90
3/6/2018
Clear
None
1
1
1
None
None
None
0.51
4/23/2018
Lt. Tan Brown
None
2
2
1
None
None
None
1.96
1/21/2017
Light Brown
None
3
1
2
None
None
None
0.8
4/3/2017
Blue / Gray
None
4
1
3
None
None
None
0.65
12/20/2017
Gray
None
2
2
2
None
None
None
0.9
3/6/2018
Clear
None
1
1
1
None
None
None
0.51
4/23/2018
Lt. Tannish
Brown
None
2
2
1
None
None
None
1.96
10/10/2018
Milky White
None
2
1
1
None
None
None
0.8
11/2/2018
Clear
None
1
1
1
None
None
None
0.53
12/14/2018
Clear
None
2
1
1
None
None
None
0.78
12/20/2018
Milk TWhite /
an
None
3
1
2
None
None
I
None
1.49
1/2019
No Qualifying Event
2/12/2019
Clear None 2 1 1 1 None None None 0.51
3/2019
No Qualifying Event
4/5/2019
Clear -White
None
1
1
1.5
None
None
None
0.92
6/7/2019
Clear- White
None
1
1
1
None
None
None
1.06
7/2019
No Qualifying Event
8/2019
No Qualifying Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW008
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge
Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
10/27/2015
Lt. Tan
None
2
1
2
None
None
None
0.5
1/15/2016
Clear
None
1
1
1
None
None
None
0.75
12/14/2018
No Flow
0.78
2/12/2019
Clear
None
1
1
1
None
I None
None
0.51
3/2019
No Qualifying Event
4/5/2019
Lt. Tan
None
1
1
2
None
None
None
0.92
6/7/2019
Clear -
White
None
1
1
1
None
None
None
1.06
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
ENERGY:
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NC5000546
Phone Number: 704.829.2350
Outfall Number: SWO09
Ic � CaVdno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge
Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
10/27/2015
Clear
None
1
2
2
None
None
None
0.5
1/15/2016
Clear
None
1
1
1
None
None
None
0.75
1/21/2017
MediumNone
Brown
4
2
3
None
None
None
0.8
12/20/2017
Clear
None
1
1
1
None
None
None
0.9
3/6/2018
Clear
None
1
1
1
None
None
None
0.51
4/23/2018
Tan
None
2
4
2
None
None
None
1.96
11/2/2018
Lt. BrownNone
/ Gray
2
1
2
None
None
None
0.53
12/14/2018
Clear
None
1
1
1
None
None
None
0.78
12/20/2018
Lt.
Orange
None
2
1
1
None
None
None
1.49
1/2019
No Qualifying
Event
2/12/2019
Clear
None
1
1
2
1 None
I None
None
0.51
3/2019
No Qualifying
Event
4/5/2019
Lt. Tan
None
1
1
2
1 None
I None
None
0.92
5/2019
No Qualifying
Event
6/7/2019
Clear -
White
None
1
1
1
None
None
None
1.06
7/23/2019
Clear
None
1
1
1
None
None
None
0.88
8/2019
No Qualifying
Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW010
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge
Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
8/19/2015
Dingy
None
2
1
2
None
None
None
0.52
11/30/2015
1 Lt. Brown
None
3
1
3
None
None
None
1.79
12/20/2017
BrownishNone
Gray
2
2
2
None
None
None
0.90
4/23/2018
ReddishNone
Tan
2
1
2
None
None
None
1.96
10/10/2018
Clear
None
2
1
1
None
None
None
0.80
11/2/2018
Brown
None
3
2
3
None
None
None
0.53
12/14/2018
Lt. Tan
None
3
1
2
None
None
None
0.78
12/20/2018
Lt. Tan
None
2
1
1
None
None
None
1.49
1/2019
No Qualifying
Event
2/12/2019
Clear
None
1
1
1
None
I None
None
0.51
3/2019
No Qualifying Event
4/5/2019
Dk.
Brown
None
4
2
4
None
None
None
0.92
5/2019
No Qualifying Event
6/7/2019
Clear -
White
None
1
1
1
None
None
None
1.06
7/23/2019
Clear
None
1
1
1
None
None
None
0.88
8/2019
No Qualifying Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW0013-7
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
11/30/2015
No Flow
1.79
1/21/20171
Lt. Tan
None
3
1
2
None
None
None
1 0.8
12/14/2018
No Access
0.78
2/12/2019
No Flow
0.51
3/2019
No Qualifying Event
6/2019
No Qualifying Event
7/23/2019
Clear
None
1
1
1
None
I None
None
0.88
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW0013-8
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge
Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
11/30/2015
Clear
None
1
1
1
None
None
Yes
1.79
12/17/20151
Lt. Brown
None
3
1
2
None
None
Yes
1.25
12/14/2018
No Access
0.78
2/12/2019
No Flow
0.51
3/2019
No Qualifying Event
4/5/2019
Clear
None
1.5
1
1.5
None
I None
None
0.92
6/2019
No Qualifying Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW0013-9
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
11/30/2015
Clear
None
1
1
2
None
None
Yes
1.79
12/14/2018
No Access
0.78
2/12/2019
No Flow
0.51
3/2019
No Qualifying Event
6/2019
No Qualifying Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW0013-10
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge
Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
11/30/2015
Clear
None
1
1
1
None
None
Yes
0.78
12/17/2015
Brown
None
4
1
1
None
None
Yes
1.25
1/21/2017
Medium
Brown
None
3
1
2
None
I None
None
0.8
12/14/2018
No Access
0.78
2/12/2019
No Flow
0.51
3/2019
No Qualifing Event
4/5/2019
Lt.Yellowl
None
1 2
1 2
1 1.5
1 None
I None
I None
1 0.92
6/2019
No Qualifying Event
7/23/2019
Clear
None
1
1
1
None
I None
None
0.88
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW0013-11
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge
Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
11/30/2015
Clear
None
1
1
1
None
None
Yes
1.79
1/21/2017
Lt. Brown
None
2
1
2
None
None
None
0.8
12/14/2018
No Access
0.78
2/12/2019
No Flow
0.51
3/2019
No Qualifying Event
6/2019
No Qualifying Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW0013-12
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge
Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
11/30/2015
Clear
None
1
1
1
None
None
Yes
1.79
1/21/2017
Medium
Brown
None
3
1
3
None
None
None
0.8
12/14/2018
No Access
0.78
2/12/2019
No Flow
0.51
3/2019
No Qualifying Event
6/2019
No Qualifying Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW0013-13
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
1/21/2017
Medium
None
3
1
3
None
None
None
0.8
12/14/20181
No Access
1 0.78
3/2019
No Qualifying Event
6/2019
No Qualifying Event
7/23/2019
Clear
I None
1
1
1
None
I None
None
0.88
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW0013-14
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
11/30/2015
Clear
None
1
1
1
None
None
None
1.79
12/14/2018
No Access
0.78
2/12/2019
No Flow
0.51
3/2019
No Qualifying Event
6/2019
No Qualifying Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW0013-15
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
11/30/2015
No Flow
1.79
1/21/2017
Medium
Brown
None
3
1
3
None
None
None
0.8
12/14/2018
No Access
0.78
2/12/2019
No Flow
0.51
3/2019
No Qualifying Event
6/2019
No Qualifying Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW0015
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge
Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
9/25/15
Clear
None
1
1
1
None
None
None
0.5
10/27/15
Clear
None
1
1
1
None
None
None
0.5
3/2019
No Qualifying
Event
6/2019
No Qualifying Event
7/23/2019
Clear
None
1
1
1
None
I None
None
0.88
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
,. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SWO16
G..,'� Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Discharge
Assessment
Date:
Erosion / Deposition
Total Event Precipitation (in)
Floating
Suspended
Color
Odor
Clarity
Foam
Oil Sheen
Solids
Solids
Reddish
12/20/2017
None
4
3
3
None
None
None
0.9
Brown
Reddish
3/6/2018
None
5
1
5
None
None
None
0.51
Brown
10/10/2018
Orange
None
4
1
3
None
None
None
0.80
Brown
Lt.
11/2/2018
Orange
None
2
1
2
None
None
None
0.53
Brown
Orange
12/14/2018
None
5
1
3
None
None
None
0.78
Brown
Orange
12/20/2018
None
4
1
4
None
None
None
1.49
Brown
1/2019
No Qualifying
Event
2/12/2019
Clear None 2 1 2 None
I None None 0.51
3/2019
No Qualifying
Event
4/2/2019
Clear
None
1
1
1
None
None
None
0.11
OrangeNone
4/5/2019
4
1
4
None
None
None
0.92
Brown
5/2019
No Qualifying
Event
Cloeuddy,
6/7/2019
None
5
3
4
None
None
None
1.06
7/23/2019
Clear
None
1
1
1
None
I None
None
0.88
8/2019
No Qualifying
Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
,. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SWO18
G..,'� Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Discharge
Assessment
Date:
Erosion / Deposition
Total Event Precipitation (in)
Floating
Suspended
Color
Odor
Clarity
Foam
Oil Sheen
Solids
Solids
1/21/2017
Clear
None
1
1
1
None
None
None
0.8
ReddishNone
4/3/2017
2
1
2
None
None
None
0.65
Brown
ReddishNone
3/6/2018
4
1
4
None
None
None
0.51
Brown
Brown
10/10/2018
None
4
1
3
None
None
None
0.8
Redish
11/2/2018
Clear
None
1
1
1
None
None
None
0.53
Orange
12/14/2018
None
5
1
3
None
None
None
0.78
Brown
Lt.
12/20/2018
None
3
1
2
None
None
None
1.49
Orange
1/2019
No Qualifying
Event
V. Lt.
2/12/2019
None
2
1
2
None
None
None
0.51
Brown
3/2019
No Qualifying
Event
4/2/2019
Clear
None
1
1
1
None
None
None
0.11
Orange
4/5/2019
None
4
2
4
None
None
None
0.92
Tan
5/2019
No Qualifying
Event
Cloeuddy,
6/7/2019
None
5
4
2
None
None
None
1.06
7/23/2019
Clear
None
1
1
1
None
I None
None
0.88
8/2019
No Qualifying
Event
9/2019
No Qualifying Event
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

DUKE
. ENERGY
Facility Name: Allen Steam Station
County: Gaston
Site Contact: Randy Gantt
Individual NPDES Permit No. NCS000546
Phone Number: 704.829.2350
Outfall Number: SW020
Cardno
Summary of Stormwater Discharge Outfall (SDO) Qualitative Monitoring Reports
Date:
Discharge
Assessment
Erosion / Deposition
Total Event Precipitation (in)
Color
Odor
Clarity
Floating
Solids
Suspended
Solids
Foam
Oil Sheen
3/6/2018
Tan
None
2
1
2
None
None
None
0.51
10/10/20181
Clear
None
1
1
1
None
None
None
0.80
11/2/2018
Lt. Brown
None
4
2
3
None
None
None
0.53
12/14/2018
Clear
j None
j 1
j 1
j 1
i None
None
None
0.78
12/20/2018
Clear
None
2
1
1
None
None
None
1.49
1/2019
No Qualifying
Event
2/12/2019
Clear
None
1
1
1
None
I None
None
0.51
3/2019
No Qualifying Event
4/5/2019
Lt. Tan
None
1
1
2
None
I None
None
0.92
5/2019
No Qualifying Event
6/2019
No Qualifying Event
7/2019
No Qualifying Event
8/2019
No Qualifying Event
9/2019
No Qualifying Event
L
I
Notes: Value assessment of 1-5 for Clarity, Floating Solids and Suspended Solid. Values increasing upward by severity 1 = Best Case and 5 = Worst Case

Duke Energy Allen Steam
Station I Renewal of
Individual NPDES
Stormwater Permit

Best Management Practices
Allen Steam Station
October 28, 2019
:-ki

Best Management Practices
Allen Steam Station
Table of Contents
1 Best Management Practices Summary...........................................................................1
1.1
Coal Pile Management........................................................................................................ 1
1.2
Fugitive Dust Emissions...................................................................................................... 1
1.3
Fuel Oil Unloading / Chemical Loading and Unloading / Miscellaneous Loading and
Unloading............................................................................................................................ 1
1.4
Liquid Storage Tanks / Large Bulk Fuel Storage / Above Ground Tanks ........................... 2
1.5
Oil Bearing Equipment Switchyards.................................................................................... 2
1.6
Residue Hauling Vehicles / Ash Loading Areas.................................................................. 2
1.7
Vehicle and Equipment Maintenance..................................................................................2
1.8
Material Storage Areas........................................................................................................ 3
1.9
Fueling Operations.............................................................................................................. 3
Appendices
Appendix A— Industrial Stormwater Fact Sheet
Appendix B — Outfall Narrative Descriptions
October 2019 Cardno Table of Contents i
Allen Steam Station - BMP 20191028

Best Management Practices
Allen Steam Station
1 Best Management Practices Summary
A number of best management practices (BMPs) are currently in place at the station. These BMPs were
instituted over a number of years as a result of various regulatory drivers and good housekeeping
objectives. While a chosen practice provides some level of pollution prevention as it relates to the
management of stormwater discharges under this permit, the historic rationale behind implementing such
a practice is comprehensive of a number of contributing factors. The ongoing implementation of these
practices are part of the Stormwater Pollution Prevention Plan (SPPP). Table 2 from the Industrial
Stormwater Fact Sheet for Steam Electric Power Generating Facilities (EPA-833-F-06-030) was reviewed
and evaluated (provided in Appendix A) for planning of a BMP strategy. A high-level review of these
BMPs is provided below along with a rationale for implementing them. The detailed listing of these BMPs
for each drainage area is provided in the outfall descriptions (Appendix B) where information regarding
the industrial activities and significant sources of pollutants are also compiled. The compiled information
in the appendix captures an ongoing assessment process for BMP selection and implementation.
The Site Environmental Coordinator shall rely on Table 2 from EPA-833-F-06-030 for the improvement,
installation and implementation of BMPs to address data collected through monitoring of stormwater
discharges. The Site Environmental Coordinator may also rely on other sources of information to
implement other appropriate BMPs not listed in Table 2. This list of BMPs shall be reviewed and updated
annually as new practices are incorporated in the plan or warranted as a result of exceedances of
analytical monitoring benchmarks.
1.1 Coal Pile Management
Rainfall and upland stormwater may be contaminated as it is exposed to the coal pile if not managed
properly. The coal pile at the station is bermed on all sides limiting the potential for run-on and directing
coal pile runoff to the coal yard sump that are directed to the Lined Retention Basin.
1.2 Fugitive Dust Emissions
The potential for fugitive dust to move off -site or into drainage areas with no stormwater or sump controls
drives the need for emission management practices. The station maintains an air permit with NCDEQ that
includes the control of fugitive dust emissions as a programmatic requirement. Fugitive dust emissions
originating from a variety of sources are to be maintained to the Best Available Control Technology
emission limits for Particulate Matter with Nominal Aerodynamic Diameter of 10 Mircometers or Less
(PM10). Fugitive dust emissions are managed through a variety of practices including negative pressure
conditions during raw material unloading, watering of fine particulate materials prior to transport, periodic
wetting of haul roads, paving of heavily used gravel surfaces, tire and vehicle wash stations, and wetting
of placed landfill material. Contractors may be assigned at any time to perform services that generate
fugitive dust related to hauling or construction. As a result, fugitive dust control is typically a contractual
requirement of all contracted work.
1.3 Fuel Oil Unloading / Chemical Loading and Unloading / Miscellaneous
Loading and Unloading
The station maintains numerous locations for the loading and unloading of oil and non -oil liquids and
chemicals. The potential for spills and leaks to release to storm drains or overland drainage pathways to
receiving waters presents a source for an unauthorized discharge and contamination of stormwater
discharges. Loading/unloading operations follow typical spill prevention and control practices and adhere
to the Department of Transportation's unloading/loading procedures (49 CFR Part 177, Subpart B).
Additional BMPs include training, attendance of a qualified individual during transfer, use of tank level
indicators, maintenance of spill kit resources nearby, and the use of transfer containment devices. For
number of these transfers, an oil/water separator or yard drainage system with a sump is located down
gradient to capture spills and leaks for clean-up and prevent them from being discharged directly to
October 2019 Cardno Best Management Practices Summary 1
Allen Steam Station - BMP 20191028

Best Management Practices
Allen Steam Station
receiving waters. Operators make daily rounds to check containments and note on checklist housed in
SPCC plan. Accumulated stormwater is inspected before being discharged
1.4 Liquid Storage Tanks / Large Bulk Fuel Storage / Above Ground Tanks
The station maintains numerous storage tanks for oil and non -oil liquids and chemicals. The potential for
spills and leaks to release to storm drains or overland drainage pathways to receiving waters exists and
presents a source for an unauthorized discharge and contamination of stormwater discharges. The
station relies on a variety of practices to reduce exposure of leak and spills to stormwater discharges.
They include the use of valve controlled and secured secondary containment systems, secured
perimeters and barriers to prevent accidental damage and vandalism to tanks, level indicators and
gauges to detect leaks, lighting, routine disposal schedules, readily available spill kits and materials, and
active SPCC plan development, implementation, and training. For a number of these tanks, a yard
drainage system with a sump is located down gradient to capture spills and leaks for clean-up and
prevent them from being discharged directly to receiving waters. Operators make daily rounds to check
containments and note on checklist housed in SPCC plan. Accumulated stormwater is inspected before
being discharged
1.5 Oil Bearing Equipment Switchyards
There are two switchyards at the station near the powerhouse and numerous oil bearing equipment (e.g.,
transformers) located at various places throughout the station to support operations. The potential for
spills and leaks to release to storm drains or overland drainage pathways to receiving waters exists and
presents a source for an unauthorized discharge and contamination of stormwater discharges. The
station relies on the use of secondary containments around transformers and oil/water separators
downgradient of switchyards to intercept significant spills. These containments are inspected daily and
noted on checklist housed in SPCC plan. Accumulated stormwater is inspected before being discharged.
In addition, the switchyards are covered with gravel surfaces and lined with perimeter ditching to reduce
the conveyance of spills and provide for areas of collection. Both switchyards are located within yard
drainage areas with sumps that discharge ultimately to the Lined Retention Basin.
1.6 Residue Hauling Vehicles / Ash Loading Areas
Fly ash stored in covered silos is loaded into dump trucks and transported to the lined CCP landfill.
Gypsum is loaded into dump trucks and transported off -site. Dry bottom ash is moved by a submerged
conveyor system from the boilers to the Dry Bottom Ash Handling Area where it is processed and
transported by dump trucks to the lined CCP landfill. CCR materials have the potential to spill from trucks
or be carried away as dust, thereby contaminating surfaces that may be later exposed to stormwater
runoff. The materials are wetted prior to loading to prevent dust emissions and truck coverings are used
for hauling off -site where material may dry in transit. Loading areas are regularly washed down with wash
water and drained to a settling basin prior to discharging through the sump system and ultimately to the
Lined Retention Basin. The discharges from these loading areas are located within the yard drainage
system that convey runoff and wash water to the Lined Retention Basin. This keeps loading areas free
from dust generation. Truck wheel wash stations are located in loading and unloading areas and used to
limit the transport of residue to haul roads.
1.7 Vehicle and Equipment Maintenance
Vehicles and equipment have the potential to leak or spill significant quantities of fuel, hydraulic fluids,
and oils if not properly maintained and operated. There is potential for unauthorized discharges as the
vehicles and equipment operate near storm drains. Maintenance is performed on a routine basis to keep
vehicles and equipment operational, thereby reducing the potential for spills and leaks from mechanical
failure. To the extent practicable, maintenance is performed off -site at commercial facilities that are
subject to local laws and regulations regarding the disposal of used materials. When maintenance must
be performed on -site, it is performed under cover and with temporary containment devices used to
capture emptying of fluids. Used materials and parts are labeled and properly disposed of in original
containers or secured packaging. Where spills or leaks do occur, spill kits are readily available for use.
October 2019 Cardno Best Management Practices Summary 2
Allen Steam Station - BMP 20191028

Best Management Practices
Allen Steam Station
Operators make daily rounds to check containments and note on checklist housed in SPCC plan.
Accumulated stormwater is inspected before being discharged
1.8 Material Storage Areas
Limestone, coal, fly ash, and gypsum are the bulk materials stored at the station. Exposure of the
materials to rainfall and stormwater run-on has the potential to contaminate stormwater runoff. All
materials except fly ash are stored outdoors in piles that are bermed to prevent run-on or contained to
drain to detention basins and/or sumps and subsequently to the Lined Retention Basin.
1.9 Fueling Operations
Fueling is performed in two distinct ways that has the potential to contribute to significant quantities of
pollutants. Lighter, all purpose vehicles and equipment such as cars and trucks are fueled from a
stationary dispenser while heavier, dedicated equipment, such as earth moving equipment, are fueled by
mobile dispensers in the areas where they are used. The potential for spills and leaks to release to storm
drains or overland drainage pathways to receiving waters presents a source for an unauthorized
discharge and contamination of stormwater discharges. For the stationary fueling operations, the
dispensary equipment is checked regularly for leaks and functional operation. Spill kits are located nearby
for minor spills and leaks during fueling.
Mobile fueling operations are handled in the same way, but typically a temporary containment is set up to
capture leaks and spills. Operators make daily rounds to check containments and note on checklist
housed in SPCC plan. Accumulated stormwater is inspected before being discharged. Mobile fueling
operations are mostly performed in areas with yard drainage and sumps or leachate collection systems so
ultimately they discharge to the Lined Retention Basin.
October 2019 Cardno Best Management Practices Summary 3
Allen Steam Station - BMP 20191028

Duke Energy Allen Steam
Station I Best Management
Practices

Industrial Stormwater Fact Sheet Series
SectorO: Steam Electric Power Generating Facilities,
Including Coal HandlingAreas
Table 2. BMPs for Potential Pollutant Sources at Steam Electric Generating Facilities, including Coal
Handling Areas
Pollutant Source
BMPs
Coal pile
❑ Confine storage to areas outside of drainage pathways and away from surface waters.
management
❑ Divert stormwater around storage areas with vegetated swales, and/or berms.
❑ Practicegood housekeeping measuressuch as frequent removal of dustand debris. Cleanup
methods may include mobile sweepers, scrapers, or scoops.
❑ Use properly designed basins for collection, containment, and recycling of pile spraying
materials.
❑ Use control measures such as berms, siltfences orwaddles to control sedimentfrom leaving
storage area.
❑ Train employees in good housekeeping measures
Fugitive dust
❑ Establish procedures to minimize off -site tracking of coal dust.
emissions
❑ Use specially designed tires.
❑ Wash vehicles before they leave the site in a designated area where wash water can be
controlled.
Delivery vehicles
❑ Develop procedure forthe inspection of all vehicles arriving on the plantsite and ensure overall
integrity of the body or container.
❑ Control leakage or spillage from vehicles orcontainers and ensure that proper protective
measurement.
Fuel oil unloading
❑ Confine loading/unloading activities to designated areasoutside drainage pathways and away
areas
from surface waters.
❑ Provide diversion berms, dikes orgrassed swales around the perimeterof the area to limit
run-on.
❑ Use containment curbs in unloading areas.
❑ Use spill and overflow protection (drip pans, drip diapers, etc.) beneath fuel oil connectors.
❑ For rail transfer, a drip pan shall be installed within the rails to collect spillage from the tank.
❑ Develop and implement spill prevention, containment, and countermeasure (SPCC) plans.
❑ Train employees in spill prevention, control and cleanup.
❑ Personnel familiarwith spill prevention and response procedures should be presentduring
unloading to ensure that any leaks or spills are immediately contained and cleaned up.
Chemical loading/
❑ Cover chemical loading/unloading areas and store chemicals indoors, when possible.
unloading areas
❑ Provide diversion berms, dikes or grassed swales around the perimeter of the area to limit
run-on.
❑ Use containment curbs at chemical loading/unloading areas.
❑ Develop and implement spill prevention, containment, and countermeasure (SPCC) plans.
❑ Train employees in spill prevention, control and cleanup.
❑ Personnel familiarwith spill prevention and response procedures should be presentduring
unloading to ensure that any leaks or spills are immediately contained and cleaned up.
Miscellaneous
❑ Confine loading/unloading activities to designated areas outside drainage pathways and away
loading/unloading
from surface waters.
❑ Inspect containers for leaks or damage prior to loading/unloading.
❑ Avoid loading/unloading materials in the rain or provide cover or other protection for loading
docks.
EPA-833-F-06-030

Industrial Stormwater Fact Sheet Series
Sector0: Steam Electric Power Generating Facilities,
Including Coal HandlingAreas
Table 2. BMPs for Potential Pollutant Sources at Steam Electric Generating Facilities, including Coal
Handling Areas (continued)
Pollutant Source
BMPs
Miscellaneous
❑ Provide diversion berms, dikes orgrassed swales around the perimeterof the area to limit
loading/unloading
run-on.
(continued)
❑ Cover loading and unloading areas and perform these activities on an impervious pad to enable
easy collection of spilled materials.
❑ Slope the impervious concrete floor or pad to collect spills and leaks and convey them to proper
containment and treatment.
❑ Regularly sweep area to minimize debris on the ground.
Liquid storage tanks
❑ Cover and/or enclose chemical storage areas (including temporary cover such as a tarp that
prevents contactwith precipitation). Provide secondarycontainmentaround chemical storage
areas.
❑ If containment structures have drains, ensure that the drains have valves, and thatvalves
are maintained in the closed position. Institute protocols for checking/testing stormwater in
containment areas prior to discharge.
❑ Use double -walled tanks with overflow protection.
❑ Locate storage areas away from high traffic areas and surfacewaters.
❑ Inspect storage tanks and piping systems (pipes, pumps, flanges, couplings, hoses, and valves)
for failures or leaks and perform preventive maintenance.
❑ Maintain an inventory of fluids to identify leakage.
❑ Provide fluid level indicators.
❑ Properly dispose of chemicals that are no longer in use.
❑ Store and handle reactive, ignitable, orflammable liquids in compliance with applicable local
fire codes, local zoning codes, and the National Electric Code.
❑ Provide drip pads/pans where chemicals are transferred from one container to another to allow
for recycling of spills and leaks.
❑ Use dry cleanup methods.
❑ Develop and implementspill plans orspill prevention, containment, and countermeasure
(SPCC) plans, if required for your facility.
❑ Train employees in spill prevention and control and proper materials management.
Large bulk fuel
❑ If area is uncovered, connectsump outlet to sanitary sewer (if possible) or an oil/water
storage
separator, catch basin filter, etc. If connecting to a sanitary sewer check with the system
operator to ensure that the discharge is acceptable. If implementing separator or filter
technologies ensure that regular inspections and maintenance procedures are in place.
Aboveground tanks
❑ Provide secondary containment, such as dikes, with a height sufficient to contain a spill
(the greater of 10 percent of the total enclosed tank volume or 110 percent of the volume
contained in the largest tank).
❑ If containment structures have drains, ensure that the drains have valves, and thatvalves
are maintained in the closed position. Institute protocols for checking/testing stormwater in
containment areas prior to discharge.
❑ Use double -walled tanks with overflow protection.
❑ Keep liquid transfer nozzles/hoses in secondary containment area.
❑ Develop and implementspill plans orspill prevention, containment, and countermeasure
(SPCC) plans, if required for your facility.
❑ Train employees in spill prevention and control.
EPA-833-F-06-030

Industrial Stormwater Fact Sheet Series
Sector0: Steam Electric Power Generating Facilities,
Including Coal HandlingAreas
Table 2. BMPs for Potential Pollutant Sources at Steam Electric Generating Facilities, including Coal
Handling Areas (continued)
Pollutant Source
BMPs
Oil bearing
❑ Construct level grades and gravel surfaces to retard flows and limit the spread of spills.
equipment
switchyards
❑ Collect stormwater runoff in perimeter ditches.
Residue hauling
❑ Inspect all residue hauling vehicles for proper covering over the load, adequate gate sealing,
vehicles
and overall integrity of the body or container.
❑ Repair vehicles lacking in the above qualities.
Ash loading areas
❑ Clear the ash building floor and immediately adjacent roadways of spillage, debris, and excess
water before each loaded vehicle departs
Vehicle and
Good Housekeeping
equipment
maintenance
❑ Eliminate floor drains that are connected to the storm or sanitary sewer; if necessary, install a
sump that is pumped regularly. Collected wastes should be properly treated or disposed of by a
licensed waste hauler.
❑ Do all cleaning at a centralized station so the solvents stay in one area.
❑ If parts are dipped in liquid, remove them slowly to avoid spills.
❑ Use drip pans, drain boards, and drying racks to direct drips back into a fluid holding tank for
reuse.
❑ Drain all parts of fluids prior to disposal. Oil filters can be crushed and recycled.
❑ Promptly transfer used fluids to the proper container; do not leave full drip pans or other open
containers around the shop. Empty and clean drip pans and containers.
❑ Clean up leaks, drips, and other spills without using large amounts of water. Use absorbents
for dry cleanup whenever possible.
❑ Prohibit the practice of hosing down an area where the practice would result in the discharge
of pollutants to a stormwater system.
❑ Do not pour liquid waste into floor drains, sinks, outdoor storm drain inlets, or other storm
drains or sewer connections.
❑ Maintain an organized inventory of materials.
❑ Eliminate or reduce the number and amount of hazardous materials and waste by substituting
nonhazardous or less hazardous materials.
❑ Label and track the recycling of waste material (e.g., used oil, spent solvents, batteries).
❑ Store batteries and other significant materials inside.
❑ Dispose of greasy rags, oil filters, airfilters, batteries, spentcoolant, and degreasers in
compliance with RCRA regulations.
Minimizing Exposure
❑ Perform all cleaning operations indoors or under covering when possible. Conduct the cleaning
operations in an area with a concrete floor with no floor drainage other than to sanitary sewers
or treatment facilities.
❑ If operations are uncovered, perform them on a concrete pad that is impervious and contained.
❑ Park vehicles and equipment indoors or under a roof whenever possible and maintain proper
control of oil leaks/spills.
❑ Check vehicles closely for leaks and use pans to collect fluid when leaks occur.
EPA-833-F-06-030

Industrial Stormwater Fact Sheet Series
Sector0: Steam Electric Power Generating Facilities,
Including Coal HandlingAreas
Table 2. BMPs for Potential Pollutant Sources at Steam Electric Generating Facilities, including Coal
Handling Areas (continued)
Pollutant Source
BMPs
Vehicle and
Management of Runoff
equipment
maintenance
❑
Use berms, curbs, orgrassed swales other diversion measures to ensure thatstormwater runoff
(continued)
from other parts of the facility does not flow over the maintenance area.
❑
Collect the stormwater runoff from the cleaning area and provide treatment or recycling.
❑
Discharge vehicle wash or rinse water to the sanitary sewer (if allowed by sewer authority),
wastewater treatment, a land application site, or recycle on -site. DO NOT discharge washwater
to a storm drain or to surface water.
Inspections and Training
❑
Inspect the maintenance area regularly to ensure BMPs are implemented.
❑
Train employees on waste control and disposal procedures.
Material storage
❑
Store materials indoors.
areas
❑
Cover material with a temporary covering made of polyethylene, polyurethane, polypropylene,
or Hypalon°.
❑
Provide diversion berms, dikes orgrassed swales around the perimeterofthe area to limit
run-on.
❑
Constructan enclosure or build a berm around the area.
❑
Regularlysweep area to minimize debris on theground.
❑
Train employees in spill prevention, control, cleanup and proper materials management
techniques.
Fueling operations
❑
Conduct fueling operations (including the transfer of fuel from tank trucks) on an impervious
or contained pad or under a roof or canopy where possible. Covering should extend beyond
spill containment pad to prevent rain from entering.
❑
When fueling in uncovered area, use a concrete pad (not asphalt, which is not chemically
resistant to the fuels being handled).
❑
Use drip pans where leaks or spills of fuel can occur and where making and breaking hose
connections.
❑
Use fueling hoses with check valves to prevent hose drainage afterfilling.
❑
Keep spill cleanup materials readily available.
❑
Clean up spills and leaks immediately.
❑
Minimize/eliminate run-on onto fueling areas with diversion dikes, berms, curbing, surface
grading or other equivalent measures.
❑
Collect stormwater runoff and provide treatment or recycling.
❑
Provide curbing or posts around fuel pumps to prevent collisions from vehicles.
❑
Use dry cleanup methods for fuel area rather than hosing the fuel area down.
❑
Perform preventive maintenance on storage tanks to detect potential leaks before they occur.
❑
Inspect the fueling area to detect problems before they occur.
❑
Discourage "topping off" of fuel tanks.
❑
Train personnel on vehicle fueling BMPs.
EPA-833-F-06-030

Duke Energy Allen Steam
Station I Best Management
Practices

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW001
Drainage Area
6 acres
Discharge Structure
12-inch-diameter CMP
Percent Impervious
0%
Location
North of Station Intake
Permit Monitoring
1
Table
Latitude - Longitude
35°11'47"N - 81 °00'33"W
Industrial Activities and
The drainage area for SW001 includes approximately 2,000 linear feet of rail
Description
lines, the sloped embank of the lined retention basin, and undeveloped
woodland. This drainage area also includes approximately 345 feet of gravel
road. There are no impervious surfaces in Drainage Area 1. Stormwater
runoff from a strip of wooded area east of the rail lines occurs as sheet flow
to the river. This drainage area is also drained by SW001A.
Significant
Coal and Limestone: Rail cars carrying coal and limestone use the rail lines
Materials/Potential
that pass through this drainage area.
Pollutants
BMP Summary
Fugitive Dust Emissions
• Establish procedures to minimize off -site tracking of coal dust.
Delivery Vehicles
• Develop procedure for the inspection of all vehicles arriving on the
plant site and ensure overall integrity of the body or container.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall I D
SW001 A
Drainage Area
6 acres
Discharge Structure
12-inch-diameter CIP
Percent Impervious
0%
Location
North of Station Intake
Permit Monitoring
1
Table
Latitude - Longitude
35°11'47"N - 81 °00'33"W
Industrial Activities and
The drainage area for SW001A includes approximately 2,000 linear feet of rail
Description
lines and the sloped embank of the lined retention basin upland of the railroad
tracks. This drainage area also includes approximately 345 feet of gravel
road. There are no impervious surfaces in Drainage Area 1. Stormwater
runoff from a strip of wooded area east of the rail lines occurs as sheet flow to
the river. This drainage area is also drained by SW001.
Significant
Coal and Limestone: Rail cars carrying coal and limestone use the rail lines
Materials/Potential
that pass through this drainage area.
Pollutants
BMP Summary
Fugitive Dust Emissions
• Establish procedures to minimize off -site tracking of coal dust.
Delivery Vehicles
• Develop procedure for the inspection of all vehicles arriving on the
plant site and ensure overall integrity of the body or container.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part 11, Section A, 1.(b)) and BMP Summary (Part 11, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW002
Drainage Area
10.8 acres
Discharge Structure
24-inch-diameter CMP
Percent Impervious
2%
Location
North of Station Intake
Permit Monitoring
1
Table
Latitude - Longitude
35°11'42"N - 81 °00'31 "W
Industrial Activities and
The drainage area for SW002 is comprised of primarily upland wooded areas
Description
west of the rail lines. The drainage area also includes a 2.5-acre graveled
FGD facility construction Iaydown yard, the south embankment of the lined
retention basin and approximately 1,000 feet of paved road. A stormwater
detention basin is present immediately down -gradient of the gravel Iaydown
yard.
Significant
Inert Materials: Various quantities of structural steel, cable, truck
Materials/Potential
trailers, and other inert materials may be stored on the
Pollutants
gravel yard area at various times.
BMP Summary
Materials Storage Areas
• Cover material with a temporary covering made of water resistant
material
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW003
Drainage Area
0.8 acre
Discharge Structure
18-inch-diameter HDPE
Percent Impervious
0%
Pipe
Location
North of Station Intake
Permit Monitoring
1
Table
Latitude - Longitude
35°11'42"N - 81 °00'31 "W
Industrial Activities and
The drainage area for SW003 is comprised entirely of a small flat area that
Description
includes approximately 1,500 linear feet of rail lines.
Significant
Coal and Limestone: Train cars carrying coal and limestone use the rail
Materials/Potential
lines that pass through this drainage area.
Pollutants
BMP Summary
Fugitive Dust Emissions
• Establish procedures to minimize off -site tracking of coal dust.
Delivery Vehicles
• Develop procedure for the inspection of all vehicles arriving on the
plant site and ensure overall integrity of the body or container.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW004
Drainage Area
1.3 acres
Discharge Structure
10-inch-diameter CIP
Percent Impervious
0%
Location
North of Station Intake
Permit Monitoring
None
Table
Latitude - Longitude
35°11'39"N - 81 °00'28"W
Industrial Activities and
The drainage area for SW004 is located east of the rail lines and north of the
Description
limestone unloading area, and is comprised of a small, flat, graveled area with
a vegetated berm forming the northeastern boundary.
Significant
None.
Materials/Potential
Pollutants
BMP Summary
Delivery Vehicles
• Develop procedure for the inspection of all vehicles arriving on the
plant site and ensure overall integrity of the body or container.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW005
Drainage Area
4.5 acres
Discharge Structure
12-inch-diameter CMP
Percent Impervious
2%
Location
Located north end of
Permit Monitoring
1
Iaydown area north of
Table
limestone storage near
Latitude - Longitude
35°11'38"N - 81 °00'28"W
Industrial Activities and
Drainage Area 5 is primarily comprised of a gravel Iaydown yard and
Description
vegetated slopes located west and upland of the limestone unloading area.
The gravel Iaydown yard comprises approximately 3 acres. The drainage area
also includes approximately 500 linear feet of paved roadway.
Significant
Inert Materials: Various quantities of structural steel, cable, truck
Materials/Potential
trailers, and other inert materials may be stored on the
Pollutants
gravel Iaydown yard area at various times.
BMP Summary
Materials Storage Areas
• Cover material with a temporary covering made of water resistant
material
Delivery Vehicles
• Develop procedure for the inspection of all vehicles arriving on the
plant site and ensure overall integrity of the body or container.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW006
Drainage Area
0.9 acre
Discharge Structure
10-inch-diameter CIP
Percent Impervious
0%
Location
North of Station Intake
Permit Monitoring
None
Table
Latitude - Longitude
35°11'37"N - 81 °00'27"W
Industrial Activities and
The drainage area for SW006 is comprised entirely of a small flat graveled
Description
area east of the limestone unloading area.
Significant
None
Materials/Potential
Pollutants
BMP Summary
Delivery Vehicles
• Develop procedure for the inspection of all vehicles arriving on the
plant site and ensure overall integrity of the body or container.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW007
Drainage Area
5 acres
Discharge Structure
18-inch-diameter CMP
Percent Impervious
2%
Location
Located near limestone
Permit Monitoring
1
storage area sump
Table
Latitude - Longitude
35°11'33"N - 81 °00'26"W
Industrial Activities and
The drainage area for SW007 is comprised of the vegetated embankment
Description
slope east of the FGD facility, rail lines, and graveled yard areas adjacent to
and extending south from the limestone unloading building. The drainage area
includes approximately 1,500 linear feet of rail lines, 400 linear feet of gravel
roadway, and 400 linear feet of limestone conveyor.
Significant
Coal and Limestone: Train cars carrying coal and limestone use the rail
Materials/Potential
lines that pass through this drainage area. Limestone
Pollutants
is transferred via conveyor through the area from the
limestone unloading building to the limestone
stockpile area.
BMP Summary
Fugitive Dust Emissions
• Establish procedures to minimize off -site tracking of dust.
Delivery Vehicles
• Develop procedure for the inspection of all vehicles arriving on the
plant site and ensure overall integrity of the body or container.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW008
Drainage Area
4.1 acres
Discharge Structure
24-inch-diameter CMP
Percent Impervious
6%
Location
Located north of station's
Permit Monitoring
1
powerhouse
Table
Latitude - Longitude
35°11'30"N - 81 °00'26"W
Industrial Activities and
The drainage area for SW008 is comprised primarily of rail lines and a gravel
Description
storage yard located south of the limestone stockpile area and south of the
North Warehouse. The area contains approximately 2,400 linear feet of rail
lines, approximately 1,000 linear feet of paved roadway and approximately
400 linear feet of limestone conveyor. Drainage Area 8 also includes a small
portion of the vegetated embankment slope east of the FGD facility.
Significant
Coal and Limestone: Train cars carrying coal and limestone use the rail
Materials/Potential
lines that pass through this drainage area.
Pollutants
Inert Materials: Various quantities of structural steel, cable, spare
equipment, and other inert materials may be stored on
the gravel storage yard area at various times.
BMP Summary
Fugitive Dust Emissions
• Establish procedures to minimize off -site tracking of coal dust.
Delivery Vehicles
• Develop procedure for the inspection of all vehicles arriving on the
plant site and ensure overall integrity of the body or container.
Materials Storage Areas
• Cover material with a temporary covering made of water resistant
material
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW009
Drainage Area
0.6 acre
Discharge Structure
3-foot-wide concrete ditch
Percent Impervious
0%
Location
Located north of station's
Permit Monitoring
1
intake structure.
Table
Latitude - Longitude
35°11'26"N - 81 °00'28"W
Industrial Activities and
The drainage area for SW009 is comprised of rail lines immediately east of the
Description
Powerhouse and a grassed embankment located between the rail lines and
the intake structure. The area contains approximately 940 linear feet of rail
lines. The station debris and clam filter is located within this drainage area.
The backwash from this filter is designed to discharge through a pipe directly
to the Catawba River (Lake Wylie). Occasionally the filter backwash will
overflow and flow overland to a discharge point near the SW009 ditch outlet
point; however, the overflow does not co -mingle with the SW009 stormwater
discharge.
Significant
Coal and Limestone: Train cars carrying coal and limestone use the rail
Materials/Potential
lines that pass through drainage area 9.
Pollutants
BMP Summary
Fugitive Dust Emissions
• Establish procedures to minimize off -site tracking of coal dust.
Delivery Vehicles
• Develop procedure for the inspection of all vehicles arriving on the
plant site and ensure overall integrity of the body or container.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW010
Drainage Area
0.7 acre
Discharge Structure
12-inch-diameter CMP
Percent Impervious
0%
Location
Located south of station's
Permit Monitoring
1
intake structure
Table
Latitude - Longitude
35°11'23"N - 81 °00'27"W
Industrial Activities and
The drainage area for SW010 is comprised of rail lines immediately east of the
Description
Powerhouse and a grassed embankment located between the rail lines and
the intake structure. The area contains approximately 1,280 linear feet of rail
lines.
Significant
Coal and Limestone: Train cars carrying coal and limestone use the rail
Materials/Potential
lines that pass through this drainage area.
Pollutants
BMP Summary
Fugitive Dust Emissions
• Establish procedures to minimize off -site tracking of coal dust.
Delivery Vehicles
• Develop procedure for the inspection of all vehicles arriving on the
plant site and ensure overall integrity of the body or container.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW013
Drainage Area
3.9 acres
Discharge Structure
Nine 10-inch-diameter
Percent Impervious
0%
CMPs
Location
Located every 200' along
Permit Monitoring
1
the retired railroad tracks
Table
and gravel road,
Latitude - Longitude
35°10'55"N - 81 °00'43"W
Industrial Activities and
The drainage area for Outfall Group SW013 is comprised of a narrow strip of
Description
land along the Catawba River south of the coal yard, between the ash landfill
and the river. The drainage area is approximately 2,400 feet long and includes
approximately 2,400 linear feet of gravel road and approximately 7,500 linear
feet of rail lines. The group contains nine outfalls spaced approximately 200
feet apart that drain the rail lines and the eastern vegetated slopes of the ash
landfill. These outfalls are located every 200 feet along the railroad tracks in
front of the coal combustion products (CCP) landfill. The outfalls discharge
onto the heavily wooded bank along the rivers edge. One outfall is identified
as accessible and recommended for sampling.
Significant
Coal and Limestone: Train cars carrying coal and limestone use the rail
Materials/Potential
lines that pass through this drainage area.
Pollutants
BMP Summary
Fugitive Dust Emissions
• Establish procedures to minimize off -site tracking of coal dust.
Delivery Vehicles
• Develop procedure for the inspection of all vehicles arriving on the
plant site and ensure overall integrity of the body or container.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW015
Drainage Area
170 acres
Discharge Structure
36-inch-diameter Reinforced
Percent Impervious
0%
Concrete Pipe (RCP)
Location
Located at the retired ash
Permit Monitoring
1
basin
Table
Latitude - Longitude
35°10'52"N - 81 °00'21 "W
Industrial Activities and
The drainage area for SW015 encompasses a large area west of the ash
Description
landfill site. The area includes a large soil borrow area; two ash structural fill
areas; the eastern, western, and southern vegetated embankments of the ash
landfill; and approximately 1 mile of gravel and dirt roads. Approximately 2,000
linear feet of gravel road within the drainage area is used by ash haul trucks to
transport ash from the dry ash handling facility to the ash landfill.
All stormwater runoff from the SW015 drainage area is collected within an
elongated detention pond system located along the southern boundary of the
ash landfill. Collected stormwater discharges through a riser/skimmer system
to the Catawba River beneath the rail lines to the east and through the
drainage area of the SW013 group.
Significant
Ash: Fly ash is transported in ash haul trucks that pass through the
Materials/Potential
area from the dry ash handling facility.
Pollutants
BMP Summary
Fugitive Dust Emissions
• Establish procedures to minimize off -site tracking of fly ash,
such vehicle washing or automated wash stations.
Residue Hauling Vehicles
• Inspect all residue hauling vehicles for proper covering over the load,
adequate gate sealing, and overall integrity of the body orcontainer.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW016
Drainage Area
21.8 acres
Discharge Structure
36-inch-diameter CMP
Percent Impervious
2%
Location
Located at the discharge
Permit Monitoring
1
canal on south bank
Table
Latitude - Longitude
35°11'22"N - 81 °00'44"W
Industrial Activities and
The drainage area for SW016 encompasses primarily vegetated upland areas
Description
along the site access road south of the discharge canal. The drainage area
includes approximately 1,700 feet of the site paved access road, and
approximately 1,000 linear feet of the paved ash haul road. Ash haul trucks
use the ash haul road to transport ash from the dry ash handling facility to the
ash landfill. The drainage area also includes an additional 700 linear feet of
paved road south of the access road, approximately 1,000 linear feet of dirt
roads north of the access road, and a gravel -surfaced Iaydown and equipment
parking area north of the access road.
Significant
Ash: Fly ash is transported in ash haul trucks that use the ash haul road.
Materials/Potential
Pollutants
Inert Materials: Various quantities of structural steel, cable, truck
trailers, and other inert materials may be stored on the
gravel Iaydown yard area at various times.
BMP Summary
Fugitive Dust Emissions
• Establish procedures to minimize off -site tracking of fly ash,
such vehicle washing or automated wash stations.
Residue Hauling Vehicles
• Inspect all residue hauling vehicles for proper covering over the load,
adequate gate sealing, and overall integrity of the body orcontainer.
Materials Storage Areas
• Cover material with a temporary covering made of water resistant
material
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW017
Drainage Area
35.1 acres
Discharge Structure
Numerous 12-inch-
Percent Impervious
0%
diameter CMPs
Location
Located at the discharge
Permit Monitoring
None
canal on either bank
Table
Latitude - Longitude
35°11'24"N - 81 °00'48"W
Industrial Activities and
The Outfall Group SW017 drainage area is comprised of a narrow strip of land
Description
on both side of the plant discharge canal. The drainage area includes gravel
access roads that run along both sides of the entire length of the canal. The
numerous SW017 stormwater outlets are spaced approximately 170 feet apart
along both sides of the discharge canal and direct runoff from vegetated
embankments along the canal, beneath the gravel roads, and into the canal.
There are currently no industrial activities in the drainage area.
Significant
None.
Materials/Potential
Pollutants
BMP Summary
None.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW018
Drainage Area
91.6 acres (on -site)
Discharge Structure
48-inch-diameter CMP
Percent Impervious
1 %
Location
Located at the discharge
Permit Monitoring
2
canal on north bank near
Table
potable water connection
building
Latitude - Longitude
35°11'24"N - 81 °00'48"W
Industrial Activities and
The drainage area for SW018 encompasses a large area north of the plant
Description
discharge canal and west of the FGD facility. The watershed for Drainage
Area 18 also extends into a large area off -site to the north of the Allen Steam
Station property. This off -site watershed area is comprised of woodlands and
residential properties north of the station and east of Highway 273. A perennial
stream originating off -site flows through Drainage Area 18 to Outfall SW018.
The drainage area includes approximately 2,000 linear feet of paved access
road from Highway 273 to the FGD facility, and approximately 250 linear feet
of the paved ash haul road. Ash haul trucks use the ash haul road to transport
ash from the dry ash handling facility to the ash landfill. Stormwater runoff from
within the ash handling facility is directed into a sump that pumps to the ash
settling basin. Gypsum haul trucks use the FGD facility access road to
transport gypsum off -site from the FGD facility.
The area includes approximately 150 linear feet of ash sluice piping from the
Powerhouse to the ash handling facility, and the gravel -surfaced CT2 Tap
switchyard located east of the ash handling facility. Drainage Area 18 also
includes a portion of an earth spoil area associated with construction of the
FGD facility, and gravel parking areas used for parking and storage during
construction of the FGD facility.
Significant
Ash: Fly ash is transported in ash haul trucks that use the short section of the
Materials/Potential
ash haul road that passes through this drainage area.
Pollutants
Gypsum: Gypsum is transported in gypsum haul trucks along the FGD facility
access road.
BMP Summary
Fugitive Dust Emissions
• Establish procedures to minimize off -site tracking of fly ash
and gypsum, such vehicle washing or automated wash
stations.
Residue Hauling Vehicles
• Inspect all residue hauling vehicles for proper covering over the load,
adequate gate sealing, and overall integrity of the body orcontainer.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW019
Drainage Area
32.8 acres
Discharge Structure
48-inch-diameter CMP
Percent Impervious
0%
Location
Located at the discharge
Permit Monitoring
None
canal on south bank
Table
Latitude - Longitude
35°11'24"N - 81 °00'52"W
Industrial Activities and
The drainage area for SW019 encompasses an undeveloped area located
Description
between the discharge canal to the north and the plant access road to the
south. An active soil borrow area is located in the western end of the drainage
area. All stormwater runoff from this borrow area is directed to a sediment
basin located northeast of the borrow area. The remaining portions of this
drainage area are grassed or wooded.
Significant
None.
Materials/Potential
Pollutants
BMP Summary
None
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

DUKE
ENERGY.
Location: Allen Steam Station
Outfall Narrative Description and BMP Summary Permit No. NCS000546
Outfall ID
SW020
Drainage Area
15.7 acres
Discharge Structure
48-inch-diameter CMP
Percent Impervious
0%
Location
Located at the discharge
Permit Monitoring
1
canal on north bank
Table
Latitude - Longitude
35'11'31"N - 81°1'20"W
Industrial Activities and
The drainage area for SW020 is comprised of upland areas west of Drainage
Description
Area 18 and located on both sides of the paved FGD facility access road.
Approximately 1,300 feet of paved access road passes through the center of
the drainage area. Gypsum haul trucks use the road to transport gypsum off -
site from the FGD facility.
Drainage Area 20 also includes a portion of an earth spoil area associated
with construction of the FGD facility, and a gravel parking area used for
parking and storage during construction of the FGD facility.
The outlet to the discharge canal was inaccessible and not located in the field.
The 48-inch-diameter concrete inlet located north of the of the haul road is
recommended for sampling.
Significant
Gypsum: Gypsum is transported in gypsum haul trucks along the FGD
Materials/Potential
facility access road.
Pollutants
BMP Summary
Fugitive Dust Emissions
• Establish procedures to minimize off -site tracking of gypsum,
such vehicle washing or automated wash stations.
Residue Hauling Vehicles
• Inspect all residue hauling vehicles for proper covering over the load,
adequate gate sealing, and overall integrity of the body orcontainer.
Notes:
1. Outfall fact sheet provides documentation for permit sections for narrative description of potential
pollutants (Part II, Section A, 1.(b)) and BMP Summary (Part II, Section A, 2.(c)).

Duke Energy Allen Steam
Station I Renewal of
Individual NPDES
Stormwater Permit

Site Changes for Allen Steam Station
N CS000546
• Removal of SWO14 outfall due to construction of the Holding Basin (NPDES Waste Water
Permit NC0004979)
• Completion of the Holding Basin - February 2019, located in the southeast corner of the
active coal pile
o receives runoff from the former SWO14 drainage area
o all flows are now discharged through NPDES wastewater (WW) outfall 006
• Completion of the Lined Retention Basins - February 2019, located north of the station
Allen Steam Station
NCS000546
Narrative

Duke Energy Allen Steam
Station I Renewal of
Individual NPDES
Stormwater Permit

North Carolina Division of Energy, mineral, and Land Resources - Stormwater Permitting
Facility Name:
Permit Number:
Location Address:
County:
Allen Stearn Station
253 Plant Allen Read
Belmont NC 28012
Gaston
"I certify, under penalty of law, that the Stormwater Pollution Prevention Plan {SPPP} document and all
attachments were developed and implemented under my direction or supervision in accordance with a system
designed to assure that qualified personnel properly gather and evaluate the information required by the SPPP.
Based on my inquiry of the person or persons who manage the system, or those persons directly responsible
for gathering the information, the information gathered is, to the best of my knowledge and belief, true,
accurate and complete."
And
"I certify that the SPPP has been developed, signed and retained at the named facility location, and the SPPP
has been fully implemented at this facility location in accordance with the terms and conditions of the
Stormwater discharge permit."
And
"I am aware that there are significant penalties for falsifying information, including the possibility of fines and
imprisonment for knowing violations."
Sig accord* to permit signatory requrrements) and return this Certification. DO NOT
SEND ..TORMWATER POLLUTION PREVENTION PLAN WITH THIS CERTIFICATION.
Signature
Terry'1'uc
Print or type name of person signing above
Date October 29, 2019
General Manager I1
Title
SPPP Certification 10/13