NC0003433_Other_20200317

('DUKE
ENERGY.
February 20, 2020
Ms. Julie Grzyb
North Carolina Department of Environmental Quality
Division of Water Resources, Complex Permitting Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
RE: Duke Energy Progress, LLC
Cape Fear Steam Electric Plant
NPDES Permit Modification NPDES Permit
NC0003433
Chatham Count
Dear Ms. Grzyb:
Cape Fear Steam Electric Plant
500 CP&L. Road
Moncure, NC 27559
LIAR 17 2020
NCDEQIDWRINPDES
Duke Energy Progress, LLC (Duke Energy) submits this letter to request modification of
the NPDES permit for Cape Fear Steam Electric Plant to add an emergency spillway at
the inactive 1963/1970 ash basin. This request is to support compliance with the North
Carolina Department of Environmental Quality (NCDEQ) Dam Safety's new regulations
for ash basin dams in North Carolina passed in April 2019. The request is in follow up to
discussions between Duke Energy and NCDEQ water quality and dam safety staff on
August 21, 2019 and Duke Energy and Division of Water Resources on November 7,
2019.
The ash basin is currently scheduled for decommissioning; however, prior to
decommissioning, the ash basin is required to contain and safely pass a design storm
event consistent with federal and state regulations. The current regulatory design storm
has been updated from 1/2 Probable Maximum Flood, PMF, to the full PMF. The PMF
equates to 27.50-inches of rainfall in a 6-hour period
In order for the combined 1963/1970 inactive ash basins to safely pass the full PMF, a
new auxiliary emergency overflow spillway is required to be constructed to release
stormwater to the Cape Fear River. The proposed spillway is designed to maintain 1-foot
of freeboard within the basin at a minimum crest of 183 ft. Additionally, the spillway is set
at an elevation sufficient to ensure that the basin will contain 100-year, 24-hour storm
without discharge. The emergency spillway will be located on the southwest corner of
the 1963 ash basin (Lat: 351134'57.37" / Long:-79°02'57.50" adjacent to Outfall 008A.
Duke Energy requests an emergency spillway be added to the NPDES permit with
discharge to the Cape Fear River. As this outfall would only discharge in an extreme
weather event and would consist primarily of rain that has fallen on the footprint of the
inactive ash basin, we request that sampling be waived in the event of a discharge as

cn
DUKE
ENERGY.
Cape Fear Steam Electric Plant
500 CP&L Road
Moncure, NC 27559
conditions are unsafe. During conditions where sampling is achievable, samples of the
same basin water discharge at adjacent Outfall 008A, located approximately 150 feet
away, can easily characterize the discharge.
Enclosed for your consideration in support of this request are the following;
1. Map of proposed emergency spillway;
2. Design Drawings;
3. A check in the amount of $1030.
Should you have any questions regarding this submittal or require additional
information, please contact Joyce Dishmon at [phone] or email
joyce.dishmon @duke-energy.com.
1 certify, under penally of law, that this document and all attachments were prepared under
my direction or supervision in accordance with a system designed to assure that qualified
personnel properly gather and evaluate the information submitted. Based on my inquiry
of the person or persons who manage the system, or those persons directly responsible
for gathering the information, the information submitted is, to the best of my knowledge
and belief, true, accurate, and complete. 1 am aware that there are significant penalties
for submitting false information, including the possibility of fines and imprisonment for
knowing violations.
Sincerely,
Issa J. Zarzar
General Manager — East Region
CCP Operations and Maintenance
Cc: Scott Vinson, NC DWR,
Water Quality Regional Office,
3800 Barrett Drive, Raleigh, NC 27609
Shannon Langley via email
Joyce Dishmon (filenet) via email
Jonathan Stamas via email

.lam T� 4` � ' � i ` , � • �� , .
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�l• Emergen Sp,nwayPermit Modification -
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NCO003433
'77 1. •' >

i
\� g LIMITS OF 1963/1970 ASH BASIN BOUNDARY
\ LOD - , P11
L
PROPERTY LINE 8 I * / a. c
8 CFR C901.031.004 REV.2
.. / NOTES.
1. TRUCK TURNAROUND IS INTENDED TO BE TEMPORARY, FOR
CONSTRUCTION PURPOSES ONLY. AREA TO BE RESTORED TO
PRE-CONSTRUCT10N GRADES AND PERMANENTLY STABILIZED
PRIOR TO REMOVAL OF EROSION AND SEDIMENT CONTROL
MEASURES.
2, ADD 44NCH THICK LAYER OF #4 AGGREGATE TO MAKE TURN
AROUND AREA LEVEL FOR TRUCKS TO DO A 3-POINT TURN.
3. TURN AROUND AREA DIMENSIONS BASED ON THE SIZE OF A DUMP
TRUCK.
4, THE PREPARED SUBGRADE SHALL BE PROOF ROLLED WITH AT
LEAST 2 PASSES OF A 20-TON LOADED DUMP TRUCK OR 1 PASS OF
A 40-TON LOADED ARTICULATED TRUCK. PROOF ROLLING SHALL
BE CONDUCTED AT THE DIRECTION OF THE CQA ENGINEER OR HIS
1970 ASH BASIN REPRESENTATIVE. ANY SOFT, SATURATED OR YIELDING AREAS
EXHIBITED BY PUMPING AND/OR RUTTING WILL REQUIRE REMOVAL
AND REPLACEMENT NTH THE APPROPRIATE COMPACTED SOIL AS
SPECIFIED.
5. TREES WITHIN THE LIMITS OF DISTURBANCE LINE TO BE REMOVED.
(SEE SHEET CFR.C901.030.010) FOR POINT LIST TABLE)
6. ALL TREES LESS THAN 3 IN. IN DIAMETER AT BREAST HEIGHT MAY
BE REMOVED EITHER BY EXCAVATION OR CUTTING FLUSH TO THE
GROUND. (SEE SHEET CFR.C901.030.009 FOR TREE REMOVAL
DETAIL)
/ 7. ALL TREES LARGER THAN 31N. IN DIAMETER AT BREAST HEIGHT
B _ P10 TOE OLIMI SLOPE
PRO MUST BE COMPLETELY REMOVED BY EXCAVATION, INCLUDING
ROOTS, AND THE RESULTING EXCAVATION PROPERLY BACKFILLED
EXISTING DAM CREST \ {Y COD NTH SELECT FILL (SEE SHEET CFRC901.030.009 FOR TREE
\ ' P12 ' ' �' \ _ LI LIMITS POSED GRADE (TYP.) REMOVAL DETAIL)
_�, COD
`OD
CAPE FEAR RIVER 4 INCH SACRIFICIAL \ / \
V LAYER OF #4 P13 L - - _ - _ a EXISTING DAM CREST-
\ AGGREGATE FOR C '.,, _ - - -
NPDES OUTFALL 008A a ACCESS
_
.-
\/�° ` P9
EXISTING 32" HOPE OUTFALL ° 19 296
PIPE (TO REMAIN IN PLACE) P14 �`
P8 �, .y34J 3302
Izaa
� P15 � ,:.I �,;:' /0 9 m° � ,'29t _ �j;� E
8 \ s o EXISTING ACCESS ROAD
P7 �:a290
L0D LOD LOD LOO LOD LOD
1
ti
EXISTING WELLS PROTECT -IN -PLACE 1 P16 13 ;,71 `z1aP17, 1 1A7 C
µ
`t55 -
Ilk
��wFLLTMw _ - '� kx°r�-,'•� / ,e 1 - - n
WELL -
1 ,: wv P5 - P6 _ _ _ ooYR FP IOOyR 8 �x
P18 IOOYR TP 100YR FP 'oo 1 ra - Loan �� 117oro
I - /
y 9 co
P3 ..-'087/9
\ P21 0
a. atemisa
�1Do n,\ '
aa19s y ti�ty 1 P1� 2 N�12a J N�yg$ v S2 \ y` 3 8 PROPOSED TEMPORARY
7
\ .. `BpT t��9s',g6 TURN AROUND AREA
aOT k �1 97 07 o I , / (SEE NOTES 1-4)
\ ' 00" �- 0DT st�e �1ot V-' 78 E
4.-177
POINT TABLE
POINT NO.
NORTHING
EASTING
ELEVATION
Pt
666890.25
1985372,60
171 FT.
P2
666894.75
1985376,D9
171 FT.
P3
666907.48
1985379,01
171 FT.
P4
666917.63
1985381.08
171 FT.
PS
666939.96
1985385,63
184 FT.
P6
666940.27
1985396.85
185 FT.
P7
665981.17
1985434.97
187 FT.
PS
666999.17
1985441.67
187 FT.
P9
667001.71
1985432.21
186 FT.
P10
667032.25
1985432.46
175 FT.
P71
667061.32
1985318.53
176 FT.
P12
667035,80
1985289.36
185 FT.
P13
667015,24
1985247.75
187 FT.
P14
66T7000.17
1985235.81
187 FT.
P15
668969.10
198523T34
185 FT.
P76
666961.14
1985246 41
184 FT.
P17
666952.40
1985249.43
181 FT.
P18
666924.84
198524.05
168 FT.
P79
666902.29
1985208.21
185 FT.
P20
66889347
1985212.80
185 FT.
P21
668905.62
1985248.51
187 FT.
1 5
� 1.J103 �
SEE NOTES 5-7 Nz _ INSET A -PROPOSED RIP -RAP
y a
LEGEND 106 rjIo9 S 4() C. =
EXISTING MAJOR CONTOURS y�105 -> - IGI5 AUXILIARY OVERFLOW SPILLWAY
EXISTING MINOR CONTOURS (�^!10?'' 5.�74 �.41 a: -7 SCALE: 1" = 20'
WOOD LINE �T% -14 20 0 20 40 FT
118
l13
PAVED PATH
-WATER SURFACE (�"y68 ~`147 v�L, { "`�� TITLE 1963/1970 BASIN
ti. 4a
UNPAVED PATH ilo 7 ? 5 wood. AUXILIARY OVERFLOW SPILLWAY DESIGN
- - - - -- LIMITS OFASH BASIN BOUNDARY 8 Y`117 �j112 064CAPE FEAR STEAM STATION
Environment 81,*- IONre SdNiarls
100YR FIR ZONE AE FLOOOPLAIN LIMIT CHATHAM COUNTY, NORTH CAROLINA
-� CC21 STIRRUP CREEK ORNE. SURE fro WRRAM
PROPOSED RIP -RAP AUXIUARY `•-`116 p�-y`113 ,-'a65 ? iEL (01913l1 aDW RIP -RAP AUXILIARY SPILLWAY PLAN
OVERFLOW EMERGENCY „�� N'?i113- (�-345 c+K I9+91 x1-�1
SPILLWAY v.,12a ; ;� SURE FOR
FGR ISSUED FOR PERMITTING
PROPOSED MAJOR CONTOURS 962 �+, "� w GE,Ooy GN>
PROPOSED MINOR CONTOURS 9121 �y56 N-7� SEAL \ 1 II / 'DUKE SCALE AS SHOWN DES: VRD
SACRIFICIAL LAYER OF #0 \� 'y .� 6, G55 �} c \ (�i DWG TYPE. DWG DFTR: VRD
�. 114N vt',^;'C,-..57 _ SI /y = ENERGY JOB NO'. 78121-02 CHKD. CK
AGGREGATE '� � v-y124r '�: E �iV ._.y
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- - - LIMITS OF PROPOSED GRADE �, 001 ' �,465 0DT ;v i+4i101 00T . Q SEAL 'f ; DATE. 12/182019 ENGR AP
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REV 11/0192019 >8ATE I �9002 DESIGN
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IKCKES 1 2 3

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1 SEE SPILLWAY CROSS-SECTION
,005 DETAIL PROPOSED AUXILIARY OVERFLOW 2 RIP RAP SPILLWAY
200.00 SPILLWAY
200.00 005 ANCHOR DETAIL
STk0+81.80
STk 0+44.50 EL£VAEi6 STk0+98.71
190.00 STk, 1+22.79
EIEV 1650 ElEV:182.J0 190.00
�''-----_- ----- ELEN 182.00 EXISTING GRADE � - ExIST1Nc
-
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001R FP - \ GROUND
180.00 ; � - - 180.00 \ 75 SURFACE
1.4%SLOPE 2 m,P )
A
_
`STk, 0+11.84 41NCH SACRIFICIAL LAYER OF W AGGREGATE 10D 1�� FP \ VPa1t;5
170.00 EI .176.D2 SRE1.16z45 170,00 N
--
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A
160.00 � �-�i I _III=1 I I_-I�_�
160.00 �_ I -._ - - III-1 -I ' 2
- -
-III- 11 11_I I I I[
RIP -RAP LIMITS -I p _- I I I I I-III-III-1 I-1 I -III _ 1 _
.III=1 Ij=1 _ T 1- -I I L__I I --III - r 2 _III -..
50.00 150.00 -III I la 1 IOEMVAMS
III
III
-0+10 0+00 0+10 0+20 0+30 D+40 0+50 0+60 0+70 0+80 0+90 1+00 1-10 1+20 1-30 1+40 1+50 1+60 1+70 1+80 1+90 2+00 2+10 2+20 I III- 1 III
- III - 111
III _ . -Ili __.�
-M
CLASS BRIP-RAP II- 1 -
HORIZONTAL SCALE: 1"-20' __- IV- 1 ILL
SECTION VIEW (A -A') -III=III-III'' II
VERTICAL SCALE.-20 1- -1
=I 7III-
ISEE SPILLWAY CROSS-SECTION 160ZSY GEOTEXTLE
1II
1,_-11I
DETAIL - I_
-_I
CLASS 2 RIP -RAP I-
200.00 200.00
STk,0+77.67 STk,094.99 PROPOSED A
ELEV:1824
OWB
.
ElEV182.1ESTk1+1002 OVERFL SPILLWAY 1so.00 LWAY CROSS-SECTION
sTk,o+,,��o SPIL
B1so.00
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F_ - STk,0+07.64 `�'� - STk1+63.96 F-
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_ _
W �• - W CLASS B RIP RAP
W 160.00 160.00 W
RIP -RAP LIMITS 16 OZJSY GEOTEXTILE
N, 150.00 150.00
-0+10 0+D0 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 0+90 1+00 1+10 1+20 1+30 1+40 1+50 1+60 1+70 1+80 1+90 2+00 2+10
EXISTING GROUND
SURFACE MR.) APRON WIDTH 10' PER PLAN
20 0 20 40 FT SECTION VIEW (B-B')
o HORIZONTAL SCALE: V=20'
a VERTICAL SCALE: 1'=20'
,as.00 III -I 1-I 11-1 I -I I-
189.00
STk 0
ElEV:187.1281.12
188.00 188.00
(7
�.1+9 2 RIP RAP SPILLWAY ANCHOR
EXISTING GRADE
.005 SCALEN.T.S
---------
187.00 --
187.00
to
p
i
\ - - - _ _
186.00 / \\ 186.00
1 PROPOSED AUXILIARY
EMERGENCY SPILLWAY 1
O
(A
10
10
LL 185.00 F_
185.00
z z
O
p
\
Q
LLI 1$4.00 PMF DEPTH = 0.83'
184.00 J
ry
E-
w �_� 1' 1� �� W
183.00 �p p 183.00
I 100'
-
182.00 p p p Q p c> 182.00
TITLE
2-FT THICK CLASS a RIP-RAP1963/1970 BASIN
. ,
4'SACRIFICULLLAYER OF#4 AGGREGATE FOR ACCESS .r'- wood AUXILIARY OVERFLOW SPILLWAY DESIGN
I •
��`
F
181.00 �p p� -.\ p` p p p p i .. �p p-- 1 00 CAPE FEAR STEAM STATION
STA:0+57.29 �. 18 EmironRlell(81Mrrtruc+ure sau6ons
El£µ18Z46`�-- ) �\ J ` lJ •1+56.J2 as+anRRuvcREE�K�oRr-aasurtElmwR�AM CHATHAM COUNTY, NORTH CAROLINA
t�> / 1e229 F I9,a,> 1 CROSS SECTION 8 PROFILE
F
c 180.00 I N w FIM3 FOR ISSUED FOR PERMITTING
180.00 N Eo _y can
0+00 0+10 0+20 0+30 0+40 0+50 0+80 0-70 0+80 0+90 1+00 1+10 1+20 1-30 1+40 1+50 1+60 1+70 1+80 1+90 2+00 2+10 SEAL \ 1 11 ' SCALE AS SHOWN DES. VRD
DUKEDWG TYPE. DWG OFTR: VRD
S/
JOB NO 7812190202 CHKO CK
` E N E RGY
. Ix SEAL r . DATE. 12/182019 ENGR AP
PROFILE VIEW (C-C') 04]270 FILENAME CFR_C901.031.004- PROPOSED PLAN.DWG APPD cu
10 0 10 20 R .'
HORIZONTAL SCALE: V=10' 2 1?/i8r2019 781219= DESIGN PLAN VRD VRD CK AP CK ISSUED FOR PERMITTING
(Iy� �Q •• DWG SIZE DRAWING NO REVISION
N 1 1]AYp19 78121902V1 DESIGN PLAN VRp VRD CK AP CK ISSUED FOR PERMfiTING // "�IN�'•,• �`
VERTICAL SCALE: 1"=1' s{�
'Ll- Z ISSUED FOR PEFWIITNNO �OqF ;V ANSI D
i�ll M p. P �j 22 3, CFR C901.031.005 2
`��
REY " JOB NCO P 0 CT ypE DES OFTR CHm ENGR pppD ION -
1111111
INCHES 1 2 3 TENTHS 10 20 30 4 5 6 ] $ 9 10