NC0038377_Other Correspondence_20170922

DUKE
ENERGY
File Mayo 12520 B-1
September 22, 2017
Mr Danny Smith, Surface Water Supervisor
North Carolina Division of Water Resources
1628 Mail Service Center
Raleigh, NC 27699-1628
Subject Duke Energy Progress, LLC
Mayo Electric Generating Plant
Special Order by Consent
EMC SOC WQ S 10-012
Final Written Account in accordance with condition 1 (b.)(2 )
Dear Mr Smith
Mayo Electric Generating Plar
10660 Boston Roa
Roxboro, NC 2757
RECEIVEDINCDEQIDWR
SEP 2 9 2017
vfk('r Ouai!izy
pelmitting Section
In accordance with the NC Environmental Management Commission Special Order by Consent, EMC
SOC WQ S10-012, Duke Energy Progress, LLC (Duke) is hereby submitting the Final Written Account,
required by the subject Order, to demonstrate the reduction of pollutants discharged from the Mayo
Electric Generating Plant to the Mayo Reservoir.
The Special Order by Consent required Duke Energy to conduct investigations into available treatment
technologies that would significantly reduce the pollutant load discharged to the Mayo Reservoir, to
submit the construction schedule to the division, and to construct the identified treatment systems
Duke Energy Progress provided the written investigative report to the Raleigh Regional Office and the
DWQ Central Office on February 1, 2013 with a follow up meeting on February 14, 2013 Duke Energy
received approval of the report March 11, 2013 The construction schedule was submitted to DWQ on
May 3, 2013 and was subsequently amended on October 17, 2013 and on July 18, 2014 During the term
of the Special Order by Consent, Duke Energy submitted quarterly reports detailing the progress of the
construction activities, the facility's compliance with all interim limits from Outfall 002, and additional
lake and fish tissue monitoring required by Addendum 1 0 of the Order
Duke Energy selected a treatment and operational strategy to meet the NPDES limits that include
implementation of a dry bottom ash handling system and associated landfill, dry fly ash reliability
upgrades, and a vapor compression evaporator (VCE) system for flue gas desulfurization (FGD)
wastewater treatment The VCE system, which began operation February 2015, eliminated the FGD
wastewater as a source impacting Mayo Reservoir All associated construction activities were complete
as of September 30, 2016 and notification of the completion was made to the Raleigh Regional Office
and DWQ Central Office on October 19, 2016
The results of additional reservoir and fish tissue monrtormg were submitted to the Division of Water
Resources on September 25, 2012, September 19, 2013, September 23, 2014, September 28, 2015 and
September 28, 2016 Operational effects of the Mayo Steam Electric Generating Plant on ecological
conditions in Mayo Reservoir have been minimal Although the concentrations of some constituents
temporarily increased shortly following commencement of FGD operation in 2009, no biologically

detrimental effects have been observed The concentrations of total dissolved solids, boron, chloride,
hardness, and specific conductance have all exhibited declines since operation of the VCE treatment
system began Concentrations of these constituents are expected to continue to decline in the future A
final fish tissue submittal is included as Attachment 1 of this submittal incorporating the most recent data
from 2017
To demonstrate compliance with the EMC SOC WQ S 10-012, the graphical representations found in
Attachment 2 show both the mass and concentration loadings of boron, manganese, mercury, selenium,
and thallium These graphs show the significant reduction of these constituents in the waste stream being
discharged into Mayo Reservoir from Outfall 002 An additional graph showing the reduction in chlorides
loading is also included Utilization of the selected treatment modifications at the Mayo Station is the
means by which Duke Energy will continue to comply with the applicable effluent limits set forth in the
current NPDES permit for the Station
If you have any questions, please contact Lori Tollie [phone] or Bert Lea [phone]
"I certhfi,, under penalty of law, that this doc intent and all attachments were prepared under my direction or supenusnon in
accordance with a sistent designed to assure that qualified peisonnelpiopetly gather and evaluate the information submitted
Based on my inquiry of the person or persons who manage the s}stern, or those persons threctly responsible for gathering the
information, the information submitted is, to the best of my knowledge and belief, true, accnuate, and complete I ant aware that
there are significant penalties foi submitting false uhfornhation, including rhe posshbdhti• of fines and unprnsonment for knowing
violations "
Sincerely,
Tom Copolo — Plant Manager
Mayo Electric Generating Plant
Attachments
Cc Wastewater Branch
NC Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1617

O
O
V
0
0
N '0
CO
w m
W
t
ti
O
t�J
a
Ri
i
t /
/
i
,I
z '
x 0
t }
E-
2 u7 r9 ey 1 }
•� 1` l
C
m rsraa'r `
Cd ui .4 1 P
i
htowo
LO C? La C,? LC) C>
N N T- r
(t)lrirl) uol}aaluaouoo wrlivalag
cam,
O�
O`
OC&
C9
5�OC4 �
�0 h
CO
`OC. i
OC-% w
U
`061
0
a+ I
0O� I
O
OOc, m
U
C& c
1900 �
CA
�O
OC,
d
00
w Cl u) Co LO Co
CV C-1 r T -
(6115d) uoilt,4uaouo3 mmualag
O�
O`
C&
ca S`
Oca
d
�O
O�
OC.,
e.
0
e
O&
00
OC -1
00
C&
C, �O
OC,
00
C4
C4
OC4
O
O�
CJ
V
w
w
ro
M=
LU
Wo
W
w
i
ate..
M
/fes
f
co
l�
�
rts
I f
.
C� s ti to N
w U) 4
�\ \
0
®
\ \
1
E co
W cc;
1
' 1
a,
�
t
I E
J c
00 w o
w Cl u) Co LO Co
CV C-1 r T -
(6115d) uoilt,4uaouo3 mmualag
O�
O`
C&
ca S`
Oca
d
�O
O�
OC.,
e.
0
e
O&
00
OC -1
00
C&
C, �O
OC,
00
C4
C4
OC4
O
O�
CJ
V
w
w
ro
M=
LU
Wo
W
w
i
ate..
M

25
z
20
c
0
16
a�
ora 10
E 6
.�
CS
w
cn
0
ATTACHMENT 1 (CONT.)
Catfish
Tran Mean Min
Max N
B :.7 1.6
9.2 12
E 2.7 1.1
4.3 6
G 2.3 0.9
3.7 6
tiZribs
Transect B — — - Transect E ------- Transect G

800.00
700.00
600.00
5: 500.00
m
v
:2 400.00
N
f0
300.00
200.00
100.00
x1 fre,
16000
12000
m
? 10000
c
0
8000
c
u 6000
c
0
u
4000
2000
x
ATTACHMENT 2
Boron (B)
N N m m m m v IT v v Ln In Ln In kD L.0 � P. -
r -I 14 1--1 ri N ri
O O O O O O O O O O O O O O O O O O O O
N N N N N N N N N N N N N N N N N N N N
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
m m m m m m m m m m m m m m m m m m m m
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
Q1 N m lD Ol N m lD Ol N m lD Ql N m lD 01 N m lD
Boron (B)
N N m m m m v v v a 1n 1.n Ln v1 �D lD �D t.0 r"
r•1 r4 ri ri ri r -I 1-4 r -I ri 1-1 r -I ri "I ri ri ri ri "1 r l N
O O O O O O O O O O O O O O O O O O O O
N N N N N N N N N N N N N N N N N N N N
m \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
m m m m m m m m m m m m m m m m m m m m
cn N m lD Ol N m l0 Q1 N m lD 01 N m 1.0 Q1 N m w
r -I r -I r-1 e-1 r -I

40.00
35.00
30.00
m 25.00
v
:2 20.00
Manganese (Mn)
15.00
-
- -
i
10.00 ' _..
---
-
-
—
-
-.-.. --
_ .
-- --
-
------
-_5.00
5.00
0.00
N
-4
N
—4
m
-1
m
ri
m
1-1
m
r-1
v
ri
v
-1
ct
-1
r -I
Lrl
14
Lr)
e-1
Ln
r-1
Ln
e-1
�D
r-1
ID
r-1
�
-4
t.0
c-1
r`
14
r-
1-I
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
\
m
\
m
\
m
\
m
\
m
\
m
\
m
\
m
\
m
\
m
\
M
\
M
\
M
\
M
\
m
\
m
\
m
\
m
\
m
\
m
\
Ol
\
N
\
M
\
l0
\
Ql
\
N
\
M
\
l0
\
01
\
N
\
m
\
lD
\
Ol
\
N
\
M
\
lD
\
Q1
\
N
\
M
\
l0
e -i
r-1
c -I
e -i
a -i
MEE
800
700
600
tw
c 500
41
�o
400
d
u
0 300
200
100
0
N N m m m m �t v v V Ln Ln u1 u1 ID l0 l0 l0 1\ r\
—1 -4 r -I c -i 1-1 -1 1-1 r-1 r-1 -4 ci -4 e-1 14 14 '-i t l 11 e-1 e1
O O O O O O O O O O O O O O O O O O O O
N N N N N N N N N N N N N N N N N N N N
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
m m m m m m m m m m m m m m m m m m m m
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
Q1 m l0 Q1 N MLD 01 N m l0 Q1 N m l0 01 N m l0
1
Manganese (Mn)

9/4/2012
12/4/2012
3/4/2013
6/4/2013
9/4/2013
12/4/2013
3/4/2014
6/4/2014
9/4/2014
12/4/2014
3/4/2015
6/4/2015
9/4/2015
12/4/2015
3/4/2016
6/4/2016
9/4/2016
12/4/2016
3/4/2017
6/4/2017
Concentration (ug/1)
00 0 0 0 0 0 0
0 0 0 0 0 � � i-, i-.
O N A O� 00 h� N A Q1 00
Mass Obs/day)
i�
0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
9/4/2012
12/4/2012
3/4/2013
6/4/2013
9/4/2013
12/4/2013
3/4/2014
6/4/2014
A
i
9/4/2014
12/4/2014
=
3/4/2015
�
6/4/2015
9/4/2015
12/4/2015
3/4/2016
6/4/2016
-•
9/4/2016
12/4/2016
3/4/2017
6/4/2017
i�

Concentration (ug/1)
F- N N N F- N
O N A a) 00 O N A O) 00 O
9/3/2012
12/3/2012
3/3/2013
6/3/2013
9/3/2013
12/3/2013
3/3/2014
6/3/2014
9/3/2014
12/3/2014
3/3/2015
6/3/2015
9/3/2015
12/3/2015
3/3/2016
6/3/2016
9/3/2016
12/3/2016
3/3/2017
6/3/2017
m
E
3
.-.
N
(D
....
O
O
9/3/2012
12/3/2012
3/3/2013
6/3/2013
9/3/2013
12/3/2013
3/3/2014
6/3/2014
9/3/2014
12/3/2014
3/3/2015
6/3/2015
9/3/2015
12/3/2015
3/3/2016
6/3/2016
9/3/2016
12/3/2016
3/3/2017
6/3/2017
Mass (lbs/day)
O O O O N
N A Q) 00 O

O
9/3/2012
12/3/2012
3/3/2013
6/3/2013
9/3/2013
12/3/2013
3/3/2014
6/3/2014
9/3/2014
12/3/2014
3/3/2015
6/3/2015
9/3/2015
12/3/2015
3/3/2016
6/3/2016
9/3/2016
12/3/2016
3/3/2017
6/3/2017
Concentration (ug/I)
O O O O N N
N A Ql 00 N N A 01 00
Mass (lbs/day)
O O O O O O O O O O O
0 0 0 0 0 0 0 0 0 o N
O N N W . In O) -I 00 W O
9/3/2012
12/3/2012
3/3/2013
6/3/2013
9/3/2013
12/3/2013
3/3/2014
6/3/2014
9/3/2014
12/3/2014
3/3/2015
6/3/2015
9/3/2015
12/3/2015
3/3/2016
6/3/2016
9/3/2016
12/3/2016
3/3/2017
6/3/2017

800
700
600
500
400
300
200
100
Chlorides (mg/L)
0
8/26/2009 8/26/2010 8/26/2011 8/26/2012 8/26/2013 8/26/2014 8/26/2015 8/26/2016