NC0004979_Review of DPC's Proposed_20080319

RE: [Fwd: [Fwd: Review of DPC's Proposed Allen Plant Bypass Flows.._
Subject: RE: [Fwd: [Fwd: Review of DPC's Proposed Allen Plant Bypass Flows on Wylie Reservoir]]
From: "Lewis, Ronald E" <[e-mail]>
Bate: Wed, 19 Mar 2008 18:26:51 -0400
To: "Jackie Nowell" <[e-mail]>
Jackie,
I received the comments and have forwarded them to our field chemistry
staff to address monitoring frequency and will get back with you on this
issue.
On the issue of compliance with the thermal limits for NPDES outfall
001, station operators presently curtail load on the units as needed to
maintain compliance with thermal limits. This same capability will
continue with installation of the supplemental cooling water pumping
system.
I've also attached a copy of the sedimentation and erosion control plan
that was determined to be needed after discussing installation plans
further with contractors. The plan was submitted to the Division of
Land Resources at the Mooresville Regional Office for expedited review
and Scott Harrell indicated today that the plan was acceptable.
If I need to provide.additional input for discussion with the Division
of Water Resources or you need me to contact their staff, please let
know.
Thanks for your assistance.
Ron
Duke Energy
Mail Code: EC13K
526 S. Church Street
Charlotte, NC 28202
Office 980-373-5710
Mobile [phone]
-----Original Message -----
From: Jackie Nowell [mailto:[e-mail]]
Sent: Wednesday, March 19, 2008 1:4.1 PM
To: Lewis, Ronald E
Subject: [Fwd: [Fwd: Review of DPC's Proposed Allen Plant Bypass Flows
on Wylie Reservoir]]
Ron,
Per our conversation this morning, here are the comments from Bryn
Tracy.
Jackie Nowell
-- ---- --- ------ - - - -- ----- ----1 --- -- - --- ---- Supplement CCW — -- -,
Content -Description: Erosion Control Plan
Supplement CCW Erosion Control Plan 3-18-08.pdf 3-18-08.pdf
Content -Type: application/octet-stream
Content -Encoding: base64
I of 1 4/1/2008 2:33 PM

S:
w�j xY .f
�v
�jfGf �
r Thermal Variances
,. Thermal wastewater discharges in North Carolina are subject to effluent limitations under North Carolina
Administrative Code Section: 15A NCAC 02B .0211 (3) 0). This rule limits thermal discharges to 2.8
degrees C (5.04 degrees F) above the natural water temperature and includes further restrictions based on
geographic regions of the state. Exceptions to these limits are allowed under the temperature variance
provisions of the federal Water Pollution Control Act, commonly known as the Clean Water Act, under
Section 316(a). Under this provision of the Clean Water Act, permittees must demonstrate that the
variance for the thermal component of the discharge assures the protection and propagation of a balanced,
indigenous population of shellfish, fish and wildlife in`the receiving water.
The permit holders listed below have requested continuance of the Clean Water Act 316(a)- temperature
variances, which allow for site by site limitations based upon studies conducted by the Permittee and
submitted to NC Division of Environment and Natural Resources (DENR). The Division of Water Quality
has determined that these studies submitted by the permittees comply with Section 316(a) of the Clean
Water Act. On the basis of North Carolina Administrative Code Section: 45A 02B .0208 (b), and other
appropriate lawful standards and regulations, the North Carolina Division of Water.Quality proposes to
continue the 316(a) variance in conjunction with the renewal of the following National- Pollutant
Discharge Elimination System (NPDES) permits:
Permit Facility County Subbasin
NC0000272
Blue Ridge Paper Products, Inc —Canton Mill -
Haywood
040305
NCO.000396
Progress Energy (formerly Carolina Power & Light)
Asheville Steam Electric Power Plant
Buncombe
040302
NC0003468
Duke Energy Corp. Dan River Steam Station
Rockingham
030203
030704
NC0004774
Duke Energy Corp. Buck Steam Station
Rowan
030833
NC0004961
Duke Energy Corp. Riverbend Steam Station
Gaston
NC0004979
Duke Energy Corp. Allen Steam Station
Gaston
Catawba
030836
030832
NC0004987
Duke Energy Corp. Marshall Steam Station
Steam Station
Rutherford
030802
NC0005088
NC0024392
Duke. Energy Corp.—Cliffside
am Station
Duke Energy Corp. McGuire Ste `
Mecklenburg
030832

[Fwd: Review of DPC's Proposed Allen Plant Bypass Flows on Wylie ...
Subject: [Fwd: Review of DPC's Proposed Allen Plant Bypass Flows on Wylie Reservoir]
From: Sergei Chernikov <[e-mail]>
Date: Thu, 13 Mar 2008 10:43:49 -0500
To: [e-mail]
Jackie,
Please see attached comments from Bryn Tracy regarding proposed Allen Steam Station major
modification.
Sergei
Sergei Chernikov, Ph.D.
Environmental Engineer 11
NPDES-West
Phone: [phone] ext. 594, fax [phone]
1617 Mail Service Center
Raleigh, NC 27699-1617
Express mail: 512 North Salisbury St.
Raleigh, NC 27606
Subject: Review of DPC's Proposed Allen Plant Bypass Flows on Wylie Reservoir
From: Bryn Tracy <[e-mail]>
Date: Sat, 01 Mar 2008 11:41:09 -0500
To: Sergei Chernikov <[e-mail]>
CC: Peter Caldwell <[e-mail]>
Sergei --
Peter Caldwell (new supervisor for the Intensive Survey (Lakes Monitoring Unit)) and I reviewed the two
documents, cover letter and the modeling report, related to DPC's Proposed Allen Plant Bypass Flows on Wylie
Reservoir. Our only comments are:
1. Cover letter, page 3, supplemental monitoring program proposal -- there is no mention of monitoring
frequency. Weekly profiles should be recommend to determine any impacts.
2. What happens l�f they observe/document any negative impacts? Will they modify plant operations?
3. If they exceed the perinit requirement for temperature even with the bypass, will they "scale back" operations?
These were are only comments. Thank you for extending to us the opportunity to review the documents. Please
keep us informed of the project's progress and if you need us to review any additional documents.
Bryn Tracy <bryn.tracy n,ncmail.net>
Environmental Senior Specialist
NC DENR
Division of Water Quality
Review of DPC's Proposed Allen Plant Bypass Flows on Wylie Reservoir Content -Type: message/rfc822
Content -Encoding: 7bit
I of 1 3/13/2008 10:16 AN

ff
PDuke
(Energy®
February 25, 2008
Mr. Sergei Chernikov
North Carolina Department of Environment
and Natural Resources
Division of Water Quality
NPDES Unit
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
CORPORATE EHS SERVICES
Duke Energy Corporation
526 South Church St.
Charlotte, NC 28202
Mailing Address:
EC13K / PO Box 1006
Charlotte, NC 28201-1006
FEB 2 6 2008
Subject: Duke Energy Carolinas, LLC DENR , WATER
�
Allen Steam Station #NC0004979 — ��n ()UALITY
Drought Related Mitigation Request �f RCE BRANC
Dear Mr. Chernikov:
As a follow-up to our meeting to discuss potential drought mitigation options on January
29, 2008, three copies of the following, request are being submitted for review and
approval to install a supplemental cooling water pumping system at Allen Steam Station.
Application of the modified Lake Wylie reservoir hydrodynamic and water quality CE -
QUAL -W2 model using low flow conditions experienced in the summers of 2002 and
2007 has shown that anticipated water quality impacts from operation of a supplemental
cooling water pumping system from July through September of each year will be
negligible (see enclosed report dated December 5, 2007 and Environmental Assessment).
Due to the predicted on-going drought conditions, Duke Energy requests approval to
install supplemental summer season cooling capacity at Allen Steam Station. Initially, in
2008 a 60,000 gpm temporary supplemental cooling water pumping system (see enclosed-'
proposed operation and site plans) would be added, followed by a 240,000 gpm
permanent supplemental cooling system intended for operation in 2009. The
supplemented cooling water flow of these systems represents an increase of 11%
(summer 2008) and 44% (summer 2009 and thereafter) of the present cooling water
pumping capacity at Allen.
The temporary system will be similar to that recently approved for pumping water from
the Dan River to Belews Lake from January through March in 2008 to offset the
evaporative loss due to drought conditions in 2007 (see enclosed photos), and will
similarly have a floating, screened intake design. The proposed 240,000 gpm permanent
supplemental pumping system planned for operation starting in July 2009 will feature
submerged wedge wire screened intake pipes. A detailed design and excavation plan, as
well as a sedimentation and erosion control plan will follow for your review and approval
prior to implementation.
www. duke -energy. com

During the three month operation of the supplemental cooling water pumping system,
Allen's condenser cooling water (CCW) discharge temperature for Outfall 001 will be
modified to include the temperature of the supplemental cooling water pumping system
based on the system flow and Allen's CCW intake temperatures. Duke Energy requests
that Allen's NPDES permit be modified to incorporate this change with initial approval
of the temporary supplemental pumping system. Enclosed is a check in the amount of
$1030.00 for the permit modification fee.
Your assistance to expedite review of this drought -related mitigation project is greatly
appreciated. As we previously discussed, setting up a meeting to further discuss plans
with you ' and other agency contacts that need to review and approve the proposed
activities will be beneficial. After your initial review of the request, please advise me of
available dates for us to coordinate a meeting to identify and expedite addressing any
issues of concern. Should you have questions regarding this request, please call (704-
607-8755 or email me relewisl&duke-energy.com.
Sincerely,
i
Ron Lewis
Water Management
Attachments
cc w/: Bryn Tracy — NCDENR Environmental Sciences Section
1621 Mail Service Center, Raleigh, NC 27699-1621

ENVIRONMENTAL ASSESSMENT OF PROPOSED SUPPLEMENTAL
COOLING WATER PUMPING SYSTEM AT ALLEN STEAM STATION
Summary of Model Results — Assessment of Potential Water Qualitypacts
Due to the predicted on-going drought conditions, Duke Energy requested that Reservoir
Environmental Management, Inc. (REMI) assess the reservoir water quality effects of
using supplemental cooling water at Allen Steam Station Application of the modified
Lake Wylie reservoir hydrodynamic and water quality CE -QUAL -W2 model by REMI
(see report dated Dec 5, 2007) using low flow conditions experienced in summers of
2002 and 2007 has shown that anticipated water quality impacts from operation of a
supplemental cooling water pumping system from July through September of each year
will be negligible. The model shows that lake effects would be generally limited to
changes in temperature in the South Fork Catawba River, and there will be minimal
temperature and dissolved oxygen changes in the main arm of Lake Wylie, including the
Catawba Nuclear Station (CNS) intake and the Wylie hydro fore bay. Under a "worst
case" modeled scenario including 24-hour Allen full generation capacity and applying
current thermal discharge NPDES limits, only modest thermal increases were predicted
for Lake Wylie. Worst case temperature increases were on the order of 1 to 2 degrees F,
limited primarily to the South Fork Catawba River downstream of Allen, although for a
short period (about 10 days) in either modeled low -flow year, results indicated a similar
temperature increase of about 1 to 2 degrees F in the vicinity of the Allen condenser
cooling water (CCW) intake. At all other sites further downstream in the reservoir,
thermal effects could not be discerned. Lake -wide, dissolved oxygen vertical profiles
were virtually unchanged when these two low -flow summers were modeled, either with
or without operation of the supplemental pumping system.
In order to assess the initial summers (2008 and 2009) of bypass operation, in light of the
modeled predictions, we propose to implement the following supplemental Lake Wylie
monitoring program (see Figure 1 for sampling locations):
o Vertical water column thermal and dissolved oxygen (DO) profiles during July,
August and September at:
• Lake Wylie fore bay (Loc 200)
• Allison Creek arm of Lake Wylie at the Catawba Nuclear Station discharge
cove (Loc 215)
• Lake Wylie at Buster Boyd Bridge (Loc 225)
• Downstream of the Allen CCW discharge near the confluence of the South
Fork and main stem Catawba River (Loc 235)
• Allen CCW discharge confluence with Lake Wylie (Loc 242)
• Upstream on the South Fork Catawba River (above the influence of Allen
(Loc 249) (surface sample)
• Allen CCW intake (Loc 250)

For initial operational summers of the temporary (2008) and permanent supplemental
systems (2009), summer thermal and DO profiles data collected at these Lake Wylie sites
will be compared to the REMI-modeled results.
Summary of Model Results — Assessment of Potential Fisheries Impacts
On-going fish monitoring studies continue to indicate that a diverse fish community is
present in the littoral portions of Lake Wylie around Plant Allen. The high number of
fish species collected during spring indicates the combined effects of fish attraction to the
Allen Steam Station discharge and the tendency for a greater variety of species to inhabit
the shoreline in spring compared to summer. Despite the repulsion of fish from the
thermal effluent of Allen during summer, "...there is a balanced and indigenous fish
community in Lake Wylie" (Duke Power Company 19941, Duke Power 20012 and
20043). Proposed operation of the supplemental cooling water pumping system from
July through September will avoid the fish spawning period of March through June and
minimize spikes of the discharge water temperature when peak electrical generation
demand is prevalent. Based on the minimal projected changes in temperature and
dissolved oxygen associated with the supplemental cooling water flows during July,
August, and September at Allen, the current fisheries monitoring program is adequate to
document any changes in the fish population of Lake Wylie resulting from operation of
the proposed supplement pumping system.
1 Duke Power Company 1994. Assessment of balanced and indigenous populations in
Lake Wylie near Plant Allen. Duke Power Company, Charlotte, NC.
2 Duke Power Company 2001. Assessment of balanced and indigenous populations in
Lake Wylie near Plant Allen. Duke Power, Charlotte, NC.
3 Duke Power Company 2004 Assessment of balanced and indigenous populations in
Lake Wylie near Plant Allen. Duke Power, Charlotte, NC.

270. Of
Lake Wylie
Sample Locations
261.0
265.0
260.0
249.0
255.0
Plant Allen
242.0 0 250.0
230.0 o ":X245. 0
235
222.0 N
W E
._ 225.0 S
219.0 220.0
219.2 220 8 # Monitoring locations
Catawba 19.4 220.6
Nuclear 0 q
Station 215.0 10.
200.0
0
Wylie Hydro
i
180.0
205.0
201.0
179.0
0 1 2 3 4 5 Miles
Figure 1. The Lake Wylie study area.

OPERATION AND SITE PLAN OF PROPOSED SUPPLEMENTAL COOLING
WATER PUMPING SYSTEM AT ALLEN STEAM STATION
The supplemental cooling water pumping system will be operated continuously from July
through September of each year in conjunction with the operation of the Allen's electrical
generating units. Initially in 2008, installation and operation of a temporary pumping
system is planned in 2008. The temporary pumping system will consist of nine floating
intake pipes with screened openings (3/8 inch square mesh) and pumps designed to
withdraw at a through screen velocity at or below 0.5 fps a total of 60,000 gpm into a
manifold connected to one pipe that will discharge into the condenser cooling water
(CCW) canal of Allen Steam Station (Figure 2). The floating intake design of the
temporary system will be similar to that approved for pumping water from the Dan River
to Belews Lake from January through March in 2008 to off set the evaporative loss
associated with drought conditions in 2007 (Figures 3-5). Only minimal disturbance of
land will be required for installation of the temporary intake piping (less than one acre
and hand cutting of trees along 120 feet of shoreline just South of Allen's existing service
water intake, see Figures 2 and 6). In this same area, the temporary intake system will be
replaced by a permanent pumping system consisting of submerged wedge wire screened
piping and pumps designed to withdraw at a through screen velocity at or below 0.5 fps a
total of 240,000 gpm into four manifolds and four pipes that will discharge into the
condenser cooling water (CCW) canal of Allen Steam Station starting in July 2009
(Figure 7). A detailed design and excavation plan, as well as a sedimentation and erosion
control plan, will follow for approval of the installation of the permanent supplemental
pumping system.
Currently Allen's CCW discharge temperature is monitored continuously and flow -
weighted daily and monthly average temperatures are reported per the monthly discharge
monitoring report for Outfall 001. During operation of the supplemental cooling water
pumping system, Allen's CCW discharge temperature for Outfall 001 will be modified to
include the temperature of the supplemental cooling water pumping -system based on the
system flow and Allen's CCW intake temperatures.

Figure 2. Conceptual layout of the temporary supplemental pumping system (60,000
gpm) with nine floating screened intake pipes connected to pumps leading to a manifold
that directs flow into a single pipe that will discharge to the condenser cooling water
canal of Allen Steam Station.
a

ANNIE
A"I

� � � R �i f
_.�.
��
``-.._
y f y
__
:-_
f,� _

Figure 5. Discharge of water pumped from the Dan River to Belews Lake in North
Carolina from January through March 2008.
k
�J
Figure 5. Discharge of water pumped from the Dan River to Belews Lake in North
Carolina from January through March 2008.

Figure 6. The frame of the photo is the width (120 feet) of the shoreline buffer that the
temporary piping will cross. Hand cutting of trees will be necessary to deploy the nine
floating intake pipes at Allen Steam Station.

�:. 00'
20 10 0 20
SCALE I" = 20'
D U K E P O W E R C O M P A N Y
ALLEN STEAM STATION
LEGEND
a ew eav ma mm PLANT CRAINAW
DISCRARGE POIN75
NPDES DISCHARGE POINTS
c:\dan\al-nodes.dan Feb. 08. 2001 10:36:15
I
W,
DRINKING WATER
WELL
/,
0[SC14ARGE
003i(fA��
a
00
pJ
v
CANAL
_
.. 0028
001
N =
INTAKE
w
o
_ W
y cclo)
�
Ah
tilc��p
GG�
ME Q04
COAL
r
-
STORAGE YARD
Owl 1
cf
OLD
.ASH BASIN
NEW. ASH BASIN'
W'
z
�:. 00'
20 10 0 20
SCALE I" = 20'
D U K E P O W E R C O M P A N Y
ALLEN STEAM STATION
LEGEND
a ew eav ma mm PLANT CRAINAW
DISCRARGE POIN75
NPDES DISCHARGE POINTS
c:\dan\al-nodes.dan Feb. 08. 2001 10:36:15

4

xu{kr/°m�
'-/7 �� �
------����=-~---- - --'-- -k7-}'-
��
n
-------' '--------- - -- 7- -' - - �
^��'
'/'
'-----''� ---'--------�-v�� -r^� - '
----------------' - -- ------'--------- /{=. o\ ,
---'---'-''----- f- ----------- 'I� ' ����' ' - - -
_--_---___--__'-- _- ~ - --
---'- '---'--------- ''' --- '--/^;�\/- - -- ---'-- --- ' J��� ^ - �xm� - -- --
. ..
|| '

i
A
1
� - -
-
- vim. •-
_
_�_
t
-
i

vvk
ip
I.lofJy oM nA2 ",-y r)'PJ
�Aq;/��

-
�
..
`;
•:
-.
��
_.
,=
,,•
..
-
_ -
r ,-
-
. �,
..
'�
i
-
_
-
/:
-
�
..
�,
r_
}
��.
5
.
_ .
- �
-�
�
-
r:
:3
:�
-
�
-
i
...
;�
-
_ r -r
-�
-
_� . � .
- �;
.,
'
.INS
_ -
�
� � F`
i
-
,�
,J
'1
�
..
r, ..
__.
I'..
,1r
��
,'
,
-
',
!
� '
,.
/�
- s
i
�

C5

FIGURE 1 USGS TOPOGRAPHIC MAP OF THE AREA
AROUND ALLEN STEAM STATION
z,)8103' 81 02'30" 8102' 8101'30" 8101' 81 00'30" 810
0
Ln
M
O
M
N
r
o
LO
M
7
T-
o
Li)
M
O
M
r
r
o
.L0
M
r
o
L0
M
O
M
O
r
0
Ln
M
W
0
Ln
M
O
M
0
0
Ln
co
80°59'30"
8103' 8102'30" 81021 8101'30" 8101' 81 00'30"
0 0.5 1 Kilometers
0 0.5 1 Miles
CONTOUR INTERVAL 10 FEET
810
80°59'30"
N