NC0004979_Engineer's Certification_20061215

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Duke Power, Allen Steam Station.
A To C No. 004979A02
Issued December 15, 20061
i
Engineer's Certifications
I, Dean M. Steinbach, as a duly registered Professional Engineer in the State of North
Carolina, having been authorized to observe (periodically/weekly/full time) the construction of
the modifications and improvements to the Allen Steam Station, Flue Gas Desulfurization
WWTP, located on 253 Plant Allen Road (NCST 2525), Belmont, in -Gaston County, hereby
state that, to the best of my abilities, due care and diligence was used in the observation of the
following construction:
,`Installation of a -0.577 MGD_ Flue Gas Desulfurization, (FGD) Wastewater Treatment -
Plant, consisting of a 177,120 gallon maintenance tank; a 177,120 gallon equalization
tank; dual 640 gpm forwarding pumps; reaction tank #1 (44,280 gallons) for the addition
of lime (to raise the p1I to 9:2); including a lime slurry feed system consisting -of a 8,000
ft3 lime silo, a 700 gallon lime -slurry tank, and dual 70 gpm lime slurry feed pumps;
reaction tank #2 (9,580 gallons) for the addition of sulfide; including a sulfide feed
system consisting of dual400 gallon tanks and -dual 8 gph feed pumps; reaction tank #3
(9;480 gallons) for the addition of ferric chloride, including a ferric chloride feed system
consisting of a 7,190 gallon tank and.dual 9 gph feed pumps; a flow splitter box;
injection of polymer (just prior to the clarifiers) and a polymer feed system consisting of
dual 400 gallon -tanks and dual 0.4 gph feed pumps; two 40 -foot diameter, 28 -foot side -
water depth clarifiers; a static mixer for the addition of hydrochloric acid (to lower the
pH to 8.0); a hydrochloric acid feed system consisting of a 7,190 gallon'storage tank and
dual 8 gph feed pumps; :three continuous backwashing, 8.33 -foot diameter gravity sand
filters; a 7,140 gallon storage -tank (selenium reduction feed tank); dual 495 gpm bio-
reactor feed pumps;, dual heat exchangers (to reduce the water temperature from 133' F to
95° F); a static mixer for the addition of a molas$es based nutrient; a molasses based
nutrient feed system consisting of a 7,190 gallon storage tank and three 26 gph feed
pumps; first stage selenium reduction bio -reactor (converting Se(IV) and Se(VI) to
elemental selenium Se(0)) consisting of six (6) parallel 18'x 20'x 26'cells tilled with14.3.
feet (depth) ,of activated carbon; dual 106,290 gallon first stage effluent transfer _
compartments (tanks)with three (3) 495 gpm transfer/recycle pumps and dual 3,600 gpm
backwash pumps; a second static mixer for the addition of a molasses based nutrient;
second stage selenium reduction bio -reactor (converting Se(IV) and Se(VI) to elemental
selenium Sc(0)) consisting six (6) parallel 18'x 20'x 26'cells filled with 14.3 feet (depth)
of activated carbon; a 9,990 gallon second stage recycle tank with dual 495 gpm
recycle/recirculation pumps; dual 13,960 gallon effluent tanks and dual 1,200 .gpm
effluent pumps; dual 99,770 gallon backwash holding compartments (tanks) with dual 70
gpm. backwash waste return pumps; a sludge treatment system consisting of six (clarifier)
125 gpm sludge transfer pumps, a 177,120 gallon sludge holding tank, three 550 gpm
filter press fast fill pumps, six 70-.gpm-filter press pressurization pumps, three (3) 1.5
meter, 250 ft -3 filter presses, three (3) sludge truck loading stations, and a 31,800 -gallon
filtrate sump pump station with dual 600 gpm. filtrate sump pumps; associated yard
piping, :access roads and site work, in conformity with the project plan, specifications,
and other. supporting data subsequently filed and approved by the Department of
Environment and Natural Resources.

R
r

'r` } Michael F. Easley, Governor
State of North Carolina
w_ William G. Ross, Jr., Secretary -
Department of Environment and Natural Resources
*r Alan W. Klimek, P.E., Director
Division of Water Quality .
September 11, 2006
Mr. Michael Ruhe
Duke Energy Corporation
P.O. Box 1006
Mail Code EC11E
Charlotte, North Carolina 28201
Subject: Issuance of NPDES Permit
NC0004979
Allen Steam Station
Gaston County
Dear Mr. Ruhe:
Division personnel have reviewed and approved your application for renewal of the subj6ct
permit. Accordingly, we are forwarding the attached NPDES discharge permit. This permit is issued
pursuant to the requirements of North Carolina General Statute 143-215.1 and the Memorandum of
Agreement between North Carolina and the U.S. Environmental Protection Agency dated May 9, 1994 (or
as subsequently amended).
This final permit contains no'significant changes from the draft you were sent on July 5, 2006.
If any parts, measurement frequencies or sampling requirements contained in this permit are
unacceptable to you, you have the right to an adjudicatory hearing upon written request within thirty
(30) days following receipt of this letter. This request must be in the form of -a written petition,
conforming to Chapter 150B of the North Carolina General Statutes, and filed with the Office of
Administrative Hearings (6714 Mail Service Center, Raleigh, North Carolina 27699-6714). Unless such
demand is made, this decision shall be final and binding.
Please note that this permit is not transferable except after notice to the Division. The Division
may require modification or revocation and reissuance of the permit. This permit does not affect the
legal requirements to obtain other permits which may be required by the Division of Water Quality or
permits required by the Division of Land Resources, the Coastal Area Management Act or any other
Federal or Local governmental permit that may be required.
If you have any questions concerning this permit, please contact Toya Fields at telephone
number (919) 733=5083, extension 551.
Sincerely,
(IL- Alan W. Klimek, P.E.
cc: Central Files
Mooresville Regional Office/Surface Water Protection
IDES Unit
Aquatic Toxicology
Marshall Hyatt, EPA Region IV
1617 Mail Service Center, Raleigh, North Carolina 27699-1617 Telephone [phone] FAX [phone]No ehCarolina
512 N. Salisbury Street, Raleigh, North Carolina 27604 On the Internet at http://h2o.enr.state.nc.us/ Nllhmallf
An Equal Opportunity/Affirmative Action Employer

Permit NC0004979
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby revoked. As of
this permit issuance, any previously issued permit bearing this number is no longer effective. Therefore, the
exclusive authority to operate and discharge from this facility arises under the permit conditions, requirements,
terms, and provisions included herein.
Duke Energy Corporation is hereby authorized to:
1. Continue to discharge:
• Once through cooling water (outfall 001)
• Operate a septic tank and ash pond with pH adjustment and discharge domestic
Wastewater, stormwater runoff, ash sluice, water treatment system wastewaters, FGD
system blowdown, and miscellaneous cleaning and maintenance wash waters (002):
• Coal yard sump, overflow (002A) and power house sump overflow (002B)
• Miscellaneous equipment non -contact cooling and sealing water (003)
Miscellaneous non -contact cooling water, vehicle washwater, and intake screen .
backwash (004)
From a facility located at the Plant Allen Steam Station on Plant Allen Road (NCSR 2525),
south of Belmont in Gaston County, and
2. Without adding detergents or chemicals of any kind, discharge Asiatic clam/debris filter
backwash (of the intake filter screen) (see Part A.7); and
3. After receiving an Authorization to Construct from the Construction Grants and Loans
Section, construct and operate a FGD wet scrubber wastewater treatment system discharging.
to the ash settling basin through internal outfall 005; and
4. Discharge from said treatment works at the location specified on the attached map into the
Catawba River (outfalls 002, 002A, 002B and 004) and the South Fork Catawba River (outfalls
001 and 003) which are classified Class WS -V B waters, respectively, in the Catawba River
Basin.
2

Duke Energy Corpord,
Allen Steam Station
State Grid/Ouad:
G14NFJBelmont
Permitted Flow: -
Not
Receiving Streams:
Catawba and South Fork Catawba Rivers
Stream Class:
WS -V & B
Drainage Basin:
Catawba River Basin
Sub -Basin:
03-(
Latitude (001):
35° 11'23" N
Longitude (001):
81°
Latitude (002):
35° 10'30" N
Longitude (002):
81°
Latitude (002A):
35° 11'34" N
Longitude (002A):
81°
Latitude (002B):
350 11'36" N
Longitude (002B):
81°
Latitude (004):
35° 11'35" N
Longitude (004):
81°
Latitude (A. Clam):
35° 11'36" N
Longitude(A. Clam):S?
v
e
ion Map not to scale
_g3
4 Facility
23" W Location �' }
22" W,�.
30" W
22" w NPDES Permit No. NC0004979
30" W NOY'th I I Gaston County

Permit NC0004979
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 001)
During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is
authorized to discharge from outfall 001- Condenser Cooling Water (CCW). Such discharges shall be limited
and monitored by the Permittee as specified below:
EFFLUEN�-81T ` , LIMITFS MONITORING ;REQUIREMENTS
°tE k - t
3a Monthly Daily Measurement �5ample�Type Sample°Location
rt €.
re uenc
Flow Baily Pump Logs Effluent
Temperature 38.9 °C Grab or
(June 1— September 30)1 (102 °F) Daily Instantaneous Effluent.:
Temperature 1 35 °C Daily Grab or Effluent
(October 1— May 31)1 (95 ,°F)Instantaneous
Notes:
1. The Regional Administrator has determined pursuant to Section 316(a).of the Act that the thermal
component of the discharge assures the protection and propagation of a balanced, indigenous population of
shellfish, fish, and wildlife in and on the receiving body of water.
Chlorination of the once through condenser cooling water, discharged through outfall 001, is not allowed,
under this permit. Should Duke Power wish to chlorinate its condenser cooling water, a permit
modification must be requested and received prior to commencing chlorination. .
3

IS
Permit NCO094979
A. (2.) EFFLUENT LIMITATIONS ND MONITORING REQUIREMENTS (Outfall 002)
During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is
authorized to discharge from outfall 002'— as pond effluent. Such discharges shall be limited and monitored
by the Permittee as specified below:
EFFLUENTS'
` LIMITS
F
MOT��IITORING
ItEQUIREltiIENTS
yy
.�
CHARACTERISTICS ,
E }
.b hs ' l
�V
e : .
4 9 ' i.0 `� li
� ::b j�'
� � k`t- d• A
°t'�
t -K � £ �, ,. d
1p Week y
Daily
Measurement
d
Sample Type
Saniple'�f ocation
Avera
'i j
I E 3
6
y_..: a
e.1 ka Aer e.....Maximum_Am
Flow
Weekly
Instantaneous
Influent or
or Estimate
Effluent
Oil and Grease
15.0 mg/1
20.0 mg/1
Quarterly
Grab
Effluent
Total Suspended Solids
30.0 mg/l
100.0 mg/1
Monthly
Grab
Effluent
Total Copper2
1.0 mg/1
2/Month
Grab
Effluent
Total Iron
1.58 mg/l
Monthly
Grab
Effluent '
Total Seleniumz,3
31.0 Vg,
L
2/Month
Grab
Effluent.
Total Selenium2.4
21.0 lzg%L
2/Month
Grab
Effluent
Total Nitrogen
+
Semi-annually
Grab..
Effluent
(NO2 NO3 + TKN)
Chronic Toxicity'
Quarterly
Grab
Effluent
pHs
Monthly
Grab
Effluent
Notes:
1. Whole Effluent Toxicity shall be monito
conducted in January, April, July and O
2. Total metals are defined by 40 CFR 136.
analysis.
3. 31 pg/L selenium limit shall be in effect
4. 21 pg/L selenium limit shall take effect
5. The pH shall not be less than 6.0 standa
There shall be no discharge of
red by chronic toxicity (Ceriodaphnia) P/F at 24%. Tests shall be
ct ber (see Part A.(9.) for details)
y method specified by 40 CFR 136 is considered acceptable for
ctober 1, 2006 through September 30, 2009.
October 1, 2009.
rd units nor greater than 9.0 standard units.
)ating solids or foam visible in -other than trace amounts.
.19

Permit NC0004979
A. (3.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 002A)
During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is
authorized to discharge from outfall 002A — Coal Yard Sump Overflows. Such discharges shall be limited and
monitored by the Permittee as specified below:
Flow
Episodic
Estimate
Effluent'
pH
Episodic
Grab
Effluent
Oil and Grease2
15.0 mg/l
20.0 mg/1
Episodic
Grab
Effluent
Total Suspended Solids2
30.0 mg/l
100.0 mg/l
Episodic
Grab
Effluent
Fecal Coliform
Episodic
Grab.
Effluent
Total Iron3
1.0 mg/l
Episodic
Grab
Effluent
Notes
1. Effluent sampling shall be conducted at a point upstream of discharge to the receiving stream.
2. Monthly average limits for total suspended solids and oil and grease only apply if the overflow occurs for
more than 24 hours.
3. Sampling for iron is required only when TSS is reported as greater than 100 mg/L.
There shall be no discharge of floating solids or foam visible in other than trace amounts
All flows shall be reported on monthly DMRs. Should no flow occur during a given month, the words "no
flow" should be clearly written on the front of the DMR. Episodic sampling is required per occurrance
when sump overflows occur for longer than one hour. All samples shall be of a representative discharge.
5

Permit NC0004979
A. (4.) EFFLUENT LIMITATIONS A D MONITORING REQUIREMENTS (Outfall 002B)
During the period beginning ,on the effective date of this permit and lasting until expiration, the Permittee is '
authorized to discharge from outfall 002B — lower House Sump Overflows. Such discharges shall be limited
and monitored by the Permittee as specified :)elow:
EFFLUENTLIIVIITS
3MOIVITORINGf
I3.EQU REMENTS
CIARACERIS ICSH
'
�s
7-1
Sample Type
SarnpleL�ocat�on
3EMonflily
.h--. LFTs
���
Flow .
Episodic
Estimate
Effluent'
pH
Episodic
Grab .
Effluent
Oil and Greasez
15.0 mg/l
20.9
mg/l
Episodic
Grab
Effluent
Total Suspended-Solids2
30.0 mg/1
100.b
mg/l
Episodic
Grab
Effluent
Total Copper3
1.0
mg/l
Episodic
Grab
Effluent
TotalIron3
1.0mg/l
Episodic
Grab
Effluent
Notes
L'. Effluent sampling shall be conducted at a point upstream of discharge to the receiving stream.
2. Monthly average limits for total suspendi d solids and oil and grease only apply if the overflow occurs for
more than 24 hours.
3. The limits for total copper and total iron only apply during a chemical metals cleaning.
There shall be no discharge of flo ting solids or visible foam in other than trace amounts
All flows shall be reported on monthly DN[Rs. Should no flow occur during a given month, the words `.'no
flow" should be clearly written on the front of the DMR. Episodic sampling is required per occurrance
when sump overflows occur for longer th n one hour. All samples shall be of a representative discharge.
rel

Permit NC0004979
A. (5.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 003)
During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is
authorized to discharge from outfall 003 — miscellaneous equipment non -contact water and sealing water.
Such discharges shall be limited and monitored by the Permittee as specified below:.
EFI,LTENT 4LIMITS , r MONITORING =REQITIREMENTSu '
Monthly Daily 1VleasurementFSample Type Sample Location
x' sr s
� r � Avera a f dXIIIlIIin Fr8 rtenC
_
,.�__,rS _F_ _sw, ..... a _, add• .,.�< ... .R. <." _ ........- _..,..� .._,. . _ s�.. ..:`5aw...
Flow Weekly Estimate Effluent
Chlorination of the once through cooling water, discharged through outfall 003, is not allowed under this
permit. Should Duke Power wish to chlorinate its once through cooling water, a permit modification must
be requested and received prior to commencing chlorination.
A.'(6.) .EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 004)
During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is
authorized to discharge from outfall 004- miscellaneous non -contact cooling water, vehicle washwater, and
intake screen backwash. Such discharges shall be limited and monitored.by the Permittee as specified below:
�EFFL7EN'T �'* �� � ` LIMITS �: � �E � ��� "sgMONI�TORI1�tG�REQZIIREMENTS` �'
MonEhly Dai ly Measurement s Sample Type Sam le lrocation
axilIlum ' Fre uenc
M"
Flow Weekly Estimate Effluent
Oil and Grease 15.0 mg/l 20.0 mg/l Quarterly Grab Effluent
Chlorination of the once through cooling water, discharged through outfall 004, is not allowed under this
permit. Should Duke Power wish to chlorinate its condenser cooling water, a permit modification must be
requested and received prior to commencing chlorination.
7

Permit NC0004979
A. (7.) EFFLUENT LIMITATIONS ND MONITORING REQUIREMENTS (Internal
Outfall 005)
During the period beginning upon submittal of an engineer's certification and lasting until permit expiration,
the Permittee is authorized to discharge fro internal outfall 005- treated FGD wet scrubber wastewater to ash
settling basin. Such discharges shall be limed and monitored by the Permittee as specified below:
EFFLUENT
LI
ITS'' _
MONITORING REQUIREMENT'S F
CHARACT3R19TiCSs
E
Monthl
¥ Daily E,EMeasurement
Sam` le �Samgle3
gyp.
Avera a
fi
Fre., uenc T hocaioni
:
„Maximum
: e
Pump logs or.
Flow
Monitor
& Report
Monthly
similar
Effluent
readings
Total Suspended Solids
Monitor
& Report.
Weekly
Grab
Effluent
Carbonaceous Oxygen Demand
Monitor
& Report
Weekly
Grab
Effluent
(COD) .
Total Arsenic
Monitcir
& Report
Weekly
Grab
Effluent
Total Cadmium
Monitoir
& Report
Weekly
Grab
Effluent
Total Chromium .
Monito� & Report
Weekly
Grab
Effluent
Chloride
Monit4 & Report
Weekly
Grab
Effluent
Total Mercury
Monit4 & Report
Weekly
Grab
Effluent
Total Nickel
Monit4 & Report
Weekly
Grab
Effluent
Total Selenium
Monitor & Report
Weekly
Grab
Effluent
Total Silver
Monit4
& Report
Weekly
Grab
Effluent
Total ZincMonito
& Report.
Weekly
Grab
Effluent
Total Beryllium
Monito
& Report
Weekly
Grab
Effluent
Notes:.
1. "Effluent' shall be defined as the disch,
to the ash settling basin.
All flows shall be reported on monthly Dr
flow" shall be clearly written on the front
DMRs for this outfall shall be submi
e from the FGD wastewater treatment system prior to discharge
s. Should no flow occur during a given month, the words "no
the DMR. All samples shall be of a representative discharge.
d only after discharge commences from the FGD system.
Sampling is only rE quired when this outfall is discharging.
A. (8.) SPECIAL CONDITION FOR JHE DISCHARGE OF ASIATIC CLAM/DEBRIS
FILTER BACKWASH
The permittee may backwash the intake filter for Unit 5 condenser cooling water on an as -needed basis. It is
understood that this wash water will contain materials indigenous to the Catawba River such as Asiatic clams
and light debris. As these are naturally occurring in the river environment, they may be discharged with no
adverse affects to the receiving stream. The Permittee may not add any detergent, chemicals or other non -
indigenous material to the wash water without explicit permission of the Division of Water Quality.
N.

Permit NC0004979
A. (9.) CHRONIC TOXICITY PASS/FAIL PERMIT LIMIT (QUARTERLY),
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant mortality to
Ceriodkphnia dubia at an effluent concentration of 24%:
The permit holder shall perform at a minimum,uaq rterly monitoring using test procedures outlined in the "North.
Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised February 1998, or subsequent versions or
"North Carolina Phase H Chronic Whole Effluent Toxicity Test Procedure" (Revised -February 1998) or subsequent
versions. The tests will be performed during the months of January, April; July and October. Effluent sampling for
this testing shall be performed at the NPDES permitted final effluent discharge below all treatment processes.
If the test procedure performed as the first test of any single quarter results in a failure or ChV. below the permit
limit, then multiple=concentration testing shall be performed at a minimum, in each of the two following months
as described in "North Carolina Phase II Chronic Whole Effluent Toxicity Test Procedure" (Revised -February
1998) or subsequent versions.
The chronic value for multiple concentration tests will be determined using the geometric mean of the highest
concentration having no detectable impairment of reproduction or survival and the lowest concentration that does
have a detectable impairment of reproduction or survival.. The definition of "detectable impairment," collection
methods, exposure regimes, and further statistical methods are specified in the "North Carolina Phase II Chronic
Whole Effluent Toxicity Test Procedure" (Revised -February 1998) or subsequent versions.
All toxicity testing results required as part of this permit condition will be entered on the Effluent Discharge
Monitoring Form (MR -1) for the months in which tests were performed, using the parameter code TGP3B for the
pass/fail results and THP3B for the Chronic Value. Additionally, DWQ Form AT -3 (original) is to be sent to the
,following address:
Attention: North Carolina Division of Water. Quality_
Environmental Sciences Section
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Completed Aquatic Toxicity Test Forms shall be filed with the Environmental Sciences Branch no later than 30 days
after the end of the reporting period for which the report is made.
Test data shall be complete, accurate, include all supporting chemical/physical. measurements and all
concentration/response data, and be certified by laboratory supervisor and ORC or approved designate signature.
Total residual chlorine of the effluent toxicity sample must be measured and reported if chlorine is employed for
disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring is required, the
permittee will complete the information located at the top of the aquatic toxicity (AT) test form indicating the facility
name, permit number, pipe number, county, and the month/year of the report with the notation of "No Flow" in the
comment area of the form. The report shall be submitted to the Environmental Sciences Branch at the address cited
above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required, monitoring will be
required during the following month.
Should any test data from this monitoring requirement or tests performed by the North Carolina Division of Water
Quality indicate potential impacts to the receiving stream, this permit may be re -opened and modified to include
alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such asminimum control organism
survival, minimum control organism reproduction, and appropriate environmental controls, shall constitute an
invalid test and will require immediate follow-up testing to be completed no later than the last day of the month
following the month of the initial monitoring.
0

Permit NC0004979
A. (10.) BIOCIDE CONDITION
The permittee shall not use any biocides exc�,
permittee shall notify the Director in writing
additional biocide used in cooling systems
reported to the Division of Water Quality. Su
Form 101 and a map locating the discharge p
101 is not necessary for those outfalls contai
introduction of a new biocide into an outfall �
A. (11.) SPECIAL CONDITIONS
The following special conditions are applical;
• There shall be no discharge of polychlori
• It has been determined from information
Station are equivalent to that of a BMP.
• The permittee shall report the presence o
• The applicant is permitted to discharge c
outlined in the 1976 Riverbend Ash Basir
permit application
• The permittee shall check the diked area;
detected
• If the permittee, after monitoring for at le
effluent limits contained herein, the perry
be reduced to a lesser frequency. ,
• Nothing contained in this permit shall be
may have pursuant to State or Federal la,
• Low volume waste is defined as follows I
"Low volume wastes sources include, bu
control systems, ion exchange water treat
and sampling streams, boiler blowdown,
house service water systems. Sanitary ar
pt those approved in conjunction with the permit application. The
not later than ninety (90) days prior to instituting use of any
ch may be toxic to aquatic life other than those previously
ch notification shall include completion of Biocide Worksheet
oint and receiving stream. Completion of Biocide Worksheet Form.
ming toxicity testing. Division approval is not necessary for the
currently being tested for toxicity:
le to all outfalls regulated by NC0004979:
iated biphenyl compounds. "
submitted that the plans and procedures in place at Allen Steam
`.cenospheres observed in any samples.
iemical metal cleaning wastes to the ash basin under the conditions
Equivalency Demonstration and the 1994 Allen Steam Station'
for leaks by a visual inspection and shall report any leakage
.st six months, determines that he/she is consistently meeting the
ttee may request of the Director that the monitoring requirement
:onstrued as a waiver by the permittee or any right to a hearing it
,s or regulations.
is per 40 CFR 423.11(b):
are not limited to: wastewaters from wet scrubber air pollution'
nent system, water treatment evaporator blowdown, laboratory
loor drains, cooling tower basin cleaning wastes, and recirculating
I air conditioning wastes are not included,"
A. (12.) SECTION 316 (B) OF CWA
The permittee shall comply with the Cooling Nater Intake Structure Rule per 40 CFR 125.95.
10

NCDENR/DWQ
FACT SHEET AMENDMENT
Duke Energy Corporation - Allen Steam Station
NC0004979
'
Notes:
1. 30Q2 for the Catawba River has been defined as the minimum daily average release at Mountain Island
Hydro.
2. Average flow (QA) for the Catawba River has been defined as mean annual flow based on operations
records from 1929 to 2003 at Mountain Island Hydro.
1.0 Proposed Changes Incorporated Into Permit Renewal
• Add language allowing the construction of the FGD system and the dry ash handling system.
• Add monitoring requirements at internal outfall 005 (treated FGD wet scrubber wastewater to
.ash settling basin).
• Remove arsenic limit and monitoring requirement due to lack of reasonable potential for
levels of -this parameter to cause an exceedance of water quality standards.
• Add 3 -year compliance schedule for 21 Vg/L selenium limit to coincide with the estimated
completion date of the dry ash handling system.
2.0 Summary
Selenium Compliance Schedule
During the comment period, Duke Power and Division staff met to discuss several proposed
changes to the draft permit. The primary point of concern involved the increase in IWC and the
resulting change in permit limits (particularly selenium). Duke indicated that at this time they
would have difficulty meeting the selenium limit, however they will be installing a dry ash
handling system that is expected to cut flows in half. Since the IWC calculation is based on actual
flows, a reduction in flow would decrease the IWC and therefore increase the allowable selenium
limit. Duke has asked Division staff to allow 3 years for the construction of the treatment system
before the 21 ug/L selenium limit takes effect. Until that time, the existing limit of 31 pg/L will
remain in the permit.
Facility Information
(1.) Facility Name:
Allen Steam Station
_..._................................._.........-----............---............._.._.....................
(2.) Permitted Flow (MGD):
_...._.............._.._..........................._.__.._...._................_......._._._.__..................._.._....__.............,._._._..__...............__......._._....__._.._.__...._...
No flow limit (6.) County:
------.......
Gaston
(3.) Facility Class:
I (7.) Regional Office:
Mooresville
................----..........._............................................................_._......................................_
(4.) Pretreatment Program:
....... __......................................................................................................_._...._....................._.._..._........................................._........;..._........................__..............---...._...._.......
N/A i (8.) USGS Topo Quad:
_.............. ...._......_.... _...........
G14NE
(5.) Permit Status:
Renewal '; (9.) USGS Quad Name:
Belmont
Stream: Characteristics
(1J Receiving Stream:
Catawba / j (7.) Drainage Area (mi2):
??/635
South Fork
Catawba Rivers
_....._...- -------._._...__._......_... ---._.._._.._.........._............._
(2.) Sub -basin:
..................._......__..._..........._.._..._..__....................... _- ................ ---- ----- - -
03-08-34 (8.) Summer 7Q10 (cfs):
- .__.._........ _ _-.........--- ---- ---._...._._.
95/124
_._....._... ------ - ...-—....---........_......_.___....._._._
(3.) Stream Index Number:
................................_..... -........:._.....................- -..__......._......._..---._....._.........._..._.......
11-123.5 j (9.) Winter 7Q10 (cfs):
......................._._........ -............. -..... -.--........... .._..._.-.....
95/227
(4.) Stream Classification:
WS -1 B j (10.) 30Q2 (cfs):
3141/309
........................_...................._.—._......_....................................._.._._...._......................
(5.) 303(d) Status:
_........ .._...__.._...__.._._............. .......-----......................................._.._..............................._.._..._....__.......__._.....;._._...._..._........_....._..................................._
Not listed (11.) Average Flow (cfs):
..... _......................................
2,4702/806 _
- -
(6.) 305(b) Status:
- j (12.) IWC %:
24 (Outfall 002)
Notes:
1. 30Q2 for the Catawba River has been defined as the minimum daily average release at Mountain Island
Hydro.
2. Average flow (QA) for the Catawba River has been defined as mean annual flow based on operations
records from 1929 to 2003 at Mountain Island Hydro.
1.0 Proposed Changes Incorporated Into Permit Renewal
• Add language allowing the construction of the FGD system and the dry ash handling system.
• Add monitoring requirements at internal outfall 005 (treated FGD wet scrubber wastewater to
.ash settling basin).
• Remove arsenic limit and monitoring requirement due to lack of reasonable potential for
levels of -this parameter to cause an exceedance of water quality standards.
• Add 3 -year compliance schedule for 21 Vg/L selenium limit to coincide with the estimated
completion date of the dry ash handling system.
2.0 Summary
Selenium Compliance Schedule
During the comment period, Duke Power and Division staff met to discuss several proposed
changes to the draft permit. The primary point of concern involved the increase in IWC and the
resulting change in permit limits (particularly selenium). Duke indicated that at this time they
would have difficulty meeting the selenium limit, however they will be installing a dry ash
handling system that is expected to cut flows in half. Since the IWC calculation is based on actual
flows, a reduction in flow would decrease the IWC and therefore increase the allowable selenium
limit. Duke has asked Division staff to allow 3 years for the construction of the treatment system
before the 21 ug/L selenium limit takes effect. Until that time, the existing limit of 31 pg/L will
remain in the permit.

NPDES Permit Amendment — 06/28/06
Page 2
Duke Power/ Allen Steam Station
NC0004979
Removal of Arsenic Limit
During the comment period, Duke was able to provide updated 30Q2 and QA values. The RPA
was recalculated using 30Q2= 314 (minimum daily average release as defined in the FERC
license) and QA = 2470 cfs (mean annual flow based on 1929-2003 data for mountain Island
Hydro). Based on this data, there is no longer reasonable potential for an exceedance of arsenic
water quality standards. The RPA yielded a maximum predicted concentration of 203.5 Pg/L
and an allowable concentration of 853 pg/L. The arsenic limit and monitoring requirements will
be removed.
Construction of Flue Gas Desulfurization and Dry Ash Handling Systems
Duke plans to install two major pollution control systems at Allen Steam Station in 2009: a Dry
Ash Handling system and a Flue Gas Desulfurization (FGD) system. The Dry Ash Handling
system will decrease the flow and pollutant loading to the ash basin (Outfall 002). The FGD
system will introduce an additional wastewater stream that will be treated by a dedicated
wastewater treatment system (WWTS). Effluent from the WWTS will discharge to the ash basin,
where additional treatment will occur prior to discharge. Once both systems are installed, the
flow rate from the ash basin is expected to be reduced by approximately 50%.
Duke provided expected pollutant concentrations based primarily on models and the analysis of
coal. In some situations, literature research was used along with analytical results from current
FGD sites.

7

• ' l
NPDES Permit Amendment - 06/28/06
Page 3
Flue Gas Desulfurization Wastewater Characteristics
Duke Power/ Allen Steam Station
NC0004979
Potential
Parameters of
Concern
Projected
Average
concentrations
in FGD
wastewater
(K L)
Projected
Concentrations
after WWTS
(pg/L)
Projected
Average
Concentrations
at Outfall 002
(pg/L)
Applicable
Water
Quality
Standards
(pg/L)
Antimony
0.02
0.01
0.01
5.6E
Arsenic
0.28
<0.1.4
0.14
10c
Barium
4.9
<2.5
0.52
1000
Beryllium
0.035
<0.02
<0.0005
0.0068c
Boron
20
10
1.54
750E
Cadmium
0.07
0.035
<0.0005
15.OA
COD
450
225
31
Chloride
2997
1499
184
250000
Chromium
0.40
0.20
0.06
1022A
Cobalt
0.37
0.18
<0.030
-
Co er
0.44
0.22
0.04
7.3A
Fluoride
52.2
26.1
3.46
1800
Lead
0.30
0.15
0.02
33.8A
Manganese
5.74
2.8
0.40
200
Mercury
0.35
0.0005
<0.0001
0.012
Molybdenum
0.43
0.21
0.07
-
Nickel
0.70
0.40
0.06
261A
Selenium
6.9
0.05
0.01
56A
Silver
0.07
0.03
<0.005
1.23A
Sulfate
1500
750
142.1
250000
Temperature
133 OF
95 OF
Ambient
Narrative
Thallium
0.22
0.11
0.01
0.35E
TSS
16000
15
10
-
Vanadium
0.21
0.11
0.01
24E
Zinc
0.37
0.18
0.04
67A
C= carcinogen
A= acute criteria
E= EPA criteria
Duke has received permit modifications at several other plants for the addition of FGD systems.
Each of those has received monthly flow monitoring as well as weekly monitoring at an internal
outfall (discharge to ash basin) for the following parameters:
• TSS 0 Chloride 0 Silver
• Arsenic • Mercury 0 Zinc
• Cadmium 0 Nickel
• Chromium 0 Selenium
In addition, the following appear to be potential pollutants of concern at this facility and will also
be monitored:
• Beryllium
• COD

I
MkDuke
(Power®
January 24, 2006
To: Susan Wilson
North Carolina Department of Environment
and Natural Resources
Division of Water Quality
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Subject: Allen Steam Station
NPDES Permit No. NC0004979
NPDES Permit Modification Request
Dear Ms. Wilson:
PROCUREMENT, CONSTRUCTION AND EH&S
Duke Power
526 South Church St.
Charlotte, NC 28202
Mailing Address:
EC13K / P. 0. Box 1006
Charlotte, NC 28201
J W c
�ra 4
gi-& 2 6 2006
DENR - WATER QUALITY
POINT SOURCE BRANCH
Duke Energy Corporation (Duke) plans to install two major pollution control systems at Allen Steam
Station in 2009, a Dry Ash Handling system and a Flue Gas Desulfurization (FGD) system. The Dry
Ash Handling will significantly decrease the flow and pollutant loading to the ash basin (NPDES Outfall
002). The FGD system will introduce an additional waste water stream. Based on a review of the
projected parameter concentrations (attachment), it is concluded that a dedicated waste water treatment
system (WWTS) will be needed for the FGD system prior to discharge into the ash basin. The average
flow rate of the final discharge from the ash basin is expected to be reduced by approximately 50 %
once these systems are in operation. As required by 40 CFR 122.62, Duke requests the subject NPDES
permit be modified in order to incorporate these two changes.
Enclosed -is a check for $860 to process this permit modification request. In order to maintain the
projected construction schedule for implementation of the North Carolina Clean Air Initiative
requirements, approval of this permit modification is requested by May 1, 2006. Upon receipt of the
permit modification, the WWTS design will be completed and Duke will submit an application for
"Authorization to Construct" the additional WWTS to the North Carolina Department of Environment
and Natural Resources Construction, Grants and Loan Section.
Your efforts to complete this permit modification in a timely manner are much appreciated. If you have
questions or need additional information on this permit modification request, please contact Robert
Wylie at [phone].
Sincerely,
Daniel A. Markley, Manager
Environmental Support
cc: Ms. Caroline Ejimofor - USEPA Region IV
Attachments www.dukepower.com

R.R. Wylie
bc: Don Scruggs
Steve Immel
George Everett
Mark Hays
Allen Stowe
Ron Lewis
Tim Ervine
Tracy Beer
Richard Baker
Allen Steam Station
Allen Steam Station
EC 12H
EC11E
EC13K
EC13K
EC13K
EC11I
EC11Y
Record Number: 404.110.01 (Allen Steam Station)

ALLEN STEAM STATION
FLUE GAS DESULFURIZATION
WASTEWATER CHARACTERISTICS AND INFORMATION
Attachment
Wastewater from the FGD system is projected to have concentrations as identified below. Treatment for
this wastewater is to be provided by an additional wastewater treatment system (WWTS). The effluent
from this WWTS treatment system is to be discharged into the ash basin where additional treatment will
occur prior to the discharge at NPDES outfall 002. The average flow rate for the FGD waste stream is
calculated to be 1.2 mgd. With the addition of the FGD system and also the Dry Ash Handling system,
the projected average flow rate from the current wastewater treatment system is expected to drop to
approximately 10 mgd.
PROJECTED
PARAMETERS
IN FGD
WASTEWATER
PROJECTED AVER.
CONCENTRATIONS
IN FGD
WASTEWATER
�m 1
PROJECTED AVER.
CONCENTRATIONS IN
FGD WASTEWATER
AFTER NEW
TREATMENT SYSTEM
(ppm)
PROJECTED AVER.
CONCENTRATIONS
AT OUTFALL 002
(ppm)
Antimony
0.02
.01
0.01
Arsenic
0.28
<0.14
0.14
Barium
4.9
<2.5
0.52
Beryllium
0.035
<0.02
<0.0005
Boron .
20
10
1.54
Cadmium
0.07
0.035
<0.0005
COD
450
225
31
Chloride -
2,997
1,499
184
Chromium,
0.40
0.20
0.06
Cobalt
0.37
0.18
<0.030
Copper -
0.44
0.22
0.04
Fluoride
52.2
26.1
3.46
Lead -
0.30
0.15
0.02
Manganese
5.74
2.8
0.40
Mercury
0.35
0.0005
<0.0001
Molybdenum
0.43
0.21
0.07
Nickel
0.70
0.40
0.06
Selenium
6.9
0.05
0.01
Silver
0.07
0.03
<0.005
Sulfate
1,500
750
142.1
Temperature
133 F
95 F
Ambient
Thallium-
0.22
0.11
0.01
TSS
16,000
15
10
Vanadium
0.21
0.11
0.01
Zinc
0.37
0.18
0.04
1 The projected concentrations are based primarily on models and the analysis of coal. In some
situations literature research was used along with analytical results from current FGD sites.
2 COD is dependent on the usage of dibasic acid (DBA).

PU13LIG, N�UTIU ter w' x
4 r
$TATE O �IORTI°
AFFIDAVIT OF INSERTION OF
ADVERTISEMENT
The Gaston Gazette
Gastonia, NC
Gaston County
I, Melissa Birchfield Legal Advertising Clerk of the The Gaston Gazette, do
the advertisement of
PUBLIC NOTICE—NOTIFICATION OF INTENT TO
A NPDES WASTEWATER PERMIT
Measuring 10.66 inches appeared in The Gaston Gazette, newspaper publishe in G,
County, Gastonia, NC, in issues
L Jul
JULY 8, 2006`?
kLeelisa irchfielAdvertising Clerk
Sworn to and subscribed before me this [J day of J-�-! 2(
Carla Norris Potter, Notary Public
My Commission Expires September 14, 2008
'affect future allocations `rc '
this'`portwrl ofi the Catawba ;'
River -Basin - s
ic,iuiyat200s
.I

� � c'

State of North Carolina
Department of Environment
•
and Natural Resources
Division of Water Quality
Michael F. Easley, Governor
NCDENR
William G. Ross, Jr., Secretary
Alan W. Klimek, P.E., Director
NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
July 3, 2006 }
-05
MEMORANDUM IN � '
y
To: Britt Setzer
'JUL a :11110
NC DENR / DEH / Regional Engineer
Mooresville Regional Office ®
IUl ; I
From: Toya Fields
Point Source Branch ' 'JUL 1 0 2006
Subject: Review of Draft NPDES Permit NCO04979 DENR
AllPOINT
Allen Steam Station WATER QUALITY
Gaston County POINT SOURCE BRANCH
Please indicate below your agency's position or viewpoint on the draft permit and return this form by August 6,
2006. If you have any questions on the draft permit, please contact me at the telephone number or e-mail address
listed at the bottom of this page.
RESPONSE: (Check one)
Concur with the issuance of this permit provided the facility is operated and maintained properly, the stated effluent limits
LA i are met prior to discharge, and the discharge does not contravene the designated water quality standards.
Concurs with issuance of the above permit, provided the following conditions are met:
F-1
F-1
Opposes the issuance of the above permit, based on reasons stated below, or attached:
Signed 41XDate: °7 s - /o
1617 Mail Service Center, Raleigh, North Carolina 27699-1617 919 733-0083 (fa)o 919 733-0719
VISIT us ON THE INTERNET @ http://h2o.enr.state.nc.us/NPDES

f