I N DIANA DEPARTMENT
OF ENVIRONMENTAL MANAGEMENT W e Pr o t ec t H oos
i e r s a n d Our En v iro n m e nt. Michae

l R. Pence Gove r no r Mr. Robert Kaplan Acting Regional Administrator U.S. EPA, Region
5 77 West Jackson Bou

l evard Chicago,
IL 60604-3950 Dear Mr. Kaplan:

100 N . Sen a t e A venue

• Indianapolis

, IN 4 6 204 (800

) 451

- 60 2 7 • (317
) 2 3 2- 8 603

• www

. idem

. IN .g o v February
5, 2016
Carol S . Comer Commissioner Re: State Imp lementation Plan Submitta

l for Indi ana Regarding 1-Hour S0 2 Attainment C lifty Creek Generating Station
in Jefferson County, Indi ana; Request for Parallel Processing (Commissioner's Order #2016-02) Pursuant to Section 110 of the C

l ean Air Act and Tit le 13 of the Indiana Code, the Indiana Department
of Environmental Management

( IDEM) submits

a request for parallel processing
of an amendment

to the Indiana state implementation plan (S IP ). IDEM requests that United States Environmental Protection Agency (U.S. EPA) approve the requirements for Clifty Creek Generating Station (C lift y C r eek) in Comm

i ss

i oner's Order #2016-02. ID EM issued
a Commissioner's Order on Febr u ary 1, 2016, to establish permanent and enforceab

l e su lfur dioxide (S0 2 ) emission limit s for Clifty Creek,

l ocated
in Jefferson County, Indi ana, in order to ensure continued attainme nt of the 2010

1 - hour sulfur dioxide (S0 2 ) standard
in the area surrounding the facility. The Comm

i ssioner's Order contains

a facility-wide maximum 720 operating hour S0 2 rolling average mass emission rate app

li cab

l e to Units
1 through

6 combined, as well as reporting and recordkeeping requirements and method for compliance. The effective date for the emission limitations

in the Commissioner's Order

i s April19, 2016

. It contains and meets the requirements set forth in 42 U

. S.C

. § 7407(d)(3)(E)(i

ii) and the conditions will become app

l icable requ

i rements as defined
in 326 lA C 2-7
- 1(6).

· The rulemaking documentation

is being forwarded
to U.S. EPA with a request for para

ll e l process ing whi

l e IDEM completes the steps necessary for publ

i c notice

. When the public notice process

is complete, this SIP submitta

l wil

l be supp

l emented with an addendum that includes the public notice documentation. The public notice period

i s scheduled
to end on March 4, 20 1 6. A n E qu a l O pp or tunity Em pl oyer



### 0

<i} R ec ycl e d Pap e r A Sta t e that W orks -

## Mr. Robert Kaplan Page 2 of 2 This submittal consists of one (1) hard copy of the required documentation.
An electronic version of the submittal

in PDF format that is identical to the hard copy has been sent Doug Aburano, Chief of U.S. EPA Region

5

' s Attainment Planning and Maintenance Section

. In order to assist with your review of this state implementation plan submission

, a list of supporting documents

is attached. Throughout the development

of this Commissioner

' s Order

, staff of the Office of Air Quality worked clo s ely with your staff to ensure that any pot e ntial problems that might exist with this requested state implementation plan revision would be resolved.

I request that U.S

. EPA approve this modification
of Indiana

' s state implementation plan

. If you have any quest

i ons or need additional information

, please contact Scott Deloney, Chief, Air Programs Branch

, at (317) 233-5694

. KB/mad Attachments: Supporting Documents Sincerely, 

# (drz~ Keith Baugues Assistant Commissioner Office of Air Quality cc
: Doug Aburano,

U

. S. EPA Region
5 (no enclosures) John Mooney, U.S

. EPA Region
5 (no enclosures) Steve Rosenthal, U.S. EPA Region
5 (no enclosures) Pamela Blakley,

U

. S. EPA Region
5 (no enclosures) John Summerhays, U.S

. EPA Region
5 (no enclosures) Keith Baugues, IDEM-OAQ (no enclosures) Scott Deloney, IDEM-OAQ (no enclosures) Mark Derf

, IDEM-OAQ (no enclosures) Mike Mosier, IDEM-OAQ (no enclosure) Christine Pedersen, IDEM-OAQ (no enclosures) Jessica Reiss, IDEM-OAQ (no enclosures) File CopySupporting Documents Attachment
A: Administrative Checklist (40 CFR 51, Appendi

x V) Attachment

8: Commissioner's Order #2016-02 Attachment
C: Legal Notice of Public Hearing and Certificates
of W e b Publication Attachment

D : Modeling Summary Data

, calculations and m e thodology for determining

a facility- w ide ma x
i m um 7 2 0 operating hour rolling average S0 2 mass emission rate based on Cl

i fty Creek

' s continuous emission monitoring data (available upon request).Attachment

A Administrative Checl < list

## ADMINISTRATIVE CHECKLIST (40 CFR 51, Appendix V) 1. The submitta

l is accompanied
by a formal

l etter of submitta

l from the governor or his designee. 2 . Evidence that the State has adopted the plan in the State code or body of regulations;
or issued the pennit, order, consent agreement ("document");

in final form. a. Date of adop tion o r fin a l issuance: b. The effective

d at e of the plan, if different from the adopt io n/issuance date. 3. 

## Evidence that the State has the necessary legal authority under state law to adopt and implement the p l an. 4. A copy of the actual regulation
or document submitted for approval and incorporation
by reference into

t h e plan, including the following: a. Indication of the changes made to t he ex i sting approved plan, where applicab

l e . b. The submitta

l shall be a copy of the official State r egulation or document signed, stamped, dated by the appropr

i ate s t ate officia

l indicating that it is fully enforceab

l e by the State

. Effect

i ve date shall be stated in the document

it s elf. 5. Evidence tha t the State followed

a ll of the procedmal requirements
of the Sta t e's laws and constitution
in conducting and completing the adoption/issuance

of the plan. 6. Ev i dence

t hat pub li c notice was given, including da t e of proof of publica
ti on. 7. Certi fi cation that public hearings we r e held in acco rd ance with information provided in public
h ear in g notice. 8. Comp il ation of public comments and State's response. 9. Technical

S upp ort Document (if source specific cha n ge). Enclosed Attac h men

t 

## B January 11, 2016 18 

## days after issuance IC 13-14-1-9 

## IC 13-14-2-1 

## Attachment

B Attaclm1en

t B Attachmen

t C Include in F in a l Addendum Include in Final A dd endum Attaclm1ent

DAttachmentBCommissioner'sOrderforCliftyCreelcGeneratingStationaddressingthe1-hourS02NAAQSJeffersonCounty

### INDIANA DEPARTMENT
OF ENVIRONMENTAL MANAGEMENT W e Pr o t ec t Ho os i e rs and Our Environm

e nt . Michael R. Pence (JO\' «!fi
i OI'
100 N . S e n a te Avenue

**~** Indianapolis,
IN 46 2 04 (800) 451- 6 0 2 7 • (317) 232
- 8603

• www

. id e m

. IN

. gov Carol S. Comer Cm uml u lmwr 

## STATE OF INDIANA COUNTY OF MARTON

)



## ) SS: )



## B E FORE 

## THE INDIANA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT IN 

## THE MATTER OF:

) ORDER, OF THE COMMISSIONER

) · PURSUANT TO IC 13-14

- 2-1

) FOR CLIFTY CREEK GENERATING STATION

) OFTNDIANA

) ) 

## NO T ICE AND ORDER OF THE COMMISSIONER
OF THE DEPARTMENT OF ENVIRONMENTAL MANAGEMENT 

## TJiis Notic e

· and Order of the Commis

s ioner of the D e partm
e nt of Environmental Management ("Order")

is issued pursuant
to Indiana Code

(

" IC") 13-14-1-9, IC 13-14-2-1, and IC 13-14-2

- 7. During the Con1missi9ner's review,
it wa s **d~termin**

**d** 

## that the Petition should be granted ac c ording to the term
s specified below: PETITION 

## Petitioner

i s the Indi a na Kentucky Electric Corporation's, Clifty Cr e ek Gener
a ting Station ("Petition

e r")
, a s tationary

e lectric power plant with Sollrce I.D. Number 077
- 00001

, located at 1335 Clifty Hollow Road in Madison, Jefferson County, Indiana, and permitt

e d under thePatt 70 air operating permit program. On March 2, 2015, the U.S

. District Court ror the North
e rn Di s tri c t o f California accepted a Consent Decree between the U.S. Enviromnental Protection Ag e ncy
(

" U.S. EPA"), the Si e rra Club, and the Natural Re s ource
s Defen

s e Council to resolve litigation conc e rning deadlines for completing one (1) 

## hour sulfur dioxid
e (

" S02") National Ambient Air Quality Standard ("NAAQS") designation

s. Under th e Con
s etit Decree, U.S. EPA mu s t de s ignate certain areas as nonattainment, attaimn.ent, or uncl as sifiable in tlu

· ee phas e s. Tl1 e first Consent Decree pha s e require

s U.S. EPA to designate areas that contain stationary sources that had not b ee n announced for retirement

a s of Mar c h 2 ; 2015 and either emitted more than **16~000** 

## tons of S0 2 

## in 2012 

## or eniitted more than 

# 2 ,600 tons of S0 2 and had ati atmual average emission rat e Of 

## more than 0.45 pounds of S02 per one miliion British thermal units (''lb/MMBtu")

in 2012, according
to U
. S . EPA's Air Qu a lity Market

s Databa

s e. An Equnl Opp o rlunil y Emjll o y c r

1\ S t a t e U 1 a t W orks



## (i) fl ecyd c d f' a p e r 

# -

.ICommissioner's Order No 2016-02 Page2of4 On March 20, 2015,

. U

. S . EPA id e ntifi e . d five (5) so ilrce s in Indian
a that met th e criteria for the first phase of the Consent
D ec ree designations.

U .S. EPA'

s li s t \nclud
e d the Petitioner, Clifty Creek Gen e rating Station.

· On Sept e mber 16, 2015, th e Indiana Department
of Enviromnenta

l Man age ment (

' 'IDEM'') recomm

e nded d es ignation of the area surrounding
Cl if ty Creek G e n e rating Station as attainment. The
r eco mm e ndation was ba s ed on modelin

g that includ
e d op e ration of a flu e gas dcsulfuri za tion system that b eca me operationa

l in 

### July 2 01 3.

· On January 22, 2016

, the Petitioi1er

s ubmitted

a r e quest to th e Comm

i ssioner to impose

a perman

e nt a nd enforceab

l e S 0 2 mas s e mission rate on th e Petitioner in order to e n s me con tinu e d attainm

e nt of th e S02 NAAQS in th e a rea
s urrounding Clifty Creek Gen e rating Station. Th e Petitioner propo se d a fa c ility

- wid e S02 ma ss e mission rate of 2,624.5 S02 pounds per hour (

" lb/hr

" ) , 720 op e rating hom rolling av e rag e, a pplicabl

e to Unit No.
1 tlU'ou g h Unit No. 6, combined.



### FI NDINGS Pmsuant to IC 1 3-14-2-1 (b) and IC 13 -14-2-7(1

), the Commi ss ioner may

i ss ue Orders to secure c01hpliance with Indiana's environmental statutes and rules

, including
th 9 ambient air qu a lity
s tandard for S0 2 at 3 26 Indiana Admini

s tr a tive Code (!'lAC

" ) 1 -3- 4(b)(1)(A). Bas e d on th e foregoin

g information

, ID E M find s th e followin g: 1. A perm a nent and enforceab

l e S0 2 m ass e mission rate for Clifty Cre e k **Genet~ating** Station

· is r eq uir ed in ord e r to mod e l continued attaimnent of th e one (1) hour S0 2 NAAQS in th e ai' ea s urr o undin g the Petitio11er. 2.

I ss uanc e of a Commi ss ion e r' s Order will e nsur e th e S0 2 ma ss e mi ss ion mte
r e main
s p er man e nt and enforceable,

as requir
e d by 42 U.S.C.



### § 7407(d)(3)(E)(i

i i). Wh e rea s revising

a Part 70 Operating Permit would not create **~n** adequa tely

" p e rmanent

" r e quir e m e nt. 3. Approva

l by U .S . EPA of th e Commi ss io ne r' s Ord er as pmt of th e Indian
a State Imple

. m e nta,tion Pl a n ( "S IP

" ) will make th e Order i·equir
e ment
s fed e rally en forc ea bl e. Upon approval as part of th e Indi a na SIP, th e Order

r e quhem

e nts becom
e applicable requirements

as defin
e d in 326 lAC 2-7-'1(6)

.

· 4. Based on moctdin

g c o nduct
e d by ID E M, the S0 2 **m~ ss**  e mi ss ion rat e proposed by the Petition

e r is ad e qu a t e to assure continued attainm

e nt ofthe S02 NAAQS. 

### ORDER 1. Thi

. s Order approves the P e tition

s ubmitted by th e Petitioner accordin

g to th e t ei· ms specified

b e low. This Ord e r itnpo ses on the Petitioner the S0 2 mass emission mte d esc rib e d below. 2 . When any of Unit No. 1 through Unit No. 6, o r any combination thet

' eof, is oper at ing

, th e combined S0 2 m ass e n1issi o n r a te s h a H not excee d 2 ,6 2 4.5 lb/Iu
·, as a 72 0 operating hour roHin g average.

### Commissioner's Order No 2016-02 P age 3 of4 

## 3. The Petitioner shall comply with the 720 operating hour rolling average S02 mass em
i ss ion ra t e beginning Aprill9,

2 016. 4. A s requir
e d by 326 lAC 2.,7-2(d)(l) and 326 lAC 2-7-5, th e Petitibrtei

' shall af>ply to in corporate the se Order requirements,

in c ludin g reporting and re co rdkeeping

r e quir e 1n e nts and m e thod
s to determine compliance, into its Part 70 Operating

P er mit within **nin~ty** 

## (90) d ays of 

# · u.s. EPA's approval of th e Co mmi ssi on e r' s Order as part of the Indi a na S IP
. 5. from April 19, 20 16 until IDEM iSS\tes
a Permit inc o rpqratin

g th ese Order

r eq uir emen ts, the Petitioner

s h a ll com ply w ith the reporting

a nd reco rdk eeping requirements and methods
to det er min e compliance

s p ecified in this p a r ag r a ph. a. Reporting: The Petitioner sha ll s ubmit to ID EM, on a quarterly ba sis, a r eport of the fac ilit y-w id e maximum 

# 720 operating houi

· S0 2 

## rolling average ma ss em i ss ion r a t e for eac h da y that an y of Unit No

. 1 tlu·ou g h Unit No. 6, or any co mbina tio n thereof, operates, beghming the second quarter reporting period, which

i s Jul y 20 16. b. R ecor dkeeping: The Petit io ner shall maint ai n r ecor ds adequate
to docum

e nt comp lian ce with th e 720 opera tin g hour rolling average S0 2 mass em i ssio n rate. c. Method

t o determine compliance: Compliance

s hall b e d ete rmined by a continuous

e mis sio n monitoring sys tem
( CE MS) in accordance with 326 lAC 3-5; exce pt th at data
s ub s tituted in accordance with 40 Co de of Federal Regulations

(" CF R

" ) Part 75 will not be **consider~d**


## in this evaluation. The Petition

e r may u se the existing certified CEMS 

## to meet thi s r e quirem

e nt. 6. This Ord e r s hall apply to and be binding upon th e Petitioner, its s ucc esso rs and assigns. No c han ge in ownership, corporate, or p a rtn e rship

s tatu s of the P etit ion er s h a ll in a ny way alter it s status or responsibilities under this Order. 7. The re quir eme n ts of thi s Order supersede any

l ess stri n ge nt req ui re m e nt s a ppli cab
l y to the Petition

e r.

· 

## EFFECTIVE DATE OF ORDER Pursuant to IC 13-14-2-l(d),

. IC **4~21.5-3-1,** 

## IC 4-21.5-3-5(a)(6), and 40 C FR 51.102, IDEM will give notice of this Order to eac h entit y to whom the Order

i s directed and a t Tecte d neighbors by mniling and to the general public by w e b publication. Pursuant to IC **1.5~3 7(a)(3),**  

## IC 4-21.5-3-2(e), and IC 4-21.5-3-5, thi s Orcler m ay be appealed by filin g a P e tition for r ev iew within eighteen (18) day s after th e date affected persons were giv e n notic e of the Order by U.S

. Ih a i1. Inf or mation on petitions for review of d1i s Order ca n b e found at IC 4 -2 1.5- 3- 7. Pmsuant to IC 4-21.5-3-S(f) and
I C 4-21.5-J-2(e), the Ord e r i s effec ti ve e ight ee n (18) d ays from mailing of n otice unl ess a Petition for review

h as been filed b efore or on th e e ight ee nth (18

1 

### h) 

## day

. How eve r, th e compliance date for the S0 2 mass emission

r a t e in thi s Ol'der is Ap rill 9, 2 016

. Pursuant
to 40 CFR 51 .10 3, IDEM will
s u bm
i t this Order to U

. S . EPA as a revis ion to the Indiana SIP. Upon. app ro val by t he U.S. EPA, thi s Or d er will be part of the Indiana SIP.

## Commissiouc•·'s 01'dCI' 

## No 2016-02 

## Page4 of4 

## Pe.rsons seekingjudicial review of this Order may do so in accordance with 

# IC 4-21.5-5

. . If you have proceclural
or scheduling questions regarding your request for review, you may contact the Office of Enviromnental Adjudication

at (317) 232-8591.
If you have quystions regarding this Order, pleas e contact Mark D e rf, Office of 

# Air Quality, by telephone
at (3 

# i 7) 233- 5682 or email at MDERF@idem.IN

. gov

. Dated at Indianapoli

s, Indi a na this



# l \ -r day 

# of **~** 2016. 

# --- t6lf01S:C0111ef Commissioner Indiana Depmtm

c nt of Environmental ManagementAttachmentCPublicNoticeandCertificateofPublicationfortheCommissioner'sOrderforCliftyCreelcGeneratingStationaddressingthe1-hourS02NAAQSJeffersonCountyIDEM INDIANA DEPARTMENT
OF ENVIRONMENTAL MANAGEMENT We Protect Hoosiers and Our Environm

e nt. Michael R. Pence Governor

100 N . Senate Avenue

• Indianapolis,
IN 46204 (800) 451-6027

• (317) 232-8603

• www.idem.IN.gov
Carol s. Comer Con 1mi ssioner Legal Notice- Public Comment Period and Opportunity for Public Hearing State Implementation Plan (SIP) Submittal Clifty Creek Generating Station in Jefferson County Commissioner's Order No 2016-02 Notice is hereby given under 40 CFR 51.102 that the Indiana Departm ent of E n vi ronmental Management ("IDEM")
is accepting written comments and providing an opportunity for a public hearing regarding

a r ev ision to the Indiana state impl e ment at ion plan (SIP) for Indiana Kentucky Electric Corporation, Clifty Creek Generating Station, Source I.D. Numbe

r 077-00001

, located at 1335 Clifty Hollow Road in Madison, Jeffer so n County, Indiana. All interested persons are invited and will be given reason ab le opportunity

to express their v i ews concerning the proposed revision to the SIP. The purpose of this notice is to so licit public comment on a proposed

r ev ision to the SIP that

i s accomplished
by Commissioner's Order No. 2016-02 for Clifty Creek Generating Station. The Commissioner's Order impos es a sulfur dioxide emission limit upon Clifty Creek Generating Station. This Commissioner's Order will be s ubmitted
to the United States Envirorunental Protection Agency ("U.S. EPA") for approva

l as a revi
s ion to th e Indiana SIP. Any person may su bmit written comments on the proposed SIP revi sion. Written comments must be postmarked
or delivered in person on or before March 17, 2016. Any person may request

a public hearing on the propo sed SIP r ev i s ion. Requests for a public hearing must be submitted on or before March 4, 2016. A hearing has be e n scheduled for March 10, 2016 at 6:00p.m.

e astern time. The hearing will occur at Hanover College Science Center, 607 Ball Drive, Hanover

, Indiana, Buildin
g SCC, Room 136. If no timely request for a public hearing is received by March 4, 2016, the hearing will be cancelled. Int eres ted parties can check the online IDEM calendar
at http

: //www.in.gov/ac

ti veca

l endar/Even

t Li st.aspx or contact Mark Derf at the contact information listed below to see if the hearing has been cancelled. Interested partie

s may present oral or written conunents
at the public hearing, if held. Comments and
s uppmting documentation,

or a request for a public
h ea ring must be sent in writing to Mark D erfv ia the information provided below. Pleas
e refer to Commissioner's Order 2016-02 in all correspondence. Mark Der f Indiana Depmtment of Environmental Management Office of Air Quality 100 North Senate A venue Mail Code 61-50 IGCN 1003 Indianapolis, Indiana 46204 An E qual Opportu nit y Employer



# 0 A State **that~**

(!)

Recycled Pap erPhone

: (317) 233-5682 Fax: (317) 233-2342 E-mail: MDERF @ idem.IN.gov. A copy of the Commissioner's Order

i s available to any person up on request and is available for public in s pection at the following locations: Indiana Department of Environmental Mana ge ment Office of Air Quality Indi ana Govern ment Center-North 100 North Senate A venue lOth Floor Indianapoli

s, Indiana 46204. and Indiana Department of Environmental Management Southeast Regional Offi ce 820 Swee

t Street Brownstown, Indiana 47220 and Madison

J effe rson County Public Library 420 West Main Street Madison, Indiana 47250-3796 The Conunissioner's Order is also available on the IDEM website

a t: http://www.in

. gov/idem/4686

. htm

. For additional information

, please contact Mark D e rf at the contact information provided above.

### INDIANA DEPARTMENT
OF ENVIRONMENTAL MANAGEMENT We Protect H oos ier s and Our Env ironm en t . Mitchell E. D anie

l s Jr.

100 North Senate Avenu
e Governor

Indi a napolis

,
I ndi a na 46 20 4 (317) 232-8603 Tho ma s W. Ea s terly

Toll Free (8 00) 451

- 6027 Commissio

n er
www.idem.

I N.gov 

### February
3, 2016 CERTIFICATE
OF PUBLICATION This is to certify th at the Indiana D epart ment of E nvironm

e ntal Management (IDEM) No tic e o f th e opportunity for a Publi
c Hearing

r ega rdin g th e following: o 

### C ommi ss ion er's Order #2016

- 0 2 for Clifty Creel{ Generating Stati on of Ind
i a n a was publi

s hed on IDEM 's web site on February


### 3, 2 016. It 

### i s expecte
d that it will re main posted on the
s ite until at le as t March
4 , 2016

. The notice in full was available

o nlin e at the f o llowin
g web a ddr ess, und er "So uthe astern". http://www.in

. gov/idem/5474.htm The noti ce was a l so avai

l able th e same date at the followin

g web address. http://www.in

. gov / idem
/ 4686.htm Web publi cat ion of the noti ce was at t h e r e qu est o f Scott Deloney, Branch Ch i ef, Pro gr a m s Branch

, Office of A i r Qualit y, IDEM

. Att a clun e nt s : Copy of w e b pag e as publi

s h e d. Re c ycl e d Pap e r 

### @

By: Mik e Finklestein ID EM Webmaster A n Eq u a l O p por tun i t y E m p l o y e r

Pl e a se R ecycle QAttachmentDCliftyCreel(GeneratingStation:ModelingSummaryJeffersonCountylndiana-l<entucl<yElectricCorporation-CliftyCreel<GeneratingStationCommissioner'sOrderModelingSummaryBackgroundInitialmodeling,usingCliftyCreek'shourlyContinuousEmissionsMonitoring(CEM)datafrom2012-2014,showedhighermodeledS02concentrationsthatexceededthe1-hourS02NationalAmbientAirQualityStandards(NAAQS).ThismodelingincludedemissionsbeforeandafterCliftyCreekhadinstalledtheirFluidizedGasDesulfurization(FGD)system.AfterconsultationwithU.S.EPA,IndianaremodeledtheS02emissionsfromCliftyCreekaftertheFGDsystembecameoperationaltodeterminetheattainmentdesignationfortheareasinceemissioncontrolshavetobeinplacebythefinalS02areadesignationdateofJuly2,2016.TheFGDsystembecamefullyoperationalinJuly2013.ThemodelingperiodwassetforoneandhalfyearsfromJuly2013throughDecember2014.Thismodelingshowedattainmentofthe1-hourS02standard.FollowingthesubmittalofIndiana'srecommendationsaddressingtheRound2consentdecreeinSeptemberof2015,U.S.EPApointedoutafullthreeyearsofmodelingwouldberequiredtomakeacharacterizationofairqualityintheareaandemissionlimitswouldhavetobeestablishedthatwouldbefederallyenforceableandpermanent.Sincethiswasthecase,discussionswithCliftyCreekresultedintheirrequestfornewS02emissionlimitstobeestablished,basedonthreeyearsofmeteorologicaldata,peraCommissioner'sOrder.Theselimitswouldbefederallyenforceableandpermanentandincorporatedintotheirpermitatalaterdate.ModeledEmissionlimitsandResultsTheFGDsystemcontrolsS02emissionsfromfluegasesforallsixgeneratingunitsatCliftyCreek.Units1,2,and3areventedintoStackCS013.Units3,4,and5areventedintoStackCS046.Thetwostacksarecontainedwithinonestackshell.BaseelevationsatCliftywerereevaluatedbasedonconstructiondrawingsforthefacility.Thesenewbaseelevationswereusedinthismodelinganalysis.AllothermodelingparametersweremaintainedandcanbefoundinEnclosure3,page15ofIndiana'sRound2ConsentDecreemodelingsubmittal,datedSeptember16,2015.Three502emissionscenariosweremodeled:Scenario1wasallemissionsemittedfromStackCS013,Scenario2wasallemissionsemittedfromStackCS046,andScenario3dividedtheemissionsequallybetweenStackCS013andStackCS046.TheworstcasemodelingscenariowasScenario1,representedbyall502emissionsbeingemittedfromStackCS013.Basedonthisworstcasemodelingscenario,theemissionlimitwasdeterminedtobeanyoftheUnits1through6oranycombinationcanneverexceed4,670lbs/hrforthe1-hour502averagingperiod.AsummaryofthethreemodelingscenariosS02emissionandmodelingresultscanbeseenbelowinTable1.1Table 1: C lifty Cree l< 1-hour 50 2 Mod e ling Sce nario S ummary

a nd Results Modeled E mis s ion Rate Concentration Concentration Concentrat

i on Scenario Group ID lb/hr J.tg/m3

J.tg / m3 J.tg/m3 Scenario

1 CS013 4,670 195.98 Scenario

2 CS 046 4,670
187.93 Sce nario 3

S PLT 2,335.2

192.11 Determination

of Long er T ime

- Averaged Limits C

l ifty C r eel< requeste

d a 720 operat in g hour rolling average emiss

i o n limit that would demonstrate compliance among multiple units and model atta inm e n t ofthe

1 - hour 50 2 standard. The reduction ratio used in orde

r to demonstrate
an equiva

l ent 720 operating ho ur rolling average 50 2 mass em

i ssion limit based
o n t h e mode

l ed
1 - hour em

i ssio n limi
t

i s discussed

in C li fty Creek's Commissioner Order request and the assessme nt process

f o r developing

a lon ge r term ave
r ag in g per iod
li m it, dated January 22, 2016. Th e equ

i va

l e nt 720 operating hour
s it e rolling average 50 2 em

i ss ion limit ca

l cu

l ated from the 4,670 lb/ h r 1 - h o ur m ode

l ed e m

i ss

i on li m

i t was det e rm

i n ed to be 2,624.5
lb s of 50 2 / hr . 2