INDIANA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT 

We Protect Hoosiers and Our Environment. 

Michael R. Pence 

Governor 

Mr. Robert Kaplan 

Acting Regional Administrator 

U.S. EPA, Region 5 

77 West Jackson Boulevard 

Chicago, IL 60604-3950 

Dear Mr. Kaplan: 

100 N. Senate Avenue • Indianapolis, IN 46204 

(800) 451-6027 • (317) 232-8603 • ww.idem.IN.gov 

February 5, 2016 

Carol S. Comer 

Commissioner 

Re: State Implementation Plan Submittal for 

Indiana Regarding 1-Hour S02 Attainment 

Clifty Creek Generating Station in 

Jefferson County, Indiana; Request for 

Parallel Processing (Commissioner's 

Order #2016-02) 

Pursuant to Section 110 of the Clean Air Act and Title 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 (SIP). IDEM 

requests that United States Environmental Protection Agency (U.S. EPA) approve the 

requirements for Clifty Creek Generating Station (Clifty Creek) in Commissioner's Order 

#2016-02. 

IDEM issued a Commissioner's Order on February 1, 2016, to establish permanent 

and enforceable sulfur dioxide (S02) emission limits for Clifty Creek, located in Jefferson 

County, Indiana, in order to ensure continued attainment of the 2010 1-hour sulfur dioxide 

(S02) standard in the area surrounding the facility. The Commissioner's Order contains a 

facility-wide maximum 720 operating hour S02 rolling average mass emission rate 

applicable 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 is April 19, 2016. It contains and meets the requirements set 

forth in 42 U.S.C. § 7407(d)(3)(E)(iii) and the conditions will become applicable 

requirements as defined in 326 lAC 2-7-1(6). · 

The rulemaking documentation is being forwarded to U.S. EPA with a request for 

parallel processing while IDEM completes the steps necessary for public notice. When the 

public notice process is complete, this SIP submittal will be supplemented with an 

addendum that includes the public notice documentation. The public notice period is 

scheduled to end on March 4, 2016. 

An Equal Opportunity Employer 0 <i} Recycled Paper A State that -Works 
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 closely with your staff to ensure that any potential 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 questions 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 Copy 
Supporting Documents 

Attachment A: Administrative Checklist (40 CFR 51, Appendix V) 

Attachment 8: Commissioner's Order #2016-02 

Attachment C: Legal Notice of Public Hearing and Certificates of Web Publication 

Attachment D: Modeling Summary 

Data, calculations and methodology for determining a facility-wide maximum 720 

operating hour rolling average S02 mass emission rate based on Clifty Creek's 

continuous emission monitoring data (available upon request). 
Attachment A 

Administrative Checl<list 
ADMINISTRATIVE CHECKLIST (40 CFR 51, Appendix V) 

1. The submittal is accompanied by a formal letter of submittal 

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 adoption or final issuance: 

b. The effective date of the plan, if different 

from the adoption/issuance date. 

3. Evidence that the State has the necessary legal authority 

under state law to adopt and implement the plan. 

4. A copy of the actual regulation or document submitted for 

approval and incorporation by reference into the plan, 

including the following: 

a. Indication of the changes made to the existing 

approved plan, where applicable. 

b. The submittal shall be a copy of the official State 

regulation or document signed, stamped, dated by 

the appropriate state official indicating that it is fully 

enforceable by the State. Effective date shall be stated 

in the document itself. 

5. Evidence that the State followed all of the procedmal 

requirements of the State's laws and constitution in 

conducting and completing the adoption/issuance of the plan. 

6. Evidence that public notice was given, including date of 

proof of publication. 

7. Certification that public hearings were held in accordance 

with information provided in public hearing notice. 

8. Compilation of public comments and State's response. 

9. Technical Support Document (if source specific change). 

Enclosed 

Attachment B 

January 11, 2016 

18 days after issuance 

IC 13-14-1-9 

IC 13-14-2-1 

Attachment B 

Attaclm1ent B 

Attachment C 

Include in Final Addendum 

Include in Final Addendum 

Attaclm1ent D 
Attachment B 

Commissioner's Order for Clifty Creelc 

Generating Station addressing the 1-hour S02 

NAAQS 

Jefferson County 
INDIANA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT 

We Protect Hoosiers and Our Environment. 

Michael R. Pence 

(JO\'«!fiiOI' 

100 N. Senate Avenue � Indianapolis, IN 46204 

(800) 451-6027 • (317) 232-8603 • ww.idem.IN.gov 

Carol S. Comer 

Cmumlulmwr 

STATE OF INDIANA 

COUNTY OF MARTON 

) 

) SS: 

) 

BEFORE 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 ) 

) 

NOTICE AND ORDER OF THE 

COMMISSIONER OF THE 

DEPARTMENT OF ENVIRONMENTAL MANAGEMENT 

TJiis Notice ·and Order of the Commissioner of the Department 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 was d�termined that the Petition should be 

granted according to the terms specified below: 

PETITION 

Petitioner is the Indiana Kentucky Electric Corporation's, Clifty Creek Generating Station 

("Petitioner"), a stationary electric power plant with Sollrce I.D. Number 077-00001, located at 

1335 Clifty Hollow Road in Madison, Jefferson County, Indiana, and permitted under thePatt 70 

air operating permit program. 

On March 2, 2015, the U.S. District Court ror the Northern District of California accepted 

a Consent Decree between the U.S. Enviromnental Protection Agency ("U.S. EPA"), the Sierra 

Club, and the Natural Resources Defense Council to resolve litigation concerning deadlines for 

completing one (1) hour sulfur dioxide ("S02") National Ambient Air Quality Standard 

("NAAQS") designations. Under the Consetit Decree, U.S. EPA must designate certain areas as 

nonattainment, attaimn.ent, or unclassifiable in tlu·ee phases. 

Tl1e first Consent Decree phase requires U.S. EPA to designate areas that contain 

stationary sources that had not been announced for retirement as of March 2; 2015 and either 

emitted more than 16�000 tons of S02 in 2012 or eniitted more than 2,600 tons of S02 and had ati 

atmual average emission rate 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 Quality Markets Database. 

An Equnl Opporlunily Emjlloycr 1\ State U1at -Works (i) flecydcd f'aper 

.I 
Commissioner's Order No 2016-02 

Page2of4 

On March 20, 2015,. U.S. EPA identifie.d five (5) soilrces in Indiana that met the criteria 

for the first phase of the Consent Decree designations. U.S. EPA's list \ncluded the Petitioner, 

Clifty Creek Generating Station. · 

On September 16, 2015, the Indiana Department of Enviromnental Management 

(''IDEM'') recommended designation of the area surrounding Clifty Creek Generating Station as 

attainment. The recommendation was based on modeling that included operation of a flue gas 

dcsulfurization system that became operational in July 2013. 

· 

On January 22, 2016, the Petitioi1er submitted a request to the Commissioner to impose a 

permanent and enforceable S02 mass emission rate on the Petitioner in order to ens me continued 

attainment of the S02 NAAQS in the area surrounding Clifty Creek Generating Station. The 

Petitioner proposed a facility-wide S02 mass emission rate of 2,624.5 S02 pounds per hour 

("lb/hr"), 720 operating hom rolling average, applicable to Unit No. 1 tlU'ough Unit No. 6, 

combined. 

FINDINGS 

Pmsuant to IC 13-14-2-1 (b) and IC 13-14-2-7(1 ), the Commissioner may issue Orders to 

secure c01hpliance with Indiana's environmental statutes and rules, including th9 ambient air 

quality standard for S02 at 326 Indiana Administrative Code (!'lAC") 1-3-4(b)(1)(A). 

Based on the foregoing information, IDEM finds the following: 

1. A permanent and enforceable S02 mass emission rate for Clifty Creek Genet�ating Station · 

is required in order to model continued attaimnent of the one (1) hour S02 NAAQS in the ai'ea 

surrounding the Petitio11er. 

2. Issuance of a Commissioner's Order will ensure the S02 mass emission mte remains 

permanent and enforceable, as required by 42 U.S.C. § 7407(d)(3)(E)(iii). Whereas revising a 

Part 70 Operating Permit would not create �n adequately "permanent" requirement. 

3. Approval by U.S. EPA of the Commissioner's Order as pmt of the Indiana State 

Imple.menta,tion Plan ("SIP") will make the Order i·equirements federally enforceable. Upon 

approval as part of the Indiana SIP, the Order requhements become applicable requirements as 

defined in 326 lAC 2-7-'1(6). 

· 

4. Based on moctding conducted by IDEM, the S02 m�ss emission rate proposed by the 

Petitioner is adequate to assure continued attainment of the S02 NAAQS. 

ORDER 

1. This . Order approves the Petition submitted by the Petitioner according to the tei·ms 

specified below. This Order itnposes on the Petitioner the S02 mass emission mte described 

below. 

2. When any of Unit No. 1 through Unit No. 6, or any combination thet'eof, is operating, the 

combined S02 mass en1ission rate shaH not exceed 2,624.5 lb/Iu·, as a 720 operating hour roHing 

average. 
Commissioner's Order No 2016-02 

Page 3 of4 

3. The Petitioner shall comply with the 720 operating hour rolling average S02 mass 

emission rate beginning Aprill9, 2016. 

4. As required by 326 lAC 2.,7-2(d)( l) and 326 lAC 2-7-5, the Petitibrtei' shall af>ply to 

incorporate these Order requirements, including reporting and recordkeeping require1nents and 

methods to determine compliance, into its Part 70 Operating Permit within nin�ty (90) days of 

·u .s. EPA's approval of the Commissioner's Order as part of the Indiana SIP. 

5. from April 19, 2016 until IDEM iSS\tes a Permit incorpqrating these Order requirements, 

the Petitioner shall comply with the reporting and recordkeeping requirements and methods to 

determine compliance specified in this paragraph. 

a. Reporting: The Petitioner shall submit to IDEM, on a quarterly basis, a report of 

the facility-wide maximum 720 operating houi· S02 rolling average mass emission rate 

for each day that any of Unit No. 1 tlu·ough Unit No. 6, or any combination thereof, 

operates, beghming the second quarter reporting period, which is July 2016. 

b. Recordkeeping: The Petitioner shall maintain records adequate to document 

compliance with the 720 operating hour rolling average S02 mass emission rate. 

c. Method to determine compliance: Compliance shall be determined by a 

continuous emission monitoring system (CEMS) in accordance with 326 lAC 3-5; except 

that data substituted in accordance with 40 Code of Federal Regulations ("CFR") Part 75 

will not be consider�d in this evaluation. The Petitioner may use the existing certified 

CEMS to meet this requirement. 

6. This Order shall apply to and be binding upon the Petitioner, its successors and assigns. 

No change in ownership, corporate, or partnership status of the Petitioner shall in any way alter 

its status or responsibilities under this Order. 

7. The requirements of this Order supersede any less stringent requirements applicably to 

the Petitioner. 

· 

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 CFR 51.102, 

IDEM will give notice of this Order to each entity to whom the Order is directed and atTected 

neighbors by mniling and to the general public by web publication. 

Pursuant to IC 4-21.5�3-7(a)(3), IC 4-21.5-3-2(e), and IC 4-21.5-3-5, this Orcler may be 

appealed by filing a Petition for review within eighteen (18) days after the date affected persons 

were given notice of the Order by U.S. Ihai1. Information on petitions for review of d1is Order 

can be found at IC 4-21.5-3-7. 

Pmsuant to IC 4-21.5-3-S(f) and IC 4-21.5-J-2(e), the Order is effective eighteen (18) 

days from mailing of notice unless a Petition for review has been filed before or on the 

eighteenth (181h) day. However, the compliance date for the S02 mass emission rate in this Ol'der 

is April l9, 2016. 

Pursuant to 40 CFR 51.103, IDEM will submit this Order to U.S. EPA as a revision to the 

Indiana SIP. Upon. approval by the U.S. EPA, this Order will be part of the Indiana SIP. 
Commissiouc•·'s 01'dCI' No 2016-02 

Page4 of4 

Pe.rsons seeking judicial 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, please contact Mark Derf, Office of Air Quality, by telephone at (3 i 7) 233-

5682 or email at MDERF@idem.IN.gov. 

Dated at Indianapolis, Indiana this l \ -r day of� 2016. 

t6lf01S: 

Commissioner 

Indiana Depmtmcnt of Environmental Management 
Attachment C 

Public Notice and Certificate of Publication for 

the Commissioner's Order for Clifty Creelc 

Generating Station addressing the 1-hour S02 

NAAQS 

Jefferson County 
IDEM INDIANA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT 

We Protect Hoosiers and Our Environment. 

Michael R. Pence 

Governor 

100 N. Senate Avenue • Indianapolis, IN 46204 

(800) 451-6027 • (317) 232-8603 • ww.idem.IN.gov 

Carol s. Comer 

Con1missioner 

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 Department of Environmental 

Management ("IDEM") is accepting written comments and providing an opportunity for a public 

hearing regarding a revision to the Indiana state implementation plan (SIP) for Indiana Kentucky 

Electric Corporation, Clifty Creek Generating Station, Source I.D. Number 077-00001, located at 

1335 Clifty Hollow Road in Madison, Jefferson County, Indiana. All interested persons are 

invited and will be given reasonable opportunity to express their views concerning the proposed 

revision to the SIP. 

The purpose of this notice is to solicit public comment on a proposed revision to the SIP that is 

accomplished by Commissioner's Order No. 2016-02 for Clifty Creek Generating Station. The 

Commissioner's Order imposes a sulfur dioxide emission limit upon Clifty Creek Generating 

Station. This Commissioner's Order will be submitted to the United States Envirorunental 

Protection Agency ("U.S. EPA") for approval as a revision to the Indiana SIP. 

Any person may submit written comments on the proposed SIP revision. Written comments must 

be postmarked or delivered in person on or before March 17, 2016. 

Any person may request a public hearing on the proposed SIP revision. Requests for a public 

hearing must be submitted on or before March 4, 2016. A hearing has been scheduled for March 

10, 2016 at 6:00 p.m. eastern time. The hearing will occur at Hanover College Science Center, 

607 Ball Drive, Hanover, Indiana, Building SCC, Room 136. If no timely request for a public 

hearing is received by March 4, 2016, the hearing will be cancelled. Interested parties can check 

the online IDEM calendar at http://www.in.gov/activecalendar/EventList.aspx or contact Mark 

Derf at the contact information listed below to see if the hearing has been cancelled. Interested 

parties may present oral or written conunents at the public hearing, if held. 

Comments and suppmting documentation, or a request for a public hearing must be sent in 

writing to Mark Derf via the information provided below. Please refer to Commissioner's Order 

2016-02 in all correspondence. 

Mark Derf 

Indiana Depmtment of Environmental Management 

Office of Air Quality 

100 North Senate A venue 

Mail Code 61-50 IGCN 1003 

Indianapolis, Indiana 46204 

An Equal Opportunity Employer 0 

A State that� (!) Recycled Paper 
Phone: (317) 233-5682 

Fax: (317) 233-2342 

E-mail: MDERF@idem.IN.gov. 

A copy of the Commissioner's Order is available to any person upon request and is 

available for public inspection at the following locations: 

Indiana Department of Environmental Management 

Office of Air Quality 

Indiana Government Center-North 

100 North Senate A venue 

lOth Floor 

Indianapolis, Indiana 46204. 

and 

Indiana Department of Environmental Management 

Southeast Regional Office 

820 Sweet Street 

Brownstown, Indiana 47220 

and 

Madison Jefferson County Public Library 

420 West Main Street 

Madison, Indiana 47250-3796 

The Conunissioner's Order is also available on the IDEM website at: 

http://ww.in.gov/idem/4686.htm. 

For additional information, please contact Mark Derf at the contact information provided 

above. 
INDIANA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT 

We Protect Hoosiers and Our Environment. 

Mitchell E. Daniels Jr. 100 North Senate Avenue 

Governor Indianapolis, Indiana 46204 

(317) 232-8603 

Thomas W. Easterly Toll Free (800) 451-6027 

Commissioner ww

.idem.IN.gov 

February 3, 2016 

CERTIFICATE OF PUBLICATION 

This is to certify that the Indiana Department of Environmental Management (IDEM) Notice of 

the opportunity for a Public Hearing regarding the following: 

o Commissioner's Order #2016-02 for Clifty Creel{ Generating Station of Indiana 

was published on IDEM's web site on February 3, 2016. It is expected that it will remain posted 

on the site until at least March 4, 2016. 

The notice in full was available online at the following web address, under "Southeastern". 

http://ww.in.gov/idem/5474.htm 

The notice was also available the same date at the following web address. 

http://www.in.gov/idem/4686.htm 

Web publication of the notice was at the request of Scott Deloney, Branch Chief, Programs 

Branch, Office of Air Quality, IDEM. 

Attaclunents: 

Copy of web page as published. 

Recycled Paper @ 

By: 

Mike Finklestein 

IDEM Webmaster 

An Equal Opportunity Employer Please Recycle Q 
Attachment D 

Clifty Creel( Generating Station: 

Modeling Summary 

Jefferson County 
lndiana-l<entucl<y Electric Corporation -Clifty Creel< Generating Station 

Commissioner's Order Modeling Summary 

Background 

Initial modeling, using Clifty Creek's hourly Continuous Emissions Monitoring (CEM) data from 2012-

2014, showed higher modeled S02 concentrations that exceeded the 1-hour S02 National Ambient Air 

Quality Standards (NAAQS). This modeling included emissions before and after Clifty Creek had installed 

their Fluidized Gas Desulfurization (FGD) system. After consultation with U.S. EPA, Indiana remodeled 

the S02 emissions from Clifty Creek after the FGD system became operational to determine the 

attainment designation for the area since emission controls have to be in place by the final S02 area 

designation date of July 2, 2016. The FGD system became fully operational in July 2013. The modeling 

period was set for one and half years from July 2013 through December 2014. This modeling showed 

attainment of the 1-hour S02 standard. Following the submittal of Indiana's recommendations 

addressing the Round 2 consent decree in September of 2015, U.S. EPA pointed out a full three years of 

modeling would be required to make a characterization of air quality in the area and emission limits 

would have to be established that would be federally enforceable and permanent. Since this was the 

case, discussions with Clifty Creek resulted in their request for new S02 emission limits to be established, 

based on three years of meteorological data, per a Commissioner's Order. These limits would be 

federally enforceable and permanent and incorporated into their permit at a later date. 

Modeled Emission limits and Results 

The FGD system controls S02 emissions from flue gases for all six generating units at Clifty Creek. Units 

1, 2, and 3 are vented into Stack CS013. Units 3, 4, and 5 are vented into Stack CS046. The two stacks 

are contained within one stack shell. Base elevations at Clifty were reevaluated based on construction 

drawings for the facility. These new base elevations were used in this modeling analysis. All other 

modeling parameters were maintained and can be found in Enclosure 3, page 15 of Indiana's Round 2 

Consent Decree modeling submittal, dated September 16, 2015. 

Three 502 emission scenarios were modeled: Scenario 1 was all emissions emitted from Stack CS013, 

Scenario 2 was all emissions emitted from Stack CS046, and Scenario 3 divided the emissions equally 

between Stack CS013 and Stack CS046. The worst case modeling scenario was Scenario 1, represented 

by all 502 emissions being emitted from Stack CS013. Based on this worst case modeling scenario, the 

emission limit was determined to be any of the Units 1 through 6 or any combination can never exceed 

4,670 lbs/hr for the 1-hour 502 averaging period. A summary of the three modeling scenarios S02 

emission and modeling results can be seen below in Table 1. 

1 
Table 1: Clifty Creel< 1-hour 502 Modeling Scenario Summary and Results 

Modeled 

Emission Rate Concentration Concentration Concentration 

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

Scenario 1 CS013 4,670 195.98 

Scenario 2 CS046 4,670 187.93 

Scenario 3 SPLT 2,335.2 192.11 

Determination of Longer Time-Averaged Limits 

Clifty Creel< requested a 720 operating hour rolling average emission limit that would demonstrate 

compliance among multiple units and model attainment of the 1-hour 502 standard. The reduction ratio 

used in order to demonstrate an equivalent 720 operating hour rolling average 502 mass emission limit 

based on the modeled 1-hour emission limit is discussed in Clifty Creek's Commissioner Order request 

and the assessment process for developing a longer term averaging period limit, dated January 22, 2016. 

The equivalent 720 operating hour site rolling average 502 emission limit calculated from the 4,670 lb/hr 

1-hour modeled emission limit was determined to be 2,624.5 lbs of 502 /hr. 

2 
Assessment Process

Indiana-Kentucky Electric Corporation

Clifty Creek Station

Evaluation for 720 Operating Hour Site Rolling Average SO2 Mass Emissions Limits Using Flue Gas 

Desulfurization (FGD)

Step 1: Facility Description and Modeled Limits

The Indiana-Kentucky Electric Corporation’s (IKEC’s) Clifty Creek Station has six coal-fired electric 

generating units (Units 1 through 6) that were placed into commercial operation in 1955 and 1956. All 

six units have pulverized-coal, front-wall-fired, wet-bottom boilers and a nameplate generating capacity 

of approximately 217 megawatts.

Prior to being exhausted to the atmosphere, the flue gases from Units 1, 2, and 3 are combined and 

scrubbed for SO2 removal in a jet-bubbling reactor (JBR) scrubber. The scrubber for Units 1, 2 and 3 is 

referred to as JBR13, and the combined scrubbed flue gases from these three units is exhausted through 

Common Stack CS013 (also known as Flue 13). The flue gases from Units 4, 5, and 6 are combined and 

scrubbed in JBR46 prior to being exhausted through Common Stack CS046 (also known as Flue 46). The 

two flues associated with each scrubber are contained in one stack shell (Stack 14), and the emissions 

from each flue are represented of the combined scrubbed emissions from all six units. The scrubbers 

were designed to allow the Clifty Creek Station to use local Illinois Basin coal with sulfur content in the 5 

lb per mmBtu range.

For modeling purposes, IKEC identified an appropriate mass emissions limit as a site average for the 

Clifty Creek Generating Station that smodels attainment of the 2010 1-hour primary NAAQS for SO2.

Per the request of IKEC), Mr. Dave Long - at American Electric Power (AEP) performed modeling using 

the representative Clifty Creek Station post scrubber emissions data supplied to him by OVEC. Based on 

numerous modeling runs, Mr. Long determined that an emission value of 2,624.6 lbs/hour as a SITE

average emissions rate as averaged over a 30 day period will assist the Indiana Department of 

Environmental Management (IDEM) in complying with the 2010 SO2 NAAQS. 

Step 2: Compile Representative Emissions Data Set

Data was obtained for hourly SO2 mass emissions (lbs/hour) for each stack at the Clifty Creek Station 

from June 1, 2013 00:00 hour through December 31, 2015 23:00 hour. This starting date was chosen 

based upon the startup dates for each of the two JBR scrubbers that were placed into service at the 

Clifty Creek Station in 2013 (CS013: 3/20/2013, CS046: 5/15/2013). Since a site limit was developed for 

the entire Clifty Creek Generating Station, the following criteria were used to “clean up” the data set:

1. At least one unit on each stack had to be operating. Periods when only one single stack was in 

operation was discarded.

2. The data from each stack was obtained using either the primary or backup certified SO2 

monitoring system. Hours when either stack had data generated using the missing data 

algorithm was discarded.

3. Two data sets were generated. One data set included all data meeting criteria 1 & 2 from June 1, 

2013 00:00 hour through December 31, 2015 23:00 hour. The second data set included data 
meeting criteria 1 & 2, but only for the years 2014 and 2015, which IKEC believes is more 

representative based on fuel source and operational mode. The coal blend consumed in 2013 

included a significant proportion of residual Powder River Basin coal, which is no longer 

consumed at the Clifty Creek Generating Station. This fuels source was still being consumed 

during 2013 due to contractual obligations in place prior to the commencement of scrubber 

operation. Utilization of the data from this time period could result in a low biasing of SO2 

emissions, which would not have been representative of future operations, nor of the design 

criteria for scrubbers themselves. The data for 2014 & 2015 was not impacted to a significant 

degree by any PRB fuel blending and therefore is more representative of expected longer term 

fuel source and future operations.

Step 3: Calculate 720 Operating Hour Site Rolling Average

After summing the hourly mass emissions for SO2 from each stack, this data was then used to calculate a 

720 Operating Hour Site Rolling Average mass emission value for each hour in the data collection period. 

The “cleaned up” data set resulted in a 720 Operating Hour Site Rolling Average that did not include 

hours where valid data was not available from both stacks and did not include hours where only one 

stack was operating. It should be noted that there are no values calculated for the first 720 hours of the 

data set.

Step 4: Calculate the 99th Percentile Values

The 99th percentile values were calculated for the 1-hour site emissions data set and the 720 Operating 

Hour Site Rolling Average. The Site 1 Hour Data set the 99th Percentile value was determined to be 2,394 

lbs/hour. The 720 Operating Hour Site Rolling Average data set the 99th Percentile Value was 

determined to be 1,346 lbs/hour.

Step 5: Calculate the Ration of the 99th Percentile Values

Dividing the 99th percentile value of the 720 Operating Hour Site Rolling Average by the 99th percentile 

value for the Site 1-Hour Data yields a quotient of 56.2%.

1,346 lbs/hour / 2,394 lbs/hour *100%= 56.2%

Discussion

The attached graph shows the 720 Operating Hour Site Rolling Average and the 2,624.5 lbs/hour 

modeled value trended alongside the 99th percentile value for this particular data set. 

IKEC proposes that the value of 2,624.5 pounds per hour (2,624.5 lb/hr) Site Average mass SO2 emission 

rate be utilized for the IDEM Commissioner’s Order. This compliance value would be an unweighted 

average calculated by IKEC using data collected by existing certified CEMS. Data used for determining 

this compliance value will be unbiased data. Additionally, data generated the using Part 75 Missing Data 

Algorithms will not be used to determine compliance. This is analogous to the manner in which data is 

handled under the existing Part 60 and MATS programs, which are utilized by IKEC for Title V and MATS 

compliance demonstration. The hourly data should be calculated as a 720 operating hour site rolling 

average. IKEC also believes the Commissioner’s Order should state that IKEC is not out of compliance 

during periods where the certified CEMS is not producing valid data for both stacks if the scrubber 

parametric data remains within the limits listed below:
Normal operation of either JBR reactors shall be deemed to be 

(a) Slurry level at or between the range of 19.33 to 21.06 feet, and;

(b) Slurry pH at or between 4.0 S.U. to 6.5 S.U.
10

 

I Hour y te 502 Mass Emiss ons (pounds) from January 1, 2014 hrough December 3 1, 20151 �======== == == == ======� -------

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2SO 124 Hour Rolling Average 502 Mass Emissions (pounds) from January 1, 2014 through December 31, 20151 

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I no Hour Rolling Average 502 Mass Emissions (pounds) from January 1, 2014 through December 31, 20151 

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Figure 4 

-Sum of Plant 

S02bs/lv Emis

ons 

-99th Percentile 

V�ue of Hourty 0.

 

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5.0 lbs/hr 

Figure 5 

-24 Hour 

Rolling Average 

-99th Percenti'e 

Vakleof24 Hour Rollinc 

Aver;ageOiU 

Figure 6 

-no Hour 

Rolling Average 

-99th Percenti'e 

Vakleof120 Hour Rollinc 

Aver;ageOiU 
1000.0 

24 Hour Rolling Average 502 Mass Emissions (pounds) from June 1, 2013 through December 31, 2015 

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Figure 2 

24 Hour Rol c 

Average 

-99th Percent le Value 

of z• Hour oling 

Average Data 

Figure 3 

o Hour inc 

Average 

-99th Percent le Value 

of 720 Hour o Jinc 

Average Data 
720 How Aollq Awnp 502 Mas

 Emisions (pounds) from June 1, 2013 throuch December 31,2015 

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