IDEM INDIANA DEPARTMENT
OF ENVIRONMENTAL MANAGEMENT We Pr o t ec t H oos

i e rs and O ur E nvir o nm e nt . Micha
e l R . Penc e Gove nw r Mr

. Robert Kaplan Acting Regional Administrator U.S. EPA

, Region

5 77 West Jackson Boulevard Chicago,
IL 60604

- 3950 Dear Mr. Kaplan:

1 00 N . Senate
A venue

• In d ianap
o

l is , IN 46204 (8 0 0) 451-60

2 7 • (317) 232-8603

• www. ide m

. IN

. gov January 27, 2016

C aro

l S. Comer Commissio

n e r Re

: State Implem

e ntation Plan Submittal for Indiana Regarding

1 - Hour S0 2 Atta

i nment A.B. Brown Generating Station
in Posey County; Request for Parallel Processing (Commissioner's Order #2016-01) 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 A.B. Brown Generating Station (A.B. Brown)
in Commissioner

' s Order #2016-01. IDEM issued

. a Commissioner's Order on January 11, 2016, to establish permanent and enforceable sulfur dioxide (S0 2 ) emission limits for A.B. Brown

, located

in Posey County,

in order to ensure continued attainment
of the 2010 1-hour sulfur dioxide (S0 2 ) standard

in the area surrounding the facility

. The Commissioner's Order contains emission limitations for Units
1 & 2, as well as reporting and recordkeeping requirements and method for compliance. The effective date for the emission limitations

in the Commissione

r'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 February 16, 2016

. An Eq u a l O pp o rtu ni t y E mpl oyer

0 A State **that~**

(!} Re cycle d Pap e rMr. 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, 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 CopySupportingDocumentsAttachmentA:AdministrativeChecklist(40CFR51,AppendixV)AttachmentB:Commissioner'sOrder#2015-01AttachmentC:LegalNoticeofPublicHearingandCertificatesofWebPublicationAttachmentD:ModelingSummaryData,calculationsandmethodologyfordetermining24-hourrollingaverageSOzemissionlimitsbasedonA.B.Brown'scontinuousemissionmonitoringdata(availableuponrequest).Attachment

A Administrative Checklist

# ADMINISTRATIVE CHECKLIST

( 40 CFR 51, Appendix V) 

# 1. The submittal

is accompanied
by a forma1letter
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 permit, order, consent agreement ("document");

in final fotm. 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 procedural requirements
of the State's laws and constitution

in conducting and completing the adoption/issuance ofthe 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 Attachment

B Attachment

C Include in Final Addendum Include in Final Addendum Attachment

D

# Attachment

B Commissioner's Order for A.B. Brown Generating

Station addressing

the 1-hour S0 2 

# NAAQS Posey CountyINDIANA DEPARTMENT
OF ENVIRONMENTAL MANAGEMENT We Protect Hoosie1:s and Our Environment. Mi c hael R. Pence Gm•cnmr

100 N . Senate Avenue

• Indianapolis,

IN 46204 (800) 451·6027

• (317) 232-8603

• \WNI.idem

. IN

. gov Carol s. Conier C ummt .. **u~r** STATE OF INDIANA COUNTY OF MARION

.

) ) SS: ) BEFORE THE INDIANA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT IN THE MATTER OF:

) ORDER OF THE COMMISSIONER

) PURSUANT TO IC 13 - 14-2-1

) FOR A.B. BROWN GENERATING STATION

) OF INDIANA

) ) NOTICE AND ORDER OF THE COMMISSIONER

OF THE DEPARTMENT
OF ENVIRONMENTAL MANAGEMENT This Notice and Order of the Conunissioner

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 Commissioner's review,

it was determined that the Petition should be granted according
to the tenns specified below: PETITION Petitioner

is Southern Indiana Gas and Electric Company (SIGECO) A.B. Brown Generating Station ("Petitioner"),

a stationary electric power plant with Somce J.D. Number 129
- 00010, located at 8511 Welborn Road in Mount Vernon, Posey County, Indiana, and permitted under the Pati 70 air operating permit program. On March 2, 2015, the U.S

. District Comt for the Northern District of California accepted a Consent Decree between the U.S. Envirorunental Protection Agency ("U.S. EPA"), the Sierra Club, and the Natural Resources Defense Council to resolve litigation concerning deadlines for completing 1-hour sulfur dioxide ("S0

2 ") National Ambient Air Quality Standard ("NAAQS") designations. Under the Consent Decree, U.S

. EPA must designate certain areas as nonattainment, attainment,
or unclassifiable

in tluee phases. The 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 emitted more than 2,600 tons of S0 2 and had an annual average emission rate of more than 0.45 pounds of S0 2 per one million British thermal units

( " lb/MMBtu")

in 2012, according
to U.S. EPA's Air Quality Markets Database

. On March 20, 2015, U.S. EPA identified five (5) sources in Indiana that met the criteria for the first phase of Consent Decree designations.

U

. S. EPA's list included the Petitioner, A.B. Brown Generating Station. An Equnl Opp o rtunity Employ

e r

0

(i) R ec y c l e d P11per A S t a t e **~**

# Commissioner's Order No 2016-01 

# Page 2 of5 

# On September
16, 2015, the Indiana Depaliment
of Environmental Management ("IDEM") recommended designation
of the area smTOunding A.B. Brown Generating Station as attainment. The recommendation
was based on modeling that included

a petmanent and enforceable S0 2 

# emission limitations and emission rates at A.B. Brown Generating Station. On December 21, 2015, the Petitioner submitted

a request to the Commissioner

to impose permanent and enforceable S0 2 

# emission limitations and emission rates on the Petitioner
in order to ensure continued attailll11ent
of the S0 2 

# NAAQS
in the area smTounding A.B. Brown Generating Station.

· The Petitioner proposed S0 2 

# emission limitations, expressed
in S0 2 

# lb/MMBtu, and emission rates, expressed
in S0 2 

# pounds per hour ("lbllu·"), applicable

to both Unit No.

I and Unit No. 2, as follows: a.
0. 363 lb/MMBtu, twenty-four (24) hour rolling average; b. 183 I .61b/lu, twenty-four (24) hour rolling average; and c. 2152.2lb/hr, one (I) hour average. FINDINGS 

# Pursuant
to IC 13-14-2-l{b) aud IC 13-14-2-7(1),
the Commissioner may issue Orders to secure compliance with Indiana's environmental statutes and rules, including the ambient air quality standard for S0 2 

# at 326 Indiana Administrative Code ("lAC") 1-3-4(b)(l)(A). Based on the foregoing information, IDEM finds the following: 1. 

# Pennanent and enforceable S0 2 

# emission limitations and emission rates for A.B. Brown Generating Station are required
in order to model continued attainment
of the !-hour S0 2 

# NAAQS
in the area sunounding the Petitioner. 2. Adding S0 2 

# emission limitations and emission rates to the Petitioner's Part 70 Operating Permit is not adequately permanent

to assure continued attainment
of the S0 2 

# NAAQS. Instead, a Colllll1issioner's Order is required
to ensure S0 2 

# emission limitations and emission rates remain permanent and enforceable,

as required by 42 U.S.C.

§ 7407(d)(3)(E)(iii). 3. Approval by U.S. EPA of the Conunissioner's Order into the Indiana State Implementation Plan ("SIP")

is required
to make Order requirements federally enforceable. Upon approval into the Indiana SIP, the Order requirements become applicable requirements

as defined
in 326 lAC 2-7-1(6). 4. Based on modeling conducted by IDEM, the S0 2 

# emission limitations and emission rates proposed by the Petitioner must be clarified and adjusted in order to assure continued attainment of the 

# SOz NAAQS.Commissione•·'s Ot·del' No **2016~01** Page 3 of5 ORDER 1. This Order approves the Petition submitted by the Petitioner according
to the tetms specified below. This Order imposes on the Petitioner
the 80 2 emission limitations and emission rates described below. 2. When Unit No.
1 is operating alone, the unit shall not exceed 80 2 emission limitations and emission rates as follows: a. 2152.21b/ln·, one (I) hour average or emission rate of0.855 lb/MMBtu, one (1) hour average; and b. 1831.6 lb/hr, twenty-four (24) hour rolling average or emission rate of 0.727 lb/MMBtu, twenty-four (24) hour rolling average. 3. When both Unit No.
1 and Unit No. 2* are in operation, both units shall not exceed combined 80 2 emission limitations and emission rates as follows: a. 2152.2 lb/hr, one (I) hour average or emission rate of 0.426 lb/MMBtu, one (I) hour average; and b. 1831.6 lb/Ju·, twenty-four (24) hour rolling average or emission rate of 0.363 lb/MMBtu, twenty-four (24) hour rolling average. 4. When Unit No. 2* is operating alone, the unit shall not exceed S02 emission limitations and emission rates as follows: a. 1745.7lb/hr, one (1) hour average or emission rate of0.690 lb/MMBtu, one(!) hour average; and b. 1485.59 lb/Ju·, twenty-four (24) hour rolling average or emission rate of 0.588 lb/MMBtu, twenty-four (24) hour rolling average. *Pursuant

to PSD (65) 1355 issued on February 22, 1979, Unit No.2 shall not exceed an S0 2 emission limitation of 0.69 lb/MMBtu, thirty (30) day rolling average. The S02 emission limitation applies to Unit No. 2 whenever Unit No. 2 is operating; this includes when Unit No. 2 is operating alone and when both Unit No.
1 and Unit No. 2 are in operation. 5. The Petitioner shall comply with the S0 2 emission limitations and emission rates beginning April 19, 2016. 6. As required by 326 lAC 2-7-2(d)(l) and 326 IAC 2-7-5, the Petitioner shall apply to incorporate Order requirements, including reporting and recordkeeping requirements and methods
to determine compliance, into its Part 70 Operating Permit within ninety (90) days of U.S. EPA approval of the Commissioner's Order into the Indiana SIP.

# Commissioner's Order No 2016-01 

# Page 4 of5 

# 7. From April 19, 2016 until IDEM issues

a Permit incorporating 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 repmt of the daily maximum twenty-four (24) hour S02 rolling average for Unit No. I, for Unit No. 2, and for Unit No.
I and Unit No. 2 combined. b. Recordkeeping: The Petitioner shall maintain records adequate
to document compliance with the S02 emission limitations and emission rates. c. Method
to determine compliance: Compliance shall be determined
by a continuous emission monitoring system in accordance with 326 lAC 3-5. 8. 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. 9. The requirements
of this Order supersede any less stringent requirements applicable
to the Petitioner. 

# EFFECTIVE DATE OF ORDER Pursuant
to IC 13-14-2-1(d),

IC 4-21.5-3-1,
IC 4-21.5-3-5(a)(6),
and 40 Code of Federal Regulations ("CFR") 51.102, IDEM will give notice of this Order to each entity to whom the Order is directed and affected neighbors by mailing 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 Order 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. mail. Information
on petitions for review of this Order can be found at IC 4-21.5-3-7. Pursuant
to IC 4-21.5-3-5(f) and IC 4-21.5-3-2(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 (18

1 ") 

# day. However, the compliance date for the emission limitations
in this Order is Aprill9, 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. Persons seeking judicial review of this Order may do so in accordance with IC 4-21.5-5.Commissioner'sOrdet·No2016-01Page5of5Ifyouhaveproceduralorschedulingquestionsregardingyourrequestforreview,youmaycontacttheOfficeofEnvironmentalAdjudicationat(317)232-8591.IfyouhavequestionsregardingthisOrder,pleasecontactMarkDert;OfficeofAirQuality,bytelephoneat(317)233-5682oremailatMDERF@idem.IN.gov.DatedatIndianapolis,IndianadayofJanuary,2016.CommissionerIndianaDepartmentofEnvironmentalManagement

# Attachment

C Public Notice and Certificate
of Publication for the Commissioner's Order for A.B. Brown Generating

Station addressing

the 1-hour S0 2 

# NAAQS Posey CountyLegal Notice- Public Comment Period and Opportunity for Public Hearing State Implementation Plan (SIP) Submittal A.B. Brown Generating Station in Posey County Commissioner's Order No 2016-01 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 Southern Indiana Gas and Electric Company, A.B. Brown Generating Station, Source I.D. Number 129-00010, located at 8511 Welborn Road in Mount Vernon, Posey County, Indiana. All interested persons are invited and will be given reasonable oppmiunity

to express their views concerning the proposed revision to the SIP. The purpose of this notice is to solicit public connnent on a proposed revision
to the SIP that is accomplished
by Commissioner's Order No. 2016-01 for A.B. Brown Generating Station. The Commissioner's Order imposes sulfur dioxide emissions limits and emissions rates upon A.B. Brown Generating Station. This Commissioner's Order will be submitted
to the United States Environmental 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 February 16, 2016. Any person may request

a public hearing on the proposed SIP revision. Requests for a public hearing must be submitted on or before February 16,2016.
If no timely request for a public hearing
is received,

a hearing will not be held. If a hearing
is scheduled, another legal notice will be published stating the date, time, and location of the meeting. Interested parties may present oral or written comments

at the public hearing, if held. Comments and suppotiing documentation,

or a request for a public hearing must be sent in writing to Mark Derf via the information provided below. Interested pmiies can also contact Mark Derfto see if a hearing has been scheduled. Please refer to Commissioner's Order 2016-01 in all con·espondence. MarkDerf Indiana Depmiment
of Environmental Management Office of Air Quality I 00 North Senate Avenue Mail Code 61-50 IGCN 1003 Indianapolis, Indiana 46204 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-Notth 100 North Senate Avenue lOth Floor Indianapolis, Indiana 46204. and Indiana Department
of Environmental Management Southwest Regional Office 1120 Notth Vincennes Avenue Petersburg, Indiana 47567. and Alexandrian Public Library 115 West Fifth Street Mount Vernon, Indiana

4 7620. The Commissioner's Order is also available on the IDEM website at: http://www.in.gov/idem/4686.htm. For additional information, please contact Mark Derf at the contact information provided above.INDIANADEPARTMEKTOFENYIRO!\:li!El\:'TALMANAGEMENTW"Prorc;ctHoosillr.iandOurEm,ironm"nt.MIDhfllR.Pen!lll(il.>..:nult100N.SMaleAVffii.E•lnl£-anapors,IN4&20:!l(ll00)451-&127••January13,2016CERTIFICATEOFPUBLICATIONa.ComorThisistocertifythattheIndianaDepartmentofEnvirorunentalManagement(IDEM)noticeofpubliccommentperiodandopportunityforaPublicHearingregardingthefollowing:•Commissione•·tsOrder#2016-0lfo1·A.B.Bro1rnGtntl'atingStationofIndianawaspublishedonIDEM'swebsiteonJanuary13,2016.ItisthatitwillremainpostedonthesiteuntilatleastFebm:uy16,2016.Thenoticeinfnllwasalsomadeavailablethesamedayonlineatthefollowingwebaddress,under"Commissioner'sOrden;"_http://wmv.ingovlidem/4686.h1mWebpublicationofthenoticewasattherequestofScottDeloney,BranchChief,ProgramsBranch,OfficeofAirQuality,IDEM.Attachments:CopyofwebpageaspublishedAllEqn!Oppurtullity:Emplo-ywBy:MikeFinklesteinIDEMWebmasterAttachmentDA.B.BrownGeneratingStation:ModelingSummaryPoseyCountyA.B. Brown Generating Station Modeling Summary for Commissioner's Order #2016-01 Background Initial modeling, using hourly continuous emissions monitoring (CEM) data from 2012-2014, showed higher modeled !-hour sulfur dioxide (SOz) concentrations. Modeling for A.B. Brown, using Mercury and Air Toxics Standard (MATS) S0 2 compliance emission rates, was then provided
in Indiana's Preliminary Recommendations Concerning Round

2 Air Quality Designations
for the 20 I 0 Primary !-hour SOz Standard submitted
to United States Environmental Protection Agency for review/consideration

on September 16, 2015.

1 Since A.B. Brown decided to use the hydrochloric acid (HCl) emission limit to comply with the MATS instead of the SOz emission limits, those rates could not be used and would not satisfy the Consent Decree. As requested by A.B. Brown, IDEM issued

a Commissioner's Order on January II, 2016, to establish permanent and enforceable sulfur dioxide (S0
2 ) emission limits for A.B. Brown in order to ensure continued attainment
of the 2010 primary !-hour S0 2 standard in the area surrounding the facility. The Commissioner's Order contains emission limitations and emission rates for Units

I & 2, as well as reporting and recordkeeping requirements and method for compliance. Modeled Limits The Commissioner's Order limits A.B. Brown's S0 2 emissions
to 0.855 lbs S0 2 /MMBtu (pounds per one million British thermal units) for Unit

I and 0.69 lbs S0 2 /MMBtu limit for Unit 2 when operating alone based on a 1-hour S0 2 averaging time. Both units can never exceed 2,152.2 lbs SOz/hr. (0.426 lbs SOz/MMBtu) when operating together. Therefore, Indiana modeled the S0 2 proposed emission limitations recommended

by A.B. Brown. Five scenarios were modeled. Modeled concentrations
for all five of A.B. Brown's operating scenarios were added to the temporally varying seasonal SOz background concentrations,

as well as the emission limitations and emission rates for all five scenarios
as outlined
in Table
1. The worst case operating scenario was Scenario
5: Unit 2 operating

at 0.69 lbs SOz/MMBtu and Unit

I operating at 0.1611bs SOz/MMBtu. Again, both units, when operating, cannot exceed 2,152.2lbs S0 2 /hr. Since that is the case, Unit

I cannot operate at full capacity when Unit 2 is running
at 0.69 lbs SOz/MMBtu. Also, when Unit
1 is operating
at 0.855 lbs S0 2 /MMBtu, Unit 2 cannot be operating.

Table

1 Scenaro

1 Scenario

2 Scenario

3 Scenario4 Scenario

5 Group ID Emission Rate

Bl BGAII
Bl GOAII 43_AII
B2 GOAII
B2 69AII Boilerl lb/MMBtu 0.854725973

0.6 0.4275 0.256417792 0.161437649 Boiler2 lb/MMBtu

- 0.253517787 0.4275 0.595470356 0.69 Boilerl Modeled lb/hr 2152.2 1510.8 1076.445 645.66 406.5 Boiler2 Modeled lb/hr

641.4 1081.575 1506.54 1745.7 Total lb/hr 2152.2 2152.2 2152.2 2152.2 2152.2 Concentration ug/m3 188.64213 190.57711 193.45872 194.71424 195.51998 1 http://www.in.gov/idem/airgualitv/2432.htm

I

# All other modeling parameters for A.B. 

# Brown were maintained from the Consent Decree modeling included on Pages 19-23 of Enclosure

3 oflndiana's Preliminary Recommendations Concerning Round

2 Air Quality Designations
for the 2010 Primary 1-hour S0 2 

# Standard. 2