UNITEDSTATESENVIRONMENTALPROTECTIONAGENCYREGION711201RennerBoulevardLenexa,Kansas66219MAR1 92015MEMORANDUMSUBJECT:FROM:THRU:TechnicalSupportDocumentfortheIowaStateImplementationPlan(SIP)RevisionforPermitModifications,MuscatinePowerandWater,andUnionTankCarCompany,Muscatine,IowaHeatherHamilton,IowaState\1lt.£CommunityPartnershipProgramsSectionAirPlanningandDevelopmentBranchMichaelJay,SectionChiefAtmosphericProgramsSectionAirPlanningandDevelopmentBranchJoshuaTapp,BranchChiefAirPlanningandDevelopmentBranchTO:IA-167A;EPA-R07-0AR-2015-0159OnDecember1,2014,EPARegion7tookfinalactiontoapproveacontrolstrategySIPfortheStateofIowa's200624-hourPM2.sNationalAmbientAirQualityStandard(NAAQS)forMuscatine,Iowa.ThecontrolstrategySIPincludedconstructionpermitsforGrainProcessingCorporation,MuscatinePowerandWater(MPW),andUnionTankCarCompany(UTLX).OnNovember10,2014,EPAreceivedthestate'srequesttoapprovechangestotheMPWandUTLXPM2.spermits.Therequestwasaccompaniedbyarevisedmodelinganalysisthatdemonstratedcontinuedattainmentaswellasdocumentationfromthenoticetothepublictocommentandreviewonthedrafts.Thisrequest,tomodifyMPWandUTLXpermits,precededtheEPA'sactionapprovingtheMuscatinePM2.sSIP.Inanefforttoexpeditiouslymoveforwardwiththefinalactionforthestate'srequesttoapprovethecontrolstrategyforthe2006PM2.sinMuscatine,EPARegion7madethedecisiontofinalizethecontrolstrategySIPanddevelopaseparateactionfortheconstructionpermitmodifications.TheIowaDepartmentofNaturalResources(IDNR)noticestothepublictocommentandreviewthedraftswerepublishedintheMuscatineJournalonJuly30,2014,andAugust1,2014,forUTLXandMPW,respectively,withacommentperiodof30days.TearsheetsweresubmittedwiththeNovember10,2014,requestasproofofpublication.Inadditiontohardcopysubscriptions,theMuscatineJournalPrintedonRecycledPaperhasoptionsforanon-lineeditionaswellasRSSfeeds.Thepublicnoticeforbothfacilities'permitmodificationsgavethepublicoptionstocommentontheIDNRwebsite,TheMusserPublicLibrary,ormailcommentstoIDNR.PublicmeetingswereheldattheMusserPublicLibraryonAugust20,2014.Citizenswereinattendance;therewerenocomments.ThemodifiedpermitsforMPWandUTLXwerereviewedbyEPARegion7PermittingEngineersandcomparedwiththeoriginalpermits.NotethatIDNRissuesasingleconstructionpermitforeachemissionpoint.MPW:MPWisamunicipalelectricgeneratingstationandtheprimarysourcesofPM2.semissionsarefromthreecoal-firedboilersandtheassociatedcoalhandlingandstorageequipment.Thefacility-wideactualPM2.semissionsforMPWare58.3tonsperyear.(NOTE-thisisforagivenyearandfluctuatesfromyeartoyear).Theestimatedemissionreductionsfromtheimplementationofthecontrolstrategyis1.2%.Duetotestingdifficulties(requiredsamplingtimewasprohibitivelylong),IDNRincreasedthepermittedlimitforfouremissionunitsasillustratedinthefollowingtable.IDNRmodeledtheincreaseandtheincreasedidnotimpactthePM2.sNAAQS.EPARegion7technicalstaff(modeling)concurred.EPARegion7PermittingEngineersnotedthataprojectwithanincreaseinemissionsofthislevelisrelativelyinsignificantandwouldnottypicallyrequireapermitorapermitrevision.BecausethesepermitsarepartoftheMuscatinePM2.s.SIP,thepermitmodificationswerepublicnoticedandtheexistingpermitsintheSIPwillbereplacedwiththemodifiedpermits.MPWOriginalemissionpermitRevisedpermitsunitlimitsPMz.slimitsPMz.sIncreaseNotesEU20EU21.0006lblhr.036lblhr.045tonsEU22peryearIncreaseincludesallunitsEU23.00121lblhr.036lblhr(tpy)collectively.UTLX:UTLXsuppliesandreconditionsrailtankcarsforusethroughrentalagreements.TheprimarysourcesofPM2.sareremovalofpaintfromrailtankcars,repairofrailtankcarsandpaintapplicationthroughaspraysystemfortherailtankcars.UTLXisnotconsideredamajorsourceofPM2.sbutislocatednearthePM2.smonitor.Duetotheresultsofastacktest,IDNRincreasedthepermittedlimitintherubberliningareaasillustratedinthefollowingtable.Aprojectwithanincreaseinemissionsofthislevelisrelativelyinsignificantandwouldnottypicallyrequireapermitorapermitrevision.BecausethesepermitsarepartoftheMuscatinePM2.s.SIP,thepermitmodificationswerepublicnoticedandtheexistingpermitsintheSIPwillbereplacedwiththemodifiedpermits.2Stacks

were modified

from vertical

to horizontal configuration

due

to issues related

to the filtration systems

for three emission

units

in the railcar interior

coating

line,

the railcar

repair

area

and qualification

(cut shop)

area. There

was

no increase

in emissions

from

these emission

units,

and

in general,

no permit revision

is required;

however,

a permit revision

and dispersion

modeling

analysis were required

since

the changes

could impact

the ambient

PM2.s concentrations

outside

the fence

line. The modeling

was reviewed

by

the EPA Region

7 technical

staff (modeling)

and concluded

that impacts are below

the significant

impact

level. UTLX

Original

Revised emission

permit

permits unit

limits

PM2.s

limits

PM2.s

Increase

Notes Revision

required

since change could

affect concentrations

outside of fence

line. Modeling

indicated EU6

No change

No change

No change concentrations

were

not affected. EU7

.0062lblhr

.0085lblhr

.010

tpy

Does

not impact

PM2.s NAAQS Revision

required

since change could

affect concentrations

outside of fence

line. Modeling

indicated EU8

No change

No change

No change concentrations

were

not affected. Revision

required

since change could

affect concentrations

outside of fence

line. Modeling

indicated EU9

No change

No change

No change concentrations

were

not affected. UTLX permits

were

also modified

to include facility-wide

compliance methodology

requirements

for National Emission

Standards

for Hazardous

Air Pollutants (NESHAP)

40 CFR

Part

63 Subpart MMMM (Miscellaneous

Metal

Parts

and Products

Surface Coating).

Facilities

are given multiple compliance options

for this NESHAP

and

the permit

is being revised

to clarify

the option

that Union

Tank

Car Company

has elected (facility-wide

rather

than individual

EU limits).

There

is

no PM2

. s emission increase

from

this revision. For

a detailed explanation

of the modeling methodology

and inventory development,

please

refer

to page

30

of the IDNR control strategy

SIP submittal

(Docket: EPA-R07-0AR-2015-0159). SUMMARY: EPA

is approving

revisions

with direct

final action

to the

SIP

for

the State

of Iowa

to include modified permits

for Muscatine

County,

Iowa.

The

SIP revision addresses modifications

to construction

permits that were included

in the 2006 24-hour

PM2.s NAAQS

control strategy proposed

in the Federal Register on August

11, 2014,

and published

as

a final

rule

on December

1, 2014,

with

the effective

date

of December

31, 2014

(79

FR 71025).

The state's submission

of modified

permits included

a technical demonstration

and

a revised

air dispersion

modeling

analysis

that demonstrated

continued

attainment

of the 2006 24-hour

PM2.s NAAQS. This action

will

also make

an administrative

correction

to

a permit number. 3