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# OAR Box 1787 Prepped by Ollie Stewart



### Document

Number: 

# 7DII-C-2 9

Docket Number: 

# A-90-3 7

Printed 11/4/2008 10:22:19 AM

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UNITE D STATE S ENVIRONMENTA L PROTECTIO N AGENC Y

Offic e o f Ai rQualit yPlannin g an d Standard s Researc h Triangl e Park , Nort h Carolin a 2771 1

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- !-)T \ / P"" » P^"* ' "" ' HP . Richard E . Grusnldc Chie f Ai r Divisio n Alabama Departmen t o f Environmenta l Managemen t 175 1 Federa l Driv e Montgomery , Alabam

a 3613 0
Dea r Mr . Grusnick : Thi s i s i nrespons e t o you r Jun e 19 , 1987 , lette r concernin g bes t availabl e contro l technolog y (BACT ) determinations . Th e fssue s yo urais e highligh t perhap s th e mos t crucia l aspect s o f BAC T determinations , an d I hop e tha t th e followin g respond s adequatel y t o them . Th e firs t issu e yo uraise dconcern s th e rol e o f new sourc e performanc e standard s (NSPS ) i nBAC T determinations . Th e NSP S ar e establishe dafte r long andcarefu l consideratio no f a standar dtha t ca nb e reasonabl y achieve dby

every ne w sourc e anywher e i nth e nation . Thi s mean s tha t eve na very

recen t NSP S doe s no t represen t th e bes t technology available ; i t Instea drepresent s th e bes t technolog y availabl e nationwide , regard les s o f climate , wate r availability , andman y othe r highl y

variabl e case-specifi c factors . Th e NSP S 1 s th e leas t commo ndenominato r an dmus t b e met ; ther e ar e n o variances . Th e BAC T requirement , o nth e othe r hand , i s th e greates t degre e o f emission s contro l tha t ca nb e achieve da t a specifi c sourc e an

daccount s fo r site-specifi c variable s ona case-by-cas e basis . Sinc e anapplicabl e NSP S mus t alway s b e met , i t provide s a lega l "floor " fo r th e BACT , whic hcanno t b e les s stringent . A BAC T determinatio n shoul dnearl y

a7way s b e mor e stringen t tha nth e NSP S becaus e th e USPS establishe s wha t every sourc e ca nachieve , no t th e bes t tha t a sourc e coul ddo . I nonl y

a few BAC T case s shoul dyo uencounte r th e s .m e criteri a tha t limite dth e stringenc y o f th e NSPS , s o BAC T shoul dusuall y b e mor e stringen t tha nth e NSPS . States , a s yo upointe dout , don' t alway s hav e th e technica l expertis e tha t i s availabl e t o EPA , Fo r tha t reason , th e BAC T determinatio nproces s bes t fo r man

y agencie s i s tha t whic h1 s currentl y use db y man y State/loca l permi t agencies . Thi s proces s consist s o f requirin g th e sourc e t o eithe r us e th e mos t stringen t contro l technolog y o r t o show

1 ndetai l wh y

1 t cannot . Th e BACT/LAER * Clearinghous e i s ofte nused-t o fin dth e mos t stringen t contro l technology , a s ar e call s t o experience dpermi t revie w

* lowes t achievabl e "emissio nrat e

### >\9-

_ i engineer s i nothe r States , discussion s wit hcontro l equipmen t manufacturers ,

an dreview s o f literatur e sucha s th e Mcllvain e newsletter . Thi s approac h wa s allude dt o b

y th e EP A Administrato r 1 nth e recen t H-Powe r reman d (cop y enclosed ) wher e i t state s tha t "substantia l an d uniqu e factor s mus t b e show nt o Justif y

a les s efficien t contro l technology. * Fo r additiona l detai l onthi s approach , contac t Wayn e Blackard , Chief , New Sourc e Section , EPA , Regio nIX , 21 5 Fremon t Street , Sa nFrancisco , Californi a 94105 , (415 ) 974-8249 . Th e secondissu e involve s th e relationshi pbetwee n8AC T an dai r qualit y Impacts . Th a applicatio no f BAC T i s a specifi c requiremen t fo r a preventio no f significan t deterioratio n(PSD ) permi t tha t stand s alon e i n th e sens e that , a s a minimum , a PS D sourc e mus t Instal l BAC T regardles s o f th e ai r qualit y

impact , T

nothe r words , BAC T 1 s BACT , eve n1 f th e sourc e woul donl y

consume 5 percen t o f th e availabl e Increment . I certainl y di dno t mea nt o impl y

tha t EP A

"decides " ho

w muc hincremen t a sourc e ca n have ; EP A

does , however , hav e oversigh t responsibilitie s I nBAC T decisions . I nyou r example , EPA

woul dno t deny

a permi t t o a sourc e consumin g 9 5 percen t o f th e incremen t provide dal l els e wa s acceptable , includin g th e BAC T determination . However , modele dviolation s o f a nationa l ambien t ai r qualit y

standar do r PS D incremen t ma y driv e a BAC T determinatio nt o a greate r leve l o f control . Itfia t w e woul dden

y i s a permi t fo r a sourc e wher e a BAC T determinatio nwa s "relaxed " (o r eve nn o contro l a t al l wa s required ) simpl y

becaus e th e sourc e di dno t consume al l o f th e increment . Othe r aspect s o f th e environmenta l impac t o f th e BAC T decisio noccu r whe na contro l optio nincrease s th e emission s o f on e pollutan t whil e reducin g emission s o f another , o r a contro l optio nma y produc e a nenviron mentall y harmfu l byproduct . Fo r example , th e us e o f wate r injectio ni n controllin g nitroge noxide s fro m ga s turbine s wil l increas e carbo nmonoxid e emissions . I nsummary , sectio n16 9 o f th e Clea nAi r Ac t define s BAC T a s "base d onth e maximu

m degre e o f reductio n.. . o na case-by-cas e basis. " Conse quently , BAC T represent s th e bes t leve l o f contro l th e sourc e ca nprovid e andshoul dno t b e base do na category-wid e minima l standar dlik e a n applicabl e NSPS . Sincerely ,

CWe f Ne wSourc e Revie wSectio n 1 Enclosur e
cc : Bruc e Mille rP. 4

Fo r enclosure t o docket

itemII-C-1 , Jul

y 28 , 198 7 letter

fro mGar y McCutchen t o Richar

d Grusnick , se e docket

itemindicated

. II-K- 2 Honolulu Resourc e Recover y Facilit y PS D Appea

l No

. 86- 8 Remand , June 22,1987

.