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# OAR Box 1778 Prepped by Ollie Stewart



### Document

Number: 

# 175 ) ll-F- 2
Docket Number: 

# A-90-0 6

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Sheet 175of 276P. 2

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NOT E 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

Jun e 20 , 199 0

TO : Harve y

Nozic k ANR-44 3
RE : Revise dInterpretativ e Rulin g Attache di s th e revise dinterpretativ e rulin g whic hexempt s add-o n control s from

NS R and NSP S requirements . W e hav e revise dth e actio nmem o t o discus s th e comment s w e receive ddurin g Re d Borde r and how the y wer e considere di

n th e fina l package . Othe r portion s o f th e packag e shoul d alread y b e i n D.C . We believ e th e packag e i s no w read y fo r OM B review . Pleas e giv e m e a cal l a t FT S 629-558 6 i f yo u hav e any questions .

Ef dLilli s Attachmen t

cc : K . Berr y G . McCutche n B . Lamaso nP. 3 

# (as) UNITE D STATE S ENVIRONMENTA L PROTECTIO N AGENC Y WASHINGTON

, D.C

. 2046 0

V Pno ,t C

Ms . Lind a G . Stunt z AI RAND RADIATIO

N Deput y Unde r Secretar y Policy , Plannin g and Analysi s U.S . Departmen t o f Energ y Washington , D.C . 2058 5
Dea r Ms . Stuntz : Enclose di s a cop y

o f a n interpretativ e ruling o n emission s contro l system improvement s prepare dby m y office . I t i s no

w bein g reviewe d by

th e Offic e o f Managemen t an d Budge t (OMB) . Unde r thi s interpretativ e ruling , al l contro l technolog y

retrofi t project s o r simila r emission s contro l technolog y demonstratio nproject s approve d b y th e Environmenta l Protectio nAgency , addin g emission s contro l system s an d meetin g certai nenvironmenta l safeguards , woul d b e exclude d fro

m th e new

sourc e performanc e standard s an d preventio no f significan t deterioratio nprovision s o f th e Clea nAi r Act . Th e rulin g identifie s fabri c filters , scrubbers , absorbers , catalysts , an dtherma l reduction/oxidatio na s example s o f "add-on " emission s contro l equipment . Us e o f a differen t fue l ma y als o b e considere d a n "add-on " contro l system i f suc hchange s ar e properl y determine d t o b e a pollutio ncontro l measure . Suc hdetermination s wil l b e mad e on a case-by-cas e basis . Fo r example , som e physica l change s t o accommodat e a new fue l coul d b e properl y characterize d a s pollutio ncontro l system s (e.g. , a clea ncoa l technolog y demonstratio no f nitroge noxide s rebumin g technolog y usin g natura l ga s o n a coal-fire d utilit y

boiler) . Thi s i s consisten t wit hth e provision s o f th e Bumpers ' Amendmen t incorporate dint o S . 1630 . We expec t th e enclose dinterpretativ e rulin g wil l b e publishe d i n th e Federa l Registe r onc e OMB' s revie w i s completed . Sincerely ,

William G . Rosenber g Assistan t Administrato r fo r Ai r an

d Radiatio n Enclosur eP. 4

° £\ L o UNITE D STATE S ENVIRONMENTA L PROTECTIO N AGENC Y ^MK W i

Offic e of Ai rQualit yPlannin g an d Standard s \ ^[\^jl~^ Researc h Triangl e Park , Nort h Carolin a 2771 1 \ "t OPO' ^ Jun e 20 , 199 0

MEMORANDU

M SUBJECT : Offic e o f Managemen t an d Budge t (OMB ) Revie w o f Interpretativ e Rulin g o n Ai r Pollutio nControl ^ System improvement s FROM : I A Geral dA . Emison , Directo r ^ClS/tors^C***^--*^

[^Offic e o f Ai r Qualit y Plannin g an

d Stajjjard s (MD-10 ) TO : Ro bBrenner , Steerin g Committe e Representativ e

fo r Ai r an

d Radiatio n(ANR-443 )

Attache dfo r OM B review i s a n interpretativ e rulin g on new sourc e revie w (NSR ) an d new sourc e performanc e standard s (NSPS ) applicabilit y exclusion s fo r th e installatio no f temporar y an d permanen t "add-on " ai r pollutio ncontro l system s a t existin g sources . Thi s rulin g reflect s th e Environmenta l Protectio nAgency' s (EPA's ) positio ntha t th e NS R an d NSP S provision s d o not , andshoul dnot , appl y t o existing source s whic hdecid e t o instal l o r improve "add-on " emission s contro l system s o r devices , provide dcertai nenvironmenta l criteri a ar e met . Th e rulin g als o applie s t o temporar y contro l equipment relate dchange s a t existin g source s participatin g i n th e clea ncoa l technolog y (CCT ) program

o r t o simila r emission s contro l technolog y demonstratio n project s approve db

y EPA . Th e rulin g identifie s fabri c filters , scrubbers , absorbers , catalysts , andtherma l reduction/oxidatio na s example s o f "add-on " emission s contro l equipment . Us e o f a differen t fue l ma y sometime s b e considere da n "add-on " contro l system

i f suc hchang e i s properl y determine dt o b e a pollutio ncontro l system . Suc hdetermination s wil l b e mad e b y th e Administrato r o n a case-by cas e basis . Fo r example , som e physica l change s t o accommodat e a ne w fue l coul db e properl y

characterize da s pollutio ncontro l system s (e.g. , a CC T demonstratio no f nitroge noxide s rebumin g technolog y usin g natura l ga s o n a coal-fire dutilit y

boiler) . Thi s packag e complete dRe d Borde r Revie w o n Apri l 2 , 1990 . W

e ar e requestin g 10-da y

OM B review

a s th e attache dpackag e i s a mino r action . A s yo uknow , ther e continue s t o b e considerabl e interes t i n completin g thi s action . Question s concernin g th e packag e ma y be conveye dt o Bil l Lamaso na t FT S 629-5374 . Attachmen tP. 5



## <^H p 

# DRAF T

UNITE D STATE S ENVIRONMENTA L PROTECTIO N AGENC Y

WASHINGTON

, D.C

. 2046 0

OFFIC E O F AI RAN D RADIATIO N MEMORANDU

M
SUBJECT : Interpretativ e Rulin g on Ai r Pollutio nContro l System

Improvements--ACTIO N

MEMORANDU

M FROM : Willia m

G . Rosenberg , Assistan t Administrato r fo r Ai r an

d Radiatio n(ANR-443 ) TO : Th e Administrato r (A-100 )

PURPOSE : Attache d fo r you r approva l i s a n interpretativ e rulin g entitle d "Applicabilit y

o f Ne w Sourc e Revie w

an d Ne w Source Performanc e Standard s Requirements. " Thi s rulin g respond s t o Departmen t o f Energy (DOE ) concern s tha t ne w sourc e performanc e standard s (NSPS ) an d new sourc e revie w

(NSR ) requirement s ar e impedin g th e implementatio no f th e clea ncoa l technolog y (CCT ) program . Th e actio nclarifie s th e definition s o f "majo r modification " and "modification " t o provid e exclusion s from NSP S an

d NS R requirement s fo r retrofi t CC T project s an d othe r approved , add-o nemission s contro l system improvement s includin g th e us e o f les s pollutin g fuel s wher e applie d a s pollutio ncontro l measures . BACKGROUND : Th e Environmenta l Protectio nAgenc y (EPA ) ha s become awar e tha t th e definition s o f "majo r modification " i n 4 0 CF R Part s 5 1 an d 52 , and "modification " i

n 4 0 CF R Par t 60 , can b e interprete d i n suc ha manne r a s t o subjec t certai nenvironmentally-desirabl e activitie s a t existin g stationar y source s t o NS R o r NSPS , o r both . Neithe r Congres s no r EPA intende d thes e desirabl e activitie s t o b e covere d b y th e Clea nAi r Act' s (CAA's ) new sourc e requirements . Thes e desirabl e activitie s consis t o f th e additio no r us e o f system s o r device s whos e primar y functio ni s th e reductio no f ai r pollutants , andwhic har e no t les s environmentally-beneficia l tha nan y emission s contro l system s o r device s the y replace . Thi s rulin g explain s EPA' s positio ntha t suc hactivities , whic hinclud e CC T demonstratio nprojects , ar e no t physica l change s o r change s in th e metho d o f operatio ni f the y mee t certai ncriteria , an dthu s ar e no t modification s fo r NS R o r NSP S purposes . Th e electri c utilit y industry

ha s generall y

bee nreluctan t t o allo w th e us e o f it s plant s fo r CC T an d simila r EPA

project s becaus e o f th e concer n that , b y s o doing , thos e plant s coul d become subjec t t o NS R an d NSPS , eve n whe nth e CC T o r simila r demonstratio nprojec t i s temporar y i n natur e an

d th e sourc e i s returne dt o it s pre-projec t conditio nafte r th e projec t i s completed . Th e EPA , DOE , an d th e Departmen t o f Commerc e ar e als o concerned ,P. 6

bot ha s a matte r o f equit y an dbecaus e thes e concern s coul drestric t th e availabilit y

o f CC T demonstratio nsites . Th e EPA initiall y

attempted , wit honl y limite dsuccess , t o alleviat e industr y concern s b

y issuin g "n o actio nassurance " letter s t o specifi c utilities , statin g tha t EP A woul dno t undertak e civi l enforcemen t actio n agains t th e company

unde r NSP S o r NS Rprovision s tha t migh t hav e applie d b y virtu e o f th e company' s participatio ni na temporar y

CC T project . Thi s interpretativ e rulin g provide s mor e certaint y b y stating , i

na generi c fashion , EPA' s lega l interpretatio nthat , unde r curren t regulations , source s whic had

do r improve ai r pollutio ncontro l systems , whethe r a s a complianc e measur e o r pursuan t t o a CC T o r simila r EPA-approve dcontro l technolog y demonstratio nproject , o r fo r some othe r reason , wil l no t b e subjecte dt o NS R o r NSP S coverage , s o lon g a s th e appropriat e reviewin g authorit y determine s tha t th e criteri a discusse di nthi s rulin g ar e met . Fo r thos e State s wit h approve dStat e implementatio nplans , thi s interpretativ e ruling , a s i t applie s t o NS Rrules , i s onl y advisor y

i nnature . Thos e State s ar e no t oblige d t o follo w EPA' s lea di

nallowin g thi s exclusion , althoug hEP A encourage s the m

t o d o so . Thi s rulin g represent s th e maximu m exten t t o whic hEPA ca ninterpre t th e curren t regulation s an dstatute s t o exemp t environmentally-beneficia l project s from NS RandNSPS . Thus , i t doe s no t generall y provid e exclusion s from NS R andNSP S fo r CC T project s whic hinvolv e mor e tha nth e additio no f a contro l syste m o r devic e (e.g. , repowerin g an dnew coal-fire d cogeneratio n facilities) . Suc hproject s ar e clearl y th e sor t o f "modification " o r "new source " tha t Congres s intende dt o cove r unde r ne w sourc e requirement s wher e the y increas e emission s ove r baselin e levels . Th e NS Ran

dNSP S provision s o f th e CA A appl y bot ht o new

source s an

dt o modification s o f existin g sources . Th e criteri a governin g whethe r modification s ar e subjec t t o thes e provision s ar e specifie di nth e EPA regulations . Ingeneral , modification s tha t trigge r thes e ne w sourc e requirement s ar e thos e involvin g physica l o r operationa l change s whic h increas e emission s ove r baselin e levels . Th e ter m "physica l o r operationa l change " i s construe dbroadl y an dma y includ e th e installation , use , o r dismantlin g o f pollutio ncontro l equipment . Th e EPA ha s alway s recognize dtha t Congres s di dno t intendt o requir e ever y activit y

t o b e potentiall y

subjec t t o new

sourc e requirements , an dha s substantiall y

narrowe dthi s term

i nit s NSP S an

dNS Rregulator y

definition s throug hth e adoptio no f common-sens e exclusions . Th e existin g regulation s [se e 4 0 CFR60.14(e)(5) ] contai na nexclusio n from NSP S fo r th e additio no r us e o f an y devic e whos e primar y functio ni s th e reductio no f ai r pollutants . Thus , NSP S woul dno t appl y t o th e installatio n o r improvemen t o f emission s contro l equipmen t whic hreduce s hourl y emission s rates . However , th e NSP S provision s coul dappl y t o majo r facilitie s a t th e conclusio no f temporar y CC T demonstratio nprojects , whe nth e contro l equipmen t i s remove dan

demission s ris e bac k t o th e leve l tha t existe dbefor e th e demonstration .P. 7



### Th e NS Rregulation s d o no t hav e a simila r exclusion , an dne t emission s increase s ar e determine db y summin g al l contemporaneous , creditable , actua l emission s increase s an ddecreases . Th e definitio no f "actua l emissions " i s suc hthat , generally , th e compariso ni s betwee nactua l emission s befor e th e x 

### modificatio nan

dth e potentia l t o emi t o f th e facilit y afte r th e modification 1 

### . A physica l o r operationa l chang e wil l trigge r NS Ri f th e annua l potentia l t o emi t o f th e sourc e afte r th e chang e i s greate r tha nit s representativ e actua l emission s prio r t o th e change . Dismantlin g th e contro l equipmen t a t th e conclusio no f a temporar y demonstratio nproject , an dreturnin g th e sourc e t o it s pre-projec t condition , coul dals o trigge r NSR . Th e EPA believe s tha t thi s methodolog y

generall y

serve s th e purpose s o f NSR , for mos t situations , becaus e i t subject s t o revie w

project s tha t migh t lea dt o a nincreas e i

nactua l emissions . However , th e NS Rprovision s coul db e interprete dt o appl y t o majo r facilitie s simpl y

installin g o r improvin g contro l equipment , including CC T demonstratio nprojects , unde r circumstance s wher e a permanen t increas e i n pollutio ni s highl y

unlikely . RECOMMENDE D INTERPRETATIV E RULING : Th e interpretativ e rulin g i s designe dt o accomplis htw o goals . First , i t announce s EPA' s interpretatio nthat , unde r curren t regulations , NS Ran dNSP S modificatio nprovision s generall y d o no t appl y

t o th e installatio no r improvemen t o f emission s contro l system s o r devices , whethe r thes e change s b e temporar y

o r permanent . Second , i t provide s certai nsafeguard s t o ensur e that ' thes e project s ar e no t environmentall y harmfu l befor e excludin g the m from th e coverag e o f th e new

sourc e requirements . Thus , th e resul t o f thi s interpretativ e rul e shoul db e t o encourag e source s t o instal l o r demonstrat e improve demission s control s and , therefore , facilitat e th e replacemen t o r improvemen t o f les s efficien t emission s contro l system s wit hmor e environmentally-beneficia l systems . Th e interpretativ e rulin g applie s onl y t o th e additio no f emission s contro l system s o r device s a t existin g sources , includin g CC T an dsimila r emission s contro l demonstratio nproject s an dcompliance-relate drequirements . Fo r th e purpos e o f thi s ruling , th e ter m "emission s contro l system or device " generall y

mean s an"add-on " typ e o f emission s contro l equipment . I t does , however , includ e alteration s tha t allow th e us e o f les s pollutin g fuel s wher e suc hus e constitute s a nemission s contro l system . I t doe s no t otherwis e includ e a switc ht o a differen t fue l o r ra w material , a differen t metho do f operation , o r a differen t typ e o f proces s equipment . However , th e appropriat e reviewin g authorit y

wil l determin e ona case-by-cas e basi s i f a projec t i s designe dprimaril y

t o reduc e ai r pollution . Th e interpretativ e ruling doe s no t includ e change s whic hwoul drestor e o r increas e origina l capacit y o f th e facility . Th e interpretativ e rulin g i s intende dt o appl y onl y t o activitie s tha t ar e determine dt o b e environmentall y beneficial . Also , fo r thos e State s wit h approve dStat e implementatio nplan s (SIP's) , today' s interpretativ e rule , a s i t applie s t o NS Rrules , i s onl y advisor y

i nnature .P. 8



### A napplicant' s reques t fo r a napplicabilit y

determinatio nmus t contai na genera l descriptio no f th e facilit y an dth e propose dactivity , informatio non curren t andprojecte dusag e o f th e facility , an dsufficien t informatio nt o justif y applyin g thi s exclusion . Fo r a temporar y CC T demonstratio nproject , fo r example , a rational e woul db e neede dfo r why th e emission s contro l syste m o r devic e t o b e teste dshoul db e considere dt o b e advance dcontro l technology . Inaddition , th e reques t mus t demonstrat e th e following : 1 . Th e sourc e will , durin g an dafte r th e propose dchange , continu e t o mee t al l curren t requirement s an dstandard s applicabl e t o existin g source s unde r th e CAA . Thi s include s demonstration s tha t th e sourc e wil l continu e t o mee t applicabl e nationa l ambien t ai r qualit y standards , preventio no f significan t deterioratio n(PSD ) increments , permi t conditions , an dSIP's . 2 . Ther e wil l b e no environmenta l har m resultin g fro

m th e propose d activities . Thi s include s condition s tha t th e propose dchang e woul dno t b_ y itself : (a ) increas e th e maximu m hourl y actua l emission s rat e o f an y pollutan t regulate dunde r th e CAA ; (b ) increas e th e annua l emission s o f any pollutan t regulate dunde r th e CAA; (c ) adversel y

impac t anai r qualit y relate dvalu e (e.g. , visibility ) i nan y Clas s I area ; o r (d ) allow

anincreas e i

nemission s o f toxi c pollutant s no t regulate db y th e CA A whic hwoul dcaus e a healt ho r welfar e impact . Change s whic har e expecte dt o increas e emission s t o th e atmosphere , suc h a s change s whic hincreas e a source' s hourl y operatin g capacit y

(e.g. , eliminatin g a bottleneck) , hourl y emission s rat e (e.g. , on e pollutan t decrease s bu t anothe r increases) , o r utilizatio nrat e (e.g. , a nanticipate d increas e inhour s o f operatio nresultin g fro m th e installatio no f controls ) woul dno t b e affecte db y thi s interpretatio nan dwoul dcontinu e t o b e potentiall y

subjec t t o NS Ran

dNSPS . Th e EP

A wil l presume , however , tha t th e additio no f a contro l devic e wil l not , b v itself , resul t i

na nincreas e i

n capacit y utilization . However , thi s presumptio nwil l b e reverse di f ther e i s a clea r likelihoo dtha t operatin g hour s o r productio nrate s wil l increas e becaus e o f th e installatio no f th e device . ISSUES : Ther e ar e no majo r outstandin g issue s withi nth e EPA . I t shoul db e noted , however , tha t thi s interpretativ e rulin g doe s no t respon dt o al l o f DOE' s interest s i

nCC T projects . Som

e CC T an dothe r demonstratio nproject s wil l continu e t o b e subjec t t o NS Ran dNSP S whe nthei r emission s trigge r applicabilit y

provision s o f thes e rules . Thes e projects involv e th e constructio nan

doperatio no f new

emissio nunits , suc ha s repowering , an d ther e i s h o latitud e fo r interpretatio no f th e existin g regulations , regardles s o f th e ultimat e meri t o f th e project .P. 9



### Anothe r potentia l issue i s th e utilit y industry' s continue deffort s t o portra y EPA' s action s i

nth e Wisconsi nElectri c Powe r Company (WEPCO ) cas e a s affectin g CC T projects , whic hi t doe s not . Repowerin g andNew

Facilitie s Sinc e repowerin g project s an dnew facilitie s involv e replacemen t o r constructio no f essentia l steam-generatin g facilities , the y implicat e th e cor e concern s o f th e NSP S an dPS D "modification " an d"new source " provision s unde r curren t legislation . Consequently , the y canno t simpl y

b e exclude dfro

m coverag e b

y administrativ e actio nbu t onl y b y legislativ e change s t o th e CAA . T o th e exten t tha t repowerin g project s decreas e emission s o f eac hregulate d pollutan t ove r baselin e levels , the y ar e no t subjec t t o ne w sourc e requirement s inany

event . I t appears , however , tha t fo r some technologie s an dsome pollutants , repowerin g wil l resul t i nincrease s inmaximum hourl y emission s o r annua l actua l emissions , mostl y du e t o capacit y

increase s an

d expande dutilization . I nthes e instances , source s utilizin g thes e technologie s mus t addres s emissio nincrease s throug hNS Ran dNSP S requirements . WEPC O Ther e i s n o direc t linkag e betwee nth e WEPC O decisio nandCC T projects . Som e representative s o f th e utility industr y

hav e confuse dth e WEPC O projec t andCC T projects , suggestin g tha t EPA' s decisio nonWEPC O woul ddiscourag e utilitie s from

participatin g inCC T projects . Infact , th e WEPC O decisio n addresse dth e applicatio no f EPA' s NSP S an dNS Rrule s t o a nonroutin e change , i nwhic hWEPC O wa s replacin g a majo r componen t o f t s steam-generatin g facility . I t di dno t involve th e additio no f pollutio ncontro l technolog y o r a CC T demonstratio nproject . Therefore , i t i s clea r tha t th e WEPC O projec t an dth e CC T program

ca nan dshoul db e addresse dseparately . ENVIRONMENTAL , ECONOMIC , AND ENERGYIMPACTS : Ther e shoul db e no negativ e environmental , economic , o r energ y impact s from thi s interpretativ e ruling . Th e actio napplie s t o thos e project s whic h instal l o r improv e add-o nemission s contro l system s an dsho w tha t thes e change s wil l no t b e les s environmentall y beneficial . Th e rulin g i s intended , i npart , t o facilitat e th e installatio no f CC T project s whic hpotentiall y provid e environmental , economic , an denerg y improvement s relativ e t o existin g systems . RESOURC E REQUIREMENTS : No additiona l EPA , State , o r loca l resource s wil l b e requiredfo r thi s actio na s procedure s fo r implementin g th e rulin g ar e currentl y i nus e i n determinin g applicabilit y o f NSP S an

dNS Rregulation s t o modification s a t sources .P.1 0

REPORTIN GAN D RECORDKEEPIN GREQUIREMENTS : Ther e ar e n o ne w

reportin g an

drecordkeepin g requirement s associate d wit hthi s action . PUBLI C PARTICIPATION :
A s thi s i s aninterpretativ e rulin g rathe r tha na rulemaking , it i s no t subjec t t o notic e andcommen t rulemakin g provision s o f 5 U.S.C . §533 . However , th e substanc e o f thi s rulin g ha s bee nprovide di nou r comment s ona permi t issue db

y th e Stat e o f Indian a fo r a CC T projec t a t th e Norther n Indian a Publi c Servic e Company' s Baill y station , an

di na respons e t o a lette r b y DO E expressin g concern s ove r NS Ran dNSP S consequence s fo r CC T projects . Th e rulin g itsel f wa s sen t t o DO E fo r thei r review concurren t wit hreview b y th e Offic e o f Managemen t an dBudget . ANTICIPATE D REACTIONS : No strong oppositio ni s expecte dt o resul t fro m thi s action . CHANGE S SINC E RE D BORDER : Al l office s participatin g i nRe dBorde r revie w

fo r thi s actio nconcurred . Severa l office s concurre dwit hmostl y mino r editoria l comments . Two comment s di dsugges t possibl e substantiv e change s t o th e interpretativ e ruling . Inon e comment , th e Offic e o f Policy , Plannin g andEvaluatio nsuggeste dtha t utilit y emission s b e considere dona "system-wide " basis , thereby ignorin g change s i

n emission s (an

dmodifications ) a t individua l powe r plants . Thi s suggestio nwa s rejecte dsinc e "system-wide " averagin g fo r utilitie s ha s broade r application s tha nai r pollutio ncontro l system improvement s an

dshoul db e considere di na separat e rulemaking . Th e secondcomment , b y th e Offic e o f Genera l Counse l (OGC) , suggeste dth e us e o f les s pollutin g fuel s (e.g. , natura l gas ) i nretrofi t pollutio ncontro l project s b e considere da s "addon " contro l system s exemp t fro m NS Ran dNSP S unde r th e interpretativ e ruling . Thi s offic e agree s wit hthi s positio nan d OGC' s recommende dchang e ha s bee nadde dt o th e ruling .

RECOMMENDATIONS : Give nth e considerabl e interes t b y DO E an dother s fo r promp t actio n fo r NSP S an

dNS Rexclusion s fo r CC T retrofi t projects , w e recommen dtha t yo u sig nth e attache dFedera l Registe r notic e a s soona s possible . Attachment sP.1 1



### 6560-5 0 ENVIRONMENTA L PROTECTIO N AGENC Y 4 0 CF RPart s 51 , 5 2 an d6 0 [AD-FRL - ] APPLICABILIT YO F NEW

SOURC E REVIE W

AN D NEW SOURC E PERFORMANC E STANDARD S REQUIREMENT S

AGENCY : Environmenta l Protectio nAgenc y (EPA) . ACTION : Interpretativ e Ruling . SUMMARY : Thi s rulin g clarifie s th e definitio no f "majo r modification " i n 4 0 CF RPart s 5 1 an

d52 , an d"modification " i

n4 0 CF RPar t 60 . Th e clarificatio nestablishe s tha t certai nactivitie s a t existin g stationar y
source s o f ai r pollutio nar e no t "physica l changes " o r "change s i nth e metho d

o f operation " and , hence , ar e no t subjec t t o eithe r new sourc e revie w

(NSR ) requirement s o r new

sourc e performanc e standard s (NSPS) . Thi s rulin g doe s no t appl y t o th e constructio no f ne w emission s units . Th e resul t o f thi s interpretatio ni s tha t th e improvemen t o f existin g add-o nemission s contro l system s o r device s a t a source , th e installatio no f

ne w add-o nemission s system s o r devices , an dus e o f les s pollutin g fuel s wher e applie da s pollutio ncontro l measures , d o no t subjec t th e sourc e t o NS Ro r NSPS , provide dEP A

o r th e appropriat e reviewin g agenc y determine s tha t certai n criteri a ar e met . Fo r thos e State s wit happrove dStat e implementatio nplan s (SIP's) , today' s interpretativ e rul e i s onl y advisor y

i nnatur e a s i t applie s t o th e NS Rprogram . Thos e State s ar e encourage dt o follow EPA' s lea d,P.1 2

i nallowin g thi s exclusion . Thi s interpretatio nextend s t o th e additio no f
contro l device s fo r compliance-relate d purposes , fo r Departmen t o f Energy (DOE ) clea ncoa l technolog y (CCT ) demonstratio nproject s and simila r project s funde do r approve db y EP A fo r reducin g emissions , an d fo r othe r voluntar y purposes .

DATES : Thi s rulin g i s effectiv e immediately .

ADDRESSES : Supportin g informatio nuse di ndevelopin g th e interpretativ e rulin g i s containe d i nDocke t No . A-90-06 . Thi s docket i s availabl e fo r publi c inspectio nan dcopyin g betwee n8:3 0 a.m . an d 3:3 0 p.m. , weekday s a t EPA' s Ai r Docke t (LE-131) , Roo m M-1500 , 40 1 M

Stree t SW. , Washington , D.C . 20460 . A

reasonabl e fe e ma y

b e charge d fo r copying .

FO RFURTHE RINFORMATION CONTACT : William

Lamaso no r Eri c Nobl e a t Mai l
Dro p 15 , U.S . Environmenta l Protectio nAgency , Researc hTriangl e Park , Nort h Carolin a 27711 , telephon e (919 ) 541-537 4 (FT S 629-5374 ) o r (919 ) 541-536 2 (FT S 629-5362) .

SUPPLEMENTAR YINFORMATION :

I . SUMMAR

YO F TODAY' S ACTION . Thi s interpretativ e rulin g set s fort hEPA' s interpretatio no f th e definitio no f "majo r modification " i n4 0 CF R51.165 , 51.166 , 52.21 , 52.2 4 an d Par t 5 1 Appendi xS , an d"modification " i

n4 0 CF R60. 2 an

d 60.14 . Fo r NSP SP.1 3



### purposes , a modificatio ni s define db y regulatio na s an

y physica l chang e in , o r chang e i

nth e metho do f operatio nof , a stationar y source , whic hincrease s (i nterm s o f hourl y

emission s capacity ) th e amoun t o f an y ai r pollutan t tha t

a NSP S applie s emitte db y suc hsource , o r whic hresult s i nth e emissio no f an

y ai r pollutan t t o whic ha nNSP S applie s no t previousl y emitted . Fo r NS R purposes , a majo r modificatio ni s define dby regulatio na s a modificatio n whic hresult s i

na significan t ne t emission s increas e (i nterm s o f actua l

annua l emissions) . Th e EPA ha s becom e awar e tha t thes e definition s ca nb e interprete di n
suc ha manne r a s t o subjec t t o NS Ro r NSPS , o r both , certai nenvironmentally desirabl e activitie s a t existin g stationar y source s whic hneithe r Congres s no r EPA intende dt o b e covere db y th e new sourc e requirement s o f th e Clea nAi r Ac t (CAA) . Moreover , NS Ro r NSP S coverag e could , i nsom e instances , hav e th e effec t o f discouragin g suc hactivities . Thes e desirabl e activitie s consis t o f th e additio no r us e o f a system o r devic e whos e primar y functio ni s th e reductio no f ai r pollutants , s o long a s tha t syste m o r devic e i s no t les s environmentall y

beneficial , a s determine db y th e Administrator , tha nthe emission s contro l system o r devic e i t replaces , i f any . Today' s rulin g explain s EPA' s positio ntha t suc hactivities , including CC T demonstratio n projects , ar e no t physica l change s o r change s i nth e metho do f operation , s o long a s the y

mee t th e criteri a discusse dherei nan dth e reviewin g authorit y issue s a napplicabilit y

exclusion . Hence , suc hactivitie s ar e no t modification s fo r NS Ro r NSP S purposes , althoug hthey ma y stil l b e subjec t t o Stat e o r loca l agenc y

mino r sourc e permittin g requirements .P.1 4



### II . BACKGROUN D Th e NS Ran

dNSP S provision s o f th e CA A appl y t o wholl y

new facilities , an dt o modification s a t existin g facilities , whe ncertai ncondition s ar e met . Th e rule s governin g th e applicabilit y o f NS Ran

dNSP S t o modification s a t existin g facilitie s ar e describe di ndetai l i

nth e EPA

regulation s (se e 4 0 CF R51.16 5 an

dAppendi xS , 52.21 , 60.1 4 an d60.15) . I ngeneral , th e modification s tha t woul dtrigge r thes e new sourc e requirement s ar e thos e involvin g physica l o r operationa l change s whic hincreas e emission s ove r baselin e levels . [I naddition , fo r NSP S purpose s unde r EPA regulations , a reconstructio noccur s an da sourc e i s considere d"new " i f th e physica l o r operationa l chang e cost s mor e tha n5 0 percen t o f th e replacemen t cos t o f th e affecte dfacility , generall y excludin g th e cos t o f ai r pollutio ncontro l system s no t integra l t o proces s equipment , regardles s o f whethe r a nemission s increas e occurs. ] Th e ter m "physica l o r operationa l change " i s construe d broadl y an dma y includ e the installation , use , o r dismantlin g o f pollutio n contro l equipment .

A . Backgroun do f th e NSP S an dNS RModificatio nProvisions . Th e 197 0 CA

A require dEP

A t o promulgat e technology-base dNSP S applicabl e t o th e constructio no r modificatio no f stationar y source s tha t caus e o r contribut e significantl y t o ai r pollutio nwhic hma y reasonabl y

b e anticipate d t o endange r publi c healt ho r welfar e [se e 4 2 U.S.C . §7411(b)(1)(A)] . Congres s decree dthat , i

nadditio nt o wholl y

ne w sources , NSP S woul dappl y t o the modificatio no f a

nexistin g source, define dbroadl y a s "an y physica l chang e in , o r chang e i

nth e metho do f operatio nof , a stationar y sourc e whic hP.1 5



### increase s th e amoun t o f an y ai r pollutan t emitte db y suc hsourc e o r whic h result s i

nth e emissio no f an

y ai r pollutan t no t previousl y emitted " [se e CA A sectio n111(a)(4) , 4 2 U.S.C . 7411(a)(4)] . Th e NSP S provision s wer e "designe dt o preven t new [air ] pollutio n problems " b

y regulatin g bot hnewly-constructe dsource s o f pollutio nan d change s a t existin g source s tha t resul t i nemission s increase s [se e Nationa l Asphal t Pavemen t Assoc , v . Train . 53 9 F.2 d775 , 78 3 (D.C . Cir . 1976) ; se e als o H.R . Rep . No . 1146 , 91s t Cong. , 2 dSess . 3 , reprinte di n197 0 U.S . Cod e Cong . & Admin . New s 5356 , 5358] . A resul t o f includin g modifie dsources , a s wel l a s newly-constructe dsources , unde r th e provision s o f sectio n11 1 wa s th e nee dt o establis ha "baseline " leve l o f emission s abov e whic hanexistin g sourc e ma y
no t pollut e withou t becomin g subjec t t o th e NSPS . I nAugus t 1977 , Congres s adopte dfurthe r extensiv e change s t o th e CA A (Pub . L . 95-95) . Thes e include dreview-and-permittin g program s fo r new an d modifie dsource s combinin g th e technology-base dapproac ho f NSP S wit hspecifi c
measure s t o ensur e tha t ambien t ai r qualit y goal s unde r th e CA

A ar e met . Congres s intende dNS Rt o appl y "wher e industria l change s migh t increas e pollutio ni

nanarea " [se e Alabama Powe r Co . v . Costle . 63 6 F . 2 d323 , 40 0 (D.C . Cir . 1979)] . Par t D o f th e 197 7 amendment s applie s t o area s whic hhav e
no t me t nationa l ambien t ai r qualit y standard s (NAAQS ) unde r sectio n109 . T o receiv e a permi t i

nsuc hareas , majo r new an dmodifie dsource s mus t (among othe r things ) obtai nemission s offset s tha t assur e reasonabl e progres s towar d attainmen t o f th e NAAQ S an dmus t compl y

wit hth e "lowes t achievabl e emissio n rate, " whic hca nb e no les s stringen t tha na napplicabl e NSP S (se eP.1 6



### section s 171-173) . Th e 197 7 amendment s als o adde da new Par t C t o th e CA

A including , insection s 160-169 , anNS Rprogram fo r th e preventio no f significan t deterioratio no f ai r qualit y (th e "PSD " program ) i narea s whic h hav e attaine dth e NAAQS . T o receiv e a PS D permit , a prospectiv e majo r ne w o r modifie dsourc e mus t (among othe r things ) sho w tha t i t wil l no t excee dth e availabl e ai r qualit y

"increment " (designe dt o preven t pollutan t concentration s from

deterioratin g t o th e specifie dlevels) , an dtha t i t wil l

us e th e bes t availabl e contro l technolog y (BACT) , whic hmus t b e a t leas t a s stringen t a s any

applicabl e NSPS . Bot hth e Par t D NS Rprogram applicabl e t o nonattainmen t area s an dth e Par t C NS Rprogram applicabl e t o attainmen t area s adopte dth e NSP S definitio no f "modification " [se e section s 171(4 ) an d 169(2)(C)] . I t i s eviden t from

th e structur e o f th e NS Ran dNSP S program s tha t Congres s sough t t o focu s ai r pollutio ncontro l effort s a t anefficien t an d logica l point : th e makin g o f substantia l capita l investment s in , o r othe r long-term

decision s regarding , pollution-generatin g facilities . I nadoptin g NS Rmeasure s inparticular , Congres s sough t t o reconcil e th e legislativ e goa l

o f environmenta l protectio nwit ha concurren t desir e fo r continue deconomi c growt h[se e section s 160(l)-(4)] . Consequently , a ke y theme o f th e NS R program i s th e carefu l evaluatio nof , an dpubli c participatio nin , "an y decisio nt o permi t increase dai r pollution " [se e sectio n160(5)] . A s discusse dbelow , th e curren t regulation s implementin g NSP S an dNS Rwer e designe dt o appl y

thes e program s i

na manne r consisten t wit hthei r respectiv e statutor y

purposes . Today' s rulin g represent s a furthe r focusin g o f thes e existin g regulations .P.1 7



### B . Th e Two-Ste pTes t fo r Modifications . Th e modificatio nprovision s o f th e NSP S an dNS Rprogram s gro w

fro m a singl e statutor y

basis , th e ver y

broa ddefinitio no f "modification " i n sectio n111(a)(4) . Unde r bot hrespectiv e programs , EP A develope da two-ste p tes t fo r determinin g whethe r activitie s a t anexistin g facilit y constitut e a modificatio nsubjec t t o new sourc e requirements . Inth e firs t step , whic hi s largel y th e same fo r NSP S an

dNSR , th e reviewin g authorit y determine s whethe r
a physica l o r operationa l chang e wil l occur . I f so , EPA proceed s i

nth e
secondste pt o determin e whethe r th e physica l o r operationa l chang e wil l resul t i nanemission s increas e ove r baselin e levels . Inthi s secondstep , th e applicabl e rule s branc hapart , reflectin g th e fundamenta l distinction s betwee nth e technology-base dpurpose s o f NSP S an dth e technolog y

a M ai r qualit y concern s o f NSR . Briefly , th e NSP S program i s concerne dwit hhourl y emission s rates , expresse di nkilogram s o r pound s pe r hour . Emission s increase s fo r NSP S purpose s ar e determine dby change s i

nth e hourl y

emission s rate s a t maximu

m physica l capacity . Th e NS Rregulation s ar e concerne dwit h

1 

### A nhourl y emission s rat e ma y

b e determine db

y a stac k tes t o r calculate dfro

m th e produc t o f th e instantaneou s emission s rate , i.e. , the amoun t o f pollutio nemitte db y a source , afte r control , pe r uni t o f fue l combuste do r materia l processe d(suc ha s pound s o f sulfu r dioxid e emitte dpe r to no f coa l burned) , time s th e productio nrat e (suc ha s ton s o f coa l burne d pe r hour) .P.1 8

tota l annua l emission s t o th e atmosphere , expresse d i nton s pe r yea r (tpy). 2 Emission s increase s unde r NS Rar e determine d b y change s i

nannua l emission s t o th e atmosphere .

C . Physica l o r Operationa l Chang e Th e ver y broa ddefinitio no f physica l o r operationa l chang e i n sectio n111(a)(4 ) could , standin g alone , encompas s th e mos t mundan e activitie s a t a

nindustria l facility—eve nth e repai r o r replacemen t o f a singl e leaky

pipe , o r a chang e inth e wa y tha t pip e i s utilized . Th e definitio ncertainl y i s broa d enoug ht o encompas s th e additio no r enhancemen t o f pollutio ncontro l equipment . However , EP A ha s alway s recognize dtha t Congres s obviousl y di d no t inten

d t o requir e ever y

activit y

t o b e potentiall y

subjec t t o ne w

sourc e requirements , an d tha t i t woul d b e administrativel y

impractica l t o d o so . Accordingly , EP A ha s substantiall y

narrowe d thi s term

i nit s NSP S and NS Rregulator y definition s throug hth e adoptio no f common-sens e exclusions . Fo r example , bot hset s o f regulation s contai nsimila r exclusion s fo r routin e maintenance , repair , an d replacement ; fo r certai nincrease s i nth e hour s o f operatio no r i nth e productio nrate ; an d fo r certai ntype s o f fue l switche s [se e 4 0 CF R60.14(e) ; se e also , e.g. ,

2 Annua l emission s ma y b e calculate d fro

m th e produc t o f th e hourl y emission s rat e time s th e utilizatio nrate , expresse d a s hour s o f operatio npe r yea r o r fro

m th e produc t o f a

nemission s facto r (e.g. , fro m Compilatio n<?

f Ai r Pnllutan t Emissio nFactors . AP-42 , 4t hEd . an d subsequen t supplements ) i n unit s o f mas s emitte d pe r uni t o f proces s throughpu t an d th e annua l throughput . 8P.1 9



### 4 0 CF R52.2 1 (b)(2)(iii)] . Inaddition , wit hrespec t t o pollutio ncontro l equipment , th e NSP S regulation s contai na nexclusio nfor : Th e additio no r us e o f any syste m o r devic e whos e primar y functio n i s th e reductio no f ai r pollutants , excep t whe nanemission s contro l system i s remove do r i s replace db y a system

whic hth e Administrato r determine s t o b e les s environmentall y beneficia l [se e 4 0 CF R60.14(e)(5)] . Th e EPA ha s hel dtha t thi s exclusio ndoe s no t appl y t o a sourc e which , upo n origina l construction , employe dwe t scrubbers , bu t late r [uponrelaxatio no f a Stat e pla nunde r sectio n111(d) ] desire dt o remov e th e contro l equipment , whic hwoul dhav e resulte di nmuc hhighe r level s o f pollutio ntha nth e plan t ha deve r emitte d[se e Nationa l Southwir e Aluminu m Company v . EPA . 83 8 F . 2 d 83 5 (6t hCir.) , cert , denied . 10 9 S . Ct . 39 0 (1988)] . I nth e past , EPA

ha s take nvariou s view s a s t o whethe r th e exclusio ni nsectio n60.14(e)(5 ) shoul d appl y fo r NS Rpurposes . A s note dearlier , th e NS Rstatutor y definition s o f modificatio nsimpl y

adop t th e NSP S definitio ni nsectio n111(a)(4) . In addition , th e legislativ e histor y reflect s that , a s a genera l matter , Congress intende dt o confor m

th e meanin g o f "modification " fo r PS D purpose s t o usag e unde r NSP S [se e 12 3 Cong . Rec . H1195 7 (Nov . 1 , 1977)] . Fo r thi s reason , EPA initiall y

rule dtha t th e NSP S exclusio nfo r additio no f contro l device s applie dautomaticall y

t o PS D (se e memorandu m fro m Edwar dE . Reic han

d Willia m F . Pederse nt o EPA

Regio nVI , Apri l 21 , 1983) . Th e EPA reverse d

cours e ina 198 6 applicabilit y determination , issue dfo r bot hPS D an d nonattainmen t NS Rpurposes , notin g tha t th e NSP S exclusio nwa s highl y qualitativ e an

dfaile dt o giv e du e accoun t t o eithe r th e ai r qualit yP.2 0

managemen t componen t o r th e largel y quantitativ e orientatio no f th e NS R applicabilit y

regulation s (se e memorandum fro m Geral d A . Emiso nt o Regiona l Ai r Divisio nDirectors , Jul y 7 , 1986) .

D . NSP S Applicabilit y A nNSP S modificatio ni s any "physica l o r operationa l chang e t o a n existin g facilit y

whic hresult s i

na nincreas e i

nth e emissio nrat e t o th e atmospher e o f any

pollutan t t o whic ha standar d applies " (se e 4 0 CF R60. 2 an d 60.14) . Unde r NSPS , emission s increases , fo r applicabilit y purposes , ar e calculate db

y comparin g th e hourl y emissio nrate , a t maximu m physica l capacity , immediatel y befor e an

dafte r th e physica l o r operationa l change . Al l operatin g parameter s whic hma y affec t emission s mus t b e th e sam e befor e

andafte r testin g t o th e maximu m exten t feasibl e [se e 4 0 CF R60.14(b)(2)] . Absen t th e exclusion s fro m modification s specifie d a t 4 0 CF R60.14(e) , an y increas e inemission s t o th e atmospher e ove r th e previou s emission s rat e wil l subjec t th e modificatio nt o NSP S [se e sectio n60.14(a ) an d (b)] . I

naddition , physica l o r operationa l change s whic hwoul d cos t 5 0 percen t o r mor e o f th e

cos t o f a comparabl e new facility , generall y excludin g th e cos t o f ai r pollutio ncontro l system s no t integra l t o proces s equipment , ar e classifie d a s reconstructio n(se e 4 0 CF R60.15 ) an dar e subjec t t o NSP S a s a new source ,
eve ni f ther e i s n o emission s increase . Thus , i t i s clea r tha t unde r th e existin g regulations , NSP S woul d no t appl y t o th e installatio no r improvemen t o f emission s contro l equipmen t whic h reduce s hourl y

emission s rates , becaus e i t i s unlikel y tha t th e reconstructio n



### 1 0P.2 1

provision s come int o play . I nth e unlikel y

even t tha t th e reconstructio n provision s d o apply , the nsuc hchange s woul d trigge r NSPS . Th e NSP S provision s could , however , appl y t o majo r facilitie s wit h temporar y

CC T demonstratio nproject s a t th e en d o f th e demonstratio nwhe nth e contro l equipmen t i s remove dan demission s ris e bac k t o th e leve l tha t existe d befor e th e demonstration . Fo r example , th e placemen t o f temporar y CC T control s whic hreduc e th e hourl y sulfu r dioxid e (SOg ) emission s rat e a t a

sourc e woul dno t b e a nNSP S modificatio n(assumin g th e cost s o f th e modificatio nar e unde r 5 0 percent) . Th e dismantlin g o f th e CC T control s a t th e conclusio no f th e demonstratio nprojec t woul d resul t i na nincreas e in hourl y SOg emission s (u

pt o pre-demonstratio nlevels ) an d th e sourc e coul d b e considere dsubjec t t o NSPS . Today' s interpretativ e rulin g i s tha t temporar y CC T an d simila r demonstratio nproject s ar e no t subjec t t o NSP S (a s th e resul t o f a nincrease )

a t th e conclusio no f thes e projects . Increase s i nemission s up t o level s whic hexiste dbefor e th e temporar y demonstratio nprojec t d o no t trigge r NSP S provide dth e appropriat e reviewin g authorit y determine s tha t th e criteri a withi nthi s rulin g ar e met . Reconstructio nprovisions , however , coul d subjec t bot htemporar y

andpermanen t CC T demonstratio nprojects , an d certai nothe r emission s contro l system installation s o r improvements , t o NSPS . Still , th e reconstructio nprovision s o f th e CA A shoul d rarely , i f ever , appl y t o th e typ e

o f activit y

whic hwoul db e considere dfo r exclusio nfro m th e definitio no f a



### 1 1P.2 2

3 physica l chang e o r a chang e i nth e metho d o f operation . Thus , th e triggerin g

o f th e reconstructio nprovision s i s anindicatio ntha t th e propose d activitie s

ar e mor e extensiv e tha njus t th e addition , o r replacement , o f anemission s contro l system

o r device , an

d s o ar e no t appropriat e fo r exclusion .

E . NS RApplicabilit y Modifie d source s ar e subjec t t o NS Runde r Part s C o r D o f th e CA A i f th e modificatio ni s "major. " Majo r modification s mus t consis t o f a physica l chang e o r chang e i

nth e metho d o f operatio no f a majo r stationar y sourc e [se e 4 0 CF R52.21(b)(1) ] whic hresult s ina "significant " ne t emission s increas e o f

any pollutan t subjec t t o regulatio nunde r th e CAA . Significanc e level s ar e expresse d i

ntpy an d diffe r fo r eac hpollutan t [se e 4 0 CF R52.21(b)(23)] . Ne t emission s increase s ar e determine d [se e 4 0 CF R52.21(b)(3) ] b y summin g al l contemporaneou s creditabl e actua l emission s increase s an d decreases . Actua l emission s befor e th e chang e a t a facilit y ar e generall y

determine d b

y averagin g th e emission s fo r th e 2 year s prio r t o submitta l o f th e permi t applicatio n(o r some othe r period , i f th e las t 2 year s ar e no t representativ e

o f norma l uni t operation ) [see , e.g. , 4 0 CF R52.21(b)(21)(ii)] . Th e definitio no f "actua l emissions " i s suc hthat , generally , th e compariso ni s betwee nactua l emission s befor e th e modificatio nan d th e potentia l t o emi t o f

* Se e memorandum

fro m JohnB . Rasnic , Actin g Director , Stationar y Sourc e Complianc e Division , U.S . EPA , t o Jame s T . Wilburn , Chief , Ai r Complianc e Branch , Regio nIV , U.S . EPA , o n"Interpretatio no f Reconstruction, " Novembe r 25 , 1986 .

4 Th e determinatio no f "significan t ne t emission s increase " als o include s an

y sourc e whic hwoul d "construc t withi n1 0 kilometer s o f a Clas s I area , an d hav e animpac t onsuc hare a equa l t o o r greate r tha n1 microgram pe r cubi c meter " regardles s o f emissio nrat e [se e 4 0 CF R52.21(b)(23)(iii)] . 1 2th e facilit y afte r th e modificatio n[se e 4 0 CF R52.21(b)(21)] . Sinc e th e emission s rat e afte r a physica l o r operationa l chang e canno t b e predicte d i n advance , EP A

regulation s assume tha t a source' s actua l emission s wil l equa l it s maximu

m "potentia l t o emit, " whic hi s base d o nconstan t ful l load operatio nfo r anentir e yea r (unles s restricte d by federally-enforceabl e limitations ) [see , e.g. , section s 52.21(b)(21)(iv) ; 52.21(b)(4)] . Thus , a physica l o r operationa l chang e wil l trigge r NS Ri f th e annua l potentia l t o emi t o f th e sourc e i s significantl y greate r afte r th e chang e tha nit s representativ e actua l annua l emission s befor e th e change, unles s th e company agree s t o federally-enforceabl e operationa l restriction s whic hlimi t it s potentia l t o emi t t o level s no t significantl y greate r tha nit s actua l emission s befor e th e change . I f th e sourc e ha s no t bee noperatin g nea r ful l capacity , eve nth e additio no f a contro l devic e coul d b e considere d a significan t ne t emission s increas e whe ncomparin g representativ e actua l emission s wit ha new potentia l t o emit , eve nthoug hther e ma y b e a substantia l reductio nfrom

representativ e actua l emissions . Thi s actual-to-potentia l methodolog y applie s t o physica l o r operationa l change s a t new

o r modifie d emission s unit s [se e 4 5 E R52676 , 52677 , 5271 8 (1980)] . Recen t decision s by two court s o f appeal s hav e addresse d EPA' s modificatio nprovisions , Puert o Rica nCemen t Co . v . EPA . 88 9 F.2 d 29 2 (1s t Cir . 1989) , an

d Wisconsi nElectri c Powe r Company (WEPC0 1 v . Reillv . No . 88-326 4 an

d 89-133 9 (7t hCir. , sli p op . Januar y 19 , 1990) . InPuert o Rica nCement , th e Firs t Circui t uphel d EPA' s metho d o f calculatin g emission s increase s fo r new

o r modifie d (i.e. , physicall y o r operationall y

changed )



### 1 3P.2 4

units . I nWEPCO . th e Sevent hCircui t state d tha t thi s metho d i s inappropriat e i nth e cas e o f "like-kin d replacements " a t existin g units . A s explaine d below , EPA believe s tha t thi s methodolog y generall y

serve s th e purpose s o f NS Rbecaus e i t subject s t o revie w industria l change s tha t migh t lea d t o anincreas e i nactua l pollutio n[se e Alabam a Powe r Co . v . Costle . 63 6 F.2 d 323 , 40 1 (D.C . Cir . 1979)] . However , th e NS Rprovision s i n th e existin g regulation s coul d b e interprete d t o appl y t o majo r facilitie s simpl y installin g o r improvin g contro l equipment , includin g CC T demonstratio n projects , unde r circumstance s wher e a permanen t increas e i npollutio ni s highl y unlikel y

a s a resul t o f tha t action . Suppose , fo r example , tha t a nexistin g sourc e wit ha potentia l t o emi t o f 500 0 tpy o f S0 2 ha s operate d a t 3 0 percen t capacit y fo r th e las t 2 years , emittin g 150 0 tpy

o f actua l S0 2 emissions . I t elect s t o participat e i na CC T projec t whic hwil l reduc e th e hourl y SOg emission s rat e b y 6 0 percent . Fo r NS Rapplicabilit y

purposes , absen t today' s ruling , actua l SO g emission s befor e th e chang e woul d b e compare d t o it s ful l potentia l t o emi t afte r th e chang e t o determin e th e ne t emission s increase , becaus e th e sourc e migh t decid e t o operat e a t ful l capacit y afte r th e change . Potentia l SOg emission s a t ful l capacit y operatio nafte r th e chang e woul d b e 500 0 tpy , les s th e 6 0 percen t decrease , fo r a tota l o f 200 0 tpy . Thus , th e - ior actua l emission s o f 150 0 tpy woul d b e compare d t o th e futur e potentia l emission s o f 200 0 tpy , resultin g ina ne t increas e o f 50 0 tpy , eve nthoughther e i s n o increas e i nth e hourl y emission s rate . Unde r NS Rregulations , thi s i s a significan t increas e ( a significan t ne t SOg emission s increas e i s define d a s 4 0 tp y o r mor e an

d woul d



### 1 4mak e a modificatio n"major") , s o th e sourc e coul d b e considere d subjec t t o NS R

requirements . Also , i f th e capacit y utilizatio ndurin g th e demonstratio nprojec t remaine d a t 3 0 percen t (an d th e sourc e too k n o federally-enforceabl e permi t restrictions) , dismantlin g th e CC T contro l equipmen t a t th e conclusio no f th e demonstratio nan

d returnin g th e sourc e t o it s pre-projec t conditio ncoul d trigge r NSR , Usin g th e abov e example , SO g emission s woul d increas e fro m eithe r 60 0 tpy

(150 0 tpy , les s 6 0 percen t bette r contro l durin g th e demonstration , equal s 60 0 tpy ) o r 150 0 tpy (i f th e pre-demonstratio nactua l emission s wer e deeme d mor e representativ e o f "normal " operations ) t o potentia l emission s o f 500 0 tpy . Unde r today' s interpretativ e ruling , existin g source s whic hcoul d otherwis e becom e subjec t t o NS Ronl y becaus e the y

decid e t o instal l o r improve emissio ncontrols , o r participat e i nth e CC T progra

m o r simila r demonstratio n project s approve d b

y EPA , woul d instea d b e exclude d from NS Rcoverage , s o long

a s th e appropriat e reviewin g authorit y determine s tha t th e criteri a discusse d herei nar e met . Th e centra l premis e o f thi s ruling i s tha t th e additio no f a contro l devic e wil l not , b y itself , resul t i

na nincreas e incapacit y utilizatio nand , hence , a nincreas e i

nannua l actua l emissions .

III . DISCUSSIO N Today' s rulin g i s designe d t o accomplis htw o goals . First , i t announce s EPA' s interpretatio nthat , unde r curren t regulations , NS Rand NSP S modificatio nprovision s generall y d o no t appl y

t o th e installatio no r improvemen t o f emission s contro l system s o r devices . . Second , i t provide s



### 1 5P.2 6



### certai nsafeguard s t o ensur e tha t thes e project s ar e no t environmentall y harmfu l befor e excludin g the m from th e coverag e o f th e new sourc e requirements . Thus , th e resul t o f thi s interpretativ e rul e i s t o no t discourag e source s from installin g o r demonstratin g improve demissio ncontrol s and , therefore , facilitat e th e replacemen t o r improvemen t o f les s efficien t emission s contro l system s wit hmor e environmentall y beneficia l systems . Thi s rulin g applie s onl y t o th e additio no f a

nemission s contro l system
o r devic e t o existin g emission s unit s o r affecte dfacilitie s a t existin g
sources , includin g CC T an dsimila r emission s contro l demonstratio nproject s
an dcompliance-relate drequirements . I t doe s no t appl y 1 ) t o wholl y

ne w
source s o r 2 ) t o ne w

emission s unit s o r ne w affecte dfacilitie s a t existin g
sources . Fo r purpose s of . thi s ruling , th e ter m "emission s contro l system o r device " generall y

mean s a n"add-on " typ e o f emission s contro l equipment , suc h

a s fabri c filters , scrubbers , absorbers , catalysts , an dtherma l reduction/oxidation . Thi s ma y als o includ e the us e o f a les s pollutin g fue l wher e th e appropriat e reviewin g authorit y determine s fro

m al l available informatio ntha t th e projec t i s designe dprimaril y t o reduc e ai r pollutio nan d tha t ther e i s n o reasonabl e caus e t o expec t a nincreas e i

nutilizatio no f th e
sourc e solel y

du e t o th e project . Fo r example , som e physica l change s t o accommodat e a new

fue l coul db e properl y characterize da s pollutio ncontro l system s [e.g. , a CC T demonstratio no f nitroge noxide s (NOx ) rebumin g technolog y

usin g natura l ga s ona coal-fire dutilit y boiler ; o r project s t o
conver t t o natura l ga s o r t o gas/coa l co-firin g implemente dt o compl y wit ha n

1 6P.2 7



### environmenta l regulator y requirement] . Suc hdetermination s wil l b e mad e b y th e appropriat e reviewin g authorit y o na case-by-cas e basis . Change s whic hrestor e origina l capacity , o r ar e mad e primaril y t o improve th e operationa l efficienc y o f th e facility , ar e no t considere dt o be the installatio no r improvemen t o f a n"emission s contro l system o r device " fo r purpose s o f thi s ruling , eve ni f suc hchange s als o involv e th e installatio no r improvemen t o f anemission s contro l system . Specifically , thi s interpretativ e rulin g doe s no t appl y

t o "lif e extension " o r "repowering " projects , bot ho f whic hinvolve extensiv e change s t o th e pollutio ngeneratin g equipmen t a t a stationar y

source , an

dar e intende dprimaril y t o improve operatin g capability , capacity , o r efficiency , rathe r tha nreduc e emissions . Bot hlif e extensio n
andrepowerin g project s implicat e th e cor e concern s o f th e statutor y new
sourc e requirements , an dbot htype s o f project s provid e a direc t incentiv e t o increas e capacit y

utilizatio nove r curren t levels . A s such , EPA believe s the y
ar e fundamentall y

differen t fro

m th e additio no f a pollutio ncontro l device . Today' s rulin g contain s EPA' s lega l interpretatio no f certai nexistin g regulator y

provision s tha t gover nNS Ran dNSP S applicability , an dset s fort h criteri a tha t EPA

generall y

intend s t o us e i

nissuing specifi c NS Ran dNSP S applicabilit y

determination s an

dadvisor y

opinion s t o State s havin g authorit y t o mak e suc hdeterminations . Consequently , EPA believe s tha t today' s rulin g doe s no t constitut e a fina l Agenc y actio ntha t i s rip e fo r judicia l review unde r sectio n307(b)(1 ) o f th e CAA . Rather , th e impac t o f th e view s embodie d

5 

### Se e lette r fro

m Patric k W . McCarter , Colorad o Publi c Servic e Co . t o William K . Reilly , Administrator , U S EPA , regardin g CC T project s a t the Arapaho e an

dCheroke e generatin g stations , Ma y 9 , 1990 . Thi s lette r in ' include di

nth e docket . 1 7P.2 8



### i nthi s ruling , i f any , canonl y b e measure di

nth e factua l contex t o f a specifi c applicabilit y determinatio no r relate dfina l Agenc y action , an

dEPA believe s tha t i t i s onl y i nsuc hcircumstance s tha t judicia l revie w o f th e matter s addresse dinth e rulin g woul db e appropriate .

A . Condition s fo r Exclusio nb y th e Interpretativ e Ruling . Th e interpretativ e rulin g i s intende dt o b e a narro w interpretatio n applyin g onl y

t o activitie s tha t ar e determine dt o b e environmentall y beneficial , bu t whic hwoul dlikel y no t occu r shoul dth e owne r o r operato r b e subjec t t o NS Ro r NSP S fo r takin g suchaction . Onth e othe r hand , ther e ar e
many activitie s tha t tak e plac e a t existin g source s wher e th e inten t o f bot h th e CA A an dEPA' s regulatio ni s t o requir e a ful l an drigorou s NS Ranalysi s [includin g applicatio no f BAC T o r lowes t achievabl e emissio nrat e (LAER) ] o r adherenc e t o NSPS . Th e EPA realize s tha t certai nCC T (an dothe r demonstrations ) an

dcompliance-relate dproject s involv e th e constructio no f

new emission s unit s o r coul dresul t i nincrease demission s o f a pollutan t (althoughdecreasin g emission s o f the specifi c pollutan t o f interest) . Th e exclusio no f suc hproject s from NS Ran dNSPS , regardles s o f thei r ultimat e benefit , i s clearl y

i nconflic t wit hth e regulation s and , therefore , beyond th e scop e o f aninterpretativ e rule . Th e resolutio no f possibl e exclusion s fo r suc hproject s depend s o nth e outcome o f deliberation s onth e amendment s t o th e CA A submitte dt o Congres s t o addres s thi s issue . A nowne r o r operato r proposin g t o conduc t activitie s t o whic hthi s interpretativ e rulin g ma y appl y shoul dreques t a

napplicabilit y

determinatio n fro m EP A (o r th e agenc y

t o whic hsuchauthorit y ha s bee ntransferred) . [Fo r

1 8P.2 9

thos e State s wit happrove dSIP's , today' s interpretativ e rul e i s onl y advisory i nnatur e a s i t applie s t o th e NS Rprogram . Thos e State s ar e encourage dt o follo w EPA' s lea d i

nallowin g thi s exclusio nfo r NS Rpurpose s an d mus t do s o wit hrespec t t o th e NSP S program. ] Th e reques t mus t contai na genera l descriptio no f th e facilit y an dth e propose d activity , informatio noncurren t

andprojecte dusag e o f th e facility , andsufficien t othe r informatio nt o justif y applyin g thi s exclusion . Inaddition , th e reques t mus t demonstrate : (1 ) tha t th e sourc e will , durin g an d afte r th e propose d change , continu e t o

mee t al l curren t requirement s an dstandard s applicabl e t o existin g

source s unde r th e CAA ; an d (2 ) tha t ther e i s n o environmenta l har m resultin g fro

m th e propose d change . Th e firs t criterion , tha t th e sourc e continu e t o mee t al l curren t requirement s andstandard s fo r existin g sources , include s demonstration s tha t th e sourc e wil l continu e t o mee t al l applicabl e NAAQS , PS D increments , permi t conditions , and SI P limitations . Th e inten t o f th e firs t criterio ni s t o clarif y tha t EP A

cannot , throug h

aninterpretativ e ruling , waiv e NS Ran dNSP S requirement s whic har e clearl y applicabl e t o existin g source s unde r provision s o f th e CAA . Fo r example , conside r tw

o scenarios . Suppos e tha t a sourc e propose s t o ad d a contro l devic e t o contro l on e pollutan t tha t wil l 1 ) resul t i nemission s exceedin g a permit limi t fo r anothe r criteri a pollutant , o r 2 ) althoug hmeetin g al l existin g permit limits , resul t i na NAAQ S o r PS D incremen t violation . In eithe r case , th e sourc e mus t sho w tha t suc heffect s wil l no t occur .



### 1 9P.3 0

Th e second criterion , tha t ther e i s n o environmenta l har m resultin g from th e propose dchang e include s a requirement tha t th e propose d change , b y itsel f doe s not : (a ) increas e th e maximu m hourl y emission s rat e o f an y pollutan t regulate d unde r th e CAA ; (b ) increas e th e annua l emission s o f any pollutan t regulate d unde r th e CAA ; (c ) adversel y

impac t anai r qualit y relate d valu e (e.g. , visibility ) inan y Clas s I area ; o r (d ) allo

w a nincreas e i

nemission s o f an

y toxi c pollutan t no t regulate d by th e CA A whic hma y

caus e a healt ho r welfar e impact . I nmakin g suc ha finding , th e appropriat e permittin g authorit y reviewin g th e propose dactivitie s mus t explicitl y determine , base d onconsideratio no f thes e

an d othe r relevan t criteria , tha t th e ne t effec t wil l no t b e on e o f environmenta l harm . Th e inten t o f th e firs t and second criteri a i s t o ensur e tha t activitie s whic himplicat e th e cor e concern s o f NS Ran d NSP S remai nsubjec t t o new sourc e requirements . T o tha t end , th e interpretativ e rulin g doe s no t extend t o change s whic har e likel y t o increas e emission s t o th e atmosphere , suc ha s change s whic hincreas e a plant' s overal l hourl y operatin g capacit y

(e.g. , eliminatin g a bottleneck) , hourl y emission s rat e (e.g. , on e pollutan t decrease s bu t anothe r increases) , o r utilizatio nrat e (e.g. , a nanticipate d increas e i

nhour s pe r yea r o f operation) . Th e constrain t onannua l emission s i s intende d t o preven t increase s tha t ca nb e readil y attribute d t o th e propose d activity . I t doe s no t preclud e increase s whic hmigh t resul t solel y fro m cycli c fluctuation s i nproduc t demand . Thus , EP A wil l presum e tha t th e



### 20P.3 1

additio no f a contro l devic e wil l not , b y itself , resul t i

na nincreas e i

n capacit y utilization . However , thi s presumptio nma y b e overcom e if , base d on th e informatio nsubmitted , EP A conclude s tha t ther e i s a clea r likelihoo d tha t operatin g hour s o r productio nrate s wil l increas e becaus e o f th e installatio n

o f th e device . Th e protectio nfo r Clas s I ai r qualit y relate d value s an

d th e requiremen t fo r n o overal l environmenta l harm provid e additiona l safeguards . Inprovidin g informatio nt o th e reviewin g authority , a nowne r o r operato r shoul dconduc t sufficien t modelin g t o ensur e tha t an y ne w o r increase d emission s o f unregulate dtoxi c pollutant s resultin g from th e additio no r replacemen t o f contro l equipment , wil l no t caus e o r contribut e t o advers e healt ho r welfar e impacts . Th e owner s o r operator s shoul d als o explai n whethe r the y

intend t o operat e th e sourc e a t greate r hourl y emission s rates ,
o r fo r mor e hours , tha ndurin g th e mos t recen t 2 year s (o r some othe r period , i f th e las t 2 year s ar e no t representativ e o f norma l operation) . I nassessin g whethe r any

ne t increas e i

nactua l emission s o f an y pollutant , ove r representativ e actua l emission s rates , i s likel y t o occu r a s a resul t o f th e additio no f controls , th e reviewin g agenc y shoul d conside r th e economi c incentive s t o increas e productio nrate s o r hour s o f operatio nassociate d wit h th e installatio nandus e o f th e contro l device . Wher e increase d emission s du e t o increase dutilizatio no f th e facilit y ar e clearl y

a likel y

resul t fro

m additio no f th e device , th e chang e shoul dno t b e consideredenvironmentall y beneficial . Becaus e o f th e benefit s inheren t i nCC T an

d simila r contro l technolog y demonstratio nprojects , th e condition s relatin g t o increase s inmaximu m hourl y emission s an

dannua l emission s shoul d b e waive d fo r suc hprojects , i f th e



### 2 1P.3 2

project s ar e temporar y i nduration . Thi s specia l consideratio nprovide s the flexibilit y

t o encourag e temporar y demonstratio nproject s whic har e considere d
t o b e environmentall y beneficia l overall , despit e increase s i nhourl y emission s o f som

e pollutant s o r i

nth e annua l hour s o f operatio ntha t ma y

occu r durin g th e cours e o f th e demonstration . Temporar y demonstratio nprojec t application s mus t mee t al l o f th e othe r criteri a applicabl e t o th e permanen t project s discusse dabove . "Temporary " project s ar e thos e whic hlas t les s tha n5 year s fro m th e dat e

o f startu po f tha t projec t (a s define d i n4 0 CF R60.2 , "th e settin g i n operatio no f anaffecte dfacilit y fo r an y purpose") . A t th e end o f a temporar y

project , th e facility mus t b e returne d t o pre-demonstratio n condition s an

dhourl y

emissio nrate s (o r lower) . Th e retur no f th e facility
t o it s pre-demonstratio nphysica l an doperationa l conditio nwoul d no t resul t i nth e "surrender " o f th e margi nbetwee npre-demonstratio nactua l emission s rat e an dSlP-allowabl e emission s rate s fo r tha t facility . Rather , EP A woul d
trea t th e facilit y

a s i f th e temporar y demonstratio nprojec t ha d neve r occurred . [Thi s woul db e th e cas e eve ni f ther e wer e smal l bu t negligibl e difference s i

nth e post-demonstratio nphysica l an d operationa l condition s du e t o a technica l inabilit y t o restor e th e uni t t o it s precis e pre-demonstratio n condition , o r du e t o norma l variabilit y i nth e coa l used. ] Thus , EPA woul d

no t see k t o appl y

NSP S o r PS D du e t o a post-demonstratio nemission s increas e attributabl e solel y

t o a nincreas e i

nth e hour s o f operatio no r productio n rat e o f th e uni t (subjec t t o th e NSP S limitatio ntha t th e productio nrat e increas e mus t b e accomplishe d withou t a capita l expenditure) . Today' s rulin g doe s no t extendt o emission s increase s whic har e unrelate d t o th e conduc t o f



### 22P.3 3

temporar y

demonstratio nprojects . Emission s increase s (abov e th e pre demonstratio nlevels ) tha t ar e attributabl e t o physica l o r operationa l changes , othe r tha nthos e necessar y t o restor e tha t uni t t o it s pre demonstratio nconditio nma y rende r th e facilit y subjec t t o NSP S o r PS D an d

ar e beyon dth e scop e o f thi s interpretativ e ruling . A temporar y

demonstratio nprojec t ma y b e converte d t o a permanen t statu s

a t an y time , provide di t meet s al l o f th e permanen t chang e criteri a a t th e time o f conversion . Thus , fo r example , i f hourl y o r annua l emission s had increase dbecaus e o f th e temporar y demonstration , afte r th e chang e t o permanen t status , thes e emission s ca nb e n o greate r tha nthos e whic hexiste d prio r t o initiatio no f th e temporar y demonstratio nproject .

B . Curren t Provision s i nth e CA A fo r Innovativ e Contro l Technologies . I f anexistin g sourc e undertake s aninnovativ e additio no r improvemen t o f

a nemission s contro l system o r device , i

ngoo d faith , bu t doe s no t obtai na n applicabilit y

exclusio nfro

m NS Ran dNSP S unde r thi s interpretativ e ruling , i t

ma y stil l appl y

fo r us e o f on e o r mor e innovativ e contro l technolog y provision s i

nth e CAA . Sectio nlll(j ) o f th e CA A allow s a waive r t o b e grante d fo r a new

o r modifie d sourc e tha t wishe s t o us e innovativ e contro l technolog y

tha t i s likel y

t o produc e greate r emission s reductions , o r achiev e

a t leas t equivalen t emission s reduction s a t les s cos t interm s o f energy , economics , o r environmenta l impac t othe r tha nonai r quality . Thi s sectio n provide s u

pt o 4 year s fro

m startu p o r 7 year s fro m grantin g o f th e waive r (whicheve r i s earlier ) fo r th e sourc e t o compl y wit happlicabl e NSP S emission s limits . I f th e innovativ e technolog y fails , th e sourc e ma y hav e u p t o 3 mor e



### 2 3P.3 4

year s t o instal l conventiona l technolog y t o mee t th e standards . Th e PS D innovativ e contro l technolog y regulation s [e.g. , 4 0 CF R51.166(s ) ar e essentiall y

simila r t o sectio nlll(j ) o f th e CAA] . [However , befor e waive r approva l ca nb e granted , th e consen t o f th e governor s o f th e othe r affecte d State s mus t als o b e obtained. ] Othe r provision s i nth e curren t NSP S regulation s ar e designe dt o encourag e th e us e o f innovativ e contro l technology . Commercia l Demonstratio nPermit s (Subpar t Da , 4 0 CF R60.45a ) provid e relaxe dNSP S emissio nlimits , bu t th e sam e complianc e tim

e (18 0 day s from startup ) fo r a limite dnumbe r o f demonstration s o f fou r liste d contro l technologies . Th e liste dtechnologie s are : solven t refine d coal , 8 0 percen t SO g reduction ; coa l liquefaction , 0.7 0 l bNOx/millio nBritis htherma l unit s (MMBtu) ; atmospheri c fluidize dbed , 8 5 percen t SO g reduction ; an

d pressurize d fluidize dbed , 8 5 percen t SOg reduction . Thes e provision s ma y b e usefu l t o CC T participants . Fo r example , a permanen t add-o nprojec t t o demonstrat e SO g contro l coul d resul t i na n increas e i

nparticulat e matte r emissions . Fo r purpose s o f NSPS , thi s coul d b e exempte dfro

m becomin g a modificatio nb y th e provision s o f 4 0 CFR60.14(e)(5) . However , i f th e condition s o f 60.14(e)(5 ) ar e no t met , th e NSP S standard s woul dapply . I

nsuc ha case , th e sourc e owne r o r operato r ma y appl y fo r a n innovativ e technolog y waive r unde r sectio nlll(j ) o f th e CAA . Thes e provision s ca nb e combined . Fo r example , i f a permanen t repowere d sourc e need s t o compl y

wit hbot hNSP S an

d PS D requirement s an d need s a relaxe d emissio nlimi t an

dmor e tim

e t o compl y

wit hemission s limits , a Commercia l Demonstratio nPermi t an da lll(j ) waive r coul d b e issued b y th e Administrator ,



### 2 4P.3 5

providin g relaxe demission s limit s an dmor e tim

e t o compl y

wit hNSPS , respectively .

C . Th e WEPC O Decision . 1 . Background . Ina serie s o f applicabilit y determination s i

n198 8 and 1989 , EPA rule d tha t NS Ran

d NSP S applie d t o a lif e extensio nprogram propose d b

y th e WEPC O [se e letter s date dSept . 9 , 1988 , fro m Do nR . Clay , EPA

Assistan t Administrato r fo r Ai r an d Radiation , t o Davi d A . Kee , EPA Regio nV ; Octobe r 14 , 198 8 fro

m Le e Thomas , EPA

Administrator , t o JohnW . Boston , V.P. , WEPCO ;

an dFebruar y

15 , 198 9 lette r from Do nR . Cla y

t o Joh nW . Boston] . Thos e ruling s hav e engendere dconsiderabl e concer namon g industr y groups . Th e followin g discussio npresent s some backgroun d informatio nonth e WEPC O decisio nan

dexplain s why , despit e concern s expresse d b y industry , EP

A doe s

no t fee l tha t th e decision s mad e fo r tha t projec t ar e german e t o th e interpretativ e rulin g se t fort htoday . Inth e WEPC O decision , EP A emphasize dtha t substantia l physica l o r operationa l change s a t existin g facilitie s ma y rende r thos e facilitie s subjec t t o NS Ro r NSPS , i f the y increas e emission s ove r representativ e o r curren t baselin e levels , respectively , despit e th e fac t tha t origina l desig n capacities , andassociate d emission s levels , ar e no t exceeded . Th e WEPC O lif e extensio nproject , a s i t wa s presente d t o EPA , involve d a substantia l financia l investmen t i npollution-generatin g facilitie s tha t woul d restor e

6 EPA' s decisio nha s bee nreviewe d b y the cour t o f appeals . Wisconsi n Electri c Powe r Co . v . Reilly , No' s 88-326 4 an d 89-133 9 (7t hCir. , sli p op . Jan . 19 , 1990) . 

### 2 5P.3 6

"lost " capacity . Thi s recovere dcapacity , i f used , woul d significantl y increas e emission s from th e sourc e ove r a lon g perio d o f time . Th e WEPCO' s lif e extensio nprojec t woul d hav e increase d pollutan t emission s ove r th e NS Ran dNSP S baseline s a s a resul t o f th e replacemen t o f
steam drums , ai r heaters , an dothe r majo r component s tha t ar e integra l t o th e continue d economi c viabilit y (and , i

npart , th e physica l operability ) o f th e

source . Th e propose d wor k woul dno t simpl y maintai nth e facilitie s i nthei r

curren t stat e but , i nsom e cases , woul d significantl y an d permanentl y

enhanc e thei r presen t physica l capacity , an dsubstantiall y

exten d thei r usefu l economi c lif e (u

p t o 2 0 year s beyon d th e previou s planne d replacemen t date) . I naddition , becaus e o f th e highe r efficienc y projecte d fo r th e renovate d facility , WEPC O planne d t o increas e capacity utilizatio nfro

m abou t 1 0 percen t currentl y

t o 5 0 percent . Accordingly , EP A conclude d tha t WEPCO' s projec t wa s precisel y

th e sor t o f long-term investmen t i

npollution-generating equipmen t whic hCongres s intende dshoul db e subjec t t o NS Ran d NSPS . I na simila r case , th e cour t o f appeal s uphel dEPA' s NS Rregulation s [se e Puert o Rica nCemen t Co .
v . EPA , 889 , F.2 d29 2 (1s t Cir. , 1989)] . I ntha t case , modification s a t a

cemen t plant , tha t woul dno t increas e th e source' s curren t desig ncapacit y o r potentia l t o emit , bu t would , throug hmodernizatio nan d increase d efficiency , provid e direc t incentive s t o increas e productio nand , possibly , representativ e level s o f actua l emissions . I nreviewin g EPA' s decisio nregardin g WEPCO , a differen t cour t o f appeal s distinguishe dth e "like-kind replacements " a t th e WEPC O plan t i

ntha t cas e fro

m th e chang e i

nproductio nproces s involve d i n Puert o Rica nCement . Th e cour t hel d tha t EP A shoul d no t assume , fo r PS D purposes , tha t th e company woul doperat e a t ful l capacit y followin g the



### 2 6P.3 7

renovations . Hence , th e cour t remande dEPA' s calculatio no f PS D emission s increase s t o th e Agenc y fo r furthe r action . I nal l othe r respects , EPA' s NSP S

an dPS D applicabilit y

determination s wer e uphel d [se e Wisconsi nElectri c r.n T

v . Reillv . Nos . 88-326 4 an d89-133 9 (7t hCir. , sli p op . Jan . 19 , 1990)] . A s note dabove , EPA

i s stil l studyin g tha t portio no f th e decisio nwhic hordere d

a remand . 2 . Difference s Betwee nWEPC O an d Today' s Interpretativ e Rulin g Th e majo r difference s betwee nth e WEPC O projec t an d project s withi nth e scop e o f today' s interpretativ e rulin g ar e that : (a ) Th e WEPC O modification s wer e designe d mainl y t o restor e "lost " capacit y

an d exten dth e usefu l lif e o f th e facility , rathe r tha nt o reduc e emissions . Th e interpretativ e rulin g doe s no t exclud e suc h change s a t a sourc e fro m NSP S o r NSR , eve ni f concurren t wit ha chang e t o whic hth e rulin g doe s apply . (b ) Th e WEPC O modification s wer e clearl y intende d t o increas e utilizatio no f th e facility , from

abou t 1 0 t o 5 0 percent . Thi s substantia l increas e i n operatin g rate s an

doperatin g hour s woul dlead t o a nincreas e i

n emission s fo r a t leas t some pollutants .

IV . ADMINISTRATIV E

A . Docke t Th e docke t i s a norganize d an dcomplet e fil e o f al l informatio n considere di

nth e developmen t o f thi s ruling . Th e docke t i s intende d t o allow th e publi c t o identif y an d locat e document s relate d t o thi s ruling .



### 27P.3 8

B . Paperwor k Reductio nAc t No additiona l publi c reportin g burde nwil l resul t fro m thi s interpretativ e ruling . Al l informatio ncollectio nrequirement s o f th e Federa l
NS RandNSP S regulation s hav e bee napprove d b y th e Offic e o f Managemen t an d Budge t (OMB ) unde r th e provision s o f th e Paperwor k Reductio nAct , 4 4 U.S.C . 3501 , et . seq. , andhav e bee nassigne d OM B contro l number s 2060-000 3 fo r NSR ,
and2060-0023 , 2060-002 6 an d2060-007 2 fo r NSPS . Th e effec t o f th e interpretativ e rul e woul db e a reductio ni npaperwor k relate d t o complyin g wit hNS RandNSP S requirements , sinc e thi s rulin g provide s additiona l clarificatio na s t o modification s tha t ma y b e exclude d from

thes e requirements .

C . OM B Revie w Unde r Executiv e Orde r 1229 1 (E.O . 12291) , EPA mus t judg e whethe r a rul e i s "major " an

dtherefor e subjec t t o th e requiremen t o f a regulator y impac t analysis . Th e interpretativ e rulin g i s no t a majo r rule , becaus e i t wil l no t resul t i

nanadvers e economi c effec t se t fort hi nsectio n1 o f E.O . 1229 1 a s ground s fo r findin g anactio nt o b e major . Thi s interpretativ e rulin g wa s submitte dt o th e OM B fo r review a s require d b

y E.O . 12291 . Any

writte n comment s fro

m OMB t o EPA

an dan y EPA respons e t o thos e comment s ar e include d i nDocke t A-90-06 .



### 28P.3 9

D . Effectiv e Dat e A s state d earlie r i

nthi s notice , thi s interpretativ e rulin g i s effectiv e immediatel y

upo npublicatio ni

nth e FEDERAL REGISTER . Th e EP A ha s conclude d tha t th e requirement s o f sectio n4(d ) o f th e Administrativ e Procedure s Ac t (APA) , 5 U.S.C . 553(d) , fo r a 30-da y waitin g perio d befor e makin g a substantiv e rul e effectiv e i s no t applicable , becaus e thi s i s a n interpretativ e rulin g no t subjec t t o th e notice-and-commen t rulemakin g requirement s o f th e AP A [se e 5 U.S.C . sectio n533(b)(A)] .

E . Regulator y

Flexibilit y

Ac t Thi s actio ni s no t subjec t t o th e provision s o f 5 U.S.C . 605(b) , becaus e interpretativ e ruling s ar e exemp t fro m notice-and-commen t requirement s o f 5 U.S.C . §553 . Lis t o f Subject s 4 0 CF RPar t 5 1 Administrativ e procedur e an d practices , intergovernmenta l relations , ai r pollutio ncontrol , new sourc e review , clea ncoa l technolog y demonstrations , sulfu r oxides , particulat e matter , nitroge ndioxide , carbo nmonoxide , hydrocarbons , lead . 4 0 CF RPar t 5 2 Ai r pollutio ncontrol , ne w sourc e review , clea ncoa l technolog y demonstrations , sulfu r oxides , particulat e matter , nitroge ndioxide , carbo n monoxide , hydrocarbons , lead .



### 2 9P.4 0



### 4 0 CF RPar t 6 0 Ai r pollutio ncontrol , ne w sourc e performanc e standards , clea ncoa l technolog y

demonstrations , sulfu r oxides , particulat e matter , nitroge n dioxide , carbo nmonoxide , hydrocarbons , lead .

Dat e William K . Reill y Administrato r

3 0P.4 1

Fo r th e reason s se t fort hi nth e preamble , Part s 51 , 52 , an d 6 0 o f Chapte r 1

o f Titl e 4 0 ar e amende da s follows :

Par t 5 1 - REQUIREMENT S FO RTH E PREPARATION , ADOPTION , AN D SUBMITTA L O F IMPLEMENTATIO N PLAN S
A ne w appendi xi s adde da t th e en do f Par t 5 1 a s follows : APPENDI XV

- EXCLUSION S FROM

NE W SOURC E REVIE W

REQUIREMENT S FORTH E INSTALLATIO N ORIMPROVEMEN T O F EMISSION S CONTRO L SYSTEM S Thi s appendi xset s fort hth e Environmenta l Protectio nAgency' s (EPA's ) interpretativ e rulin g onth e definitio no f "majo r modification " i n 4 0 CF R51.16 5 an

d51.16 6 an

dAppendi xS . Thi s rulin g describe s a numbe r o f activitie s regardin g emission s contro l system s o r device s whic har e no t considere dby

EPA t o b e a "physica l change " o r "chang e i nth e metho d o f operation " o f stationar y source s withi nth e meanin g o f section s 51.16 5 an d 51.16 6 an

dAppendi xS . Thi s rulin g clarifie s EPA' s interpretatio ntha t th e installatio nan

dus e o f clea ncoa l technolog y an d othe r EPA-approve d contro l technolog y

demonstratio nprojects , th e remova l o f temporar y demonstratio n emission s contro l system s o r devices , an d th e additio no r improvemen t o f a n emission s contro l system o r devic e ona voluntar y basi s o r fo r compliance relate dpurposes , i s no t a "majo r modification " subjec t t o th e new sourc e revie w provision s o f sectio n51.16 5 o r 51.166 , o r Appendi xS , provide d suc h installatio nan

d us e meet s th e condition s specifie d belo w an d th e appropriat e reviewin g authority

issue s a

napplicabilit y

exclusion . Th e principa l conditio ni s tha t th e installatio no r operatio no f th e emission s contro l



### 3 1P.4 2

system mus t b e designe d primaril y t o improv e th e contro l o r preventio no f ai r pollutio nemissions . I f th e installatio no f a nemission s contro l syste m o r approve d contro l technolog y demonstratio nprojec t b y a sourc e woul d trigge r

new sourc e revie w

becaus e an

y applicabl e "significant " ne t emission s increas e threshol d woul d b e exceede d [a s define d a t 4 0 CF R51.166(b)(23)] , the sourc e shoul d no t commenc e installatio no f th e contro l syste m o r demonstratio n projec t unti l th e reviewin g authorit y notifie s th e sourc e tha t i t qualifie s fo r anexclusion . Fo r purpose s o f thi s ruling , th e ter m "emission s contro l syste m o r device " generall y

mean s a

n"add-on " typ e o f emission s contro l equipment , suc h

a s fabri c filters , scrubbers , absorbers , catalysts , an d therma l reduction/oxidation . Thi s ma y als o includ e th e us e o f a les s pollutin g fue l i f suc hchang e i s properl y determine d t o b e a pollutio ncontro l system . Suc h determination s wil l b e mad e b y th e appropriat e reviewin g authorit y ona case by-cas e basis . Fo r example , som e physica l change s t o accommodat e a ne w fue l coul d b e properl y

characterize d a s pollutio ncontro l system s (e.g. , a CC T demonstratio no f nitroge noxide s (N0 X ) rebumin g technolog y usin g natura l ga s

ona coal-fire d utilit y boiler ; o r project s t o conver t t o natura l ga s o r t o gas/coa l cofirin g implemente d t o compl y wit ha nenvironmenta l regulator y requirement) . Othe r type s o f changes , suc ha s proces s changes , ar e no t considere d emission s contro l system s o r devices . Th e EP A wil l exclud e fro

m review onl y th e typ e o f chang e specified ; othe r changes , eve ni f planne d i nconjunctio n wit ha nexclude d change , wil l no t b e exclude d fro m th e definitio no f a physica l chang e o r chang e i nth e metho d o f operation . Th e appropriat e



### 32P.4 3

reviewin g authorit y

wil l mak e th e determinatio no f nonapplicability , o na case-by-cas e basis , bu t withi nth e genera l framewor k o f thi s ruling , applyin g th e principa l tes t tha t th e system i s primaril y

designe d an

d installe d t o reduce ai r pollution . Th e rulin g i s applicabl e t o bot htemporar y demonstratio nproject s an d
permanen t emission s contro l system o r devic e changes . Owner s o r operator s shoul d provid e a descriptio no f th e propose d activit y an d a justificatio nfo r wh y the y shoul dqualif y

fo r anexclusio nfrom th e definition s o f a "physica l change " o r a "chang e inth e metho d o f operation " o f a sourc e unde r thi s interpretativ e ruling . Th e owne r o r operato r shoul d demonstrat e tha t th e propose demission s contro l system o r devic e wil l consis t o f th e replacemen t o f

a nexistin g emission s contro l system o r a devic e wit ha

nimprove d o r upgrade d emission s contro l system o r device , o r th e installatio no f a ne w emission s contro l system

o r devic e a t a

nexistin g uncontrolle d source . Physica l o r operationa l change s whic hrestor e origina l capacity , o r ar e mad e t o improve th e operatio no r efficienc y o f th e source , ar e no t considere d a nemission s contro l system

installatio no r improvement , eve ni f conducte d i nconjunctio n wit hth e installatio no r improvemen t o f a nemission s contro l system . Th e

owne r o r operato r shoul ddemonstrat e tha t th e propose d emission s contro l syste m o r devic e wil l mee t th e followin g conditions : Conditio n1 . Th e replacemen t o r additio no f th e emission s contro l syste m wil l no t caus e o r contribut e t o a violatio no f a Stat e implementatio nplan , a conditio ni na permi t issue d pursuan t t o regulation s approve do r promulgate dunde r th e Clea nAi r Ac t



### 3 3(CAA) , o r an y applicabl e nationa l ambien t ai r qualit y standar d

o r preventio no f significan t deterioratio nincrement ; Conditio n2 . Th e replacemen t o r additio no f th e emission s contro l syste m wil l no t resul t inanenvironmenta l harm . Thi s include s th e followin g criteria :
A . Ther e wil l b e n o increas e i nth e maximu

m hourl y emission s rat e (kilogram s pe r hou r o r equivalent ) o f an y pollutan t subjec t t o regulatio nunde r th e CAA , a s determine d b y 4 0 CF R60.14(b) . Thi s include s no t onl y th e emission s uni t directl y

affected , bu t als o th e entir e source , i f th e activitie s woul d caus e suc hincreas e elsewher e withi nth e

source . B . Ther e wil l b e no increas e i nannua l emission s o f an y pollutan t subjec t t o regulatio nunde r th e CA A a s a resul t

o f th e activities . A nincreas e i

nannua l emission s o f on e

o r mor e pollutant s (no t necessaril y thos e fo r whic hth e control s hav e bee ninstalled ) ca nb e anticipate d whe n ther e i s a clea r likelihoo d tha t th e additio no f th e contro l system

o r devic e woul d increas e th e utilizatio no f th e sourc e (e.g. , mor e hour s o f operatio npe r year) , an d whe nsuc hincrease d utilizatio ni s no t offse t by a correspondin g decreas e i nhourl y emission s rate(s) . C . Ther e wil l b e no advers e impac t ona nai r qualit y

relate d value s (e.g. , visibility ) i nan y Clas s I area .



### 34P.4 5

D . An y

ne t increase s i

nemission s o f an

y toxi c pollutan t no t subjec t t o regulatio nunde r th e CAA , resultin g fro m th e change incontro l equipment , wil l no t caus e o r contribut e t o an y advers e healt ho r welfar e effects . Fo r temporar y

contro l technolog y

demonstratio nprojects , condition s 2. A

an d2. B abov e ma y

b e waived , i

nwhol e o r part , i f th e reviewin g authorit y determine s tha t th e demonstratio nprojec t i s environmentall y beneficial . Temporar y

demonstratio nproject s ar e project s whic hwil l las t n o mor e tha n5
year s (includin g th e tim e require d t o restor e th e sourc e t o it s origina l condition ) fro

m th e dat e onwhic hstartu po f th e projec t begin s (a s define d a t 4 0 CF R60.2) . However , tw o additiona l criteri a whic hmus t b e me t ar e that : Conditio n3 . Th e projec t i s a temporar y projec t t o demonstrat e a nemission s contro l system

o r device , andth e projec t i s eithe r a ) federall y

funde do r b ) EPA

approved . Conditio n4 . Th e sourc e wil l b e returne d t o it s pre-projec t physica l an d operationa l condition , an d hourl y

emission s rat e (i nkilogram s pe r hou r o r equivalent ) an dannua l emission s rate , o r t o an

eve nlowe r emission s rate , whe nth e demonstratio ni s completed ,
o r a t th e en

do f th e "temporary " tim e perio d approve d b

y EPA , whicheve r i s earlies t (allowin g fo r ver y smal l negligibl e difference s i

nth e post-demonstratio nphysica l an d operationa l conditio ndu e t o a technica l inabilit y t o restor e th e uni t t o it s precis e pre-demonstratio ncondition , o r du e t o norma l variabilit y

i nth e coa l used) .



### 3 5P.4 6

Par t 5 2 - APPROVA L AN D PROMULGATION O F IMPLEMENTATIO N

PLAN S
A new appendi xi s adde d a t th e en d o f Par t 5 2 a s follows : APPENDI XF - EXCLUSION S FRO M NE W SOURC E REVIEW

REQUIREMENT S FORTH E INSTALLATIO N AN D IMPROVEMEN T O F EMISSION S CONTRO L SYSTEM S

Thi s appendi xset s fort hth e Environmenta l Protectio nAgency' s (EPA's ) interpretativ e rulin g onth e definitio no f a "majo r modification " i n 4 0 CF R52.2 1 and 52.24 . Thi s rulin g describe s a numbe r o f activitie s regardin g emission s contro l system s o r device s whic har e no t considere d by EPA t o b e a "physica l change " o r "chang e i nth e metho d o f operation " o f stationar y

source s withi nth e meanin g o f section s 52.2 1 an d 52.24 . Thi s rulin g clarifie s EPA' s interpretatio ntha t th e installatio nan d us e o f clea ncoa l technolog y

and othe r EPA-approve d contro l technolog y demonstratio nprojects , th e remova l

o f temporar y

demonstratio nemission s contro l system s o r devices , an d th e additio no r improvemen t o f a nemission s contro l syste m o r devic e o

na voluntar y

basi s o r fo r compliance-relate d purpose s i s no t a "majo r modification " subjec t t o th e ne w sourc e review

provision s o f section s 52.2 1 o r 52.24 , provide d suc hinstallatio nan d us e meet s th e condition s specifie d below

an d th e appropriat e reviewin g authorit y issue s a

napplicabilit y

exclusion . Th e principa l conditio ni s tha t th e installatio no r operatio no f th e emission s contro l syste m

o r devic e mus t b e designe d primaril y t o improve th e contro l o r preventio no f ai r pollutio nemissions . I f th e installatio no f anemission s contro l system

o r EPA-approve d contro l technolog y demonstratio nprojec t b y a



### 3 6P.4 7

sourc e woul dtrigge r new sourc e review

becaus e an

y applicabl e "significant "

ne t emission s increas e threshol dwoul db e exceede d [a s define d a t 4 0 CF R52.21(b)(23)] , th e sourc e shoul d no t commenc e installatio no f th e contro l system

o r demonstratio nprojec t unti l th e reviewin g authorit y notifie s th e sourc e tha t i t qualifie s fo r a nexclusion . Fo r purpose s o f thi s ruling , th e ter m "emission s contro l system o r device " generall y

mean s an"add-on " typ e o f emission s contro l equipment , suc h

a s fabri c filters , scrubbers , absorbers , catalysts , an d therma l reduction/oxidation . Thi s ma y als o includ e th e us e o f a les s pollutin g fue l i f suc hchang e i s properl y determine d t o b e a pollutio ncontro l system . Suc h determination s wil l b e mad e by th e appropriat e reviewin g authorit y o na case by-cas e basis . Fo r example , some physica l change s t o accommodat e a new fue l coul db e properl y

characterize da s pollutio ncontro l system s (e.g. , a CC T demonstratio no f nitroge noxide s (NO J rebumin g technolog y usin g natura l ga s

ona coal-fire d utilit y boiler ; o r project s t o conver t t o natura l ga s o r t o gas/coa l cofirin g implemente dt o compl y wit ha nenvironmenta l regulator y requirement) . Othe r type s o f changes , suc ha s proces s changes , ar e no t considere d emission s contro l system s o r devices . Th e EPA wil l exclud e fro

m review onl y th e typ e o f chang e specified ; othe r changes , eve ni f planne d i nconjunctio n wit ha nexclude d change , wil l no t b e exclude d fro m th e definitio no f a physica l chang e o r chang e i nth e metho d o f operation . Th e appropriat e reviewin g authorit y

wil l mak e th e determinatio no f nonapplicability , o na case-by-cas e basis , bu t withi nth e genera l framewor k o f thi s ruling , applyin g



### 37P.4 8

' V . f

th e principa l tes t tha t th e system i s primaril y

designe d an

d installe d t o reduc e ai r pollution . Th e rulin g i s applicabl e t o bot htemporar y demonstratio nproject s an d
permanen t emission s contro l syste m o r devic e changes . Owner s o r operator s shoul dprovid e a descriptio no f th e propose d activit y an d a rational e fo r wh y the y shoul dqualif y

fo r a nexclusio nfro

m th e definition s o f a "physica l change " o r a "chang e i nth e metho do f operation " o f a sourc e unde r thi s interpretativ e ruling . Th e owne r o r operato r shoul d demonstrat e tha t a n emission s contro l system o r devic e installatio nwil l consis t o f th e replacemen t o f a

nexistin g emission s contro l syste m o r devic e wit ha

nimprove d

o r upgrade demission s contro l system o r device , o r th e installatio no f a new emission s contro l system o r devic e a t a

nexistin g uncontrolle d source . Physica l o r operationa l change s whic hrestor e origina l capacity , o r ar e mad e t o improve th e operatio no r efficienc y o f th e source , ar e no t considere d a n emission s contro l system installatio no r improvement , eve ni f conducte d i n conjunctio nwit hth e installatio no r improvemen t o f a nemission s contro l system . Th e owne r o r operato r shoul d als o demonstrat e tha t a nemission s contro l system

o r devic e installatio nwil l mee t th e followin g conditions : Conditio n1 . Th e replacemen t o r additio no f th e emission s contro l system

wil l no t caus e o r contribut e t o a violatio no f a Stat e implementatio nplan , a conditio ni na permi t issue d pursuan t t o regulation s approve do r promulgate dunde r th e Clea nAi r Ac t (CAA) , o r an

y applicabl e nationa l ambien t ai r qualit y standar d

o r preventio no f significan t deterioratio nincrement ;



### 3 8P.4 9

Conditio n2 . Th e replacemen t o r additio no f th e emission s contro l system

wil l no t resul t i

na nenvironmenta l harm . Thi s include s th e followin g criteria : A . Ther e wil l b e n o increas e i nth e maximum

hourl y emission s rat e (kilogram s pe r hou r o r equivalent ) o f any pollutan t subjec t t o regulatio nunde r th e CAA , a s determine db y 4 0 CF R60.14(b) . Thi s include s no t onl y th e emission s uni t directl y

affected , bu t als o th e entir e source , i f th e activitie s woul dcaus e suc hincreas e elsewher e withi nth e

source . B . Ther e wil l b e n o increas e i nannua l emission s o f an y pollutan t subjec t t o regulatio nunde r th e CA A a s a resul t O f th e activities . A nincreas e i

nannua l emission s o f on e

o r mor e pollutant s (no t necessaril y thos e fo r whic hth e control s hav e bee ninstalled ) ca nb e anticipate dwhe n ther e i s a clea r likelihoo dtha t th e additio no f th e contro l syste m

o r devic e woul dincreas e th e utilizatio no f th e sourc e (e.g. , operatio nmor e hour s pe r year) , an dwhe n

suc hincrease dutilizatio ni s no t offse t b y a correspondin g decreas e i nhourl y emission s rate(s) . C . Ther e wil l b e n o advers e impac t o na nai r qualit y relate d valu e (e.g. , visibility ) i nan y Clas s I area . D . Any ne t increase s i

nemission s o f an

y toxi c pollutan t no t subjec t t o regulatio nunde r th e CAA , resultin g fro m th e



### 3 9P.5 0

V . *

chang e i ncontro l equipment , wil l no t caus e o r contribut e t o an y advers e healt ho r welfar e effects . Fo r temporar y

contro l technolog y

demonstratio nprojects , condition s 2. A

an d 2. B abov e ma y

b e waived , i

nwhol e o r part , i f th e reviewin g authorit y determine s tha t th e demonstratio nprojec t i s environmentall y beneficial . Temporar y

demonstratio nproject s ar e project s whic hwil l las t n o mor e tha n5
year s (includin g th e time require dt o restor e th e sourc e t o it s origina l condition ) from

th e dat e onwhic hstartu p o f th e projec t begin s (a s define d a t 4 0 CF R60.2) . However , tw o additiona l criteri a whic hmus t b e me t ar e that : Conditio n3 . Th e projec t i s a temporar y projec t t o demonstrat e a nemission s contro l system

o r device , an

d th e projec t i s eithe r a ) federall y

funde do r b ) EPA

approved . Conditio n4 . Th e sourc e wil l b e returne d t o it s pre-projec t physica l an d operationa l condition , an dhourl y

emission s rat e (i nkilogram s pe r hou r o r equivalent ) andannua l emission s rate , o r t o a n

eve nlowe r emission s rate , whe nth e demonstratio ni s completed ,
o r a t th e endo f th e "temporary " time perio d approve d by EPA , whicheve r i s earlies t (allowin g fo r ver y smal l negligibl e difference s i

nth e post-demonstratio nphysica l and operationa l conditio ndu e t o a technica l inabilit y t o restor e th e uni t t o it s precis e pre-demonstratio ncondition , o r du e t o norma l variabilit y

i nth e coa l used) .



### 4 0P.5 1 J '• ' '

Par t 6 0 - STANDARD S O F PERFORMANC E FO RNE W STATIONAR YSOURCE S

A ne w appendi xi s adde d a t th e en d o f Par t 6 0 a s follows :

APPENDI XJ - EXCLUSIO N FO RTEMPORAR YCONTRO L TECHNOLOG YPROJECT S

Thi s appendi xset s fort hth e Environmenta l Protectio nAgency' s (EPA's ) interpretativ e rulin g o nth e definitio no f "modification " i n4 0 CF R60.14 . Th e definitio nlist s a numbe r o f emission s contro l syste m change s whic har e

no t considere d by

EPA t o b e "physica l changes " o r "change s i nth e metho d o f operation " o f stationar y sources , an

d therefor e no t a modification . Thi s rulin g clarifie s EPA' s interpretatio ntha t temporar y clea ncoa l technolog y an d othe r approve d temporar y contro l technolog y

demonstratio nproject s ar e no t subjec t t o sectio n60.1 4 (subjec t t o th e condition s specifie d below) . Temporar y

contro l technolog y

demonstration s ar e project s whic hwil l las t

n o mor e tha n5 year s includin g th e time require d t o restor e th e sourc e t o it s origina l conditio nfrom th e dat e o

nwhic hstartu p o f th e projec t begin s (a s define d i

n4 0 CF R60.2) . Suc htemporar y contro l technolog y

demonstratio n project s mus t b e approve d b y EP A prio r t o th e demonstration . A s applie d t o th e definitio no f modificationi n4 0 CF R60.14 , the followin g shal l not , by itself , b e considere d a modificatio nunde r thi s part :

a physica l chang e to , o r chang e i nth e metho d o f operatio nof , a n existin g facilit y

fo r th e sol e purpos e o f cessation , o r removal , o f



### 4 1P.5 2 

## r —— —

a nai r pollutio ncontro l technolog y demonstratio nprojec t tha t result s i

na nemission s increas e o f any pollutan t t o whic ha standar dapplies , upt o th e pre-demonstratio nlevel .



### rt