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# OAR Box 1168 Prepped by Ollie Stewart



### Document

Number: 

# 104 ) ll-C-3 3
Docket Number: 

# A-89-1 0

Printed 4/29/2008 11:23:20 AM Sheet 104 of 131

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# u a D STATE S ENVIRONMENTA L PROTEC T Offic e of Ai rQualit

yPlannin g an d Sta n Researc h Triangl e Park/Nort h Carolin a 

# A-89-1 0
II-C-3 3

Dea r Re g Ne g Committee : A s promise di

n Phil' s not e o f 10/31 , enclose dfo r you r revie w and commen t i s a revise ddraf t o f th e preambl e sectio no n th e us e o f th e data . Thi s sectio ni s bein g circulate dfo r earl y revie w t o ensur e i t reflect s th e Committee' s thinkin g an d becaus e o f interes t expresse dby severa l members . Thi s draf t ha s bee nrevise dt o reflect , wit hon e exception , th e comment s w e receive dfrom

Committe e members . Th e exceptio ndeal s wit hth e commen t tha t w e nee dt o verif y

th e "accuracy " o f th e dat a i n Tabl e 1 . Du e t o tim e demand s o f othe r issues , i t ha s no t bee npossibl e t o chec k Tabl e 1 . Agai ni n thi s draft , w e hav e focuse dprimaril y on th e principl e basi s fo r th e provision s an d hav e no t attempte dt o ensur e tha t al l number s ar e correc t and consistent . Thes e detail s wil l b e addresse dshortly . Wor k i s continuin g o n th e preambl e an d i f yo u hav e any

question s on progres s fee l fre e t o cal l m e o r Rick . Sincerely ,

Ja nMeye r



## Y > *P. 3

Th e Dat a an

d Informatio nConsidere d Backgroun d an

d Summar yo f Informatio n

I n th e lat e 1970' s and earl y1980's , EP Aconducte d severa l studie s t o evaluat e and quantif yemission s fro mequipmen t leak s in refiner yoperations

and i n chemica l plants
. I n thes e studies , EP Acollecte d dat a and evaluate d lea k frequency , mas s emissions , and method s and effectivenes s o f lea k prevention
. Thes e studie s showe d tha t equipmen t leak s wer e a significan t

sourc e o f emission s and tha t th e majorit yo f emission s wer e associate d wit h equipmen t leak s measure d a t concentration s greate r tha n 10,00 0 ppm . Thes e studie s als o demonstrate d tha t a progra m consistin g o f inspectio n o f equipmen t

and maintenance o f th e leakin g equipmen t wa s a n effectiv e mean s o f reducin g emissions
. Th e contro l measure s identifie d a t tha t tim e wer e estimate d t o achiev e overal l a 6 0 t o 7 0 percen t reductio n i n emission s fro mequipmen t leaks
. Th e dat a and conclusion s fro mthes e studie s serve d a s a basi s fo r EPA' s equipmen t lea k regulation s and guideline s tha t wer e issue d i n th e earl y 1980's
. Informatio n obtaine d i n thes e studie s als o showe d tha t lea k frequencie s varie d widel yamon g proces s unit s an d sourc e type s and tha t factor s tha t affec t lea k frequencie s wer e no t wel l understood
. Specifically , studie s suc h

a s EPA' s studyo f 2 4 chemica l proces s unit s (24-Uni t Study ) showe d tha t th e frequenc yo f leak s greate r tha n 10,00 0 pp mrange d fro m0 t o approximatel y3 0 percen t amon g 1 5 differen t chemica l processes . Simila r chemica l processe s als o showe d larg e difference s i n lea k frequencies ; fo r example , th e lea k frequencie s fo r ga s valve s varie d fro m 0 t o 1 8 percen t fo r 3 ethylen e dichloride units
. I n subsequen t studies , EP Aevaluate d lea k frequenc ya s a

1P. 4

functio no f proces s parameter s an dequipmen t desig nan didentifie dno singl e facto r tha t determine dlea k frequency . Lea k frequencie s ar e believe dt o b e a functio no f componen t design , construction , material , an dage , componen t desig nspecifications , qualit y an dfrequenc y

o f maintenance , operatin g an d trainin g practice s use db y th e company , diligence , an dothe r unidentifie d factors . Th e curren t EPA rule s an

dguideline s d o no t requir e source s t o achiev e particula r performanc e level s o r t o instal l low emissio ndesig n equipment . A s such , th e residua l emission s wil l var y amon g proces s unit s an d bes t controlle dunit s wil l emi t les s tha ntypicall y controlle dunits . I nth e las t thre e years , EPA ha s receive dinformatio ntha t show s significantl y

lowe r lea k frequencie s a t 10,00 0 pp m fo r som

e chemica l processe s tha nwa s representativ e fo r th e industr y a s a whol e i

nth e earl y

1980's . Thi s informatio nwa s on e consideratio ni nEPA' s decisio nt o develo pa ne w regulator y

approac hfo r equipmen t leak s throug hth e regulator y negotiatio n process . Th e informatio ni s briefl y summarize di

nth e paragraph s below . I n addition , wher e sufficien t informatio ni s available , thes e dat a ar e include d i nTabl e 1 whic hcompare s lea k frequenc y by componen t typ e wit hth e previousl y calculate dSOCM I averag e lea k frequency . Ingeneral , thes e dat a wer e collecte dfollowin g th e procedure s specifie di nReferenc e Metho d21 , an dth e result s represen t a singl e monitorin g surve y conducte dove r a discret e tim e period . Unit s subjec t t o th e Benzen e Equipmen t Lea k NESHAP . Durin g EPA' s reconsideratio no f th e benzen e equipmen t lea k NESHA P (5 4 F R38044) , EPA examine dcomplianc e report s fro m 198 7 an

d198 8 fo r a randoml y selecte dsampl e
o f 2 5 facilitie s subjec t t o th e standard , whic hrequire s a 10,00 0 pp m lea k detectio nan

drepai r program . Thi s revie w showe dtha t man y

facilitie s ha dn oP. 5

valve s o r pump s exceedin g 10,00 0 pp m an dn o facilitie s ha dmor e tha n1. 5 percen t valve s o r mor e tha n12. 5 percen t pump s exceedin g 10,00 0 ppm . Th e averag e frequencie s o f source s exceedin g 10,00 0 pp m wer e 0.2 7 percen t fo r valve s an

d2. 3 percen t fo r pumps . Thes e frequencies , i ngeneral , ar e lowe r tha nth e averag e frequencie s o f 3 t o 5 percen t fo r valve s an dapproximatel y

1 0 percen t fo r pump s exceedin g 10,00 0 pp m whic hha dbee nexpecte dunde r th e standard . Acrolei nproces s units . I n198 9 EPA

receive dscreenin g dat a an dproces s informatio no

ntwo acrolei nproces s units . Thes e dat a wer e collecte d voluntaril y

b y th e compan y

t o provid e bette r emissio nestimate s tha ncoul db e obtaine dusin g th e SOCM I averag e factors . Th e monitorin g dat a represente d eigh t type s o f equipmen t (ga s valves , ligh t liqui dvalves , ligh t liqui dpumps , flange s an

dothe r connectors , pressur e relie f valves , sampl e points , open ende dline s an

dcompressors) . Thes e monitorin g dat a wer e collecte dfollowin g th e procedure s specifie di n"Protocol s fo r Generatin g Unit-Specifi c Emissio n Estimate s fo r Equipmen t Leak s o f VO C an dVHAP" , (Protocols ) EPA-450/3-88-010 . I ngeneral , particula r car e wa s take ni nmeasurement s o f equipmen t wit hnea r
zer o o r les s tha n20 0 pp m emissions . I

naddition , on e o f th e unit s ha d approximatel y

6 0 percen t seale dbellow s valve s andth e othe r uni t hadno seale dbellow s valves . Th e screenin g dat a indicate daverag e lea k frequencie s o f 0.2 6 t o 0.0 9 percen t fo r valve s an do f 0.1 3 t o 0 percen t fo r flange s an dothe r connector s
a t lea k definition s o f 100 , 1,000 , an d10,00 0 ppm . Thes e dat a als o demonstrate dtha t bot hconventiona l an dseale dbello w

valv e design s achiev e
ver y goo dperformance . Pum plea k frequencie s wer e les s tha n4 percen t a t 100 , 1000 , an d10,00 0 ppm . O f al l th e component s screened , mor e tha n9 8 percen t ha dP. 6



### screenin g value s belo w

1 0 ppm . Thes e lea k frequencie s ar e substantiall y below th e level s foundb

y EPA i nstudie s conducte di

nth e earl y

1980's . Amin e Uni t W.VA . I

n1987 , EP A

receive dmonitorin g dat a fo r tw o proces s unit s handlin g amines . Thes e unit s wer e selecte dfo r testin g becaus e o f th e relativel y

sever e servic e condition s (i.e. , temperatur e andpressure ) an dhigh vapo r pressure s o f th e proces s materials . On e uni t (uni t 1 ) wa s characterize d
a s handlin g relativel y

nontoxi c an

dinnocuou s substance s andth e othe r uni t (uni t 2 ) wa s characterize da s handlin g a mor e toxi c compound , on e wit ha threshol dlimi t valu e (TLV ) o f 1 0 ppm , whic hwa s capabl e o f causin g a publi c nuisance . Thes e dat a wer e collecte dvoluntaril y b y th e compan y

t o calculat e a uni t specifi c emissio nestimat e usin g EPA' s leak/n o lea k emissio nfactors . Monitorin g dat a wer e provide dfo r pumps , valves , an dflange s an

dothe r connectors . Th e monitorin g dat a fo r uni t 1 showe d3 3 percen t o f th e pumps , 1 6 percen t o f th e ligh t liqui dvalves , 2 7 percen t o f th e ga s valves , an d0. 4 percen t o f th e flange s an dothe r connector s exceedin g 10,00 0 ppm . Uni t 2 had 5. 6 percen t o f th e pumps , 0. 8 percen t o f th e ligh t liqui dvalves , 1 percen t o f th e ga s valves , an

d0. 1 percen t o f th e flange s an dothe r connector s exceedin g 10,00 0 ppm . Th e dat a fo r uni t 2 indicat e tha t technolog y i s availabl e t o reduc e leak s an

dsugges t tha t healt han dsafet y consideration s ar e importan t factor s affectin g us e o f bette r technologie s an dmaintenanc e practices . Ethvlbenzene/Stvren e (EB/S ) Uni t Tx . Limite dinformatio nwa s receive d
onscreenin g value s measure da t thi s facility' s ethylbenzene/styren e proces s unit , whic hi s subjec t t o th e benzen e equipmen t lea k NESHAP . Screenin g dat a
wer e provide dfo r a tota l o f approximatel y 250 0 valve s andpumps . Th e dat a
wer e provide da s time aggregate dsummarie s o f screenin g valve s fo r a on e yea rP. 7

perio dfrom

198 7 t o 1988 . Thes e dat a indicate dtha t 9 9 percen t o f th e tim e th e valve s an

d9 0 percen t o f th e time th e pump s hadscreenin g value s les s tha n 50 0 ppm . Informatio nsubmitte dfo r complianc e wit hth e benzen e equipmen t lea k NESHA P showe dona

nannua l averag e basi s 0.0 4 percen t o f th e valve s an d3. 6 percen t o f th e pump s exceede d10,00 0 ppm . N o descriptio nwa s provide do f th e procedure s use di

nth e dat a collection , othe r tha nReferenc e Metho d2 1 wa s used . Chemica l Manufacturer s Associatio nStudie s o f Butadien e (BD) . Ethylen e Oxid e (EO) . an

dPhosgen e Proces s Units . I nadditio nt o th e precedin g information , comprehensiv e screenin g dat a wer e als o provide dt o EPA o n3 3 butadien e (BD) , ethylen e oxid e (E0) , an dphosgen e productio nproces s units . Th e monitorin g dat a represente deigh t type s o f equipmen t (ga s valves , ligh t liqui dvalves , ligh t liqui d pumps , flange s an dothe r connectors , pressur e relie f valves , sampl e points , open-ende dline s an dcompressors ) a t essentiall y al l BD , EO , an

dphosgen e producer s operatin g i nth e Unite dStates . Thes e dat a
wer e collecte dvoluntaril y b y th e CM A committee s t o provid e EPA wit hbette r industry-wid e estimate s o f emission s fro m equipmen t leak s a t thes e proces s unit s tha ncoul db e obtaine dusin g EPA averag e factor s fo r SOCMI . Thes e monitorin g dat a wer e collecte dfollowin g th e procedure s specifie di nth e Protocol . Thes e studie s provid e th e mos t comprehensiv e equipmen t screenin g dat a availabl e tha t documen t th e ful l rang e o f lea k frequencie s fo r larg e number s o f proces s unit s use dfo r th e productio no f specifi c chemicals . Condition s i

nth e equipmen t surveye dspanne da wid e rang e o f temperature s an d pressure s (5 0 F t o 55 0 F an d5 t o 50 0 psig) . Th e screenin g dat a indicate dtha t mos t proces s unit s a t thes e facilitie s
ar e characterize db

y equipmen t lea k frequencie s fa r belo w level s foun db

y EPAP. 8

i nstudie s conducte di nth e 1970' s an

d1980's . Inaddition , th e dat a bas e indicate dmuc hlowe r lea k frequencie s a t th e phosgen e proces s unit s tha na t th e EO an

dB D units , an

dth e EO unit s i

ngenera l hadlowe r lea k frequencie s tha nth e B D units . Tabl e 1 present s th e plant-specifi c lea k frequenc y dat a b y componen t type , a t variou s lea k definition s fo r th e thre e processes . Th e dat a show ni nTabl e 1 ar e th e screenin g dat a tha t wer e judge dt o b e consisten t wit h prope r calibratio nan dus e o f th e tes t equipment . Th e screenin g value s fo r th e te nB D an

dnin e E O proces s unit s wer e als o adjuste dfo r th e instrumen t respons e facto r t o represen t mor e accuratel y th e screenin g concentratio no f equipmen t i

nB D o r E O service . Th e dat a presente di nTabl e 1 represen t proces s unit s i

nvariou s stage s o f contro l andoperations . Some plant s operate dusin g forma l LDA Rprogram s an

dother s di dnot ; some unit s wer e
screene djus t befor e a shutdow nfo r maintenanc e an dother s wer e screene djus t afte r startu pfollowin g a schedule dmaintenanc e shutdown . Texa s Ai r Contro l Boar dData . Additiona l dat a from thre e plan t site s
wer e provide db

y th e Committe e membe r representin g th e Texa s Ai r Pollutio n Contro l Board . Thes e plant s ar e subjec t t o a Texa s regulatio ntha t require s lea k detectio nan

drepai r (LDAR ) wit hdirecte dmaintenanc e a t a 50 0 ppm v lea k definition . Thi s requiremen t ha s bee napplie da s par t th e permi t progra m fo r
new an dmodifie dsources . Dat a wer e provide dfo r cumene , phenol/acetone , an d butyraldehyde/butano l proces s unit s whic hha dbee noperatin g a 50 0 pp m LDA R program fo r on e t o si xquarters . Thes e unit s ha daverag e lea k frequencie s a t 50 0 pp m fo r valve s rangin g fro m 0 t o 3. 6 percent , fo r pump s o f 3.6 , 4 , an d5 percent , an

dfo r flange s o f 0 an d2 percent . Thes e dat a show fo r severa l chemical s tha t a 50 0 pp m LDA Rprogra m

i s effectiv e andwil l significantl y decreas e lea k frequency .
6P. 9

Th e abov e information , whe ncompare dwit hth e earlie r studie s an d analyse s show s tha t th e performanc e o f availabl e technolog y i s bette r tha n tha t expecte dfrom

a 10,00 0 pp

m LDA Rprogram . Moreover , lik e earlie r studies , thes e studie s d o no t identif y an y on e singl e facto r o r technolog y a s bein g responsibl e fo r th e bette r performance . Rather , th e recen t dat a confir m tha t effectiv e lea k contro l involve s a combinatio no f factors . Fo r example , statistica l analysi s o f th e recen t E O an dB D dat a faile dt o identif y specifi c proces s parameter s o r equipmen t design s tha t alon e significantl y affecte dlea k frequencies . I nadditio nt o considerin g th e availabl e screenin g data , th e Committe e visite d3 integrate dchemica l plants ; 1 larg e integrate dchemica l plan t ha d2 0 operatin g unit s including a phosgen e unit , a toluen e diisocyanat e unit , an da hydroge nfluorid e unit . On e conclusio ndrawnfrom thes e visit s wa s tha t th e acut e toxicit y

o f phosgen e andtoluen e diisocyanat e ha s resulte di nth e routin e us e o f a numbe r o f effectiv e lea k contro l practice s i nthes e proces s units . Measure s take nt o preven t an dminimiz e leak s i

nphosgen e an

d isocyanat e unit s includ e desig nt o minimiz e th e numbe r o f components , stringen t qualit y

assurance/contro l programs , benc htestin g o f equipmen t fo r leaks , an

dcarefu l managemen t an dextensiv e continuou s monitorin g o f th e uni t t o detec t leak s andproblems . Inaddition,,phosgen e andisocyanat e unit s ar e shu t dow nfo r immediat e repai r wheneve r an y lea k i s detected . Immediat e shutdow ni s possibl e becaus e phosgen e an disocyanat e proces s unit s ar e smal l

an dar e no t operate da s par t o f a nintegrate dprocess . Inunit s wher e les s acutel y toxi c compound s ar e use do r produced , suc hmeasure s wer e no t observe d

an dth e unit s ar e no t immediatel y shu t dow

nfo r repai r wheneve r a lea k i s detected . Rather , thes e unit s ar e typicall y operate dfo r a fixe dtime perio dP.1 0

befor e the y

ar e shu t dow

nfo r maintenanc e an drepair . Representativ e operatin g time s betwee nschedule dshutdown s rang e from 6 month s t o severa l years , wit htypica l tim e betwee nturnaround s o f approximatel y 3 years . Th e Committe e als o conclude dtha t equipmen t desig nan da non-goin g qualit y control/assuranc e progra m ha s a significan t rol e i nachievin g low

lea k frequencies . Thi s conclusio nwa s supporte dby-remark s mad e t o th e Committe e b y a chemica l industr y

representativ e wh o describe dhi s company' s recen t experienc e wit htw

o ethylen e oxid e productio nunits . Followin g completio no f

a screenin g study , th e compan y undertoo k a progra m t o reduc e th e lea k frequenc y

an demission s from

th e units . Step s take nconsiste do f componen t inspection , complet e o r partia l replacemen t o f ove r 70 0 valve s an d200 0 gaskets , modificatio no f desig nt o reduc e leaks , andregula r monitorin g an d inspectio nfo r leaks . Th e compan y reporte dtha t ther e wa s anoveral l reductio no f abou t 8 0 percen t i nth e numbe r o f leakin g component s followin g completio no f thi s project . Committe e Analysi s an dConsideratio no f th e Dat a Th e Committe e considere dth e dat a an dinformatio ndescribe di nth e precedin g sectio nan

dconclude dtha t th e EO , BD , an dPhosgen e dat a shoul d

serv e a s th e principl e basi s fo r establishin g th e performanc e o f MAC T fo r SOCM I processes . Th e EO , BD , an dPhosgen e data , however , wer e considere di n ligh t o f th e broade r data ; especially , th e Texa s 50 0 pp m LDA Rprogra m

an dth e sit e visits . O

nthi s basis , th e Committe e agree dtha t phosgen e unit s ar e no t simila r i

ndesign , operation , an dmaintenanc e t o mos t SOCM I processes . Some o f th e maintenanc e an

doperatin g practice s fo r phosgen e unit s contro l program s
wen t beyon dmaximu

m availabl e contro l technolog y (MACT ) fo r othe r SOCM I processes . Specifically , th e practic e o f immediat e shu t downi s economicall y

8P.1 1

an dtechnicall y

infeasibl e fo r othe r processe s becaus e shu t dow no f th e on e uni t woul drequir e shu t dow no f al l th e integrate doperation s a t th e sit e an d i t woul db e impractica l t o clea r larg e volume s o f chemical s i nshor t time frames . I

nsom e cases , emission s from clearin g proces s materia l from par t o r al l o f th e unit s coul dgreatl y excee dth e emission s tha t woul dresul t from th e leakin g equipment . Therefore , whil e th e phosgen e unit s performanc e di d provid e a

nindicatio no f th e potentia l fo r lea k reduction , th e Committe e conclude dtha t th e EO an dB D unit s ar e mor e representativ e o f th e rang e o f processe s i

nSOCM I tha nar e phosgen e o r toluen e diisocyanat e units . Th e Committe e di drecognize , a s indicate db y th e framewor k an

dth e performanc e levels , tha t ver y

lo w lea k frequencie s ar e generall y achievabl e an

dtha t th e rul e shoul dencourag e attainin g low emissions . From th e dat a an

dobservations , th e Committe e als o conclude dtha t low emissio nperformanc e result s from combination s o f monitorin g (o r surveillance) , repai r o f leakin g equipment , us e o f qualit y assure dan

dqualit y controlle dequipmen t suitabl e fo r th e proces s operatin g conditions , an da qualit y controlle dmaintenanc e an drepai r program . Th e Committe e conclude d tha t suc hcombination s ar e MAC T fo r SOCM I processes . Th e informatio n availabl e di dno t identif y an y singl e factor , suc ha s particula r equipmen t desig no r specifi c wor k practice s o r maintenanc e program s tha t by itsel f woul d guarante e lo

w emissio nperformanc e i nal l cases . Furthermore , th e Committe e di dno t identif y

th e result s a t any

on e specifi c proces s uni t o r performanc e leve l a s representin g MAC T performanc e becaus e ther e i s no apparen t brea k poin t tha t represent s a limi t o f wha t i s achievabl e wit ha combinatio no f technologie s tha t ar e available . Thus , th e Committe e identifie dth e bes t performin g E O proces s units , th e EB/ S unit , th e Texa s 50 0 pp m units , andP.1 2

possibl y th e bes t performin g B D proces s unit s a s reflectin g th e performanc e o f MAC T fo r toxi c chemica l processes . Regulator y

Approac h Becaus e availabl e informatio nindicate dtha t bes t performanc e fo r equipmen t leak s coul dno t b e define do r reflecte di na singl e numerica l standard , typ e o f technology , o r grou po f wor k practices , th e Committe e focuse do

ndevelopin g a regulator y framewor k that , whe ncombine dwit h performanc e levels , woul dreflec t MACT . Ke y principle s tha t evolve dan dtha t le dt o th e regulator y framewor k are : (1 ) Motivatio ni s a majo r facto r determinin g performance . Incentive s shoul db e include di

nth e standar dt o rewar dgoo dperformanc e an dprescribe d correctiv e action s shoul db e include dt o ensur e poo r performanc e i s correcte d i na timel y

manner . (2 ) Flexibilit y

i nachievin g specifie dresult s i s important . Thi s i s
necessar y

t o allo w

consideratio no f proces s t o proces s variation s i noperatin g condition s an

dequipmen t specification s an dt o provid e incentive s fo r identifyin g th e mos t effectiv e combinatio no f equipmen t an dpractices . (3 ) Time ha s t o b e provide dfo r source s t o identify , implement , an d desig nsystem s t o mee t th e specifie dresults . Effectiv e contro l require s continua l analysi s an dadjustmen t an

dma y involv e severa l technologie s whic h

canno t b e identifie do r applie da t on e tim e o r i non e step . (4 ) Mor e frequen t monitorin g an dmaintenanc e o r a prescribe dprogra m shoul db e employed , a t a minimum , fo r thos e proces s unit s tha t d o no t achiev e th e specifie dresult s throug ha program o f thei r ow

ndesig no r throug h quarterl y

inspectio nan

dmaintenanc e alone . (5 ) Ther e i s insufficien t informatio navailabl e t o se t a not-to-be 1 0P.1 3

exceede dstandard . Th e existin g informatio ni s to o limite di n scop e t o predic t wha t leve l o f performanc e coul db e achieve db y processe s fo r whic hn o dat a wer e available . Th e majorit y

o f th e Committe e deliberation s concerne ddevelopmen t o f a regulator y

framewor k an

d performanc e level s tha t woul dincorporat e th e abov e ke y principles , whil e reflectin g th e performanc e o f MACT . Thes e deliberation s primaril y

focuse do n developin g provision s fo r valves , pumps , an d flange s becaus e thes e emissio nsource s offere dth e greates t potentia l fo r emissio n reductions . Th e Committe e use dth e existin g LDA Rprogra m

a s a startin g poin t fo r developmen t o f th e framewor k fo r thes e sources . Early-on , th e Committe e recognize dth e nee dfo r a phased-i napproac hfo r valve s an d pump s tha t woul d provid e time fo r plant s t o develo pan d implemen t effectiv e program s an d t o focu s o n large r emissio nsource s first . Th e agree dapproac hdefine s MAC T fo r valve s an

d pump s a s consistin g o f thre e phase s o f increasin g stringency . Th e phase-i napproac hi s necessar y becaus e effectiv e contro l require s continua l analysi s an

d adjustmen t o f program s a s experienc e i s gained . Therefore , eac h phase , a s i t occur s reflect s th e performanc e o f MAC T fo r unit s i n tha t phase . Th e Committe e als o deliberate d on severa l method s o f linkin g monitorin g frequenc y

wit hperformanc e an d o f providin g incentive s t o us e lo w emissio n equipmen t o r t o reduc e th e amoun t o f equipmen t i n VHA P service . Th e fina l decisio nwa s t o lin k reduce dmonitorin g frequenc y wit hlowe r lea k frequencies , an dt o giv e credi t fo r remova l o f equipmen t o r us e o f lo w lea k desig n equipment . Thi s approac hi s consisten t wit hth e dat a whic hindicat e tha t ther e ar e combination s o f technology , maintenanc e practices , an d qualit y
assuranc e program s tha t ca n achiev e ver y lo w lea k frequencie s whil e usin g les s frequen t monitorin g intervals .
1 1

__•_._____ •P. M

Th e Committe e als o debate dwhethe r t o requir e shu t downo f proces s unit s fo r repai r o f leakin g equipmen t wheneve r performanc e deteriorate s belo w som e performanc e level . Th e Committe e ultimatel y conclude dtha t proces s unit s shoul dno t b e shu t dow nt o mee t a performanc e level . I t wa s generall y agree d tha t clearin g o f proces s material s coul dcaus e greate r emission s tha ndelayin g repair s unti l th e next schedule dshutdown . Th e Committe e als o agree dt o retai nth e existin g equipmen t standard s fo r pressur e relie f devices , sampl e points , open-ende dlines , produc t accumulato r vessels , an

dcompressors . Th e existin g standard s fo r thes e item s o f equipmen t requir e installatio no f equipmen t o r contro l device s an dessentiall y

eliminat e emission s fro

m equipmen t leaks . Th e Committe e considere dthes e requirement s t o b e MACT . Fo r th e valve , pump , an dconnecto r standards , th e Committe e primaril y
use dth e dat a from

th e bette r performin g E O units , th e bes t performin g B D units , th e Texa s 50 0 pp m units , an

dth e EB/ S uni t t o establis hth e performanc e level s fo r th e monitorin g frequency . A majo r consideratio ni nth e selectio n
o f performanc e level s wa s th e understanding.tha t th e level s ar e interrelate d wit hth e framewor k an dphasin g an

dar e no t necessaril y th e level s tha t woul d hav e bee nchose nfo r a not-to-be-exceede dframework . Inth e cas e o f th e valv e standard , th e selectio no f th e performanc e level s wa s als o influence db y th e inclusio no f provision s tha t provid e a nalternativ e t o monthl y monitoring . Referre dt o a s th e Qualit y Improvemen t Program (QIP) , thi s progra m ensure s tha t plant s subjec t t o thes e provision s instal l low emissio nperformin g replacemen t equipmen t (durin g norma l replacement ) an dimplemen t a qualit y assurance/contro l progra m t o ensur e tha t al l element s o f MAC T ar e utilized . Also , th e QI P wa s include di nth e framewor k t o allo w thos e proces s unit s tha t

1 2P.1 5

d o us e al l element s o f MAC T bu t d o no t achiev e th e specifie dnumerica l performanc e level s fo r les s frequen t monitorin g t o remai no na quarterl y monitorin g schedule . Th e basi s fo r th e specifi c provision s an dperformanc e level s selecte d fo r eac htyp e o f equipmen t i s discusse dbelow . Valves . Fo r valve s th e Committe e initiall y considere dbot hequipmen t standard s an

dLDA Rprogram s an

dultimatel y

agree dupo na thre e phas e LDA R program . Initially , th e Committe e considere drequirin g th e us e o f equipmen t

suc ha s seale dbellow s valve s becaus e th e equipmen t i s ofte nbelieve d t o hav e
zer o emissions . Thi s optio nwa s no t selecte dfo r severa l reasons . First , thes e valve s ar e no t suitabl e fo r us e i nal l operatin g condition s an dservice s encountere di

nSOCM I processes . Specifically , thes e valve s ca nno t b e use di n corrosiv e streams , wit hgritt y materials , o r i

nextremel y

hig hpressur e o r temperatur e conditions . Second , seale dbellow s valve s ca nlea k internally , an dwil l eventuall y

fail . Whe nfailur e occurs , ther e i s potentia l fo r massiv e leaks . Du e t o thi s possibilit y fo r leaks , monitorin g o f thes e valve s i s necessary . Considerin g this , th e Committe e though t tha t th e lea k detection , repair , an

dperformanc e standard s framewor k describe dabov e woul dbes t reflec t MACT . Thi s approac hallow s an dwoul dgiv e credi t fo r an y lo w emissio n performin g valv e regardles s o f its ' design . Th e Committe e considere d severa l LDA Rprogram s whic htie dmonitorin g frequenc y

t o th e performanc e leve l achieve dan dcreate da framewor k tha t consist s o f severa l combination s o f wor k practice s an dperformanc e levels . In determinin g th e maximu m monitorin g frequencie s fo r Phas e III , th e Committe e considere drequirin g weekl y monitorin g an

dmonthl y

monitoring . Th e weekl y monitorin g progra m

wa s rejecte da s bein g impractica l andunreasonable . Th e

1 3Committe e agree dtha t a monthl y progra m wa s th e maximum

frequenc y

tha t woul d b e generall y

feasible , an

dwoul dreduc e emissions , whil e bein g sufficientl y costl y t o caus e source s t o identif y mor e cost-effectiv e approaches . Fo r plant s tha t d o no t achiev e th e performanc e leve l fo r quarterl y monitoring , th e standar drequire s monthl y monitorin g o r participatio ni nth e QI P progra m

fo r valves . Inaddition , th e Committe e als o decide dt o allo w les s frequen t monitorin g t o provid e a nincentiv e t o achiev e bette r performanc e tha ntha t require dfo r th e bas e quarterl y monitorin g program . Annua l an dsemi-annua l frequencie s wer e selecte dfo r th e incentiv e programs . Inselectin g th e performanc e leve l an dlea k definition , th e Committe e considere dth e performanc e o f th e bette r performin g EO unit s (an dpossibl y

th e bes t B D units ) an

dth e performanc e o f th e unit s subjec t t o th e Texa s 50 0 pp m standard . Usin g thes e data , th e Committe e considere dlea k definition s i nth e rang e o f 5 0 t o 100 0 pp m an dperformanc e level s from 1 t o 5 percen t leakin g valves . Thes e dat a an dth e fac t that , i

npractice , lo

w lea k frequencie s wer e achieve db

y a 50 0 pp

m LDA Rprogra m

alon e supporte dth e practicalit y an d achievabilit y

o f a performanc e limi t fo r a quarterl y LDA Rprogra m

o f 2 percen t leakin g valve s a t a 50 0 pp m lea k definition . Lea k definition s lowe r tha n50 0 pp m wer e no t selecte ddu e t o uncertaintie s abou t th e practica l abilit y t o
measur e an

drepai r smalle r leaks . Concentration s greate r tha n50 0 pp m wer e
no t selecte di

nligh t o f data demonstratin g th e practicalit y o f a 50 0 pp

m LDA R program . Th e Committe e als o agree dtha t unit s wit hles s tha n1 percen t leakin g valve s coul dmonito r th e valve s semiannuall y an dthos e wit hles s tha n0. 5 percen t leakin g valve s coul dmonito r annually . Thes e performanc e level s wer e selecte dconsiderin g th e Committe e ha dpreviousl y agree dt o exclud e nonrepairabl e valve s (u pt o a maximum

o f on e percen t o f th e tota l valv e pool )

1 4P.1 7

fro m th e calculatio no f percen t leaking - se e sectio nE. 3 o f thi s notic e fo r discussio no f th e basi s fo r th e nonrepairabl e provision . Thes e performanc e level s hav e bee ndemonstrate db y th e bette r performin g E O proces s units , th e EB/ S unit , an

db y th e plant s subjec t t o th e Texa s 50 0 pp m regulation . Th e Committe e considere dthes e level s t o reflec t th e bes t performanc e o f 1 0 percen t o f th e unit s an dt o represen t th e performanc e o f MACT . Pumps . Indeliberation s o nth e standard , th e Committe e considere dth e dat a summarize di

nTabl e 1 , additiona l analyse s o f th e EO/B D data , an dth e comment s o f pum

psea l manufacturers . Th e EO/B D dat a showe dpum plea k frequencie s an

doveral l performanc e t o b e highl y variabl e wit hlea k frequencie s rangin g from 0 t o 5 0 percen t a t a 100 0 pp m lea k definition . Additiona l analyse s wer e don e t o compar e th e performanc e o f dua l mechanica l

sea l (DMS ) an

dsingl e mechanica l sea l (SMS ) pumps . Thes e comparison s showe d that , i ngeneral , DM S pump s screene da t 0 pp m andtha t SM S pump s performanc e varie dwidel y

amon g th e proces s units . I nsome cases , th e SM S pump s screene d

a t les s tha n10 0 pp

m an dcoul db e viewe da s havin g comparabl e performanc e t o tha t o f DM S pumps . Fo r th e majorit y o f SM S pump s screenin g a t les s tha n10,00 0 ppm , th e screenin g value s wer e fairl y uniforml y

distribute dfro

m 10 0 t o 910 0 ppm . Thus , th e dat a di dno t provid e a clea r indicatio no f th e performanc e leve l tha t ca nb e achieve dby SM S withou t incurrin g hig hmaintenanc e costs . Fro m it s consideratio no f th e availabl e data , th e Committe e generall y conclude dthat, , a s a group , pump s equippe dwit hDM S hav e lowe r lea k frequencie s tha nthos e equippe dwit hSMS . Consequently , th e Committe e deliberate da t grea t lengt honwhethe r MAC T i s reflecte db y a nequipmen t standar dfo r DM S onal l pump s o r b y a performanc e standard . Th e Committe e decide dno t t o establis ha nequipmen t standar dbecaus e DM S ar e no t suitabl e

1 5P.1 8



### Tabl e 1 : Summar y

o f Equipmen t Screenin g Dat a Uni t I D

E O 1 EO 2 EO 3 E O 4 EO 5 E O 6 EO 7 EO 8 E O 9
B D 1 B D 3 B D 4 B D 5 B D 6 B D 7 B D 8 B D 1 0 B D 1 1 B D 1 2 Acrolei n TAC B 

### A B C

Averag e SOCM I a t 10,00 0 Valve s %



### 250 0. 6 2. 8 1. 4 2 0. 4 1. 6 1. 2 2. 9 5. 3 10. 7 

### 5. 6 7. 3 1 1 7. 5 2. 2 21. 9 

### 2 5 11. 3 

### 5. 9 0. 1

pp m 50 0 0. 4 2. 2 1. 1 1. 3 0. 2 1. 4 1. 2 2. 5 4. 5 8. 8 4. 8 6. 3 7. 7 5. 4 2. 2 18. 4 19. 8 10. 1 

### 4. 5 0. 1

3. 6 0 0. 7

11. 5 Leaker s 100 0 

### 0. 3 1. 1 1. 1 0. 9 0. 2 1. 3 1. 2 1. 5 4 7. 5 4. 2 5. 4 5 3. 3 2. 2 15. 1 17. 1 

### 8 3. 7 0. 1 Pump s %



### 50 0

0 2 3 36 0 0 6 2 5

2 4 2. 9 5 0 33 n/ a 58 0 16. 7 

### 1 0 4

4 4 5 100 0



### 0 1 8 27 0 0 0 2 5

2 1 0
n/ a 5 0 0 16. 7 

### 1 0 4 Leaker s 200 0



### 0 1 4 9 0 0 0 2 5

1 5 0
n/ a 41. 7 

### 0 16. 7 

### 1 0 4

9 500 0



### 0 9 9 0 0 0 2 5

1 3 0
n/ a 41. 7 

### 0 16. 7 

### 1 0 4 Connector s %



### 25 0 0 0. 9 3. 2 2. 8 0 4. 1 0 2. 5 7. 6 0 0. 7 1 0 3. 4 n/ a 0 7. 4 5. 1 1. 4 0. 6 0. 1 50 0 0 0. 9 3. 2 1. 5 0 4. 1 0 2. 5 5. 9 0 0. 7 8. 6 1. 5 n/ a 0 6. 7 2. 5 1. 4 0. 6 0. 1

0 n/ a 2

2. 1 Leaker s 100 0 

### 0 0. 9 3. 2 0. 7 0 4. 1 0 2. 5 4. 9 0 0. 7 7. 1 1. 1 n/ a 0 5. 9 1. 9 0. 7 0. 6 0. 1P.1 9



### fo r us e i

nal l case s an

dbecaus e a DM S equipmen t standar dwoul db e ver y costl y
an dwoul dpreclud e effectiv e lowe r cos t options . Dua l mechanica l seal s ca nno t b e use dwit hmaterial s wher e leakag e o f th e barrie r flui dwoul daffec t produc t purity , wit hpolymerizin g monomers , o r o nreciprocatin g pumps . Also , th e pum p casin g o f som

e existin g packe dsea l an dSM S pump s doe s no t allow installatio n
o f a DM S assembly. I

nsuc hcases , a DM S equipmen t standar dwoul drequir e replacemen t o f th e entir e pump . Th e cos t o f a DM S equipmen t standar dwa s considere donl y

i na genera l sense ; estimate s o f th e cos t o f pum preplacement s
an dth e cos t o f installatio no f DM S system s wer e no t th e subjec t o f Coiranitte e discussions . Th e opinio ntha t a DM S equipmen t standar dwoul db e ver y costl y
wa s base do

ngenera l knowledg e an dth e experienc e o f some Committe e members . However , t o giv e al l Committe e member s some perspectiv e onth e potentia l costs , EPA

provide da

nestimat e o f th e annualize dcos t fo r retrofittin g a n existin g pum

pwit ha DM S system . Thi s estimat e showe dth e cos t woul db e approximatel y

$2,200/yea r (199 0 dollars ) fo r eac hpump . Inpreviou s rulemakings , EP

A ha s estimate dtha t a requiremen t o f DM S onpump s ha s a n incrementa l cos t effectivenes s ove r a 10,00 0 pp m LDA Rprogra m

o f $5,600/megagra m

o f tota l VO C (197 8 dollars) , whic hi s comparabl e t o approximatel y

$15,000/megagra m

i ncurren t dollars . Som e Committe e member s expresse da

nadditiona l concer ntha t a DM S equipmen t standar dwoul dhav e significan t economi c effect s o nsmal l producers . Sinc e th e Committe e though t
a performanc e standar dcoul db e develope dfo r pumps , th e expecte dcost s o f a DM S equipmen t standar dwer e no t evaluated . T o establis ha performanc e standar dtha t woul dreflec t MAC T fo r pumps , th e Committe e considere dth e performanc e capabilitie s o f SM S (an dpacke d seals ) compare dt o th e performance , applicability , an dcos t o f DMS . 1 6Discussion s amon g th e Committe e members , chemica l industr y representatives , an dpum psea l manufacturer s lea dt o th e conclusio ntha t i t i s no t possibl e t o identif y precisel y

bes t performanc e level s achievabl e b y SM S an dthat , althoug hadvance s i

ntechnolog y

coul dreasonabl y

b e expecte dove r th e nex t 5 years , th e limit s o nthes e advance s coul dno t b e established . Becaus e o f technica l limitation s o nth e us e o f DM S onpump s i nfood/medica l servic e an d th e us e o f mechanica l seal s o npump s handlin g polymerizin g monomers , th e Committe e agree dt o establis hseparat e performanc e standard s fo r pump s i n thos e two services . Fo r pump s i

ngenera l service , th e Committe e agree dtha t 100 0 pp m represente da performanc e targe t reflectin g MAC T an dtha t repai r o f pump s wit h

a lea k rat e les s tha n200 0 pp m woul dresul t i

nsignifican t an

dcostl y maintenance , withou t an y attendan t emissio nreduction . Therefore , 200 0 pp m
wa s establishe da s th e concentratio na t whic hrepai r i s required . Th e Committe e als o conclude dtha t a 1 0 percen t lea k frequenc y (o r 3 leakin g pumps ) i s th e appropriat e poin t t o impos e a qualit y improvemen t program tha t include s
a mandator y

replacemen t provision . O nbalance , i t wa s believe dtha t thi s combinatio no f requirement s woul dprovid e th e time an dincentiv e neede dt o achiev e bes t performanc e fro m SMS , woul dallow

us e o f SM S wher e the y ca n achiev e lo

w emissions , an

dwoul dallow

us e o f bot hSM S an

dDM S pumps , a s appropriate , t o achiev e th e standard . Fo r pump s i

nfood/medica l service , th e Committe e selecte d200 0 pp m an d 1 0 percen t lea k frequenc y a s th e performanc e level . Th e lea k definitio nwa s
se t a t 200 0 pp

m t o accoun t fo r th e limite d applicabilit y o f DM S pump s an

dth e uncertaint y

tha t SM S seal s coul dachiev e lowe r performanc e level s withou t excessiv e replacement s i nthi s service . Th e Committe e als o agree dtha t

1 7P.2 1



### processe s wit hpump s i nfood/medica l servic e tha t excee d1 0 percen t leakin g pump s woul dno t b e subjec t t o th e mandator y replacemen t provision s i nth e qualit y improvemen t program . Fo r pump s handlin g polymerizin g monomers , th e Committe e selecte d500 0 pp m an d1 0 percen t lea k frequenc y fo r th e performanc e level . Thi s decisio nwa s base donth e lac k o f dat a an duncertaintie s ontb e limit s o f performanc e o f SM S o r packe dseal s i

nthi s service . I t wa s als o agree dtha t facilitie s tha t
excee d1 0 percen t lea k frequenc y woul dno t b e subjec t t o th e mandator y replacemen t provisio no f th e qualit y improvemen t program . Connectors . Provision s fo r a LDA Rprogram

fo r connector s wer e develope d afte r th e Committe e generall y agree dtha t connector s coul db e a significan t
sourc e o f emission s a t a well-controlle dplan t an dtha t emission s coul db e reduced . Inth e developmen t o f thes e provisions , th e Coiranitte e considere dth e dat a summarize dinTabl e 1 an dth e contributio no f connecto r emission s t o tota l emission s fo r severa l EO/B D proces s units . Thes e dat a showe dconnecto r lea k frequencie s a s higha s 3 percent , a t a lea k definitio no f 10,00 0 ppm , an d contributio nth e majorit y o f th e tota l emissions . Becaus e some EO/B D unit s ha d0 percen t leakin g connector s a t variou s lea k definitions , includin g 25 0
an d10,00 0 ppm , th e Committe e conclude dtha t connecto r leak s ca nb e controlle d t o lo w levels . Th e genera l view wa s tha t th e relativel y hig hlea k rate s observe da t some proces s unit s wa s a resul t o f infrequen t o r n o inspection s
an dmaintenance . A

LDA Rprogram

wa s establishe dto ensur e tha t low lea k frequencie s ar e attained . Indevelopmen t o f thes e provisions , th e Committe e agree dtha t LDA Rca n reduc e connecto r lea k frequencie s an dtha t assurin g MAC T performanc e require s les s frequen t monitorin g tha ni s necessar y fo r pump s o r valves . Les s frequen t

1 8

### monitorin g i s neede dbecaus e flange s an dothe r connector s hav e no movin g part s
an donc e repaire dthe y

shoul dremai nlea k fre e fo r extende dperiods . Informatio nprovide db

y industr y

member s o

nth e Committe e indicate dtha t a numbe r o f action s ca nb e take nt o reduc e o r eliminat e leaks . Inmos t cases , i t
wa s expecte dtha t tightenin g th e flang e bolt s woul deliminat e th e leak . I t wa s als o expecte dtha t i

nothe r case s i t ma y

b e necessar y

t o replac e th e gaske t o r t o correc t fault y

alignmen t o f surfaces . Thes e latte r case s ar e expecte dt o b e relativel y

infrequent . Th e Committee , therefore , decide dtha t a nannua l bas e program wa s th e maximu

m frequenc y

tha t wa s reasonable . Th e Committe e als o conclude dtha t proces s unit s tha t demonstrat e sustaine dperformanc e a t th e leve l o f th e standar dshoul db e allowe dt o monito r les s frequentl y tha n annually . Thi s concep t i s simila r t o th e skip-perio dprovision s fo r valve s i n th e existin g equipmen t lea k regulations . Thi s approac hi s consisten t wit h qualit y contro l principle s an dth e Committe e conclude dtha t thi s approac hwil l
ensur e MAC T performance . Th e Committe e selecte dth e performanc e leve l an dlea k definitio n considerin g th e dat a from th e EO/B D units , th e Texa s 50 0 pp m LDA Runits , and th e genera l conclusion s draw nfrom th e Committee' s discussions . Thes e dat a
an dth e fac t that , i

npractice , low

lea k frequencie s wer e achievabl e persuade d th e Committe e tha t a lea k definitio no f 50 0 pp m an da performanc e limi t o f 0. 5 percen t leakin g connector s woul dreflec t MACT . Proces s unit s tha t hav e 0. 5 percent , o r greater , leakin g connector s ar e require dt o implemen t a nannua l LDA Rprogram

fo r connectors . Proces s unit s tha t hav e les s tha n0. 5 percen t leakin g connector s ar e allowe dt o monito r al l connector s i na biennia l o r quadrennia l program .

1 9

_X____D