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# OAR Box 

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## A-90-1 9 ll-F-3 1

TO : TroyHillier , OMB FROM : Jan Meyer , EP A DATE : Octobe r 23 , 199 2 Attache d pleas e fin d the revise d Sectio nVII . A(rational e fo r Subpar t G) . Th e revise d languag e reflect s change s mad e t o the proces s vent s discussion s a s wel l a s clarifying changes . W e ar e stil l making clarifying edit s t o thi s discussion . Th e attache d i s being provide d t o giv e yo u an opportunit yt o star t th e revie wbefor e yo u receiv e th e complete , consolidate d revise d packag e late r today . I tried repeatedl yFrida yevening an d ove r the weekend t o fa xyo u thi s material . Becaus e your fa x machin e wa s no t on , I wa s no t abl e t o sen d thi s t o yo u unti l now . Yo u maynotic e some forma t an d editoria l difference s betwee n th e attache d draf t an d the 10/ 6 draft . Thes e difference s shoul d b e ignored an

d wil l no t exis t i n th e fina l version . Pleas e cal l m e a t (919 ) 541-525 4 i f yo u hav e an yquestion s o r wan t t o discus s the draf t revisions .



### 1992P. 3

VII . RATIONAL E FO RPROVISION S I NSUBPAR T G A . Selectio no f Emissio n Contro l Requirement s Th e Ac t specifie s tha t th e EP Amus t selec t emissio n contro l requirement s fo r source s bein g regulate d unde r Sectio n11 2 tha t ar e a t leas t a s stringen t as , o r mor e stringen t than , th e emissio n contro l identifie d a s th e floor . A s a result , EP Abega n th e proces s o f selectin g contro l requirement s fo r th e HO Nby determinin g th e floo r fo r th e source s tha t woul d b e subjec t t o th e HON . Onc e th e floo r wa s establishe d fo r bot hne wan d existin g sources , EP Aconsidere d additiona l contro l fo r eac hkin d o f emissio npoin t and th e sourc e a s a whol e takin g int o consideratio n th e criteri a enumerate d i n Sectio n 112(d ) o f th e Act : cos t o f achievin g suc hreductions , anynon-ai r qualit y healt hand environmenta l impacts , and energ yrequirements . Thi s sectio n o f th e preambl e describe s th e proces s EP Ause d t o determin e th e floo r fo r ne wand existin g sources , th e criteri a EP Ause d t o evaluat e additiona l contro l requirement s and th e outcom e o f EPA' s floo r analysi s and contro l selectio nproces s fo r eac hkin d o f emissio n poin t i n th e source . Sectio nV o f thi s preambl e give s a novervie wo f th e dat a bas e use d i nthi s proces s and memorand a i n th e docke t provid e a detaile d descriptio no f th e methodolog yand dat a use d t o deriv e th e floor s fo r ne wand existin g sources . 1 . Overvie wo f th e Proces s an d Factor s Considere d Fo r SOCMI , wha t distinguishe s a well-controlle d facilit yi sP. 4

no t onl ythe typ e o f contro l equipmen t used , bu t als o the numbe r o f emissio n point s that.ar e controlled . Facilitie s diffe r i n the number , combination , an d design o f thei r chemica l manufacturing processes ; the productio ncapacitie s o f thei r processes ; the particula r chemical s manufactured ; an d the contro l equipmen t used . Consequently , althoughSOCM I consist s o f simila r kind s o f emissio n point s an

d th e same control s ar e applicable , actua l emission s an

d characteristic s o f SOCM I facilitie s var ywidel y fro mplan t sit e t o plan t site . Du e t o thi s diversity , n o "typical " sourc e coul d b e identifie d tha t woul d b e representative acros s th e sourc e category . Thi s diversit yaffecte d the approac h use d t o defin e the floo r fo r existing an d newsources . Specifically , thi s diversit ypreclude d the us e o f mas s emissio n rat e a s a measur e o f performanc e sinc e a mas s rat e base d ona n "average " sourc e coul d requir e n o contro l a t some source s an d b e unachievabl e a t othe r sources . Therefore , i t wa s necessaryfo r EP At o combin e dat a on contro l efficiencie s achieve d o neachkin d o f emissio n poin t t o develop the source-wid e floor . Thi s proces s can b e expecte d t o resul t i n a floo r determinatio n tha t i s a t leas t a s stringen t a s tha t whic hwoul d have bee ngenerate d wit h actua l sourc e wid e data . Th e informatio n EP

Ause d i n determining th e source-wid e floo r consiste d o f the estimate s o f th e numbe r an d characteristic s o f th e mode l emissio n points , th e emissio n contro l requirement s expecte d fo r eac hemissio n poin t i n the absenc e o f thi s standard , an d th e expecte d contro l efficiencie sP. 5

fo r th e contro l technology . A s discusse d earlie r i n thi s notice , EP Ause d dat a on the contro l requirement s i n existing Stat e an d Federa l regulation s t o identif ythos e emissio npoint s tha t mus t b e controlle d an

d t o identif yth e require d controls . (Th e regulation s wer e use d a s a surrogat e fo r actua l dat a on the contro l level s achieve d i npractice . I nthi s analysis , EP A assume d al l facilitie s woul d b e i ncomplianc e wit hal l applicabl e regulations. ) Th e requirement s i n existing Stat e an d Federa l regulation s wer e used t o estimat e the control s tha t woul d b e i n plac e on the mode l emissio n point s a t th e time o f promulgatio no f th e HON . I n th e analysi s o f existing regulations , EP Afoun d tha t wher e Stat e an

d Federa l rule s requir e control s on emissio n points , theytypicall yrequir e us e o f the mos t effectiv e contro l technologie s (or performanc e levels ) tha t ar e generall y applicable . Thes e contro l technologie s ar e th e same a s the control s require d i n previou s NSP S standard s fo r the SOCM I an d ar e widel yaccepte d b yth e industr

yan d regulatoryagencie s a s technologie s appropriat e a s base s fo r emissio nstandards . Thes e contro l technologie s hav e bee n designate d a s th e "referenc e contro l technologies " fo r th e purpos e o f the standard being propose d today . Th e referenc e contro l technologie s (an d thei r performanc e levels ) specifie d i n the propose d standard reflec t informatio n an d knowledg e o f SOCM I tha t EP Aha s bee n developing sinc e 1976 . Throughdevelopmen t o f standard s unde r Sectio n11 1 an dP. 6

Sectio n 11 2 fo r SOCMI , EP Aha s develope d extensiv e knowledg e o f th e rang e o f demonstrate d contro l technologie s applicabl e t o SOCM I an d th e expecte d performanc e o f thes e technologies . Th e selecte d technologie s identifie d a s th e basi s fo r th e referenc e contro l requirement s are :

9 8 percen t combustio n contro l fo r proces s vent s and transfe r operations . Fo r halogenate d streams , 9 8 percen t contro l i s achieve d usin g a therma l incinerator , boiler , o r proces s heater , plu s aci d ga s scrubbing . Fo r nonhalogenate d streams , 9 8 percen t contro l i s achieve d usin g eithe r a therma l incinerator , a flare , o r a boile r o r proces s heater . 9 5 t o 9 8 percen t volatil e organi c HA P contro l o f wastewate r (fo r highl yvolatil e chemicals ) o r contro l t o a targe t concentratio n usin g a controlle d stea m strippe r o r othe r treatmen t technology . Th e actua l contro l depend s o n individua l chemica l properties , approximatel y9 5 percen t contro l o f storag e tank s throug htan k modification s o r applicatio no f a vapo r recover ysyste mand contro l devices . Th e actua l efficienc ydepend s o n th e individua l chemica l properties . Th e abov e contro l technologie s an d wor k practice s wer e selecte d a s th e technologica l basi s fo r th e standar d sinc e EP A wa s no t awar e o f anydemonstrate d contro l technologie s and operation s tha t woul d perfor mwit hhighe r efficiencie s and als oP. 7

b e universall yapplicabl e t o SOCMI . I nman ycases , applicatio n o f the referenc e contro l technolog yi s alread

yrequire d b

yeithe r a n existing Stat e o r Federa l regulation . T o determin e the source-wid e floo r fo r existing sources , EP A nex t examine d the supporting informatio n t o identif ythe characteristic s o f emissio n point s whic hhad a t leas t 1 2 percen t controlle d b

yth e referenc e contro l technology . Thi s analysi s wa s don e fo r eachkin d o f emissio npoint . Th e characteristic s use d t o identif ygroup s o f emissio n point s wer e physica l parameter s suc ha s flowrate , HAP concentration , an d vapo r pressure . Al l th e identifie d group s o f emissio npoint s controlle d b

ythe referenc e contro l technolog ywer e the ncombine d t o defin e th e weighte d averag e % reductio n achieve d b ythe bes t performing 12 % o f the sources . (Becaus e o f the assumptio no f a singl e contro l efficiencyfo r eac hreferenc e technology , the averag e o f th e bes t performing 12 % i s th e same a s th e performanc e o f th e 12t hpercentile. ) Th e result s o f thi s analysi s ar e describe d i n th e nex t sectio n a s par t o f th e discussio no f specifi c consideration s fo r eac hkin d o f emissio npoint . Asimila r metho d wa s use d t o determin e th e source-wid e floo r fo r newsources . Fo r eac hkin d o f emissio n point , the characteristic s o f th e smalles t emissio npoin t controlle d b ythe referenc e contro l technolog ywa s identifie d a s determining th e bes t controlled . Again , th e source-wid e floo r wa s determine d b y the combinatio n o f contro l level s fo r al l emissio npoints . Onc e the floor s wer e established , EP Aconsidere d whethe r t oP. 8

establis ha standard tha t require s a n emissio n reductio n tha t i s mor e stringen t than the floor . I nselecting th e standard , EP A considere d the magnitud e o f the reductio n i nHA Memissions , th e cos t an d economi c impacts , energ yimpacts , non-ai r qualit yhealt h impacts , an

d othe r environmenta l impacts . Th e objectiv e i nthi s consideratio n i s t o achieve the maximu m degre e o f emissio n reductio n tha t doe s no t resul t i n unreasonabl e economi c o r othe r impacts . A s wit hth e floors , EP Adetermine d the standard fo r th e sourc e b

ycombining selecte d contro l level s fo r eac hkin d o f emissio n point . The nex t sectio n present s th e additiona l contro l level s considere d fo r eac hkin d o f emissio n poin t an d the basi s fo r th e selecte d level . 2 . Alternativ e Contro l Level s an d Selectio n o f Requirement s I n th e selectio n o f th e propose d standard , EP Afirs t considere d alternative contro l level s fo r eac hkin d o f emissio n poin t an

d selecte d contro l requirement s considering th e overal l impact s o f the grou p o f decision s a s wel l a s the merit s o f the individua l decision s i n ligh t o f th e statutorycriteria . I nthe firs t step o f th e process , regulatoryalternative s wer e develope d fo r eachkin

d o f emissio npoint . Thes e alternative s differe d onl yi n the numbe r o f emissio npoint s tha t woul d b e controlle d b y the referenc e contro l technology . Regulatoryalternative s wer e develope d using informatio n fo r th e chemica l processe s tha t coul d b e characterize d sufficientl yt o permi t assignmen t o f mode l emissio n points . Approximatel y9 7 percen t o f the nationwid eP. 9

chemica l productio n capacit yi s associate d wit hthes e well

characterize d processes . Th e emissio n reductio nan d contro l cos t estimate s fo r th e regulatoryalternative s ar e summarize d i n Table s 5 an

d 6 . Tabl e 5 provide s th e contro l cost s an d emissio n reduction s associate d wit halternative contro l level s considere d fo r existing source s i n the sourc e category . Tabl e 6 present s the same informatio n fo r th e alternative contro l level s considere d fo r newsource s i n th e sourc e category . Th e estimate s presente d i n Table s 5 an d 6 diffe r fro

mthe estimate s summarize d i n Sectio n I

V o f thi s notic e becaus e thos e earlie r estimate s includ e an extrapolatio n t o accoun t fo r processe s tha t coul d no t b e modeled . I n selectio n o f th e propose d standard , EP Aconsidered : (1 ) th e technica l feasibility ; (2 ) economi c impact s an d feasibility ; (3 ) the magnitud e o f th e emissio n reduction ; (4 ) the qualit yo f th e emissio n an d cos t estimates ; (5 ) consistencywit h previou s NSP S an

d NESHAP standards , CTG' s an d othe r regulations ; an d (6 ) an

d othe r environmenta l an d energ yimpacts . Based on consideratio n o f thes e factors , EP Aselecte d a standard tha t woul d ensur e a significan t reductio n i nHAP emission s fro mthe SOCMI . Th e EPA' s analysi s estimate s tha t th e selecte d standard woul d reduc e HAP emission s fro mth e four kind s o f emissio npoint s b y322,00 0 megagram s pe r yea r fro mexisting source s an d 63,00 0 megagram s pe r yea r fro mnewsource s i nth e fift hyea r o f th e standard . Thi s represent s an emissio n reductio no f abou t 8 6 percen t fo r existing source s (8 7 percen t fo r newsources ) i nP.1 0

compariso n t o th e emission s tha t woul d have occurre d withou t th e standard . Th e tota l nationwid e annua lP.1 1

Tabl e5P.1 2

Tabl e6

1 0P.1 3

cos t associate d wit hthi s emissio nreductio n i s estimate d t o be abou t $9 1 millio n ($28 0 pe r megagram) . (A s state d above , thes e estimate s represen t processe s sufficientl ywel l characterize d t o assign model s an

d ar e lowe r thanth e nationa l number s presente d i n Sectio n IV. ) Th e contro l requirement s an d applicabilit ycriteri a fo r storag e vessel s an

d transfe r operation s woul d als o resul t i n significan t emissio n reductions , relative t o the curren t emissio n level s fo r thes e kind s o f emissio n points . a . Proces s vents : existing sources . Th e selectio n o f a criterio n t o us e i n identifying th e grou p o f proces s vent s no t controlle d wit hth e referenc e contro l technolog ywa s base d on consideratio n o f th e variou s parameter s tha t affec t emissio n rate s (flo

wrate , HAP concentration , ne t heating value , an d corrosio n properties) . Thes e parameter s ar e highl yvariabl e fro m on e proces s t o anothe r depending onth e constituent s o f th e ven t stream . Therefore , i t i s no t appropriat e t o selec t an yon e o f themo r eve n an

yspecifi c combinatio n o f al l o f themsinc e the combinatio n woul d b e differen t fro mon e proces s t o another . A surrogat e measur e fo r thes e parameter s tha t influenc e whethe r o r no t a ven t strea

mi s controlle d an

d th e specifi c contro l technolog

yapplie d i s cos t effectiveness . Cost-effectivenes s value s can b e use d t o reflec t al l possibl e combination s o f thes e parameter s an

d th e cos t o f controlling stream s wit hthe referenc e contro l technolog

y(9 8 percen t efficien t combustio ncontrol) . Us e o f th e singl e criterio no f cos t effectivenes s woul d resul t i n 1 1P.1 4

a mor e understandabl e an d enforceabl e rule . Th e procedur e used t o defin e the group s o f proces s vent s wa s t o ran k al l proces s vent s i nth e dat a bas e fro mhighes t t o lowes t cost-effectivenes s o f contro l an d t o determin e the poin t wher e les s than 1 2 percen t o f th e vent s wer e controlled . Thi s analysi s showe d tha t th e dividing line betwee nthe group s occurre d a t a cos t effectivenes s o f $1,500/Mg . O f th e proces s vent s wit hcos t effectivenes s value s o f les s than$1,500/Mg , 4 4 percen t wer e controlle d wit hth e 9 8 percen t efficien t combustio ndevices . Th e grou p o f proces s vent s wit hcos t effectivenes s value s o f $1,500/Mg an

d highe r had fewe r than1 0 percen t controlle d a t baseline . Thus , al l proces s vent s wit hcos t effectivenes s o f $1,500/Mg an

d highe r woul d b e considere d uncontrolle d i nthe determinatio n o f the source-wid e floor . I n selectio n o f th e propose d standard fo r existing sources , EPAbelieve s tha t a leve l o f emissio n reductio nfro m proces s vent s mor e stringen t than th e leve l associate d wit hth e floo r i s achievable . Th e EPAi s proposing t o requir e th e contro l leve l i n Optio n 2 , whic hha s an incrementa l cost-effectivenes s o f $1,800/Mg ($1635/ton ) an d woul d requir e contro l o f vent s tha t have cost-effectivenes s value s o f u p t o $2,000/Mg ($1,814/ton) . AlthoughEP

Ai s proposing thi s specifi c contro l level , EP Ai s requesting commen t o n Option s 1 through4 . Thes e option s span the rang e o f contro l fo r vent s wit hTR E cost-effectivenes s value s o f u p t o $1,500/Mg ($l,360/ton ) i nOptio n 1 (th e floo r component ) t o thos e wit hTR E cost-effectivenes s value s o f u p t o $5,000/M

g 1 2P.1 5

($4,540/ton ) i n Optio n 4 . Th e EP Aanticipate s tha t i n consideratio n o f the fina l decisio n EP Awil l give mor e weigh t t o Option s 1 through3 . Th e Optio n 2 contro l leve l wa s selecte d i n the propose d rul e base d onconsideration s specifi c t o the SOCM I categoryan

d woul d no t necessaril yb e appropriat e fo r othe r sourc e categories . Therefore , i t shoul d no t b e viewe d a s a preceden t fo r decision s o n othe r standards . Th e EP Arecognize s tha t ther e ar e differing view s regarding the appropriat e criteri a fo r determining the contro l level . Consequently , EP Ai s requesting comment s on th e appropriatenes s o f particula r contro l choice s withi n the rang e o f option s describe d above an d ask s tha t commenter s provid e supporting rational e fo r thei r preferences . Th e EP Aselecte d the propose d contro l leve l considering th e emissio n reductio n achieve d b yth e alternative contro l option s an d considering th e criteri a enumerate d i nSectio n112(d ) o f the Act : the cos t o f achieving suc hemissio n reduction ; an ynon-ai r qualit yhealt han

d environmenta l impacts ; an d energ y requirements . A s a matte r o f genera l policyi ndecision s t o selec t contro l level s above the floor , EP Abelieve s tha t the cost-effectivenes s o f control s an d a compariso no f benefits , bot h quantifiabl e an

d nonquantifiable , an d cost s i s a primar y consideration . I n an ysuc hcompariso no f cost s an d benefits , th e uncertaintie s associate d wit hth e benefi t an d cos t estimate s shoul d b e characterized . I n thi s propose d rulemaking , however , EPA' s abilit yt o d o sucha compariso n wa s severel ylimite d du e t o th e limite d dat a on 1 3P.1 6

the characteristic s o f th e emissio n source s an d th e complexit yo f the SOCM I category . Apreliminaryassessmen t o f the benefit s o f th e potentia l emissio n reduction s wa s prepare d using th e availabl e data . However , becaus e o f the dat a limitation s cite d above , EP

Adoe s no t believ e tha t th e analysi s provide s a n adequat e basi s fo r decisionmaking . Thi s analysi s ha s bee nplace d i n Docke t A-90-19 . Th e EPAinvite s commen t o nthi s analysis , it s usefulnes s an

d defensibility , an d request s the submitta l o f dat a on method s tha t coul d improve th e analysis . Th e EP Awil l review an ysuc hcomment s ari d dat a an

d will , t o th e exten t practicable , evaluat e thei r implication s fo r th e ris k assessmen t prio r t o the fina l rule . Despit e th e difficult yo f estimating quantitativ e benefit s fo r thi s rulemaking , du e t o the complexit yo f the sourc e category , dat a limitations , an d timing o f the rule , EP Aremain s committe d t o evaluating benefit s a s wel l a s cost s associate d wit h decision s t o g o above th e floo r i nfutur e MAC T standards . Th e EP Aals o intend s t o reviewcost-effectivenes s o f decision s a s par t o f thes e futur e rulemakings . Du e t o thi s lac k o f a benefit s assessment , EP Aused benchmark s fro

mpreviou s ai r toxic s regulator ydecision s an

d pas t ai r toxic s benefit s studie s a s a surrogat e measur e fo r benefit s consideration s i n the decisio n o nthe propose d contro l level . Th e informatio n considere d consiste d o f the Benzen e NESHAP decision s ( F

R) an

d the Viny l Chlorid e NESHAP ( F R) . Fo r example , on e decisio ntha t reflecte d consideratio n o f balancing emissio n reduction s agains t cost s wa s th e benzen e 1 4P.1 7

storag e standar d ( F R) . I ntha t decision , th e cost effectivenes s o f th e selecte d optio nwa s estimate d t o rang e fro m $128/M g t o $909/M g i n 1982 $ ( $160/M g t o 1,100/M g i n1989 $ ) . Althoug hth e cost-effectivenes s measure s fro mpas t decision s wer e considere d i n selectio n o f th e propose d contro l level , EP A als o considere d th e difference s betwee nthi s propose d rul e and th e earlie r decision s o nbenzen e an d viny l chloride . Thi s rul e applie s t o emission s o f ove r 10 0 HAP' s whil e th e earlie r rule s onl yaddresse d cance r healt heffect s o f a singl e HA P (i.e. , benzen e o r viny l chloride) . Becaus e manyo f th e 10 0 HAP' s emitte d fro m

HO Nfacilitie s hav e noncance r healt heffects , ther e ar e question s abou t th e relevanc e o f th e pas t decision s t o thi s proposal . Additiona l factor s wer e considere d i nth e selectio no f th e propose d contro l level . Thes e f.actor s includ e th e magnitud e o f th e emissio n reduction , th e cos t o f thi s reduction , consistenc y wit hpas t decisions , locatio no f facilitie s nea r populatio n centers , an d othe r environmenta l benefit s fro mth e control . Th e consideratio no f thes e factor s i s summarize d below . Existin g sourc e proces s vent s ar e th e singl e larges t contributo r o f HA P emission s fro mth e SOCM I sourc e category . Th e additiona l emissio n reductio n beyon d tha t achieve d a t th e floo r tha t woul d resul t fro m th e propose d contro l leve l i s abou t 1,60 0 Mg/yr , which , du e t o th e magnitud e o f th e baselin e emissions , represent s 0.7 % o f th e emissio nreductio nachieve d a t th e floor . Thi s additiona l contro l ha s a cos t effectivenes s o f 1 5P.1 8

$1,800/Mg o f HAP an d wit ha TR E equivalen t t o a cost effectivenes s o f $2,000/Mg . Th e cos t o f thi s additiona l contro l (alon g wit hthe cos t o f the othe r propose d contro l requirements ) i s estimate d t o resul t i nles s than a 3 % pric e increas e fo r SOCM I chemicals . Th e EP

Arequest s comment s on whethe r the cost s o f the selecte d contro l requirement s ar e reasonabl e an d the basi s fo r the commenter s assessmen t o f the costs . The EP Ai s requesting commen t o na rang e o f contro l option s becaus e o f th e uncertaintie s i nth e measur e o f th e benefit s o f contro l an

d th e uncertaintie s i n th e cos t tha t woul d actuall yb e experienced . Becaus e o f th e conservativ e assumption s use d t o develop the contro l cost s an d th e TR E forma t o f th e ven t provisions , i t i s unlikel ytha t an ysourc e woul d actuall yincur cos t a t th e TR E leve l (th e criterio n fo r defining vent s tha t mus t appl ycontrol ) tha t i s equivalen t t o $2,000/Mg ($1,814/ton) . Th e cos t analysi s use d i n developing th e supporting informatio nfo r thi s standard wa s base d on us e o f a dedicate d contro l devic e fo r eac hvent . Actua l cost s woul d b e lowe r wher e on e devic e coul d be used t o contro l emission s fro msevera l vents . Th e cos t o f contro l woul d als o b e lowe r i nthos e case s wher e i t i s feasibl e t o us e a boile r o r proces s heater . Finally , th e provision s ar e structure d using a TR E indexapproach . Sinc e th e standard i s i n a TR E format , man

yfacilitie s ma

yb e abl e t o us e produc t recovery t o chang e ven t strea mcharacteristic s s o tha t theyar e belowthe relevan t applicabilit ycriteria . Thi s flexibilit yi s expecte d t o allowsom

e source s throughchange s i nequipmen t o r operation s t o 1 6P.1 9

lowe r thei r cos t o f compliance . A s a result , the impact s analysi s ma

yoverstat e the cost s o f complying wit hthe propose d contro l requirement . The EP Asolicit s comment s concerning whethe r the contro l cost s fo r proces s vent s ar e overestimate d an d th e exten t o f the overestimate . b . Proces s vents : newsources . Th e analysi s o f the dat a bas e als o showe d tha t th e maximu mdegre e o f emissio nreductio n being achieve d b

yth e best-controlle d ven t occur s a t a cos t effectivenes s valu e o f $11,000/Mg ($9,980/ton) . I nth e determinatio n o f th e proces s ven t componen t o f th e source-wid e floo r fo r a newsource , vent s wit ha cos t effectivenes s valu e fo r contro l o f $11,000/Mg ($9,980/ton ) woul d b e controlled . Fo r th e standard fo r newsources , EP Aconsidere d selecting a leve l o f emissio n reductio nmor e stringen t thanth e leve l associate d wit hthe source-wid e floor . However , a standard mor e stringen t than th e floo r componen t i s no t being propose d becaus e the cost s wer e considere d highgive n th e ver ysmal l additiona l emissio n reductio n available . Th e additiona l contro l woul d achieve a

n additiona l emissio nreductio no f abou t 10 0 Mg/yr a t a cos t o f abou t $ 5 million/yr . Therefore , the contro l leve l associate d wit hthe source-wid e floo r wa s considere d t o represen t th e maximu

mreductio n achievabl e considering cos t an d othe r impacts . Th e propose d standard fo r newsource s reflect s the floo r leve l o f contro l fo r newvents . c . Storag e vessels : existing sources . I n th e analysi s o f th e dat a bas e t o determin e th e storag e vesse l component s o f th e 1 7P.2 0

source-wid e floor , EP Adivide d th e populatio no f mode l vessel s int o thre e siz e ranges . Th e siz e range s were : 3 8 m3 t o 7 5 in 3 (10,00 0 t o 20,00 0 gal ) (small) ; 7 5 t o 15 1 m3 (20,00 0 t o 40,00 0 gal ) (medium) ; an d greate r thano r equa l t o 15 1 m 3 (40,00 0 gal ) (large) . Th e firs t two o f th e range s ar e the two smalles t mode l vesse l size s i n the dat a bas e an d the third rang e i s th e combinatio n o f th e remaining four mode l vesse l siz e ranges . Th e large r siz e rang e vessel s wer e aggregate d int o one grou p becaus e n o difference s base d o nvesse l capacit ywer e expecte d fo r the vessel s exceeding 40,00 0 gallon s capacity . Onl y on e Stat e regulatio n distinguishe s among vessel s wit hcapacitie s greate r than 15 1 m 3 (40,00 0 gal ) an d non e o f th e greate r than 15 1

m 3 (40,00 0 gal ) storag e vessel s i n th e dat a bas e ar e affecte d b y thos e requirements . Consequently , separat e analysi s o f eacho f th e large r capacit yrang e mode l vessel s woul d provid e the same result s a s a combine d analysis . Th e paramete r use d i n th e analysi s t o determin e the storag e vesse l component s o f the source-wid e floo r wa s the vapo r pressur e o f th e liqui d being stored . Vapo r pressur e i s on e o f thre e majo r factor s tha t mos t influenc e emission s fro m storag e vessel s an d potentia l emissio n reductions . Furthermore , vapo r pressur e i s commonl ya prime determining facto r i n whethe r o r no t a vesse l i s controlled . Fo r eachsegmen t o f th e storag e vesse l population , th e procedur e use d t o defin e component s fo r the source-wid e floo r wa s t o ran k storag e vessel s fro mlowes t t o highes t vapo r pressure . 1 8P.2 1

Next , the vapo r pressur e a t whic ha t leas t 1 2 percen t o f th e vessel s i s controlle d b ythe referenc e contro l technolog ywa s determined . Th e analysi s showe d tha t mor e than 1 2 percen t o f the mediu man d larg e vessel s storing liquid s wit hvapo r pressure s o f 13. 1 kP a (1. 9 psia ) an d highe r ar e controlle d wit hthe referenc e technology . O f th e vessel s storing liquid s wit hvapo r pressure s o f 13. 1 kP a (1. 9 psia ) an d higher , abou t 3 0 percen t o f the mediu m vessel s an

d 4 5 percen t o f the larg e vessel s wer e controlle d wit h th e referenc e technology . Therefore , the storag e vesse l component s o f th e source-wid e floo r ar e contro l o f vessel s 7 5 m3 (20,00 0 gal ) an

d highe r tha t stor e liquid s wit hvapo r pressure s o f 13. 1 kP a (1. 9 psia ) an d higher . Fo r smal l vessels , th e analysi s o f th e dat a bas e showe d tha t onl y6 percen t o f th e vessel s wer e expecte d t o b e controlle d wit hthe referenc e technology . Therefore , sinc e les s than12 % o f th e smal l vessel s ar e controlle d wit hthe refeerenc e contro l technolog ythe smal l vesse l componen t o f th e source-wid e floo r i s n o control . Fo r eac ho f the thre e population s o f storag e vessels , EP A considere d severa l alternative level s o f emissio nlimitation . Th e alternative s differe d i nthe vapo r pressure s o f the liquid s tha t woul d requir e contro l an d range d fro

mth e vapo r pressur e associate d wit hthe componen t o f the source-wid e floo r (i.e. , 13. 1 kP a [1. 9 psia] ) t o vapo r pressure s o f 0.0 7 kP a (0.0 1 psia) . Afte r considering th e alternative s an d the associate d impacts , EP Apropose s t o requir e th e following storag e vessel s b e equippe d wit hth e referenc e contro l technology : (1 ) vessel s wit ha 1 9P.2 2

capacit ygreate r tha no r equa l t o 15 1 m 3 (40,00 0 gal ) storin g HAP' s wit hvapo r pressure s o f 5. 2 kP a (0.7 5 psia ) o r greate r and (2 ) vessel s wit ha capacit ygreate r tha no r equa l t o 7 5 ir T (20,00 0 gal ) storin g HAP' s wit hvapo r pressure s o f 13. 1 kP a (1. 9 psia ) and greater . N o contro l requirement s ar e bein g propose d fo r storag e vessel s wit hcapacitie s les s tha n7 5 m 3 (20,00 0 gal) . I n th e selectio no f thes e propose d contro l requirements , EP A believes , base d o nth e availabl e data , tha t a nemissio nreductio n mor e stringen t tha n th e leve l associate d wit hth e floo r componen t fo r larg e vessel s i s achievabl e considerin g th e statutor y criteria . Th e EP Aals o believe s tha t n o emissio nlevel s mor e stringen t tha n th e leve l associate d wit hth e floo r component s fo r medium and smal l vessel s ar e achievabl e considerin g th e statutor y criteria . Th e statutor ycriteri a considere d i nselectio no f th e propose d contro l requirement s wer e th e magnitud e o f th e emissio n reductions , th e cos t and economi c impacts , energ yimpacts , non ai r qualit yhealt himpacts , and othe r environmenta l impacts . Th e specifi c consideration s o f th e statutor yfactor s i neac ho f thes e decision s ar e summarize d below .

Th e propose d contro l requirement s fo r larg e storag e vessel s containin g liquid s wit hHA P vapo r pressure s o f 5. 2 kP a (0.7 5 psia ) o r highe r ar e estimate d t o achiev e a nemissio n reductio no f 4,80 0 Mg/y r (5,28 0 tons/yr ) o f HAP' s compare d t o emission s tha t woul d occu r withou t th e standard . Thi s represent s a 4 8 percen t reductio n o f emission s fro mthi s segmen t o f th e SOCM I storag e vesse l population . Th e annua l cos t t o achiev e thi s 2 0P.2 3

reductio n i s abou t $7. 3 millio n an d th e incrementa l cost effectivenes s o f the contro l beyon d the floo r i s $1,000/Mg . AlthoughEP

Aconside r controlling HAP' s wit hvapo r pressure s o f 10. 3 kPA(1. 5 psia) , i t wa s foun d tha t thi s optio n wa s les s economicall yefficien t (i.e. , highe r incrementa l cost effectiveness ) than th e proposed

- option . Th e cost-effectivenes s o f th e propose d optio n i s i n th e rang e o f th e cost-effectivenes s value s o f the Benzen e Storag e NESHAP an d th e rang e o f value s fro m the NSP S fo r VO L storag e (Subpar t Kbo f 4 0 CFRPar t 60) . The non-ai r qualit yhealt himpact s a s wel l a s th e energ yan d othe r environmenta l impact s o f the alternative contro l level s wer e als o considere d i n the selectio n o f the propose d requirement s fo r larg e storag e vessel s a t existing sources . No non-ai r qualit yhealt himpact s wer e expecte d fro man yo f the alternative s an

d the energ

yan d othe r environmenta l impact s di d no t var ysignificantl yamong th e alternatives . Thus , thes e consideration s di d no t affec t the choic e o f th e propose d requirements . Th e control s require d b ythe propose d requirement s ar e no t expecte d t o creat e an ysecondaryemission s o f carbo n monoxid e o r nitroge n oxides . I naddition , n o secondar ybenefit s o f contro l o f non-HAP VOC' s ar e expected . Th e energ yimpact s estimate d fo r the selecte d contro l requirement s wer e abou t 5,400,00 0 kW-hr/yr fo r electricity . Th e energ yrequirement s associate d wit hcontro l o f al l larg e vessel s storing HAP' s o f an y vapo r pressur e wa s abou t 20 % greater . Th e energ yrequire d fo r th e contro l equipmen t represent s a smal l percentag e o f the tota l 2 1P.2 4

energ yrequiremen t fo r thi s industry . Base d o npreviou s studie s o f SOCMI , n o unreasonabl e advers e energ yimpact s ar e expecte d fro manyo f th e alternativ e contro l level s considered . Amor e stringen t leve l o f emissio n reductio ni s no t bein g propose d becaus e th e additiona l reductio ntha t coul d b e achieve d throug hfurthe r contro l o f larg e storag e vessel s wa s no t considere d significant , give n th e additiona l cost . Th e additiona l emissio nreductio n achieve d throug hcontro l o f HAP' s wit hvapo r pressure s lowe r tha n5. 2 kP a (0.7 5 psia ) i s abou t 4,00 0 Mg/y r (4,30 0 tons/yr) . Thi s contro l woul d cos t $11. 2 millio n pe r year . Th e cost-effectivenes s o f thi s additiona l emissio n reductio ni s $2,900/Mg . Th e cos t o f achievin g thi s emissio n reductio n wa s no t considere d reasonable . I nselectin g th e propose d emissio n limitation s fo r smal l and medium storag e vessel s a t existin g sources , EP Aconsidere d level s o f emissio nreductio n mor e stringen t tha nth e leve l associate d wit hth e source-wid e floo r fo r thes e emissio npoints . Th e alternativ e contro l option s considere d fo r smal l vessel s were : (1 ) vapo r pressure s o f 76. 6 kP a (11. 1 psia ) and higher ; (2 ) vapo r pressure s o f 5. 2 kP a (1. 9 psia ) and higher ; and (3 ) vapo r pressure s greate r tha n0.0 7 kP a (0.0 1 psia) . Th e alternativ e contro l option s beyon d th e floo r componen t considere d fo r medium vessel s were : (1 ) vapo r pressure s o f 0. 7 kP a (0. 1 psia ) and higher ; and (2 ) vapo r pressure s greate r tha n0.0 7 kP a (0.0 1 psia) . Non e o f th e alternativ e option s fo r eithe r smal l o r medium vessel s i s bein g propose d sinc e th e cost s wer e considere d 2 2P.2 5

highgive n the ver

ysmal l potentia l emissio nreductions . Contro l beyon d the floo r componen t fo r mediu mstorag e vessel s woul d reduc e emission s b

yles s than10 0 Mg/yr (11 0 tons/yr ) a t a cos t o f $3. 6 million/yr . Wit hsmal l storag e vessel s th e maximu m potentia l reductio n o f 36 0 Mg/yr woul d cos t abou t $1 9 million/yr . Th e averag e cos t effectivenes s o f thes e contro l requirement s varie d fro

m$53,000/Mg ($48,000/ton ) fo r smal l vessel s t o abou t $14,000/Mg ($12,700/ton ) fo r mediu mvessels . Therefore , EP A believe s tha t th e contro l leve l fo r th e smal l an d mediu m storag e vessel s component s o f the source-wid e floo r represente d th e maximu mreductio n achievabl e considering cos t an d othe r impacts . Th e EP Ai s proposing t o requir e contro l o f mediu m storag e vessel s storing HAP' s wit hvapo r pressure s o f 5. 2 kP a (1. 9 psia ) an d higher . No contro l requirement s ar e being propose d fo r smal l storag e vessels . Fo r bot hsmal l an d mediu m storag e vessels , thi s proposa l require s n o contro l beyon d the respective component s o f the source-wid e floor . A n additiona l consideratio ni n th e selectio no f the propose d option s wa s th e non-ai r qualit yhealt himpact s a s wel l a s th e energ yan d othe r environmenta l impact s o f the alternative contro l levels . No non-ai r qualit yhealt himpact s wer e expecte d fro man y o f the alternative s an d th e othe r environmenta l impact s di d no t varysignificantl yamong th e alternatives . Thus , thes e consideration s di d no t affec t the choic e o f the propose d requirements . Th e co-control s require d b ythe propose d requirement s ar e no t expecte d t o creat e an ysecondaryemission s 2 3P.2 6

o f carbo n monoxid e o r nitroge noxides . I naddition , n o secondary benefit s o f co-contro l o f non-HAP VOC' s ar e expected . Th e energ y impact s fo r the require d control s fo r mediu mstorag e vessel s woul d be abou t 2,600,00 0 kW-hr/yr fo r electricity . Th e energ y requirement s associate d wit hcontro l o f mediu m storag e vessel s containing liqui d HAP' s o f an yvapo r pressur e i s slightl y greater , bu t i s no t considere d significant . The energ yrequire d fo r th e contro l equipmen t represent s a smal l percentag e o f the tota l energ

yrequiremen t fo r thi s industry . Based onpreviou s studie s o f SOCMI , n o unreasonabl e advers e energ yimpact s ar e expecte d fro

m an yo f th e alternative contro l level s considered . d . Storag e vessels : ne wsources . Th e determinatio n o f th e bes t controlle d storag e vessel s als o use d th e thre e siz e range s o f mode l vessels . Fo r th e reason s previousl ydescribed , the paramete r use d i n th e analysi s t o determin e th e storag e vesse l component s o f th e source-wid e floo r wa s the vapo r pressur e o f the liqui d being stored . Th e analysi s o f th e dat a bas e showe d tha t the maximu mdegre e o f emissio n limitatio n being achieve d b ythe best-controlle d vessel s i n eac hpopulatio nsegmen t occur s a t 13. 1 kP a (1. 9 psia ) fo r smal l an

d mediu mvessel s an

d a t 5. 2 kP a (0.7 5 psia ) fo r larg e vessels . Fo r eac ho f th e thre e segment s o f th e storag e vesse l population , EP

Aconsidere d severa l alternative level s o f emissio n limitatio n mor e stringen t than th e emissio nleve l associate d wit h the floo r component . Th e alternative s wer e structure d similarl y t o thos e fo r existing storag e vessel s bu t differe d i n the vapo r

1 2 4P.2 7

pressure s o f the liquid s tha t woul d b e require d t o appl y controls . The alternative contro l option s examine d fo r storag e vessel s a t newsource s were : (1 ) fo r larg e an d mediu m vessels , vapo r pressure s 0. 7 kP a (0. 1 psia ) an d greate r an

d vapo r pressure s o f 0.0 7 kP a (0.0 1 psia ) an d greater ; an

d (2 ) fo r smal l vessels , vapo r pressure s o f 0.0 7 kP a (0.0 1 psia) . The EP Ai s proposing t o contro l larg e storag e vessel s tha t stor e HAP' s wit hvapo r pressure s o f 0. 7 kP a (0. 1 psia ) an d higher . Thi s propose d contro l wil l resul t i na significan t emissio n reductio n a t a reasonabl e cost . The propose d contro l requiremen t fo r larg e storag e vessel s i s estimate d t o achieve a n emissio n reductio n o f 1,10 0 Mg/yr (1,20 0 tons/yr ) o f HAP' s compare d t o emission s tha t woul d occu r withou t th e standard . Thi s represent s an 8 7 percen t reductio nfro m thi s segmen t o f the SOCM I storag e vesse l population . Th e annua l cos t t o achieve thi s reductio n i s abou t $0. 8 millio n an d the cost-effectivenes s o f thi s contro l i s $735/M g ($670/ton) . Th e non-ai r qualit yhealt himpact s wer e considere d i n thi s decisio n a s wel l a s the energ yan d othe r environmenta l impact s o f the alternative contro l levels . A s wit hth e othe r decisions , thes e factor s di d no t varysignificantl yamong the alternatives . Thus , thes e consideration s di d no t affec t the choic e o f the propose d requirements . Th e energ yrequire d fo r contro l beyon d th e floo r componen t woul d b e abou t 200,00 0 kW-hr/yr fo r electricity . Th e EP Ai s no t proposing t o requir e contro l o f vapo r 2 5P.2 8

pressure s greate r tha n 0. 7 kP a (0. 1 psia ) becaus e th e additiona l emissio n reductio n achieve d throug hfurthe r contro l wa s no t significant , give n th e additiona l cost . Furthe r contro l wa s estimate d t o resul t i n onl y2 Mg/y r additiona l reductio na t a n additiona l cos t o f $233,000/yr . Thi s cos t wa s judge d t o b e disproportionatel yhigh . Fo r smal l and mediumvessels , non e o f th e alternativ e contro l option s mor e stringen t tha n th e floo r component s wer e selected . Afte r considerin g th e emissio nreductions , costs , and othe r impact s o f th e alternatives , EP Adetermine d th e cos t t o achiev e th e additiona l reductio n wa s hig hgive nth e ver ysmal l potentia l emissio nreductions . Additiona l contro l woul d reduc e emission s fro m

mediumstorag e vessel s byles s tha n2 0 Mg/y r (2 2 tons/yr ) a t a n additiona l cos t o f abou t $700,000/yr . Fo r th e smal l storag e vessel s segmen t o f th e population , furthe r contro l woul d resul t i nles s tha n 1 0 Mg/y r (1 1 tons/yr ) emissio n reductio n a t a n adde d cos t o f abou t $2. 1 million/yr . Th e incrementa l cos t effectivenes s value s fo r thes e contro l requirement s ar e abou t $304,000/M g ($276,000/ton ) fr o smal l vessel s and $42,000/M g ($38,100/ton ) fo r mediumvessels . Th e consideratio no f th e non-ai r qualit yhealt himpact s a s wel l a s th e energ yrequirement s and othe r environmenta l impact s wa s simila r t o tha t i nth e decisio nfo r existin g storag e vessels . Therefore , EP Adetermine d tha t th e contro l leve l fo r th e smal l and mediumstorag e vessel s component s o f th e sourc e wid e floo r represente d th e maximumreductio n achievabl e considerin g cos t and 2 6P.2 9

othe r impacts . e . Transfe r operations : existin g sources . I nth e analysi s o f th e dat a bas e t o determin e th e transfe r rac k component s o f th e sourc e wid e floor , EP Adivide d th e populatio no f mode l rack s int o tw o group s base d o n th e vapo r pressur e o f material s loaded . Th e vapo r pressur e grouping s wer e transfe r rack s loadin g material s wit haverag e vapo r pressure s les s tha n10. 3 kP a (1. 5 psia ) and rack s loadin g material s wit hvapo r pressure s o f 10. 3 kP a (1. 5 psia ) and higher . Thes e tw o group s ar e th e resul t o f severa l simplifyin g assumption s use d i nth e analysi s and th e fac t tha t mos t Stat e regulation s onl yrequir e contro l o f rack s loadin g chemical s wit hvapo r pressure s o f 10. 3 kP a (1. 5 psia ) and higher . Th e procedur e use d t o determin e th e transfe r rac k component s o f th e source-wid e floo r wa s t o ran k th e rack s byquantit yloade d (throughput ) i n ascendin g order . Sinc e emission s fro mtransfe r operation s ar e largel ydetermine d bythroughpu t and vapo r pressure , throughpu t wa s expecte d t o provid e a goo d measur e o f whethe r o r no t a rac k i s controlled . Fo r bot hgroups , th e throughpu t a t whic hmor e tha n 1 2 percen t o f th e rack s i s controlle d byth e referenc e contro l technolog ywa s determined . Th e analysi s showe d tha t fo r transfe r rack s tha t loa d HAP' s wit h vapo r pressure s o f 10. 3 kP a (1. 5 psia) , and higher , tha t hav e throughput s greate r tha n 6 4 3. 5 m 3 /y r (170,00 0 gal/yr ) mor e tha n 12 % o f th e rack s ar e controlle d wit hth e referenc e technology . Non e o f th e transfe r rack s tha t loa d HAP' s wit hvapo r pressure s les s tha n 10. 3 kP a (1. 5 psia ) wer e controlle d wit hth e referenc e 2 7P.3 0

technology . Onl ytw o level s o f emissio n limitatio nwer e evaluate d and considere d i n th e selectio no f th e propose d contro l requirements . Thes e alternative s wer e th e emissio n leve l associate d wit hth e transfer.rac k componen t o f th e source-wid e floo r and th e leve l associate d wit hcontro l o f al l transfe r racks . T o simplif yth e consideratio no f contro l alternatives , th e emission s and cos t informatio n fo r th e tw o group s o f rack s wer e combined . Afte r considerin g th e emissio n reductions , costs , and othe r impact s o f th e alternatives , EP Abelieve s tha t th e leve l o f emissio n limitatio n associate d wit hth e componen t o f th e source-wid e floo r i s achievable . Th e mor e stringen t leve l o f emissio nreductio n i s no t bein g propose d becaus e th e additiona l emissio nreductio n achieve d i s no t significan t and th e cos t o f thi s reductio ni s high . Contro l beyon d th e leve l associate d wit hth e source-wid e floo r woul d reduc e emission s fro mtransfe r rack s byles s tha n 7 0 Mg/y r (7 7 tons/yr ) a t a cos t o f $3. 4 million/yr . Th e averag e cos t effectivenes s o f thi s contro l i s $50,000/M g ($45,400/ton) . A s wit hth e decision s o n th e othe r emissio npoints , n o non-ai r qualit yhealt himpact s wer e expecte d fro manyo f th e alternative s and th e othe r environmenta l impact s di d no t var ysignificantl y amon g th e alternatives . Thus , thes e consideration s di d no t affec t th e choic e o f th e propose d requirements . Th e control s require d byth e propose d requirement s ar e no t expecte d t o creat e anysignifican t secondar yemission s o f carbo nmonoxid e o r nitroge n oxides . I n addition , n o secondar ybenefit s o f co 2 8P.3 1

contro l o f non-HAP VOC' s ar e expected . Th e energ yimpact s fo r the require d control s ar e als o no t believe d t o be significant . f . Transfe r operations : newsources . Th e analysi s o f th e dat a bas e showe d tha t the maximu mdegre e o f emissio nreductio n being achieve d b

ythe bes t controlle d transfe r rac k occur s a t vapo r pressure s o f 10. 3 kP a (1. 5 psia ) an d throughput s greate r than 643. 5 m3 /yr (0.1 7 millio ngal/yr) . Thus , fo r newsource s th e transfe r rac k componen t o f th e sourc e wid e floo r i s identica l t o tha t fo r existing sources . The decisio n on the contro l requirement s considere d the same two level s o f emissio n limitatio ntha t wer e considere d fo r transfe r rack s a t existing sources . Fo r the same reason s discusse d earlier , EP Ai s no t proposing t o requir e a mor e stringen t leve l o f emissio nreduction . Afte r considering emissio n reduction s an d othe r information , EP Abelieve s tha t the leve l o f emissio n limitatio nassociate d wit hth e componen t o f th e source-wid e floo r i s achievable . g . Proces s wastewater : existing sources . Th e parameter s used i n the analysi s o f th e dat a bas e t o identif yth e floo r leve l o f contro l fo r wastewate r stream s were : concentratio no f chemical s wit hhighvolatilit yi n wastewate r (e.g. , benzen e o r viny l chloride) ; concentratio n o f chemical s wit hlowe r volatilitie s than benzene , o r semi-volatil e HAP's ; an d flowrate . Thes e parameter s wer e use d becaus e theyar e among th e primar y factor s tha t mos t influenc e ai r emission s fro mwastewate r streams . 2 9P.3 2

A s previousl ynoted , EP Ause d dat a o nth e contro l requirement s i n existin g Stat e and Federa l regulation s t o identif ystream s tha t mus t b e controlle d and t o identif yth e require d controls . Th e onl ycontrolle d wastewate r stream s i n th e dat a bas e wer e thos e estimate d t o mee t th e applicabilit y requirement s o f eithe r th e Viny l Chlorid e NESHAP , 4 0 CF RPar t 6 1 Subpar t F , o r th e Benzen e Wast e Operation s NESHAP , 4 0 CF RPar t 6 1 Subpar t FF . Ther e ar e n o Stat e regulation s requirin g contro l o f ai r emission s fro m wastewater . Consequently , th e procedur e use d i n th e analysi s o f th e existin g contro l leve l fo r wastewate r operation s wa s t o determin e th e proportio no f processe s and wastewate r stream s tha t hav e concentration s abov e th e contro l criteri a i n th e Benzen e Wast e NESHA P o r Viny l Chlorid e NESHA P (greate r tha n1 0 pp mbenzen e o r viny l chlorid e compare d t o th e tota l numbe r o f processe s an d wastewate r streams . Th e estimat e o f th e numbe r o f processe s and benzen e containin g wastewate r stream s subjec t t o th e Benzen e Wast e NESHA P wa s adjuste d b yth e expecte d proportio no f th e facilitie s exceedin g th e facility-wid e threshol d fo r control . Thi s analysi s showe d tha t fewe r tha n 5 percen t o f SOCM I processe s and fewe r tha n3 percen t o f th e wastewate r stream s ar e currentl ycontrolle d t o th e efficienc yo f th e referenc e contro l technology . Therefore , sinc e les s tha n 1 2 percen t o f existin g wastewate r stream s ar e controlled , th e componen t o f th e source-wid e floo r fo r existin g wastewate r stream s i s estimate d t o b e n o control . Th e EP Aconsidere d alternativ e level s o f emissio nreductio n 3 0P.3 3

tha t varie d fro

m controlling thos e proces s wastewate r stream s tha t ar e large r an

d mor e cos t effectiv e t o contro l t o controlling al l wastewate r streams . Th e EP Ai s proposing t o requir e contro l o f proces s wastewate r stream s wit hgreate r than1 0 liter s pe r minut e flowrat e an d greate r than100 0 ppm wtota l VOHAP concentration . Th e propose d contro l leve l wa s selecte d considering th e emissio n reduction s o f th e alternative contro l option s an

d th e criteri a enumerate d i nSectio n112(d ) o f the Act . Th e propose d alternative i s considere d t o achieve the maximu m emissio n limitatio n tha t i s achievabl e considering cost , non-ai r qualit yhealt han

d environmenta l impacts , an d energ y requirements . AlthoughEP Ai s proposing thi s specifi c option , commenter s shoul d b e awar e tha t ther e ar e a numbe r o f technica l issue s regarding th e emissio n an d cos t estimatio nmethodologies . (Thes e issue s ar e discusse d i nSectio nVII.E. 3 o f thi s notice. ) Th e EP Aanticipate s tha t fo r wastewate r control s ther e ma yb e change s i n th e emissio n an d cos t estimate s tha t resul t fro mth e resolutio n o f th e technica l an d scienc e issue s an d an ynew informatio n receive d during th e publi c commen t period . Th e fina l rul e wil l b e base d on consideratio no f th e revise d estimates . The consideration s o f th e currentl yavailabl e informatio nonthe alternative contro l option s ar e summarize d below . Wastewate r stream s a t existing source s ar e believe d t o b e the secon

d larges t contributo r o f HAP emission s fro mthe emissio n point s regulate d b

yth e HON . Th e propose d contro l requirement s ar e expecte d t o achieve anemissio n reductio no f 82,10 0 Mg/yr 3 1P.3 4

(90,30 0 tons/yr ) o f HAP' s compare d t o curren t emissio nlevels . Thi s represent s a 7 7 percen t reductio nfro mth e uncontrolle d emissio n rate . Th e annua l cos t t o achiev e thi s reductio ni s $23. 9 million . Th e cost-effectivenes s o f goin g fro mn o contro l t o th e propose d contro l i s $290/M g ($265/ton) . Th e estimate d cost s o f th e propose d wastewate r contro l requirement s ar e base d o n us e o f stea mstripper s t o contro l th e wastewate r strea m and d o no t reflec t anypotentia l cos t saving s fro mus e o f th e othe r mean s o f demonstratin g complianc e tha t ar e provide d i n th e wastewate r provisions . On e o f thes e complianc e option s allow s a sourc e t o demonstrat e complianc e throug hus e o f pollutio npreventio nmeasure s and wast e treatmen t t o chang e th e wastewate r strea m characteristics . Thi s complianc e optio ni s expecte d t o lowe r th e cos t o f complianc e fo r som e sources . Thus , EP Abelieve s tha t th e cos t analysi s ma yoverstat e th e cos t o f complyin g wit hth e propose d wastewate r provisions . Industr y representative s hav e indicate d tha t the ybeliev e th e cos t estimate s t o b e understated . Th e EP Arequest s comment s o n whethe r th e cost s o f th e propose d contro l requirement s ar e reasonabl e and ask s tha t commenter s provid e supportin g informatio nfo r thei r estimates . Th e non-ai r qualit yhealt himpact s a s wel l a s th e energ yand othe r environmenta l impact s o f th e alternativ e contro l level s wer e als o considere d i n th e selectio no f th e propose d requirements . N o non-ai r qualit yhealt himpact s wer e expecte d fro manyo f th e alternative s and th e energ yand othe r 3 2P.3 5

environmenta l impact s di d no t var ysignificantl yamon g th e alternatives . Thus , thes e consideration s di d no t affec t th e choic e o f th e propose d requirements . Th e energ yimpact s estimate d fo r th e selecte d contro l requirement s wer e abou t 4,500,00 0 kW-hr/y r fo r electricit yand 4,200,00 0 millio nBtu/y r fo r steam . Th e energ yrequire d fo r th e mos t stringen t contro l leve l wa s onl yslightl ygreate r fo r electricit yand steam . Thes e energ yrequirement s represen t a smal l percentag e o f th e tota l energ yrequiremen t fo r thi s industry . Base d o npreviou s studie s o f SOCMI , n o unreasonabl e advers e energ yimpact s ar e expecte d fro manyo f th e alternativ e contro l level s considered . Whil e EP Acoul d no t quantif yth e non-ai r qualit ybenefits , EP Aconsider s contro l o f wastewate r stream s t o resul t i nnon-ai r qualit ybenefits . Thes e benefit s includ e generatio no f les s hazardou s waste , les s groundwate r contamination , and les s contaminatio no f stormwater . Anothe r secondar ynon-ai r qualit y benefi t considere d i n th e selectio no f th e propose d alternativ e i s tha t SOCM I wastewate r stream s als o ca ncontai nnon-HA P VOC's . Thes e non-HA P VOC' s wil l b e controlle d whe nstream s ar e controlle d fo r HA P emissions . Thi s co-contro l i s expecte d t o significantl yreduc e emission s o f non-HA P VOC's , thereby contributin g t o effort s t o reduc e tropospheri c ozone . Alternativ e contro l Option s 2 throug h5 wer e no t selecte d becaus e th e additiona l emissio nreductio nachieve d throug h furthe r contro l wa s no t significant , give nth e cost s and th e uncertaint yregardin g th e characterizatio no f SOCM I wastewate r 3 3P.3 6

systems . Specifically , contro l o f wastewate r stream s wit hflow s o f 5 liter s pe r minut e o r greate r an d concentration s o f 50 0 ppm w VOHAP (Option 2 ) wa s estimate d t o resul t i n abou t 70 0 Mg/yr additiona l reductio n a t a cos t o f abou t $1. 8 million/yr . Thi s contro l optio n ha s a cost-effectivenes s valu e o f $2,600/Mg . Option s 3 through5 achieve onl ya smal l additiona l emissio n reductio n a t cost-effectivenes s value s o f $3,000/Mg t o $15,000/Mg . Give n the technica l uncertaintie s tha t exis t regarding the representatio no f SOCM I wastewate r stream s an d industr ypractice s i n designo f wastewate r collectio nan d treatmen t systems , i t i s uncertai nwhethe r an yo f the alternative contro l option s considere d woul d resul t i nadditiona l emissio n reductions . Therefore , EP Ai s no t proposing an yoption s mor e stringen t than Optio n 1 . h . Proces s wastewater : newsources . Th e analysi s o f th e dat a bas e als o showe d th e maximu memissio nreductio nbeing achieve d i s determine d b yth e contro l requirement s fo r the Benzen e Wast e Operation s NESHAP an d the Viny l Chlorid e NESHAP . Unde r thes e rules , wastewate r stream s wit h1 0 ppm wo r greate r an

d flowrate s greate r than 0.0 2 liter s pe r minut e have t o b e treate d prio r t o discharg e an d unit s i nwhic hwast e i s manage d befor e treatmen t mus t b e equippe d wit h9 5 percen t efficien t ai r emissio n controls . Thi s emissio n limitatio n wa s assume d t o b e equall y applicabl e t o othe r chemical s tha t have volatilitie s i nwate r equa l t o o r greate r than benzen e an d viny l chloride . Thes e chemicals , whic har e terme d WHAP , ar e listed i nTabl e 8 o f 3 4P.3 7

propose d Subpar t G . A s previousl ynoted , ther e ar e n o Stat e o r Federa l regulation s tha t woul d requir e contro l o f chemical s othe r than benzen e o r viny l chloride . Therefore , ther e i s n o contro l a t the floo r fo r chemical s wit hvolatilitie s lowe r than tha t o f benzen e o r viny l chloride . I n th e determinatio no f the source wid e floo r componen t fo r newsources , wastewate r stream s containing 1 0 ppmw , o r more , o f WHA P woul d b e require d t o b e controlle d t o th e efficiencyo f th e referenc e technolog yan d chemical s wit hlowe r volatilitie s woul d not . Th e EP Adevelope d alternative contro l option s fo r proces s wastewate r stream s a t newsource s b yfirs t considering whethe r t o requir e contro l beyon d th e floo r componen t fo r WHA P containing stream s an

d the n considering contro l option s fo r lowe r volatilit y chemical s (i.e. , VOHAP ) i nwastewate r streams . No alternative s wer e develope d fo r furthe r contro l o f WHA P sinc e th e potentia l additiona l emissio n reductio n fo r WHA P wa s minimal . Fo r the les s volatil e chemicals , EP Aexamine d severa l alternative options . Alternative s considere d include d contro l o f stream s wit htota l VOHAP concentration s o f 800 , 500 , 200 , an d 5 ppmw . Tabl e 6 show s the emissio nreduction s an d cost s associate d wit h th e floo r contro l fo r WHA P combine d wit hth e emissio n reductio n an d cost s fo r contro l o f tota l VOHAP concentration s o f eithe r 80 0 ppm w(Option 2 ) o r 5 ppm w(Option 3) . Afte r considering th e alternative s an

d the associate d impacts , EP Ai s proposing the contro l requirement s i n Optio n 2 . Th e propose d contro l requirement s fo r newsourc e wastewate r stream s woul d appl yt o 3 3 5P.3 8

set s streams : stream s wit hflowrate s o f 0.0 2 £p mo r greate r an

d concentration s o f 1 0 ppm wo r greate r o f WHA P (a s define d i n Tabl e 8 i n Sectio n 63.13 2 o f Subpar t G) ; stream s wit hflowrate s o f 1 0 £p

m o r greate r an

d concentration s o f 100 0 ppm wo r greate r o f VOHAP (a s define d i n Tabl e 9 o f Sectio n63.13 8 o f Subpar t G) ; an d al l stream s wit hconcentration s o f 10,00 0 ppm wo r greate r o f VOHAP . Th e propose d contro l leve l wa s selecte d considering th e emissio n reductio n achieve d b ythe alternative contro l option s fo r VOHAP emission s an d considering th e criteri a enumerate d i n Sectio n 112(d ) o f the Act . The propose d alternative i s considere d t o achieve th e maximu memissio nreductio nconsidering the cost , nonai r qualit yhealt heffects , environmenta l impacts , an d energ yrequirements . Th e consideration s o f thes e factor s an d th e uncertaintie s i n the estimate s ar e describe d below . Th e propose d contro l requirement s ar e estimate d t o achieve a reductio n o f 14,50 0 Mg/yr (16,00 0 tons/yr ) o f WHA P an d VOHAP compare d t o emission s i n absenc e o f thi s rule . A s wit hthe requirement s fo r existing sources , thi s represent s a n7 7 percen t reductio n fro

muncontrolle d emissio nrate s fo r wastewater . Th e annua l cos t t o achieve thi s reductio n i s abou t $6. 9 million . A s note d i n the discussio n o f th e propose d contro l fo r existing wastewate r streams , ther e i s uncertaint ywhethe r th e cost s ar e understate d o r overstated . Optio n 2 i s estimate d t o achieve an emission s reductio no f abou t 1,50 0 Mg/yr (165 0 tons/yr ) o f VOHAP emission s above th e floor . Thi s contro l woul d cos t abou t $1. 5 million/yr an d hav e a 3 6P.3 9

cost-effectivenes s valu e o f $1000/Mg ($910/ton) . I n selecting Optio n 2 fo r the propose d contro l requirements , EP Aals o considere d the non-ai r qualit yhealt heffect s a s wel l a s the energ

yrequirement s an

d othe r environmenta l impacts . Th e consideratio n o f thes e criteri a wa s simila r t o tha t i n the selectio n o f control s fo r existing wastewate r streams . No non ai r qualit yhealt himpact s wer e expecte d fro man yo f th e alternatives . I n comparing the alternatives , EP Afoun d tha t the environmenta l an

d energ yimpact s di d no t varysignificantl yamong the alternatives . The energ yan d secondaryimpact s fro mth e contro l device s wer e no t considere d significant . Th e propose d contro l requirement s ar e expecte d t o hav e secondarynon-ai r qualit ybenefit s suc ha s reduce d potentia l fo r groundwate r contamination . Th e selecte d alternative i s estimate d t o resul t i n contro l o f abou t 3 0 percen t o f th e tota l wastewate r volume fro

mne wSOCM I sources . Th e EP Ai s no t proposing a mor e stringen t leve l o f emissio n limitatio n becaus e contro l beyon d th e selecte d leve l i s estimate d t o achieve onl ya smal l additiona l emissio nreduction . Th e furthe r contro l woul d reduc e emission s b yanadditiona l 1,40 0 M g/y r (1,50 0 tons/yr ) o f VOHAP . Thi s contro l woul d cos t abou t $2 3 millio n pe r year , an increas e o f abou t $1 6 millio npe r yea r ove r the cos t o f th e propose d contro l level . Becaus e the cos t i s disproportionatel ylarg e compare d t o thi s additiona l emissio n reductio n an

d th e grea t uncertaintie s regarding th e potentia l emissio n reduction , EP Ai s no t proposing th e mor e stringen t

3 7P.4 0



### contro loption .

3 8