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# OAR Box 1830 Prepped by Ollie Stewart



### Document

Number: 

# 172)IV-C-13 9 Docket Number: 

# A-87-1 1

Printed 11/13/20087:21:00AM Sheet 172 of 232^° SUr„ 

# WS& .

# UNITE D STATE S ENVIRONMENTA L PROTECTIO N AGENC Y e C <c P WASHINGTON

. D.C

. 2045 0 OCT2 7 1988

T H E ADMINISTRATO R

Honorabl e Joh

n D . Dingel l Chairman , Subcommitte e o n Oversigh t an

d Investigation s Committe e o n Energ

yan d Commerc e Hous e o f Representative s Washington , D C 2051 5 Dea r Mr . Chairman : Than k yo u fo r you r Augus t 9 , 198 8 lette r concerning onboar d refueling vapo r contro l system s an d EPA' s propose d tes t procedure s fo r bot h refueling an d evaporativ e emission s measurement . Your lette r containe d man ycomment s mad e b

yth e Moto r Vehicl e Manufacturer s Associatio n (MVMA ) i n a n Augus t 4 , 198 8 lette r an

d question s o f you r ow n regardin

g thes e matter s alon g wit h a Jun e 28 , 198 8 lette r t o EPAfro mToyot a Moto r Corporatio n concerning EPA' s prototyp e onboard system . Al l o f thes e concern s wil l be addresse d i n thi s letter . I n addition , a s yo u ma yrecall , our Augus t 19 , 198 8 respons e t o you r Jun e 13 , 198 8 lette r responde d t o al l bu t on e se t o f questions . O n pag e four o f tha t letter , yo u raised question s regardin g NHTS Acomment s t o EPAi n a lette r date d Apri l 12 , 198 8 fro mGeorg e L . Parke r o f NHTSA . I n hi s letter , Mr . Parke r raised concern s abou t potentia l vehicl e operating an d safet yproblem s whic h maybe create d a s a resul t o f onboar d control s o r othe r regulator yfactor s relate d t o fue l economy , emissions , an

d safety . Our Augus t 19 , 198 8 lette r promise d a respons e t o you r question s upo n completio n o f the safet y analyse s bein

g prepare d fo r the onboard reproposal . Ou r respons e wit h regard t o thes e issue s i s a t the en d o f thi s letter . I n you r lette r yo u identif y1 0 contention s raised b yMVM A abou t the ne wtes t procedure s fo r refueling an d evaporativ e emission s contro l presente d b yEPAa t a Jun e 30 , 198 8 workshop . I n orde r t o addres s thes e contention s an d the inten t o f the changes , th e histor

yan d backgroun

d o f th

e tes t procedures , the need fo r change s an

d the methodolog

yused i n developing th

e procedure s wil l b e explained .



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- EPA' s reason s fo r proposing change s t o the tes t procedure s ar e t o ensur e the contro l o f refueling emission s an d evaporativ e emissions , whic h include s wha t i s no wreferre d t o a s exces s evaporativ e emission s an d runnin

g losses . I n addition , w e hav e attempte d t o develo p procedure s whic h minimiz e the testin g burde n t o the exten t possible . Thus , i n respons e t o MVM

AContention s # 1 an d #2 , thes e change s ar e no t mean t t o forc e a particula r design an d i n fac t manufacturer s woul d hav e design choices . I n the past , EPAexpecte d tha t manufacturer s woul d choos e integrate d rathe r than separat e refuelin g an d evaporativ e contro l syste

mdesign s becaus e the engineering an d productio n o f integrate d system s seem s t o be simple r an d les s costly . Becaus e unde r mos t in-us e condition s the integrate d caniste r ha s extr a capacity , EPAexpecte d tha t integrate d onboar d system s woul d contro l a larg e portio n o f non-Federa l Tes t Procedur e (FTP ) evaporativ e emission s (base d o n ou r understanding o f the scop e o f the problema t tha t time ) withou t additiona l regulator yaction . At the tim e o f the Augus t 198 7 proposal , EPAha

d no t quantifie d the exac t percentag e o f non-FT P evaporativ e emission s tha t integrate d onboar d system s woul d contro l bu t assume d tha t eac h vehicl e mode l woul d provid e contro l roughl yequivalen t t o it s refueling load . Th e comment s receive d an d ne winformatio n obtaine d sinc e Augus t 198 7 convince d EP Atha t thre e majo r change s ha d t o be mad e t o the tes t procedure s i n orde r t o represen t actua l in-us e emission s i n a laborator ytest . First , ther e wa s a need t o simplif ythe tes t procedur e fo r integrate d system s i n orde r t o mak e i t les s resourc e intensive . Second , manufacturers ' comment s indicate d tha t man ywoul d us e separat e rathe r tha n integrate d syste

mdesigns . Thi s necessitate d a reviewo f the tes t procedur e fo r separat e system s t o ensur e tha t the ywoul d provid e the sam

e leve l o f emissio n contro l a s integrate d systems . Finally , EPAgenerate d ne winformatio n o n the magnitud e o f runnin g los s an

d non-FT P emission s an d thei r relationshi p t o the ozon e problem . Sinc e thes e constitut e a muc h large r environmenta l impac t than wa s previousl ypresumed , ther e wa s a clea r nee d t o revis e the evaporativ e tes t procedur e regardles s o f whethe r refuelin g control s ar e adopted . Specifi c change s wer e mad e t o the tes t procedure s i n orde r t o addres s eac h o f thes e needs . First , w e wer e abl e t o simplif ythe caniste r conditioning sequenc e o f the integrate d refuelin

g tes t procedur e withou t forfeiting an yevaporativ e o r refuelin

g control . Second , a vapo r containmen t requiremen t an d a fue l cap remova l step wer e incorporate d int o the integrate d tes t procedur e t o provid e contro l o f runnin g losses . Third ,P. 4

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- sinc e the comment s indicate d man ymanufacturer s woul d us e separat e systems , th e non-integrate d and/o r evaporativ e syste m onl ytes t procedur e wa s revise d t o ensur e in-us e emissio n contro l equivalen t t o integrate d systems . Thi s wa s don e b y incorporatin

g th e same running los s procedur e an d b yaddin g tw o extr a diurnal s t o the evaporativ e tes t sequenc e t o provid e contro l capacit yfo r non-FT P emission s equivalen t t o tha t provide d b

ya n integrate d syste

mcanister . Therefore , contrary t o MVM AContentio n # 3 tha t EPAi s forcin g integrate d systems , the tes t procedure s fo r integrate d an d separat e syste

m design s wer e carefull ydevelope d s o tha t vehicle s teste d o n eithe r procedur e woul d provid e th e sam e evaporativ e emissio n contro l performanc e in-use . Th e methodolog

yused i n developing thes e revise d tes t procedure s include d modeling o f rea l worl d conditions . Thus , Contention s # 5 an d #6 , tha t rea l worl d condition s wer e no t adequatel yexamine d an d tha t EPA' s methodolog ywa s predicate d o n achieving equivalen t caniste r size s wit h bot h procedures , ar e no t true . Ou r goa l wa s t o assur e equivalen t in-us e performanc e fo r al l certifie d systems . Thi s doe s no t alway s requir e the sam

e caniste r size , give n the relationshi p betwee n siz e an d purg e rate . Contentio n # 4 i s correc t - - EP Ahad no t conducte d an

ytesting usin

g th e ne wprocedure s prio r t o th e workshop . However , our modeling result s appea r sufficientl y reliabl e s o tha t we believe tha t the revise d procedure s wil l resul t i n equivalen t contro l fro man ytyp e o f contro l system used . Additionally , in earl ySeptembe r we sen t copie s o f th e revise d procedures , i n regulator yformat , t o vehicl e manufacturer s fo r comment . O f course , an yintereste d part y wil l have an opportunit yt o commen t o n the procedure s sinc e the ywil l be included i n our reproposal . I n conclusion , the tes t procedure s ar e drive n b y condition s encountere d b yvehicle s i n actua l use , no t b yan attemp t b

yEPAt o forc e a particula r design . W e ar e proposing performanc e standard s whic h permi t manufacturer s t o retai n design choices . Anothe r MVM

Acommen t concern s the tes t procedur e requiremen t tha t th e caniste r begi n the preconditioning i n a loaded-to-breakthrough state . I t i s importan t t o not e tha t thi s i s no t a chang e t o the tes t procedur e a s i t wa s als o require d in bot h the volatilit yan d refuelin

g 198 7 proposals . MVMA' s contentio n # 8 argue s a lack o f fiel d dat a demonstrating caniste r saturatio n in-use . W e disagree . Base d upo n dat a fo r in-us e fue l RVP's , tan k temperature s an

d driving patterns , i t seem s clea r t o EPAtha t canister s ar e regularl yreaching3

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- saturate d state s in-use . Th e fac t tha t nearl y2 0 percen t o f the vehicl e flee t experience s 2 o r mor e consecutiv e diurna l loading s withou t bein g drive n provide s som e evidence . Also , the 198 5 AP I repor t #439 3 "Surve yo f Evaporativ e Emissio n System s Conditio n o f In-Use , High Mileag e Automobiles " foun d tha t 4 o f 2 0 (20% ) o f the randoml ychosen , in-use , carburete d vehicle s teste d ha d caniste r load s betwee n 7 5 t o 10 0 percen t o f capacity . Fo r fuel-injecte d vehicles , 4 o f 3 2 (12.5% ) ha d the caniste r loaded i n tha t range . The remainin

g MVM AContention s (#7 , # 9 an d #10 ) concer n th e suggestion s tha t a larg e caniste r wil l emi t mor e vapo r than a smal l caniste r whe n bot h ar e loaded t o a certai n percentag e o f capacity , purge d a t the sam e rat e fo r a give n amoun t o f time an d the n reloade d wit h a give n quantit yo f hydrocarbo n vapors . Some manufacturer s have raised th e ide a tha t becaus e EPA' s tes t sequenc e begin s wit h a caniste r loade d t o breakthrough , th e purg e an

d loadin

g phenomen a requirement s ma yb e unintentionall y encouraging the us e o f canister s jus t larg e enough t o pas s the test . Base d upo n ou r understanding o f caniste r performanc e characteristics , we believe tha t the bes t performing system s in-us e wil l have the smalles t caniste r size s whic h ar e abl e t o mee t th e propose d requirements . Thi s i s becaus e smalle r canister s wil l hav e increase d purg e rate s compare d t o large r canister s an

d wil l recove r thei r contro l capacit ymor e quickl y following a highl yloaded condition . Therefore , w e fin d i t desirabl e t o encourag e us e o f smalle r canisters . Overall , the importanc e o f the caniste r loadin g step deserve s t o b e emphasize d sinc e i t i s thi s requiremen t whic h ensure s tha t certifie d system s wil l have adequat e purg e t o contro l generate d vapor s an d t o recove r fro m highl yloade d states . In-us e condition s ofte n caus e caniste r loadin g beyon d breakthrough an

d the propose d tes t procedure s wil l ensur e tha t contro l system s wil l recove r fro msuch loadin

g quickl ywhe n driven . Th e remainde r o f your lette r contain s man yquestion s o n the characteristic s an d effect s o f runnin g losses . The sourc e o f th e articl e whic h appeare d i n th e Augus t 5 , 198 8 editio n o f Insid e EPAi s unknown . EP Adoe s no t agre e wit h al l o f the informatio n containe d i n the article . Ther e i s n o EPA"staf f paper * a s referre d t o in the article . W e ar e enclosing al l document s relate d t o runnin g losse s tha t ar e currentl yi n (o r bein g processe d t o b

e entere d in ) the publi c docket s fo r the volatilit y(A-85-21 ) o r refuelin

g (A-87-11 ) rulemakings . EPA i s stil l gathering informatio n o n thi s topi c an d wil l submi t additiona l relevan t paper s t o thes e docket s a s the ybecome available . Suc h informatio n i s nowbein g compile d in suppor t o f our upcoming reproposa l an d wil l be availabl e b ythe time the reproposa l i s published .P. 6

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- Aquantificatio n o f the runnin g los s problemwa s mad e b y EPAusing dat a obtaine d fro m vehicl e testin

g base d o n variou s RVPs , temperature s an d tri p length s representativ e o f in-us e conditions . Th e dat a wer e weighte d t o reflec t the percentag e o f vehicle s whic h experienc e the variou s in-us e conditions . The weighte d averag e o f thes e dat a i s 1. 7 gram s pe r mile . (Unde r certai n conditions , vehicle s wit h runnin g losse s a s high a s 1 0 gram s pe r mil e wer e measure d i n our testing. ) I f uncontrolled , thi s translate s t o 1.8 5 millio n ton s pe r yea r o f volatil e organi c compound s (VOCs ) du e t o runnin g losse s i n the yea r 201 0 assuming 11. 7 RVP fuel . Thi s amount s t o 17. 5 percen t o f the tota l nationwid e VO C inventor yo f 10.5 5 millio n ton s pe r yea r i n 201 0 whic h include s bot h exces s evaporativ e an d runnin

g los s emissions . Running losse s ar e exacerbate d b ycondition s typica l o f ozon e violatio n day s (suc h a s high fue l tan k temperatures ) whe n contro l i s neede d the most . Fewe r runnin g losse s occur a t lowe r volatilit ylevel s bu t eve n wit h 9. 0 RVP fue l a vapo r containmen t requiremen t i s necessaryt o contro l thes e emissions . Running losse s ar e bes t controlle d b ya combinatio n o f vehicl e improvement s an d volatilit ycontrols . Integrate d onboar d system s hel p t o provid e the necessar ycontro l or i t ca n als o be attaine d separatel yfro mimprovement s t o evaporativ e contro l systems . However , onc e sufficien t capacit yi s adde d t o evaporativ e system s t o handl e thes e emissions , onl ysmal l enhancement s ar e neede d t o als o contro l refueling emissions . I n summary , although availabl e dat a ar e limited , running losse s appea r t o b

e a substantia l sourc e o f VOCs . W e have bee n studyin g themfo r som

e tim e an d wer e therefor e abl e t o tak e direc t actio n onc e the scop e o f the problembecame clear . However , runnin

g losse s ar e no t th e "smokin g gun " o f th e ozon e problema s claime d i n th e Insid e EPAarticle . Your lette r contain s severa l mor e question s concerning runnin g losses . First , the Automotive/Oi l industr yproposa l t o limi t in-us e gasolin e t o 10. 5 RV P an d the n late r increas e certificatio n tes t fue l t o 10. 5 RVP woul d onl yaddres s a portio n o f th e runnin g los s an

d non-FT P evaporativ e emission s problem . I f thi s proposa l &Ss ^ implemented , ther e woul d stil l be a significan t amoun t o f uncontrolle d emission s whic h woul d "* TlK "j tv ( likel ynecessitat e a furthe r eventua l reductio n o f in-us e fue l RVP . Furthermore , th e necessaryvehicl e change s neede d t o certif yo n 10. 5 RVP fue l an d effectivel ycontro l remainin g exces s evaporatio n an d runnin

g los s emission s woul d b e considerabl ymor e costl yan d technicall ychallenging than a t 9 RVP . CM.'< ^ t'tr7 'P. 7

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- Next , yo u inquir e abou t the safetyan d fue l econom

y ramification s o f controlling runnin g losse s an

d exces s evaporativ e emissions . W e se e n o significan t safet yissue s relate d t o the contro l o f thes e emissions . However , i f on e accept s the premis e tha t venting thes e vapor s int o th e engin e compartmen t o r unde r the vehicl e a s occur s in vehicle s toda y constitute s a safet yproblem , the n ther e i s some safet ybenefi t t o the propose d contro l sinc e th e vapor s woul d be completel y containe d an

d route d onl yt o the engine . A s fo r the fue l econom yramification s o f runnin g losse s an

d exces s evaporativ e emissio n controls , our preliminaryestimat e i s tha t an averag e $8.0 0 lifetim

e fue l recover

ycredi t wil l b e attaine d b y light-dut yvehicles . Acomplet e accounting o f thes e benefit s wil l be containe d i n the reproposal . You r fina l questio n concerning runnin g losse s i s whethe r o r no t thi s informatio n ha s bee n share d wit h th e Nationa l Highwa yTraffi c Safet yAdministratio n (NHTSA ) a s par t o f the ne wprocedure s unde r th e Memorandu mo f Understanding (MOU) . O n Augus t 25,198 8 NHTS Awa s briefe d o n our reproposa l an d safet y study . Thi s briefing include d a presentatio n o n runnin g losses . Ou r draf t reproposa l ha s als o bee n forwarde d t o them for reviewa s par t o f th e MOU . EP Aha s receive d an d reviewe d the Jun e 28 , 198 8 lette r fro mToyot a Moto r Corporatio n containing thei r comment s o n EPA' s prototyp e onboar d refueling contro l system . Th e purpos e o f thi s syste

mwa s t o demonstrat e th e concep t o f a simpl e refueling contro l design . EPAha s aske d fo r an ysuggestion s fo r improvement s whic h coul d be mad e i n th e effectivenes s an d safetyo f thi s system . Although EPAdi d no t attemp t t o anticipat e ever

ypotentia l problemwit h it s prototyp e design , i t seem s tha t al l o f the problem s raise d b yToyot a ar e addressable . I t i s difficul t t o accep t al l o f Toyota' s criticism s a s vali d sinc e the yhav e no t actuall ybuil t an d teste d the prototyp e system , bu t simpl yjus t critique d the design "on paper" . I n an ycase , Toyota' s comment s an d other s like the

m wil l be addresse d a s w e procee d wit h thi s rulemaking . Finally , I woul d lik e t o respon d t o you r Jun e 13 , 198 8 question s concerning NHTSA' s comment s o n potentia l vehicl e operating o r safet yproblem s relate d t o emissio n control s o r othe r vehicula r regulator yfactors . T o begi n with , i t shoul d b e note d tha t the concern s raise d b yNHTS Aar e desig n consideration s tha t mus t be take n int o accoun t anytime a desig n chang e i s t o be mad e regardles s o f whethe r the chang e i s imposed b

yregulatio n or self-initiate d b ya manufacturer . Thes e concern s ar e no t uniqu e t o emissio n control s o r othe r regulator

yrequirements . Manufacturer s mus t routinel yconside rP. 8

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- the potentia l effect s o f design modification s mad e fro mon e mode l yea r t o another , eve n i f the chang e i s introduce d for performanc e o r safetyimprovements . Al l design change s introduc e the ris k o f potentia l unforesee n problems , bu t thi s doe s no t (nor shoul d it ) prohibi t an ydesig n change s fro meve r bein g implemented . A s a genera l rule , EP Aalway s attempt s t o conside r the potentia l effect s o f a ne wcontro l devic e o n th e performanc e o f othe r vehicl e system s o r functions , especiall yan yspecifi c concern s raise d b ycommenters . I n the cas e o f the onboar d rulemaking , we have analyze d thi s issu e i n grea t detail . Ou r analysi s show s tha t emissio n contro l system s lik e onboar d (i.e. , evaporativ e systems ) have create d onl ya minima l numbe r o f problem s i n the past , an d o f the fewproblem s tha t di d occur , onl ymino r consequence s resulted . Overall , i t i s reasonabl e t o expec t tha t onboar d system s wil l demonstrat e a simila r leve l o f performance . I t i s tru e tha t tes t procedure s an d leadtime d o hav e some effec t o n th e degre e t o whic h onboar d system s interac t wit h othe r vehicl e system s o r functions . W e wil l thoroughl y evaluat e al l comment s w e receive o n thes e issues . A s fa r a s the rol e o f automotiv e par t suppliers , we rarel y have direc t contac t wit h them . Whil e we occasionall ydiscus s componen t design/functio n wit h suppliers , the rol e an d responsibilit yo f a supplie r t o provid e a n acceptabl e produc t i s dictate d b

ythe busines s relationshi p develope d betwee n a manufacture r an

d the supplier . EP Ai s independen t fro mthi s relationship . You r Jun e 1 3 lette r als o aske d t o wha t exten t the MOUwil l hel p t o addres s the issue s discusse d above . A s a matte r o f pas t practice , NHTS Aha s alway s ha d the opportunit yt o commen t o n action s whic h have the potentia l t o affec t moto r vehicl e safety . Th e MOUwil l provid e a mor e forma l proces s t o ensur e tha t al l important safety-relate d issue s ar e take n int o consideratio n b

yNHTSA an d EPA . Finally , we woul d lik e t o emphasiz e tha t safetyi s a ke y facto r i n an

ysyste m o r componen t design an d development . Thi s issue i s no t limite d t o emissio n contro l systems ; no r ar e the potentia l problem s tha t can result . NHTSA' s record s indicat e tha t a larg e variet yo f problem s wit h numerou s vehicl e system s resul t i n recalls . NHTSAwoul d be i n the bes t positio nP. 9

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t o discus s the type s o f problem s associate d wit h variou s recalls . Our experienc e wit h emissio n contro l system s ha s show n tha t thes e system s d o no t creat e uniqu e o r unusua l problems . I f anything , th e consequence s o f an emissio n contro l syste mfailur e ar e relativel ymino r in compariso n t o othe r systemfailures . Further , NHTSA' s record s indicat e tha t emissio n contro l system s accoun t fo r onl ya ver ysmal l fractio n o f th e numbe r o f problem s tha t d o occur . Overall , emissio n contro l system s appea r t o have bee n implemente d safely . Sincerely , le e M . Thoma

s Le e M . Thoma s

Enclosure s

cc : The Honorabl e Dian e K . Stee d Administrator , NHTSA