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# OAR Box 1818 Prepped byOllie Stewart



### Document

Number: 

# 76 ) IV-A- 5 Docket Number: 

# A-87-1 1

Printed 11/6/20083:12:46

PM Sheet 76 of 79P. 2 

# /A-87-1 1 w - A-5

Summar yo f Change d Circumstance s

Contro l o f Ai r Pollutio nFro mNe wMoto r Vehicle s an dNe wMoto r Vehicl e Engines ; Refuelin g Emissio nRegulation s fo r Gasoline

Fuele d Light-Dut yVehicle s an d Truck s an dHeavy-Dut yVehicle s

Augus t 199 1

Standard s Developmen t an d Suppor t Branc h Emissio nContro l Technolog yDivisio n Offic e o f Mobil e Source s Offic e o f Ai r an dRadiatio n U.S . Environmenta l Protectio nAgenc yO nAugus t 19 , 198 7 EP Apublishe d i nth e Federa l Registe r a

Notic e o f Propose d Rulemakin g (NPRM ) fo r th e contro l o f vehicl e refuelin g emission s (5 2 F R31162) . Thi s documen t provide s a summar yo f relevan t change d circumstance s sinc e th e NPR Mwa s published
. Sectio nI detail s th e change dcircumstance s an dSectio n I I provide s a discussio no f th e impac t o f thes e change d circumstance s o nth e propose daction
. Th e change d circumstance s discusse di nthi s documen t aris e fro mthre e sources . First , th e 199 0 Clea nAi r Ac t Amendment s (CAAA ) includ e change s t o th e provision s relate dt o onboar dan d Stag e I I controls . Second , technolog ydevelopment s an dsevera l recent/pendin g regulator yaction s hav e potentia l effect s o nEPA' s analyse s relate d t o onboar dcontrols . Third , comment s receive d followin g issuanc e o f th e NPR Mindicat e tha t change s ma yb e appropriat e fo r severa l aspect s o f th e proposal .
I . Change dCircumstance s Thi s sectio ndiscusse s th e change dcircumstance s sinc e issuanc e o f th e NPRM . Th e firs t portio ndiscusse s propose do r fina l regulator yaction s an d technolog yimprovements
. Thes e includ e fue l volatilit ycontro l requirements , th e requirement s fo r improve d evaporativ e emission s control , an d vapo r contro l technolog yimprovements
. Th e secon dportio naddresse s change s du e specificall yt o enactmen t o f th e 199 0 CAAA , includin g onboar d applicability , th e leve l o f th e emissio nstandard , an d implementatio nleadtime
. Th e thir dportio ndiscusse s tes t procedur e change s whic hma yb e appropriate , base do ncomment s receive d o nth e NPR Man dth e propose dchange s i nevaporativ e emissio ntes t procedures . 

### A. Fuel VolatilityRegulation Th e regulatio no f gasolin e fue l volatilit ywa s propose da t th e sam e tim e a s th e Augus t 198 7 onboar dproposal . However , becaus e th e specifi c requirement s fo r volatilit ycontro l ha dno t bee n finalize d a t tha t time , EPA' s onboar d analysi s assume dtha t onboar d design s woul d b e base d o na fue l volatilit yo f 11. 5 ps i Rei dvapo r pressur e (RVP) . EP Aha s sinc e promulgate da fina l rul e requirin g that , beginnin g i n1992 , fue l volatilit yb e limite dt o a maximu mo f 9. 0 ps i RV P i nth e summe r months , whe ncontro l o f ozone-producin g emission s (includin g refuelin g vapors ) i s mos t critica l (5 5 F R 23658 , Jun e 11 , 1990) . Fue l volatilit yo f 7. 8 ps i RV P i s calle d fo r i nsom e souther nnonattainmen t areas . Th e volatilit y specificatio nfo r certificatio ntes t fue l wil l remai na t 9. 0 ps i RVP , thu s ensurin g tha t in-us e fue l volatilit ywil l no t excee d desig nbasi s fue l volatilit yi nth e critica l contro l months . Thes e control s affec t severa l area s o f th e analysi s whic h accompanie d th e onboar d contro l proposal . Th e mos t significan tP. 4

effec t i s a decreas e i nth e amoun t o f refuelin g emission s generated . Althoug hther e i s som e variatio namon g vehicles , ther e wil l typicall yb e a decreas e o f abou t 1 1 percen t i nth e amoun t o f emission s t o b e controlled , thu s reducin g th e ai r qualit ybenefi t o f refuelin g control s somewhat . However , fo r onboar dsystems , thi s als o allow s a reductio ni ncaniste r siz e fro mtha t estimate di nth e NPR Manalysis
. Purg e requirement s wil l als o b e ease dsomewhat . Becaus e smalle r canister s ar e les s expensiv e an deasie r t o package , i t woul d b e reasonabl e t o expec t tha t overal l cost s woul db e lower . 

### B. Improved

Evaporative EmissionsControl Sectio n20 2 (k ) o f th e amende dClea nAi r Ac t require s EP At o promulgat e regulation s t o improv e th e contro l o f evaporativ e emission s fro m

gasoline-fuele d moto r vehicles
. Thes e regulation s mus t ensur e emission s contro l durin g vehicl e operatio nan dove r a t leas t 2 day s o f nonuse . Eve nbefor e th e CAAAwer e finalized , EP A ha d propose d change s t o th e evaporativ e tes t procedur e a s par t o f th e origina l proposa l t o contro l in-us e fue l volatilit y(5 2 F R 31274 , Augus t 19 , 1987 ) . Thi s wa s supplemente db ya nadditiona l notic e o nJanuar y19 , 199 0 (5 5 F R1914) . Apubli c worksho p wa s hel d o nDecembe r 19 , 199 0 (5 5 F R49914 , Decembe r 3 , 1990) . Th e Agenc yplan s t o finaliz e th e improve devaporativ e rulemakin g thi s year . Althoug himprove d evaporativ e syste mdesign s wil l ultimatel y depen d o nth e tes t procedur e requirement s an dth e contro l strategie s electe d b yth e manufacturers , i t i s expecte dtha t caniste r size s woul d nee dt o b e increase dt o handl e increase dvapo r loads , an d tha t th e purg e syste mwoul dnee dt o b e upgrade dt o transpor t greate r amount s o f vapo r t o th e engine
. Manufacturer s woul d als o nee d t o ensur e tha t thes e greate r amount s o f vapo r d o no t increas e exhaus t emission s abov e th e standards . 

### C. TechnologyImprovements Th e technolog yanalysi s provide di nth e proposa l projecte d tha t mos t onboar d contro l system s woul db e integrate dwit hth e evaporativ e emission s contro l system , s o tha t th e implementatio no f onboar d control s wa s considere dincrementa l t o curren t evaporativ e emission s contro l requirements
. Onboar d syste mconcep t developmen t an dprototyp e testin g sinc e th e proposa l wa s issue d hav e indicate dtha t eve nfurthe r desig n simplification s ar e possible
. Basi c component s o f a simplifie d desig nar e presente d i na nEP Amemorandum , date dDecembe r 22 , 198 8 (availabl e i nPubli c Docke t No . A-89-18 , ite mII-B-6) , an di na numbe r o f othe r technica l an dbriefin g document s i nPubli c Docke t No . A-87-11 . A s i s discusse d i nthes e technica l document s an d briefings , EP Aha s develope dan dteste da simplifie donboar dsyste m i na benc hconfiguratio nan dha s installe da versio no f thi s syste m i na lat e mode l passenge r car . Th e prototyp e syste mme t EPA' sP. 5

propose d refuelin g emissio nstandar dan dperforme dsatisfactoril y i nlimite d in-us e testing
. 

### D. Applicabilityof

the Standard 1 . Vehicl e Classe s Regulate d Th e August , 198 7 proposa l cover s gasoline-fuele d light-dut y vehicle s (LDVs) , light-dut ytruck s (LDTs) , an dheavy-dut yvehicle s (HDVs) . Th e Clea nAi r Act , Sectio n202(a ) (6) , a s amende di n1990 , direct s EP At o "promulgat e standard s unde r thi s sectio nrequirin g tha t ne wlight-dut yvehicle s manufacture dbeginnin g i nth e fourt h mode l yea r afte r th e mode l yea r i nwhic hth e standard s ar e promulgate d an d thereafte r shal l b e equippe dwit h[onboard ] systems. " Light-dut yvehicle s ar e explicitl yincluded , bu t n o specifi c languag e dealin g wit hothe r vehicl e classe s i s provided
. Sectio n22 3 o f th e amendment s define s light-dut yvehicle s a s havin g th e Cod e o f Federa l Regulation s definitio ni neffec t a t th e tim e o f enactmen t o f th e amendment s (se e 4 0 CF R86.082-2) . Th e repor t o f th e join t House/Senat e conferenc e o nth e 199 0 CAAAcontain s n o legislativ e histor yspecificall ydealin g wit h onboar d controls , althoug hi t doe s poin t ou t tha t Titl e I I provision s (whic hinclud e th e paragrap hrequirin g onboar dcontrols ) ar e generall ybase d o nth e Hous e bill , H.R . 303 0 (Hous e Repor t No . 101-952 , 101s t Congress , 2n dSession , 336) . Th e repor t o f th e Hous e Committe e o nEnerg yan dCommerc e o nH.R . 3030 , date dMa y17 , 199 0 (Hous e Repor t No . 101-490 , 101s t Congress , 2n dSession , 303) , contain s wordin g simila r t o tha t o f th e fina l 199 0 CAAAo nonboar d controls , applyin g th e requiremen t t o "ne wlight-dut ymoto r vehicles"
. Th e repor t goe s o nt o sa ytha t "th e standard s require d t o b e promulgate d unde r thi s paragrap har e t o appl yt o al l ne w passenge r car s an d al l light-dut ytrucks, " implyin g tha t th e ter m "light-dut ymoto r vehicles " wa s intende dt o includ e LDV s an dLDTs . Th e Chafee-Baucu s Statemen t o f Senat e Manager s i s describe db y it s author s a s "ou r bes t effor t t o provid e th e agenc yan dth e court s wit hth e guidanc e tha t the ywil l nee di nth e cours e o f implementin g an d interpretin g thi s comple xact " (13 6 Congressiona l Record , S16933 , dail yed. , Octobe r 27 , 1990) . I ni t the ydescrib e th e Conferenc e agreemen t t o essentiall yadop t th e Hous e provisio n fo r onboar d controls , specificall ycharacterizin g th e Hous e provisio na s applyin g "t o al l ne wpassenge r vehicle s an dlight-dut y trucks. " Th e legislativ e histor ydiscusse dabov e suggest s tha t Congres s ma yhav e intende d tha t LDT s b e include dwithi nth e scop e o f th e onboar d requirements
. I naddition , Congres s di dno t preclud e impositio no f onboar d control s base do nothe r statutor y authorities
. Thus , onboar dcontrol s coul db e require dfo r LDT s an d HDV s base d o nth e Clea nAi r Act' s genera l authorit yprovision , Sectio n202(a)(1) , whic hstates : "Th e Administrato r shal l byP. 6

regulatio nprescrib e (an d fro mtim e t o tim e revise ) i naccordanc e wit hth e provision s o f thi s section , standard s applicabl e t o th e emissio no f anyai r pollutio nfro manyclas s o r classe s o f ne w moto r vehicle s o r ne wmoto r vehicl e engines , whic hi nhi s judgmen t caus e o r contribut e to , ai r pollutio nwhic hma yreasonabl yb e anticipate d t o endange r publi c healt ho r welfare. " I t i s estimate d tha t LDT s contribut e abou t one-thir do f curren t tota l refuelin g emissions
. Exemptin g LDT s fro monboar d contro l requirement s woul d reduc e th e benefi t o f th e progra m correspondingly , mitigate dperhap s temporaril yb yth e presenc e o f Stag e I I control s i nsom e non-attainmen t areas . Furthermore , becaus e man yo f thes e vehicle s ar e ver ysimila r t o LDV s i nterm s o f design , hardware , an d usage , control s woul db e similar
. Thi s i s reflecte d i nth e fac t tha t thes e vehicl e classe s ar e treate d togethe r i nothe r provision s o f th e 199 0 CAAA . Th e incrementa l cos t o f onboar d control s pe r light-dut ytruc k i s estimate di nth e EP Amemorandu mo ncos t (reference d i nSectio nI. C o f thi s document ) t o b e slightl yhighe r tha ntha t o f a typica l LDV . Thi s i s mor e tha noffset , however , b yfue l recover ycredits
. Th e refuelin g emission s contribute dbyHDV s ar e estimate dt o b e abou t 5 percen t o f th e total . Althoug hmuc hsmalle r tha ntha t o f LDV s an d LDTs , thi s i s stil l a significan t contributio nwhe n viewe d i nth e contex t o f th e ver yhig hefficienc yachievabl e by , an d require d for , onboar d controls . I naddition , man yo f th e smalle r HD V

designs , suc ha s clas s li ban dII I trucks , ar e essentiall yextrapolation s o f conventiona l LDT s an dcoul dus e simila r contro l technology . Furthermore , fue l syste mdesign s fo r othe r gasoline-fuele d HDV s ar e simila r t o thos e o f lighte r vehicles , an d s o th e approache s take nt o designin g LD V an dLD T onboar d system s coul d appl yt o thes e large r vehicle s a s well . 2 . Fue l Typ e Consideration s Th e growin g interes t i nth e us e o f alternativ e fuel s necessitate s clarificatio no f whic hvehicl e fue l type s ar e mean t t o b e subjec t t o onboar d refuelin g vapo r contro l requirements
. Th e languag e i nth e 199 0 CAAAi s no t specifi c regardin g fue l typ e an d s o doe s no t directl yresolv e thi s issue
. Althoug hth e 198 7 proposa l applie d onl yt o gasoline-fuele d vehicles , i t ma yb e appropriat e t o broade nanyonboar drequiremen t t o othe r fue l types . Thi s woul d b e consisten t wit hEPA' s pas t approac ho f establishin g a leve l playin g fiel dfo r al l fue l types . I f suc ha napproac hwer e taken , anyvehicle s whic hus e a fue l o f lo wenoug hvolatilit ytha t the yca nmee t th e refuelin g emission s performanc e standar d withou t onboar dcontro l system s would , o f course , no t b e require d t o instal l suc hsystems . I nsom e cases , i t ma yb e feasibl e t o waiv e testin g requirement s i f refuelin g emission s ar e inherentl ylow . Vehicle s designe dt o operat e o nmor e tha non e fue l typ e woul d nee dt o mee t th e refuelin g emission sP. 7

standar d unde r th e fue l compositio ncondition s wit hth e greates t refuelin g emissions
. 

### E. EmissionStandard Th e statutor ychange s als o rais e th e issu e o f th e appropriatenes s o f th e 0.1 0 gra mpe r gallo n(g/gal ) emissio n standar d originall ypropose d i nth e 198 7 NPRM . Th e 199 0 CAAA requir e a minimu memissio ncaptur e efficienc yo f 9 5 percent . A s i s show nbelow , th e propose d standar dappear s t o satisf ytha t requirement
. Usin g th e refuelin g emissio nrat e equatio ndevelope db yEP A an d th e limitin g value s o f th e applicabl e parameter s specifie di n EPA' s refuelin g tes t procedure , th e efficienc yo f th e propose d standar d i s show nbelow : E R= 0.48 5 RV P + 0.88 4 T D - 0.094 9 A T - 5.90 9

= 0.48 5 (9.0 ) + 0.88 4 (81 ) - 0.094 9 (+2 ) - 5.90 9 =5.4 3 g/ga l where : E R= th e refuelin g emissio nrat e i ng/gal . RV P = Rei d Vapo r Pressur e i npsi
. T D = Dispense d fue l Temperatur e i n°F . A T = (Tank Temperatur e - Dispense d fue l Temperature )

i n°F . Th e efficienc yi s therefor e calculate dt o be : 1 - (0.1 0 * 5.43 ) = 0.9 8 o r 98% . I nth e Augus t 198 7 NPRM , certificatio nusefu l life , recal l testing , an d warrant yperiod s wer e propose dt o b e th e sam e fo r onboar d refuelin g control s a s fo r othe r element s o f th e vehicl e emissio ncontro l syste m(5 2 F R31220 , Augus t 19 , 1987) . Th e amendment s t o th e Ac t requir e that , wit hrespec t onl yt o LDV s an d LDT s u p t o 3,75 0 lbs . loade dvehicl e weigh t an d6,00 0 lbs . gros s vehicl e weigh t rating , "i nth e cas e o f anyrequiremen t o f [Sectio n 202 ] whic hfirs t become s applicabl e afte r enactment.. . th e [usefu l life ] perio d shal l b e te nyear s o r 100,00 0 mile s (o r th e equivalent) , whicheve r firs t occurs , wit htestin g fo r purpose s o f in-us e complianc e unde r sectio n20 7 u p t o (bu t no t beyond ) seve n year s o r 75,00 0 mile s (o r th e equivalent) , whicheve r firs t occurs, " unles s otherwis e specifie d (Sectio n202(d)(1)) . Wit hrespec t t o al l othe r vehicle s an d engines , th e period s ar e presume dt o b e th e sam e a s abov e unles s th e Administrato r find s tha t longe r period s ar e appropriate
. Warrant yperiod s wer e shortene db yth e 199 0 amendment s t o tw o years/24,00 0 mile s (o r th e equivalent ) fo r mos t emissio ncontro l component s includin g onboar drefuelin g system s (Sectio n20 7 (i) ) . On e possibl e approac ht o implementin g thes e provision s woul d b e t o mak e onl yth e change s t o thi s rul e require d t o mak e i t confor mt o th e CAAA. Takin g thi s approac hwoul dmea nP. 8

that , fo r heavie r LDT s an dHDVs , th e requirement s whic hexiste d durin g th e tim e o f th e NPR Mwoul dapply . 

### F. ImplementationLeadtime I nit s 198 7 NPRM , EP Aestimated , base do nit s pas t experienc e wit hevaporativ e emissio ncontrols , tha t a minimu mleadtim e perio d o f tw o year s woul d b e require d t o design , develop , an dadequatel y tes t onboar d refuelin g systems . EP Aacknowledge dtha t som e uncertaint yexiste d i nit s estimat e an ddiscusse dth e possibilit y o f usin g a phase-i napproac ht o reduc e th e certificatio nburde nan d provid e manufacturer s mor e tim e t o addres s anymodel-specifi c safet yconcerns . Respondin g t o EPA' s proposal , mos t manufacturer s indicate d tha t a minimu m o f fou r year s leadtim e wa s necessar yt o ensur e saf e implementatio no f onboar dcontrols . Longe r leadtim e wa s als o recommende d b yth e Nationa l Highwa yTraffi c Safet y Administratio n(NHTSA) , whic hstate dtha t i t i s critica l fo r manufacturer s t o receiv e sufficien t leadtim e i norde r t o minimiz e safet yrisks
. Congres s addresse d leadtim e fo r light-dut yvehicles , mandatin g a nimplementatio nschedul e i nth e 199 0 CAAA . Th e Amendment s requir e a thre e yea r phase-i n(40,80,10 0 percent , applicabl e t o eac hmanufacturer' s sale s volume ) o f onboar drefuelin g control s o n ne wlight-dut yvehicle s beginnin g i n"th e fourt hmode l yea r afte r th e mode l yea r i nwhic hth e standard s ar e promulgated. " Becaus e i t i s probabl e tha t mos t vehicl e model s woul db e i n199 2 mode l yea r productio nbefor e th e fina l rul e i s promulgated , a nonboar dphase

i nrequiremen t coul d no t becom e effectiv e befor e th e 199 6 mode l year . 

### G. Refueling Test

Procedure I t i s desirabl e tha t th e onboar d syste mtes t procedur e provid e a naccurat e assessmen t o f th e contro l o f refuelin g emission s whil e minimizin g th e testin g burde no nbot hindustr yan dgovernment . Th e idea s discusse d belo wfo r modifyin g th e propose dtes t procedur e ar e base d o ncomment s receive d o nth e NPR Man danticipate dchange s i n th e evaporativ e tes t procedure . Thes e alternativ e approaches , eac h o f whic hi s discusse d i nfurthe r detai l below , ar e a s follows : 1 ) vehicle s whic hhav e th e onboar dsyste mintegrate dwit hevaporativ e contro l system s woul d us e al l o r par t o f th e Federa l Tes t Procedure 1 (FTP ) a s th e preconditionin g cycl e befor e a refuelin g test ; 2 ) abbreviate d preconditionin g option s woul db e adde dfo r non-integrate d systems ; 3 ) a nabbreviate dprocedur e fo r testin g seal s an d connection s woul d b e added ; 4 ) a fou r gallo npe r minut e lowe r limi t woul d b e specifie dfo r th e refuelin g dispensin g rate .

1 Th e Federa l Tes t Procedur e (FTP ) refer s t o th e testin g sequenc e tha t include s th e exhaus t an devaporativ e emissio nsystem s tes t procedures .P. 9

1 . Preconditionin g Fully-Integrate dan dPartially-Integrate d System s Th e refuelin g tes t procedur e propose di nth e Augus t 198 7 NPR M fo r fully-integrate d an d partially-integrate dsystem s i s a separate , stand-alon e sequenc e whic hwoul db e performe d independentl yfro mth e FT P sequence . I t consist s o f a vehicl e preconditionin g sequenc e followe d b yth e actua l refuelin g emission s measuremen t test . Adiagra mo f thi s propose drefuelin g tes t procedur e i s provide d i nFigur e 1 . Anumbe r o f comment s o nth e origina l onboar drefuelin g contro l proposa l concerne d th e complexit yo f th e tes t procedure . Althoug h th e propose d procedur e wa s itsel f th e produc t o f interactio n betwee nEP Aan d manufacturers , i t stil l appeare dt o represen t a significan t increas e i nimpac t o ntestin g resources . Thes e resourc e impact s wer e largel yassociate dwit hth e vehicl e preconditionin g sequence , whic hinvolve dloadin g th e vapo r storag e caniste r t o a t leas t th e breakthroug hpoin t an dthe nsimulatin g thre e day s o f norma l vehicl e driving
. Commenter s suggeste d tha t EP Ashoul d develo p a simplifie d approac ht o refuelin g testin g i n orde r t o reduc e th e test' s resourc e impacts
. I nrespons e t o th e comments , th e Agenc yundertoo k furthe r studyaime da t identifyin g alternativ e method s fo r vehicl e preconditionin g whic hwoul db e les s resourc e intensive
. On e concep t i s t o us e th e FT P fo r conditionin g o f integrate d refueling/evaporativ e emissio ncontro l systems . Since , i nth e future , th e FT P wil l likel yinclud e initia l caniste r breakthroug h loadin g an d a combinatio no f vehicl e drivin g an dcaniste r loadin g conditions , th e tes t vehicl e an d fue l vapo r emissio ncontro l syste m woul d b e conditione d a s the yprocee dthroug hth e FT P t o th e refuelin g measuremen t test . Suc ha napproac hcoul deliminat e th e nee d fo r a specia l vehicl e preconditionin g cycl e altogether , thu s greatl ysimplifyin g th e overal l tes t procedure , excep t perhap s i n test s ru nsolel yfo r th e purpos e o f assessin g complianc e wit hth e refuelin g emissio nstandard . Thi s assessmen t i s base d o nth e FT P sequenc e propose di nth e evaporativ e emission s worksho p notic e (5 5 F R49914 , Decembe r 3 , 1990) ; th e worksho p wa s hel do nDecembe r 19 , 1990 . Althoug h currentl ya proposal , i t represent s th e bes t projectio no f th e FT P likel yt o b e i nus e a t th e tim e th e onboar dsyste mtes t procedur e i s finalized
. Adiagra mo f th e FT P propose di nth e worksho p i s show ni nFigur e 2 . I t ma yb e necessar yt o modif ythi s alternativ e i f th e propose d FT P i s substantiall ychange di nth e improve d evaporativ e emission s contro l rulemakin g no wunderway .

## J :

Integrate dSystem €jDigkgF-J > " r ge » Cycli c Drive Disconnec t Vapo r Lin e t o Caniste r Drai nFue l Tan k 40 * Fuelin g Reconnec t Vapo r Lin e t o Caniste r Driv e On e LA- 4 f . On e Hou r Ho t Soak g . Repea t (e ) and(f ) Twic e li . Disconnec t Vapo r Lin e t o Caniste r i . Drai nFue l Tank j . 40 % Fuelin g k . Reconnec t Vapo r Lin e t o Caniste r 1 . Hea t Buil d(60 ° + 2° F Initial , 2 4 + 1° F Rise ) m . Repea t (e ) Through(1 ) Twic e n . Driv e On e LA- 4 Caniste r Loadingt o Breakthrough ° Drai nFue l Tank ° Soa kVehicl e for 6 Hour s " Fue l i nSUEDt o Breakthrough
Integrate dSyste

m Caniste r Purge . Continuou s Drive
a . Disconnec t Vapo r Line t o Caniste r b . Drai nFue l Tank c . 403 ; Fuelin g d . Reconnec t Vapo r Line t o Caniste r e . Driv e Repeate dLA-4 s Unti l Mileag e Accumulate d= Mileag e Require dfor Purg e Eguivalen t t o Cycli c Drive . Mileag e Accumulatio nStop s a t the Firs t Idl e Pas t the Mileag e Requiremen t

Vehi c ° Disconnec t l e Coo l Dow n Line to Caniste r ° Drai nFue l Tank ° 10 * Fueling ° Soa kVehicle 6 to 2 4 Hour s 

# 1 X Non-integrate dSystem Caniste r Purge , Continuou s Drive

a . Disconnec t Vapo r Lin e t o Caniste r b . Drai nFue l Tan k c . 95 * Fuelin g d . Reconnec t Vapo r Lin e t o Caniste r e . Drive Repeate dLA-4 s Unti l 85 * o f TankVolume I s Consume d

Refuelin gEmission s Measuremen t Reconnec t Vapo r Lin e t o Caniste r Fue l t o Automati c Nozzl e Shut-of f (85 * MimimunFueling) . Restar t Fueling Followin gAny

Prematur e Shut-off s Withi n 1 5 Seconds )
NPR MOnboar dTes t Procedur e Flo wChar t Figur eP.1 1 

# Propose d Federa l TestProcedure

Fue l 9 RVP , 40 % ful l 

# I Preconditionin g LA-4 

# I Purg e &Load Caniste r SHE D o rbenc h procedur e Refue l Col d Soa k 68-86 ° F 

# —r ~ ExhaustTest Fue l Tem p Profil e 

## ZE 7 Refue l Two HeatBuild s 2 hr s ea , fue l 72-96 F natura l coo l to 72 ° F Diurna l Tes t 2 hour s fue l 72-96 ° F Refue l Runnin g Loss Test LA-4,2*NYCC,LA-4 , 95 F SHE D o rpointsource Ho tSoa k an d Permeatio n Los

s Test 5 hour s ambien t95 ° F 

# © Refuelin g Emission s Measuremen tTes t



# © Refuelin g Emission s

Measuremen tTes t

Figur e 2P.1 2


# Refuelin g TestProcedure : Integrate d System s 

# © ©

FTP* Throug h th e Exhaus tTest

•Disconnec

tRefuelin g Caniste r •Remov e Fue l Fille rCap •Drai n Fue l Tan k •10 % Fuelin g •Replace Fue l Fille rCa p •Vehicl e Temperatur

e Stabilizatio n (80 ±3° F fo ra tleast6 hours) •Connec tRefuelin g Caniste r •Remov e Fue l Fille rCa p •Place Vehicl e i n She d

Refuelin g Emission s Measuremen tTest Fue l t o Automatic Nozzl e Shut-of f(85 % Minimu m Fuelin g : 81 ° - 84 ° F Fuel ) Restar tFuelin g Followin g AnyPrematur e Shut-offs Withi n 1 5 Second s

* Th e Federa l TestProcedur e (FTP) refer

s t o th e testin g sequence thatinclude s exhaustan d evaporative emissio n syste m testprocedure s


### Figure 3P.1 3

Fo r integrate d systems , i t ma yb e appropriat e fo r th e tes t procedur e t o adop t on e o f tw o option s whic hwoul dus e th e FT P t o conditio nth e vehicle/caniste r fo r th e refuelin g emission s measuremen t test . Th e firs t optio ni s show ni nFigure s 2 an d3 a s th e sequenc e labele d optio n"1" . Unde r thi s option , th e refuelin g emission s measuremen t tes t woul db e place da t th e en do f th e FT P an d woul d b e retaine d i nth e sam e for ma s tha t describe di nth e NPRM . Th e basi c premis e fo r positionin g th e refuelin g tes t i nthi s wa yi s tha t th e vapo r load s an d purg e requirement s involve di nth e evaporativ e emission s tes t ar e expecte dt o b e generall ysufficien t t o tes t th e integrate d system' s purg e capabilit yan dt o prepar e th e syste mfo r a refuelin g event . Therefore , a separat e refuelin g preconditionin g woul d no t b e needed . On e possibl e issu e concernin g us e o f th e FT P t o conditio n vehicles/canister s prio r t o th e refuelin g tes t i s th e amoun t o f wor k tha t mus t b e performe di f th e onl yobjectiv e i s conductin g th e refuelin g measuremen t test , suc ha s migh t occu r fo r recal l evaluatio ntestin g o r i f th e refuelin g tes t wer e voide ddurin g certificatio ntestin g by , fo r example , th e accidenta l spillag e o f fue l durin g refueling
. I nsuc hinstance s th e entir e FT P sequenc e woul d hav e t o b e performe dfo r th e purpos e o f conditionin g a vehicl e fo r a refuelin g tes t unde r Optio n1 . I t ma yb e usefu l t o conside r alternativ e method s o f determinin g i f th e vehicl e conditionin g sequenc e ca nb e furthe r abbreviated , whil e maintainin g prope r evaluatio no f th e refuelin g emissio ncontro l system . Anothe r possibl e optio ni s th e placemen t o f th e refuelin g emission s measuremen t tes t afte r th e exhaus t emission s measuremen t tes t i nth e FTP . Labele d optio n"2 " i nFigure s 2 an d3 , thi s testin g optio nwoul d provid e a shorte r preconditionin g metho dfo r integrate d systems , an d thu s woul dprovid e a saving s i ntim e an d resource s fo r thos e case s i nwhic hth e onl ydesire dobjectiv e i s th e refuelin g emission s measurement . I nthi s approach , th e vehicle/caniste r woul d b e preconditione da s i nth e propose d evaporativ e procedur e an d th e vehicl e woul db e drive nthroug hth e drivin g cycle s specifie d i nth e exhaus t tes t (exhaus t measurement s ma yo r ma yno t b e required)
. Th e refuelin g emission s measuremen t tes t woul d the nb e conducted . T o conduc t th e evaporativ e emission s test s unde r Optio n2 , th e entir e FT P woul d nee d b e performe d separately . Alternatively , i t i s possibl e t o desig na tes t procedur e tha t allow s re-entr yint o th e FT P sequenc e afte r completio no f th e refuelin g emission s measuremen t tes t i norde r t o complet e th e evaporativ e an drunnin g los s portion s o f th e test . Us e o f thi s approac hwoul drequir e tha t additiona l purg e b e provide dbefor e continuin g throug hth e res t o f th e FTP , becaus e th e refuelin g even t woul db e expecte dt o loa dth e caniste r t o nea r it s ful l capacity
. Additiona l purg e opportunit y coul d b e provide d b yinsertin g anothe r exhaus t emission s drivin g 1 1P.1 4

cycl e (withou t measurement) , o r som e comparabl e drivin g sequence , int o th e FT P afte r th e refuelin g emission s test . Anothe r approac hi s t o us e Optio n1 fo r norma l certificatio n testing , bu t t o retai nOptio n2 a s a stand-alone , shor t tes t t o b e use d a t th e Administrator' s discretion
. Thi s optio nwoul dprovid e maximu mflexibilit yan d reduc e overal l testin g resourc e impact s fo r bot hcertificatio nan d in-us e complianc e testing
. 2 . Preconditionin g Non-Integrate d System s Th e secon d tes t procedur e modificatio nwhic hma yb e appropriat e is , again , inspire db yth e desir e t o mak e th e onboar d syste mtes t les s resource-intensive
. Unde r th e Augus t 198 7 onboar d proposal , 8 5 percen t o f th e fue l tan k capacit ymus t b e consume d durin g th e preconditionin g sequenc e fo r non-integrate d systems . I n th e modificatio nbein g considered , th e manufacturer s woul dhav e th e optio no f usin g anyintege r numbe r o f continuousl ydrive nLA-4 drivin g cycle s t o sufficientl yconditio nth e caniste r (b yth e manufacturer' s definition ) prio r t o th e refuelin g tes t (Figur e 4) , provide d tha t 8 5 percen t o r les s o f th e fue l tan k capacit yi s consumed . Thi s modificatio nwoul db e expecte dt o decreas e th e amoun t o f testin g resource s require dwithou t lessenin g th e tes t procedure' s abilit yt o evaluat e th e capacit yt o contro l refuelin g emissions
. Th e us e o f thi s preconditionin g sequenc e woul db e expecte d t o lea d t o simila r caniste r siz e an dpurg e requirement s a s th e ful l drivedow n(8 5 percent ) optio nbecaus e th e manufacturer s woul dstil l b e require d t o pas s th e refuelin g emissio ntest . Consequently , thi s revise d tes t sequenc e migh t b e desirabl e becaus e i t provide s th e opportunit yt o reduc e resourc e impact s fo r bot hth e manufacturer s an d EPA . I t shoul d b e note dtha t th e optio ngive ni n th e origina l proposa l t o us e tes t track/roa dpurg e i nlie u o f vehicl e dynamomete r drivin g woul db e retained
. A s a possibl e alternativ e metho dfo r EP Atestin g o f non integrate d systems , a vehicl e woul d b e fuele dt o automati c nozzl e shut-off , drive nsom e intege r numbe r o f LA- 4 drivin g cycles , an d the nsubjecte d t o th e refuelin g emission s measuremen t tes t (Figur e 4 ) . Thi s metho d differ s fro mth e above-describe dmodificatio ni n tha t th e SHE D refuelin g even t woul ddirectl yfollo wth e driving , wit hn o intervenin g drai nan dfil l t o 1 0 percent , an di ntha t i t woul d b e conducte d a t EPA' s discretio nonly . Th e basi s fo r thi s approac hi s th e fac t tha t partia l refueling s ar e commo ni nus e an d s o a nonboar d syste mshoul dhav e adequat e desig nmargi nt o accommodat e partia l refuelings
. Th e numbe r o f LA-4 s drive nwoul d b e a t EPA' s discretio no na pe r tes t basis
.

1 2P.1 5 

# Refuelin g TestProcedure : Non-Integrate d System s

Caniste rLoadin g
•Drai n Fue l Tan k •Soa k Vehicl e fora

tLeast6 Hour

s a t80 ° ±3 ° F •Load Canister(s) t

o Breakthroug h (Identica l to Eva p Loadin g Technique) 

# I
Continuou s Driv e Caniste rPurq e

•Disconnec

tVapo rLin e to Caniste r •Drai n Fue l Tan k •95 % Fueling : 81 ° - 84 ° FFue l •ReconnectVapo rLin e to Caniste r •Driv e th e Numbe ro

fLA-4s Specifie d b

y Manufacturers (u p to 85 % o fFue l Tank

)

•Disconnec

tVapo rLin e to Caniste r •Drai n Fue l Tan k •10 % Fuelin g •Soa k Vehicl e fo ratLeast6 Hour s at80 ° ±3 ° F •ReconnectVapo rLin e to Caniste r •Remove Fue l Fille rCa p •Place Vehicl e i n She d

Refuelin g Emission s Measuremen tTes t Fue l to Automati c Nozzl e Shut-of f (85 % Minimu m Fuelin g : 81 ° - 84 ° FFuel ) •Restar tFuelin g Followin g AnyPremature Shut-offs Withi n 1 5 Second s 

# 1 Testin g Optio n fo rEPA
•Disconnec

tVapo rLin e to Caniste r •Fue l to Automati c Nozzl e Shut-of f (atLeast95 % o

fFue l Tank , 81-8 4 FFuel ) •ReconnectVapo rLin e to Caniste r •Driv e Intege rNumbe ro

fl_A-4 s Determined b yEPA •Remove Fue l Fille rCa p •Plac e Vehicl e i n She d

Refuelin g Emission s Measuremen tTest

•Fue l t o Automati c Nozzl e Shut-of f (atleastas muc h fue l as used durin g drive , 81 ° - 84 ° FFuel ) •Restar tFuelin g Followin g AnyPremature Shut-off s Withi n 1 5 Second s



### Figure 4P.1 6

Th e refuelin g emission s measuremen t tes t contain s a provisio n fo r fuelin g t o automati c shut-off , and , becaus e automati c shutof f i s commonl ypractice d i nus e (eve nfo r smal l partia l fill s suc ha s wit hrenta l ca r returns) , i t woul dappea r reasonabl e t o retai nthi s provisio nfo r thi s tes t a s well . However , th e automati c shutof f mechanism s o nfue l pump s ar e no t designe dt o ensur e tha t a measure d volum e o f fue l i s i nth e vehicl e fue l tan k a t shutoff . Therefore , i t i s likel ytha t th e refuelin g measuremen t tes t woul dad dsomewha t mor e o r les s fue l tha nwa s burne d durin g th e LA- 4 drivin g cycles , thu s introducin g uncertaint yint o th e results . Th e effec t o f thi s variabilit yi nnozzl e shutof f o na tes t involvin g jus t a fe wLA-4 cycle s o f drivedow ncoul d b e significant
. Concer nabou t pumpin g to o muc hfue l woul dten dt o b e mitigate d b yth e fac t tha t th e rat e o f hydrocarbo nreductio ndurin g purg e i s generall ymuc hhighe r whe nth e caniste r i s heavil yloade d wit h hydrocarbon s (i.e
. durin g th e initia l LA- 4 cycles ) tha nwhe nth e hydrocarbo nconcentratio ni nth e caniste r ha s bee nreduced , thu s helpin g t o ensur e tha t th e purg e provide db yinitia l drivedow no f a full yloade d caniste r wil l fre e u p mor e tha nenoug hstorag e capacit yt o accommodat e th e correspondin g partia l refuelin g vapo r load . EP Awoul d welcom e inpu t fro mother s o nwhethe r o r no t th e highe r purg e rate s presen t a t th e star t o f a purg e cycl e woul d adequatel ycove r fo r nozzl e shutof f uncertainties
. T o avoi d inaccurat e tes t result s cause db yth e pumpin g o f to o littl e fuel , th e tes t procedur e woul dnee dt o ensur e tha t th e amoun t o f fue l dispense d durin g th e refuelin g measuremen t tes t i s a t leas t a s muc ha s tha t burne d durin g th e LA- 4 driving
. T o verif y this , som e metho d o f determinin g th e amoun t o f fue l consume ddurin g th e drivin g sequenc e woul d nee d t o b e included , suc ha s b y measurin g exhaus t emission s durin g som e portio no f th e drivin g an d performin g a carbo nbalanc e calculation , o r b yusin g th e vehicle' s previousl ydetermine d fue l economyrating
. Th e amoun t o f fue l pumpe d durin g th e refuelin g tes t woul dals o nee dt o b e metere dt o ensur e that , i f automati c pump shut-of f wer e t o occu r befor e th e prope r amoun t o f fue l wa s displaced , refuelin g woul db e resume d unti l sufficien t fue l wa s pumped . EP Awoul dwelcom e othe r suggestion s fo r dealin g fo r pump shutof f variability
. On e o f th e mor e attractiv e feature s o f a non-integrate dsyste m (full yseparat e refuelin g an devaporativ e systems ) i s tha t i t permit s a lowe r purg e rat e tha nfo r a nintegrate dsyste msinc e th e purg e o f th e refuelin g caniste r ca nb e sprea dmor e evenl yove r th e drivin g associate d wit hth e fue l dispensed
. Thi s lowe r purg e rat e i s valuabl e sinc e i t allow s fo r a reductio ni nth e potentia l effect s o f purg e o nexhaus t emissions
. Considerin g th e sophisticate d purg e strategie s availabl e wit helectroni c controls , ther e i s som e concer nthat , becaus e o f potentia l purge/exhaus t emissio ninteractions , manufacturer s coul ddesig na purg e syste m whic hoperate s a t lowe r purg e rate s durin g th e exhaus t emissio n tes t tha ndurin g a subsequen t portio no f th e preconditionin g 1 4P.1 7

drivin g cycle . T o avoi d th e possibilit yo f advers e o r unrepresentativ e exhaus t emissio neffects , i t ma yb e necessar yt o includ e a requiremen t that , fo r vehicle s usin g non-integrate d systems , th e purg e volum e mus t b e essentiall yth e sam e fo r eac hLA
4 drivin g cycl e durin g th e test . Finally , i t ma yb e appropriat e t o appl yth e procedur e fo r loadin g canister s t o breakthroug hpropose di nth e evaporativ e emission s revision s t o th e FT P (5 5 F R49914 , Januar y19 , 1990 ) t o test s o f non-integrate d system s a s wel l a s integrate dsystems . Thi s woul d simplif ytestin g procedure s an dreduc e th e nee dfo r additiona l equipment
. An ysubsequen t change s t o th e loadin g procedur e resultin g fro mfinalizatio no f th e improve devaporativ e rul e woul d b e factore d i na s well . 3 . Testin g o f Seal s an d Connection s Vapo r emission s fro ma refuelin g emission s tes t ca noccu r fro m tw o sources : emission s vente dfro mth e caniste r an demission s tha t escap e fro m

th e fillpip e seal , vapo r lin e connections , an dothe r leaks . Th e tes t procedure s propose di nth e NPR Man dth e option s describe d abov e tes t fo r bot ho f thes e source s o f emissions
. Althoug hth e purge/caniste r syste mcapacit yan doperatio nwoul db e evaluate d throug hth e ful l preconditionin g an drefuelin g emission s measuremen t sequence , ther e ma yb e situation s i nwhic hi t i s desirabl e t o onl ymeasur e emission s arisin g fro marea s othe r tha n th e canister
. Therefore , i t ma yb e appropriat e t o ad da tes t procedur e option , t o b e use d a t EPA' s discretio nonly , i nwhic hth e caniste r woul d b e thoroughl ybenc hpurge d prio r t o conductin g a refuelin g emission s measuremen t test . Th e caniste r woul dthe nb e reconnecte d an d th e norma l refuelin g emission s measuremen t tes t conducted . Th e emission s woul d nee d t o mee t th e refuelin g emissio nstandar di n orde r t o pas s th e test . Th e advantag e o f thi s typ e o f tes t ove r a complet e tes t sequenc e i s tha t th e integrit yo f th e seal s an d connection s ca nb e determine d wit ha modicu mo f effor t i ncase s wher e thi s determinatio ni s th e onl ydesire dresult . 4 . Lowe r Limi t o nRefuelin g Dispensin g Rat e I nit s proposal , EP Aha d specifie d a fue l dispensin g rat e o f approximatel y1 0 gallon s pe r minut e (gal/min ) fo r refuelin g tests . A noptio nwa s included , however , fo r EP At o tes t a t lowe r flo w rate s i f desired
. Thi s wa s don e t o ensur e tha t th e Agenc ywoul d hav e th e abilit yt o adequatel ytes t system s whic hi t believe dmigh t los e contro l effectivenes s a t lo wflo wrates . Base dupo ncomment s received , i t ma yb e appropriat e t o specif ya lowe r limi t fo r suc h testing
. Sinc e extremel ylo wdispensin g rate s woul dno t b e expecte d t o occu r i nuse , the ywoul db e unrepresentative
. Consequently , replacin g th e 1 0 gal/mi npropose drat e wit ha dispensin g rat e rang e o f 4-1 0 gal/mi nma yb e a reasonabl e solution
. 1 5P.1 8

Nearl yal l in-us e refueling s occu r a t a rat e o f 5 gal/mi no r greater , an d a t leas t som e fue l dispensin g nozzle s themselve s fai l t o operat e properl yi f use d a t 3 gal/min
. II . Impac t o f Change dCircumstance s onth e Propose dActio n I nadditio nt o th e impact s o nth e tes t procedur e discusse di n Sectio nI.G , th e change d circumstance s discusse di nSectio nI o f thi s documen t hav e potentia l impact s o ncosts , benefit s (emission s reductions) , an d th e resultin g cos t effectivenes s o f onboar d controls . Arevise d cos t analysis , addressin g mos t o f th e change d circumstance s discusse d i nSectio nI o f thi s document , i s containe d i na nEP Amemorandum , date dDecembe r 22 , 1988 , availabl e i nPubli c Docke t No . A-89-18 , ite mII-B-6 . Thi s analysi s calculate donboar d contro l cost s base d o na desig nincrementa l t o improve devaporativ e controls , a simplifie d onboar d syste mdesig nconcept , an d9. 0 ps i RV P certificatio nfuel . Th e resultin g estimate dcos t incremen t wa s lowe r tha nth e NPR Mestimate
. A nadjustmen t fo r th e fue l recover y credi t provide d b ycombustio no f th e collecte dvapor s resulte di n a ne t averag e cos t saving s o f a fe wdollar s pe r vehicle
. Sinc e ther e ar e Stag e I I vapo r recover ysystem s i nsom e area s o f th e countr ynow , an d thei r us e i s expecte dt o expan dt o a numbe r o f othe r area s unde r th e CAAAo f 1990 , i t i s worthwhil e assessin g th e affect s o f Stag e I I o nEPA' s cos t analysi s fo r a nonboar dequippe d vehicle
. Base d o ncurren t onboar dan dStag e I I technologies , refuelin g event s i nnonattainmen t area s i nwhic hbot honboar dan d Stag e I I system s ar e operativ e wil l resul t i nth e refuelin g vapor s bein g capture d b yth e onboar d system ; thu s th e onboar dfue l recover ycredi t woul d b e retained
. Withou t thi s adjustmen t fo r th e fue l recover ycredi t i t i s expecte d that , instea do f a smal l pe r vehicl e ne t cos t savings , a positiv e averag e cos t o f a fe wdollar s pe r vehicl e woul d result . Th e change d circumstance s discusse di nSectio nI o f thi s documen t wil l produc e a smal l ne t decreas e i nemission s reductio n benefit s o f onboar d controls , compare dt o th e benefit s calculate d i nth e NPRM . Th e effec t o f volatilit ycontrol s wa s accounte dfo r i nth e sensitivit yanalysi s i nSectio nV o f th e NPRM , yieldin g th e conclusio ntha t th e annua l averag e gasolin e refuelin g emissio n facto r i s abou t 1 1 percen t les s fo r th e cas e i nwhic hsummertim e RV P i s controlle d i nclas s C area s a t 9. 0 ps i tha nth e cas e i n whic hi t i s se t a t 11. 5 psi
. I t i s als o possibl e tha t us e o f reformulate d gasolin e i nsom e nonattainmen t area s woul dcaus e a sligh t reductio ni nbenefits
. Th e implementatio nschedul e fo r onboar dcontrol s woul d obviousl yimpac t ho wquickl yemission s reduction s woul dbegi nt o occur . However , i t i s reasonabl e t o expec t tha t th e ful l annua l benefi t woul d eventuall yb e attaine d a s phase-i nan dflee t turnove r progresses . Th e installatio no f Stag e I I systems , require di nsom e 1 6P.1 9

nonattainmen t area s b yth e 199 0 CAAA , woul dals o temporaril yreduc e th e emission s contro l benefi t o f onboar dsystems . However , becaus e th e Ac t als o call s fo r th e retiremen t o f th e federally-mandate d Stag e I I contro l requirement s onc e onboar dcontrol s ar e i n widesprea d use , th e reductio ni nonboar dcontro l benefit s woul db e expecte d t o b e temporary . I t shoul db e note dtha t th e onboar d contro l standard s an d thei r implementatio nschedul e ar e intende dt o appl yt o vehicle s sol d i nal l part s o f th e Unite dStates , eve n wher e Stag e I I control s ar e (o r wil l be ) i nplace , suc ha s i n California
. Because , a s discusse d above , th e ne t cos t o f onboar drefuelin g emission s contro l i s projecte dt o b e modest , th e impac t o f change d circumstance s o ncalculate dbenefit s doe s no t alte r th e NPRM' s genera l conclusio nregardin g cost-effectiveness
.

1 7