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# OAR Box 1830 Prepped byOllie Stewart



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Number: 

# 199 ) IV-C-16

6 Docket Number: 

# A-87-1 1

Printed 11/13/20087:21:02 AM Sheet 199of 232P. 2 

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'*l PRC* fc & UNITE D STATE S ENVIRONMENTA LPROTECTIO N AGENC Y AN N ARBOR . MICHIGA N 4810 5 

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## MA Y24 l98 9 OFFIC E O F AI R AN D RADIATIO N

Mr . Jame s E . Pase k Manager , Federa l Activitie s Automotiv e Emissio n Contro l Genera l Motor s Corp . Genera l Motor s Technica l Cente r 3040 0 Moun d Rd . Warren , M I 48090-901 5 Dea r Mr . Pasek : 

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Thi s i s i n respons e t o you r lette r o f Marc h9 , 1989 , i n whic hyo u commente d upo nsevera l area s relatin g t o onboar d refuelin g emission s controls , an d testin g performe d b yEP At o evaluat e prototyp e contro l system s and tes t procedures . I wis h t o respond t o severa l o f the point s raise d i nyou r letter , and t o informyo u o f curren t EPAactivitie s i nthi s area . Anumbe r o f you r comment s focu s o nEP Atestin g o f tw o Exxon-prepare d vehicle s equippe d wit honboar d refuelin g controls . I n m

ypreviou s communication s wit hyou , I outline d th e intende d scop e o f thes e tests , and EPA' s positio ntha t th e two tes t vehicle s wer e substantiall ydifferen t tha nEPA' s simplifie d refuelin g contro l system , regardles s o f wha t incentive s Exxo nmayhave , had t o buil d system s "tha t woul d functio n effectively. " Becaus e thes e vehicle s wer e clearl y deficien t eve n i n term s .o f meetin g ou r propose d emission s standard , w e sawn o basi s fo r anymor e detaile d evaluatio no f eithe r vehicle . Durin g th e perio d sinc e m yJanuar y17 , 198 9 lette r t o you , EPAha s continue d a developmen t and testin g progra mtha t focuse s o n you r concer n tha t our simplifie d liqui d sea l base d concep t i s no t applicabl e t o productio nvehicles . W e hav e recentl ycomplete d installatio n and testin g o f onboar d control s o n a For d Tauru s vehicle . Our testing , whic hha s include d bot h laborator yand in-us e evaluations , ha s showntha t performanc e o f the onboard-equippe d vehicl e meet s o r exceed s stoc k vehicl e performance . W e hav e successfull yteste d th e vehicl e fo r fillabilit ya t fue l dispensin g rate s i nexces s o f 1 5 gallon s pe r minute , and a t fue l temperature s approachin g 100°F . Incidentally , lat e mode l G Mvehicle s whic hw e hav e teste d a t thes e sever e condition s ar e frequentl yunabl e t o b e refuele d a t all . Test s carrie d ou t unde r ou r ful l propose d refuelin g tes t procedur e hav e showncomplianc e v/it hou r propose d standard s and n o impact s o f th e refuelin g emission s control s o nexhaus tP. 3 

### •f-„\ V emissions . W e wil l be makin g a briefin g i nth e nea r futur e on th e vehicl e developmen t and evaluatio nresult s tha t ar e available . I als o wis ht o respond t o tw o othe r area s o f concer n raise d i nyo u letter . Th e firs t o f thes e i s th e abilit yo f onboard-equippe d vehicle s t o contro l runnin g los s emissions . Thi s sourc e o f emission s is , o f course , o f grea t interes t t o EPA . A s yo u know , w e ar e preparin g a proposa l fo r improve d evaporativ e and runnin g los s controls . A s w e hav e indicate d i n previou s communication s v/it hyou , w e believ e that , couple d v/it h ou r volatilit yproposal , running losse s ca nb e controlle d withou t the nee d fo r pressurize d fue l tank s and th e apparen t safet yrisk s associate d wit hsuc ha n approach . Th e second are a tha t I wis ht o respon d t o concern s th e caniste r conditionin g and loadin g procedur e associate d wit h refuelin g tes t procedures . I mus t reiterat e th e EP Avie wtha t onboar d vehicle s shoul d b e capabl e o f passin g th e refuelin g tes t regardles s o f caniste r loadin g o r histor ya t th e star t o f th e test . Th e propose d caniste r conditionin g procedur e i s intende d t o specif yonl ya minimumcaniste r loadin g a t th e star t o f a test , rathe r tha nt o specif ya narro wrang e o f caniste r loading s betwee ncarefull ycontrolle d uppe r and lowe r bounds . I t i s th e inten t o f EP Atha t refuelin g contro l system s b e sufficientl yrobus t t o b e insensitiv e t o initia l caniste r loading s tha t ar e abov e th e specifie d minimumload . Variabilit ytha t i s inheren t i nan ytes t procedure , includin g th e propose d refuelin g tes t procedure , i s fa r les s tha nth e real-worl d variabilit ytha t anin-us e syste mwil l b e subjecte d to . Anyrefuelin g emission s contro l syste mtha t i s sufficientl ysensitiv e t o caniste r conditionin g o r histor ytha t i t i s likel yt o fai l refuelin g test s du e t o variabilit yi nth e caniste r conditionin g procedur e i s unlikel yt o attai nth e leve l o f in-us e contro l intende d b yEPA . Finally , I woul d lik e t o inquir e abou t th e statu s o f an understandin g originatin g i n a meetin g wit hMr . Stempe l o f GM wit hEPAAdministrato r Le e Thoma s o nDecembe r 13 , 1988 . On e outcom e o f tha t meetin g wa s a commitmen t b yG Mtha t w e woul d receiv e a comprehensiv e briefin g onyou r technica l and safet y concerns . W e wil l loo k forwar d t o hearin g fro myo u abou t thi s matter . Sincerel yyours , 

# 'Ut<J Dr . Davi d B . Bartus , Chemica l Enginee r Standard s Developmen t an d Suppor t Branc h cc : Docke t A-87-1 1 7118 W