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# OAR Box 1830 Prepped by Ollie Stewart



### Document

Number: 

# 190 ) IV-C-157 Docket Number: 

# A-87-1 1

Printed 11/13/20087:21:01 AM Sheet 190of 232P. 2

^-"•l- i UNITE D STATE S ENVIRONMENTA L PROTECTIO N AGENC Y AN N ARBOR , MICHIGA N 4810 5



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Mr . Jame s E . Pasek , Manage r Automotiv e Emissio n Contro l Environmenta l Activitie s Staf f Genera l Motor s Technica l Cente r 3040 0 Moun

d Roa d Warren , M I 48090-901 5 

# ,S>^ ^ OFFIC E O F •fp AI R AN D RADIATIO N



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Dea r Mr . Pase k respons e ;on , t o your I a mwriting in t o Mr . Richar d wi l Sources . I n tha t lette r issue s relate d t o th e propose d newevaporative , procedures . Thi s lette r position s on the issue s yo u raised , poin t ou t tha t our fina l position s Decembe r 2 , 198 9 lette r Directo r o f th

e Offic e o f Mobil e yo u requeste d clarificatio n o f some Environmenta l Protectio n Agency' s exhaus t an

d refueling emission s tes t i s intende d t o provid e our curren t

However , I woul d lik e t o wil l be determine d onl y afte r w e hav e full yreviewe d al l comment s receive d i n respons e t o the onboar d refueling Supplementa l Notic e o f Propose d Rulemaking (SNPRM) . Th e firs t issu e whic hyo u requeste d clarificatio n o n wa s tha t o f the "engineering review " o f vehicl e design s i n the propose d sectio n 86.XXX-8(e) . The purpos e o f thi s requiremen t i s t o guarante e tha t al l vapor s generate d i n th e fue l tan

k ar e vente d onl yt o th

e engin e or caniste r an d neve r directl yt o the atmosphere . Th e onl yexceptio n t o thi s woul d b e t o al^o wfo r venting i n the cas e o f a n emergenc y(i.e. , crimpe d vapo r line , etc.) . W e viewthe implementatio n o f thi s requiremen t a s being simila r t o tha t o f the engin e crankcas e ventilatio n requirement s an

d fee l tha t i t wil l b e fairl ystraightforwar d t o establis hcomplianc e wit hth e requiremen t base d on suc hthing s a s componen t sizing . W e wil l be requesting comment s specificall yo n howwe ma yimprov e o r clarif yi t i n the SNPRM .Th e secon d issu e yo u raised concerne d the ca p remova l procedur e a t the star t o f the ho t soa k test . You r understanding o f our curren t positio n on th e us e o f inne r seal s on onboar d system

tan k ven t valve assemblie s (TWA ) a s state d i n you r lette r i s correct . However , a s wit h al l tes t procedure-relate d issues , our fina l positio n wil l b e develope d onl yafte r the reviewo f al l comment s receive d i n respons e t o th e SNPRM . I n you r lette r yo u aske d whethe r w e woul d conside r implementatio n o f the propose d sectio n 86.138-X X prio r to , o r i n the absenc e of , a n onboar d requirement . W e fee l tha t our inten t t o d o thi s wa s mad e clea r a t the Jun e 30 , 198 8 worksho p an d I woul d lik e t o reaffir mtha t positio n now . Yo u als o aske d whethe r overriding the inne r sea l o n a TW Awoul d b e acceptabl e during cap-of f vehicl e storag e period s t o preven t unwante d caniste r loading . W e hav e no t develope d a positio n on thi s issu e a t the present . However , i f yo u fee l tha t ther e i s a need t o allowsea l overriding w e woul d ask tha t yo u provid e an appropriat e justification . Finally , yo u reference d a n Octobe r 14 , 198 8 lette r t o Mr . Wilso n i n whic hMr . Sa mLeonard urge d th e EP Astaf f t o mak e mor e tim

e availabl e t o addres s othe r tes t procedure-relate d issues . Ameeting t o discus s man yo f Genera l Motor' s concern s wa s hel d on January5 , 198 9 betwee n member s o f you r staf f an d mine . A t tha t time we reviewe d a detaile d lis t o f tes t procedur e question s provide d b yGM . W e fee l tha t we hav e bee n responsiv e t o your concern s thu s fa r an d wil l continu e t o b e a s th e nee d arises . Sincerel yyours ,
L-eftarie s L . -dray^'Vjr .

Directo r Emissio n Contro l Technolog yDivisio n

cc : DocK : eo!s. : A-87-ll $ 6764 W