P. 1



# OAR Box 

# 1878 Prepped by Charmelle Mathews



### Document

Number: 

# 70 ) ll-F-3 3
Docket Number: 

# A-90-1 9

Printed 11/28/20081:21:24 PM

Sheet 70of 145P. 2 

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

TO : Docke t A-90-1 9 FROM : Ja n Meyer , SD B DATE : Octobe r 30 , 199 2

Attache d ar e tw o set s o f draf t languag e receive d fro m OM B fo r inclusio n i n th e discussio n o f th e contro l decisio n fo r proces s vent s i n th e HON . Attachmen t 1 wa s receive d durin g th e wee k o f 10/1 3 an

d Attachmen t 2 wa s receive d durin g th e wee k o f 10/19

. Thes e material s wer e discusse d a s par t o f th e discussion s wit h OM B a s par t o f th e revie w unde r Executiv e Orde r 12291

.P. 3

EP A i s toda y proposin

g a range of

contro l level s fo r SOCM

I proces s ueits tha

t includes th

e floor control leve l require d b y sectio

n 112(d)(3) , an

d thre e ffinstrcxhre alternativ

e contro l level s whic

h ax e mor e stringen ttha n th e floor. EP

A currentl y ha s n o analysu o f

th e benefit * to huma n healt h tha twoul d Justif y selectin g an y contro l leve l above th e floor. Thai , EP A wil l perfor

m suc h a n analysis prio

r to promulgatio

n o f th e final rul e t o determin e whethe r sufficien tbenefit s indee d exist , an d wil l base its final selectio n o f an y contro l requirement

s mor e stringen ttha n the floor oo th

e result s o f mis aosryals . Th e time oontro

l level s propose

d toda y whic h go beyon

d th e floor at e base

d o n EPA' s 198 9 an

d 199 0 benzene NESHA

P decisions . If

tbenzene , EP

A used ttwo-par

t proces s to r selecting contro l levels . Rrst , th

e Agenc y determine

d tha t1 maximu

m individua

l upper-boun

d uveas lifetime cance

r risk o f on e i n 10,00 0 lifetime s (IO - * ) constitute

d a n acceptable risk. Secon d EP A considere

d a rang e n f factor s moiudm g costafiectivenes s t o provide a n ampl e margi n o f safety . Costwa

s nota facto

r i n establishing th e maximu m acceptabl e ris k threshold . Th e appropriat

e benchmar

k for evaluatin

g th e oc^-effectivenes s o f

th e benzene standard s i s abou t$900/Mg . This i

a a roug h averag e of th e cost-^Kectivenesa c i th e contro l level s selecte

d for cot e by-preidue

trecover y (16,50 0 Mg

s cc*fcoito d a t$97QVMg

) an d storag e vessel s (56 0 t

o 1,20 0 Mg s controlle

d a tS123/M g t o $909/Mg) . Othe

r categorie

s o f emission point s ba d cost-effectivenes s ratio

s substantiall

y greate r tha n thes e levels , bu

tthe y represen

t th e hig h cos to f meetin g the acceptabl

e risk threshol

d rathe r tha n th e resulto f balancin g emissio n reduction

s againstcos tThus , tho

y do netaccuratel

y characteriz

e th e cost efiectrveness o f

th e benzen

e decision i n th

e rang e wher e costi s a relevan

tActo r o f concern . Th e cwHrffcvtivenes s rati

o usodate d wit

h the benzen

e decisio n reflect

s th e estimate

d cance r risk s associate d wit h benzene . Thus , i tprovide s only a guid e a s t o th e leve l o f coa t whic h would b e appropriat

e t o bea r t o reduc e th e risks associate

d wit h th e wid e rang

e o f HAP s regulate d unde r th e HON . Therefore, di e Agenc y i s u*u g th e nenirn c cost effectivenes s rati

o merel y a s a preliminar

y estimat e o f the risks tha

tar e associate d wit h HAP s regulate d unde r th e HON . The Agenc

y expect s tha i it s benefiu analysi s fr

x reducin g HO N amission

s ma y yiel d ris k estimate s ma tdiffe r fro m estimate

s obtaine d i n th e benzen e decision . Thus , i n additio

n t o the floo r contro

l level , EP

A i s toda y proposing control level s o f $900/Mg , $1,800/Mg , an

d $2,7O0/Mg . Th

e firstalternativ

e i s roughl

y equa l to th e value chosen in th e benzen

e NESHAP . Th

o secon d an d thir d alternadv

M s « twic e an

d thric e m e / benzen e NESHA P value , respectively . EP A currentl y believe s tha

tit s benefit

s analysis i s likel y to sho

w tiiatcontro

l level s withi

n mis rang

e ar e c^-effective , takin

g into accoun

t difference s i n ris k betwee

n benzen e no d th e inUiur c o f HAP * emitte

d fro m EO N process units . EP A request s comments , includin

g dat a an d methodologica

l suggestions , whic

h woul d b e usefu l lo r ascertainin

g th e risk s o f HON * process uni

temissions relativ e t

o benzene , includin g potenc y an d exposur e estimate s an d technique

s fo r estimatin

g m e fan&oence o f

a U relevan thealt h effects .P. 4

w o i I U ut.. nu n ij't- i uuaiu/i/ u in n nu . LUHUUUIJ I \ , VC

-\p-lnaer t "A " Given th e scop e an d potentia l impact s o f thi s rulemaking , EP A recognize s the nau d t o continue t o refin e it s estimate s o f the cost s an

d benefit s o f th s rule . Th e Agenc y intend s t o collec t additiona l dat a an d wil l conduc t subotantia l ne w analyse s prio r t o finalizin g today' s rule . Th e ne w analyse s wil l b e conducted i n accordanc e wit hthe existin g Agenc y

guidanc e o

n Regulator

y Impac t Analysi s an d th a Regulator

y Impac t Analysi s Guidanc e publishe d i n th e 199 0 Regulator

y Progra m o f the Unite

d States . Th e analyse s vil l explicitl y

examin e bot hth e cost s an d th e healt han

d environmenta l benefit s for th e ke y regulator

y requirement s contained i n th e proposal . Upo n completio

n o f th e revised analysis , EPA

wil l solici t commen t o n th e result s o f th e analyse s an d th e methodolog

y use d t o deriv

e them . Th e Agenc y wil l the n asses s thes e comments / alon g wit hcomment s whic hhav e bee n received previousl y on th e proposed rule . Throug hthes e action s EP A wil l ensur e tha t th e ne t socia l benefit s (includin g environmenta l an d healt hbenefits ) o f th e rul e proposed today ar e maximized , takin g int o accoun t costs , risks , an

d th e minimu

m technolog

y requirement s implied b y th e floor , r

f th e revised RIA , togethe r wit hth e comment s received , demonatrat e tha t th e rul e proposed toda y doe s no t achieve thi s outcome , th e Agenc y wil l mak e appropriat e modification s t o th e fina l rule .

[Adapte d from i Corrective Actio n NPRM , 5 5 F

R 390864-6 5 J