# Stage II Vap or Recovery Systems Issues Pape r

U. S. EPA Office of Air Quality Pla nning and Standards Emissions Monitoring and Analysis Division Emissions Factors and Policy Applicati ons Group (D243-02)

August 12, 2004

Contact: Thom as Drisc oll

driscoll. tom@e

pa.gov (919) 541-5 135[This page intentionally left blank.]Executive Summary

The U.S. Environmental Protection Agency (EPA) has been reviewing emissions quantification issues associated with Stage I I vapor recove ry sy stems (VRS) at gasoline dispensing facilities (GDF) to addresse the need to eva luate data to: (1) define “widespread use ” of on-board refuel ing vap or recovery

(ORVR) c anisters , (2) dec ide what a lgorith ms may be need ed to determine “wide spread u se,” and (3) dete rmine whe

ther add itional em

issions tes ting is ne eded to define “ widespre ad use.”

EPA is also

consider ing othe r ancilla ry issues as sociate d with emissions from vehicle refueling that are discussed in this document. The purpose of this paper is to: (1) provide background information reg arding available data, (2) discuss EPA’s idea s regar ding the definition of wide spread u se, and ( 3) solicit comments f

rom stake holders. Volatile organic compounds (VOC) and hazardous air pollutants (HAP) are emitted from the refueling of light-duty

gasoline vehicles and trucks (here after referred to as vehic les) at GDF and from fugitiv e sources at GDF. VOC and HAP em issions occur during S tage II processes at GDF; Stage I I re fers to d

elivery of gaso line from

the under

ground storag e tank (U ST) to the v ehicle fuel tank. VOC emissions from Stage I I processes wer e estimated to be more than 470,000 tons per yea r (ton/yr) in the 1999 ve

rsion 2.0 National Emissions Inventory (1999v2 NEI). Section 182(b)(3) of the Clean Air Act (CAA), 42 U.S.C. 7511a(b)( 3), requires the Stage I I vapor recovery program for “moderate”

or worse ozone national ambient air quality standards (NAAQS) nonattainment areas. Section 202(a)(6) of the CAA, 42 U.S.C. 7521(a)(6) requires EPA to develop standards for ORVR controls on light-duty vehicles. Section 202(a)(6) of the CAA also states that the section 182(b)(3) Stage I I requirement shall not apply in moderate areas after ORVR standards are promulgate d. On April 16, 1994, EPA promulgated regulations requiring the phase-in of ORVR controls on new vehicle s. In addition, the CAA provides that EPA may revise or

waive the Stage II control requirements of se ction 182(b)(3) for “serious” or
worse ozone nonatt

ainment a reas af ter EPA de

termines that ORVR c ontrol sy

stems are in “widespread use ” throug

hout the mo tor vehic le fleet

. St age II VRS in clu de v apo r ba lan ce a nd v acu um ass is t s yste ms . S om e va cuu m as si st St age II control systems are not f

ully compatible with ORVR-equipped vehicle s; that is, ORVR-equipped vehicle s impact the effe ctivene ss of the v acuum as sist Stag e II VRS. This inc ompatibili ty r esults in an increase in emissions from the level expected when refue ling a non-ORVR equipped vehicle . These e

xcess emiss ions are

refer red to in th

is paper as “incompatibility

excess emissions.” There are usually no incompatibility excess emissions when non-ORVR vehicles refuel at vacuu m assist VRS or for va

por bala nce VRS. N ortheas t States for Coordina ted Air Use Management (NESCAUM), California Environmenta l Protection Agency

Air Resources Board ( CARB), a

nd Americ an Petrol eum I nstitute ( API)have be en very

interest ed and a ctive in Stage I I VRS is sues, and

they have conducted s tudies to a ddress th e incompa

tibility excess emissions issue and to evaluate widespread use.ii

With respe ct to def

ining wid esprea d use, EPA

is conside

ring fo ur defin itions of widespre ad use of ORVR controls. These definitions include: (a) when “x” percent of the vehicles in service are ORVR-equ

ipped, (b ) when “x” perce nt of the v ehicle mi les trave led (VMT ) are from ORVRequipped vehicles, (c) when the total VOC emissions from ORVR-equipped vehic les are equal (or equivalent) to the total VOC emissions from Stage II VRS programs, or (d) when “x” percent of gasoline sold is dispensed to ORVR-equipped vehicles. EPA asks for comment on which of the four definitions should be used to make the widespread use deter mination, and what percentage is appropriate for definitions (a), (b), and (d). Currently , EPA is considering selecting definition (c) to d

etermine when wide spread u se occur s in a State

or area . EPA is als o considering use of the equations in MOBI LE6 to calculate vehicle

refueling emissions and using eithe r esta blis hed or to-be -devel oped e miss ions factor s for U ST ven t empt ying and br eathi ng, fugitive, and incompatibility excess emissions. EPA also anticipates that individual States or areas will make a demonstration rega rding widespread use, i.e, the widespre ad use determination will be State, region, or area-spec ific. EPA asks for comment on the approach for deter mining widespread use, using MOBI LE6 algorithms for computing widespread use, and making the definition of wide spread u se speci fic to Stat es, regions, or a

reas.
EPA is also

consider ing prov iding ad ditional SI

P credits related to use of St

age I I VRS, including: (1) the use of Stage I I controls is continued after the de termination that widespread use has occurred, (2) States opt to require Stag e II controls in new areas, and (3) improved monitoring is applied to Stage II control systems to increase rule effectiveness. Another improved monitoring option may be to implement an inspec tion, maintenance, and regular replacement schedule of equipment components on the dispenser . Adoption of some aspects of CARB’s Enhanced Vapor Recovery (EVR) program in SIPs is another option. For example, pressur e/vacuu m (P/V) va

lves, add -on air p ollution control dev ices, or unihose di spensing

could be added as SIP require

ments. EPA asks for comments on SIP credit options listed above. EPA has identified several ancillary issues, including: (1) the significance of UST vent e mptying and breathing emissions, (2) the significanc e of fugitive emissions, and (3) the potential need for new emissions factors for VOC and HAP. Each of these issues is discussed in the pa per, and EPA requests comments on these as well. It is our be lief that there has not been sufficient emissions testing of the UST vent to adequately quantify the bre athing and empty ing emissions that occur from the UST. It is our belief that there has also not been sufficient emissions testing of fugitive emissions. We understand that CARB and Western States Petroleum Association (WSPA) are planning emissions testing to measure and quantify the pressure-related fugitive emissions and UST vent emissions related to Stage II controls which will provide more information to evaluate the emissions from these emissions points. We have not yet determined what other emissions testing may also need to be conducted. EPA requests comments on the need for develo pment of add itional em issions factors to he lp quanti fy emissions from GDF.1 Stage II Vapor Recovery Systems Issues P aper The U.S. Environmental Protection Agency ’s (EPA) Office of Air Quality Planning and Standards (OAQPS), Emissions Monitoring and Analy sis Division (EMAD) has been reviewing emissions q

uantific ation issue s associa ted with Sta

ge I I va por rec overy

sys tems (VRS) . This paper evaluates data and discusses: (1) de fining “widespread use” of on-boa rd refueling vapor recovery (ORVR) canisters, (2) deciding what algorithms may be neede d to determine “widespread use ,” and (3 ) deter mining how much ad

ditional te sting (if

any ) would be

needed to define “widespread use.” I n addition, there are other ancillary issues associated with emissions from v ehicl e refue ling t hat are discu ssed i n thi s docu ment, inclu ding: 

### # potentia

l opportun

ities to pr ovide SI P credits for extending Stage II

VRS contro ls past the wides pread us e date or

enhanc ing inspe ctions of gas sta tions, 

### # the quantification of fugitive VOC emissions from gasoline dispensing , 

### # determining the incompatibility betwe en Stage II VRS and ORVR canisters, and 

### # providing new or updated emissions factors for Stag e II

. EP A re cog ni ze s t hat man y sta keh ol der s ha ve b een in vol ved in th e di scu ss io n of St age II issues an d are ve ry interest ed in par ticipatin g in thei r resolu tion. The p

urpose of this pape r is to sol ici t co mm ent s fr om st ake hol der s on EP A’s pro pos ed i dea s an d po ten ti al r eso lu ti ons to St age II issues. I. Backgro und A. Process Operations at Gasoline Dispensing Facilities Volatile organic compounds (VOC) and hazardous air pollutants (HAP) are emitted from the refueling of light-duty gasoline vehicles and trucks (here after referred to as vehic les) at gas stations or, more formally, g asoline dispensing facilities (GDF) and from f ugitive sources at GDF. Controlling these emissions has been an issue for all stakeholders involved in the reduction of ozone and the production and dispensing of g asoline since the late 1980s. VOC and HAP emissions occur from two type s of sources at GDF: Stage I and Stage II

processes. Stage I refer s to proce sses at GD F when the gaso line is del ivered or transf erred f rom the ta

nker tru ck to the under ground storag e tank (U ST). Stag e II refer s to proce sses at GD F when th e gaso line is del iv ere d or tra nsf

err ed f rom th e US T to th e ve hi cle fue l t ank . Em is si ons fro m S tag e II pr oc es se s a re th e f

oc us of th is pa pe r. St ag e I p ro ce ss es ar e m en ti on ed on ly f or cl ar it y.
Emissions f

rom GDF a

re a nat ionwide problem, a

nd gaso line use in

vehicle s and truc

ks is increasing annually . In 1999, U.S. gasoline consumption was 167 billion ga llons per year1 Annual Energy Review 2002. U.S. Department of Energy , Energy Information Administration. October 2003.

2 Draft 1999 National VOC Inventory for Gasoline Distribution . April 200 3. See: http://www.epa.gov/ttn/chief/eiip/techreport/volume03/index.html.

3 The NEI emissions estimates include vehicle r efueling losses, spillage losses, UST vent breathi ng and e mpty ing losse s, and fug

itive losse s.

4 A table of HAP species percentag es of VOC emissions can be found at http://www.epa.gov/ttn/chief/eiip/techreport/volume03/iii11_apr2001.pdf.

5 Memorandum from J. Seitz, OAQPS, to EPA Regions. June 23, 1993. Impact of the Recent O nboard D ecision on Stage II Requirements in Mod

erate N onattain

ment Are as.

6 Technica l Guidanc e: Stage II Vapor R ecover

y System s for Control

of Vehicl e Refueling Emissions at Gasoline Dispensing Facilities, Volumes I and II . U.S. Environmental Protection Agency . EPA Publication No. EPA-450/3-91-022a and EPA Publication No. EPA450/3-91-022b. November 1991.
2 (gal/y r). 1 VOC emissions from Stage II processes were estimated to be more than 470,000 tons per yea r (ton/yr) in the 1999 ve

rsion 2.0 National Emissions Inventory (1999v2 NEI). 2 , 3 From the 1999v2 NEI, the HAP emissions (pollutants listed in the Clean Air Act Amendments of 1990) from Stage I I refueling could be in the range of 22,000 to 83,000 ton/y r, based on use of emissions factors for baseline, reformulated, and oxy genated gasoline. 4

B. Statuto ry Requir ement s for Stage II Proc ess Opera

tions The Stage II

vapor recovery

program is required by

section 182(b)(3) of the Clean Air Act (CAA), 42 U.S.C. 7511a(b)(3). The CAA directs State or Local air pollution control agencies with “moderate” or worse ozone national ambient air quality standards’ (NAAQS) nonattainment areas t o requir e Stage II VRS at GDF . Howeve

r, section 202(a) (6) of th e CAA, 42 U .S.C. 7521(a) (6), sta

tes that the section 182(b)( 3) Stage II require ment shall

not apply in modera

te areas after ORVR is promulgated. (EPA issued a clarification memorandum in June 1993 regarding use of Stag e II

controls in moderate areas after ORVR promulg ation.) 5 In addition, the CAA provi des that EPA may revise or waive t

he requi rements o f section

182(b)( 3) for “ serious”
or worse ozone nona

ttainment areas a fter EPA determines that OR

VR contro l sy stems are

in “widespread use” throughout the motor vehicle fleet. This effort is especially important now as EPA has designated nonattainment areas under the new 8-hour ozone standards. (See Attachme nt A for the latest n

on-atta inment ar ea clas sificati ons.) Section 182(b )(3) als o direct s EPA to issue

a guida nce doc ument tha t addres ses the e ffectiv eness of Stage I I VRS. This document, Technica l Guidanc e: Stage II Vapor R ecover

y System s for Control

of Vehicl e Refueling Emissions at Gasoline Dispensing Facilities , was issued in November 1991. 6 Section 202(a)(6) of the CAA, 42 U.S.C. 7521(a)(6) also requir es EPA to develop standards for ORVR controls on light-duty vehicles. The ORVR controls on vehicles are7 Stage II Comparability Study for the Northeast Ozone Transport Region . U.S.

Environmental Protection Agency . EPA Publication No. EPA-452/R-94-011. January 1995.
3 generally charcoal canisters that collect the vapors by adsorbing them during refueling and, sometime afterwards, releasing them into the eng ine. EPA promulgated regulations that require d the phase -in of ORV

R controls

on new ve

hicles (5 9 FR 16262 ; April 16, 1994, and 40 CFR Par

ts 86, 88 and

200). ORV

R is requir

ed to be in stalled on

some new

vehicle s beginn

ing in 199 8; all new vehicles (including sport utility vehicles and pickup trucks) will be required to have ORVR installed by 2006. Heavy -duty vehicles a

bove 10,000 pounds gross vehicle weight rating and incomplete heavy

-duty vehicle s such as m

otor home

cab/cha ssis vehic les will no t be subje ct to ORVR requ

irements

. For the Ozone Transport Region (the OTR is comprised of e leven states in the northea stern U.S . and the D istrict of Columbia) , there i s an addit ional re quireme

nt in section 184(b)(2) of the CAA, 42 U.S.C. 7511c(b)(2) for: (1) EPA to conduct a study to identify emissions r

eduction s control

measure s compar

able to Sta

ge II controls (c alled co mparabl e measures), and (2) OTR States to revise their State I mplementation Plans (SIP) to require Stage II controls or comparable measures. The re sults of the comparable control measures study are provided in Stage II Comparability Study for the Northeast Ozone Transport Region

. 7 This requirement under section 184(b)(2) is not affe cted by EPA’s promulg ation of ORVR rules, or by any future

widespread use determination under CAA section 202(a) (6). At the point when EPA determines that ORVR is in widespread use and waives or re vises the section 182(b)(3) Stage I I requirement for se

rious and above nonattainment areas, and possibly even sooner, EPA believe s it could also be appropriate to provide an additional mechani sm for OTR

States to b e able to

phase ou t the sec tion 184(b )(2) Sta ge II or c omparab le
measure require ment. One

approac h would be

for EPA to

update the “Stag e II

Comparab ility Study” to provide an option for esta blishing a new baseline for comparability . The new baseline could coincide with the ye ar that ORVR is determined to be in widespread use, or some other year, ta king into consideration the anticipated rate of phase in of ORVR-equipped motor vehicles. The original baseline for compa rability was 1999. Be cause ORVR controls just began phasing in during model y ear 1998, in 1999 nearly

all the reductions in refueling vapors were due to Stage II . At a poss ible new f

uture ba seline, the ORVR wou ld be capturing a

signific antly greater proportion of the ref ueling vapors, and reductions attributable to Stage I I would likely

be correspondingly

reduced. Thus, the level of emissions reductions necessar y for alter native measures to qualify

as comparable to Stage I I would also be reduce d. Depending on fleet turnover rate s and the remaining utility of Stage II VRS in obtaining emissions reductions at that point, it is possible that OTR States would be able to identify measures already

in their SIPs that would qualify as comparable to Stage I I for the purpose of meeting the section 184(b)(2) requireme nt. Provided these measures are not already prescribed by the CAA and subject to the procedural requirements and substantive limitations of section 110(l), OTR States would simply need to list the comparable measures and document the associa ted emissi ons reduc

tions in the

SIP re vision for EPA to be a

ble to approve the ir reque st to remove the Stage II progra m. While this action could be coordinated with EPA’s actions to8 Ref. 6, p. 3-9
4

Figure 1. Emissi ons points fro m uncont rolled Sta ge II proc ess opera tions. waive the Stage II progra m for serious and worse nonattainment areas so that the phase out of the Stage I I pro gram un

der both o f the stat

utory provision s would ha

ppen at the same time, it would not be necessary

for these actions to occur simultaneously , or for either specific action to prece de the other. C. Emissions Points from GDF Stage II Processes
The emiss ions points

from unc ontrolled

Stage I I pro cess ope

rations a re shown in Figure 1. The emissions points include vehicle refue ling, spillage, UST vent breathing and empty ing, and fugiti

ves.

In Sta ge II pro cesses, gasoline is delive red fro m the UST to

the vehic le fuel ta

nk. Vehic le refuel ing emis sions are

gener ated whe n gasoli ne vapors in the ve

hicle fuel tank a

re displa ced to the atmosp

here thr ough the vehicle fillpipe by di spensed gasoline. Spillage emissions may

also occur during Stage I

I processes; spillage

includes nozzle drips, spit-back, or overflow of the vehicle fuel tank. 8
In gener al, emissions from the UST vent include filling losses, breathing losses, and emptying losses. F illing losses (vapors displaced during the filling of the U ST) are associated with Stage I proce sses, and therefore are not the foc us of this paper. Breathing losses are9 Ref. 6, p. 3-9 and 10.

10 Conversation with D. Good, OMS, and T. Driscoll, EPA/OAQPS/EMAD. July 22, 2004.

11 Refueling Emissions Controls at Retail Gasoline Dispensing Stations in New Jersey

. Prepared for API by

Tech Environmental, Inc. July 17, 2002.

12 Refueling Emissions Controls at Retail Gasoline Dispensing Stations in Texas

. Prepared for API by

Tech Environmental, Inc. July 16, 2002.
5 associated with temperature and barometric c hanges experienced within the UST. Empty ing losses occur when gasoline is pumped out of the UST to the vehicle fue l tank, and air is drawn into the UST to replace the volume of liquid removed. Prior to introduction of air to the UST, the vapor space a bove the gasoline in

the tank i s at equili

brium. The

introduc tion of air

upsets this equilibrium, and a small amount of gasoline evaporates into the vapor space to move the sys tem back

to equilibr

ium. This e

vaporat ion cause s an incr

ease in volume, an

d the exce ss volume may be expelled throug h the UST vent pipe. 9 For the p urposes o f this pap er, both breathing and empty

ing losses from the UST vent are included as part of the discussion of Stage I I emi ssions. Fugitiv e emission s occur f rom vapor

leaks in the refue ling and dispensin

g equip ment, UST, assoc iated pip ing, pre ssure/va cuum (P/V)

valve (n ot when th e maximum pr essure s etting is exceeded and the valve opens), and the Stag e II VRS. For the purposes of this paper, fugitive emissions a

re inclu ded as pa rt of the d iscussion of Stage II emissions. D. Controls for Emissions from Stage II Processes Controls for emissions from Stage II processes include VRS and ORVR controls. Other controls that are used to control UST v ent emissi ons includ e a P/V va

lve or an add-on a ir pollution control device (APCD). The Automotive Society of Engineers (ASE) conducted an informal estimate of the number and ty pes of VRS systems at their 1997 meeting ; they estimated th at n ati onw id e, 7 0 pe rce nt of G DF h ave no S tag e II co nt rol s, a nd t hat 30 p erc ent hav e St age II controls

. 10 A descr

iption of e ach con

trol and the effe ct of the

control on each e

mission poin

t is discussed below.

1. Stage I I va por rec overy

sys tems

. 6, 11 , 12 The emi ss io ns p oi nt s fr om con tro ll ed S tag e II process operations are shown in Figur e 2. The emissions points include vehicle refueling emissions a

t the nozzle/

fillpipe i nterfa ce (the se emissions are si gnific antly reduce d compar

ed to the uncontrolled system), spillag e (these emissions are reduced as we ll), UST vent breathing and emptying (the se emissions are reduced from the uncontrolled sy stem), and pressure-related fugitives.13 Ref. 6, p. 3-9

14 Ref. 6, p 3-10

15 Ref. 11, p. 2-2.

16 Ref. 12, p. 2-3.
6 A VRS captures the vehicle refueling va pors normally emitted at the vehic le fillpipe and returns them to the UST. 13 A VRS also has an impact on the UST vent emptying emissions as the US T is em ptied durin g refuel ing. 14 Rather than introducing air to the UST vapor space, the vapor space is filled with the returned ga soline vapors. The returned vapor from the vehicle fuel tank hea dspace may

consist of

approxima

tely 30 to 40 pe

rcent g asoline v apor and

60 to 70 percent air in the summer. 15 , 16 The returned vapors suppress evapora tion of liquid gasoline, thus has le ss eff

ect on the eq uili brium in th e UST t han th e intr oduct ion o f pure a ir. Em ptying emissions from the UST vent are reduced because there is less vapor growth. The vapor re turned to liquid dis

pensed ( V/L)ratio is a

n importan

t operat ing fac tor of VRS. The V/L

ratio is a lso refer red to as the air r eturned to liquid dis

pensed, or A/L

ratio. The V/L

ratio re fers to the ratio Figure 2. Con troll ed Sta ge II Pr ocess Opera tion s wit h vap or reco very s ystem.17 Ref. 6, p. 3-1 and 2.

18 A V/L ratio of 1 .0 is more

compatib le with ORV

R controls

.

19 Ref. 6, p. 4-2

20 Enhance

d Vapor Recovery : Initial S tatement of Reason

s for Propos ed Amend

ments to the Vapor Recove ry Certific

ation and Te

st Proced ures for Ga

soline Load

ing and Mot

or Vehicl e Gasoline R efueling

at Servic e Stations

, Hearing Notice and

Staff Repo rt. Californ

ia Environmental Protection Agency , Air Resources Board. Februa ry 4, 2000. pp. 7 and 8.

21 Ref. 10.

22 Ref. 20, p. 8.

23 Ref. 11, p. 2-3.

24 Ref. 11, p. 2-3

25 Ref. 6, p. 4-2.

26 Ref. 11, p. 2-3.

27 Ref. 20, p. 8.

28 Ref. 11, p. 2-3.
7 of the quantity of vapor

and air returned to the UST headspace to the qua ntity of gasoline pumped out of the UST. 17 , 18 The two most common types of Stag e II VRS are “vapor balance” and “ vacuum assist”; some VRS ar

e refe rred to a s “hy

brid” sy stems that are cla ssified a s vacuum a ssist. 19 , 20 The ASE estimated that 53 percent of controlled systems in the U. S. are vapor balance sy stems and 47 perce nt are va cuum assi st sy stems. 21 The vapor balanc e VRS is configure d with a corruga ted boot ov er the no zzle spout an d is designed to capture displaced vapor f rom the vehicle fuel tank. 22 , 23 The vapor balanc e VRS operate s based on

the princ iple of va

por repl acemen

t and prov

ides a va por rec overy

return li ne to collect vapors from the vehicle fuel tank displaced by the incoming liquid gasoline. 24 The vapor balance VRS depends on an adequate seal be ing established between the vehicle being refueled and the faceplate of the fueling nozzle. 25 , 26 As gasoline is pumped from the UST, a slight vacuum occurs in the UST which helps pull the vapors into the UST vapor space.

A vacuum

assist VRS is

often “b ootless” ; instead a vacuum ( by a pump) is us ed to pull the gases back through a se ries of holes in the nozzle spout (perforations) during refueling to the headspace of the UST. 27 , 28 In most cases, liquid along the wa ll of the vehicle’s fillpipe allows the dispensin g nozzle to

form a se al with the

fillpipe. For most v acuum as sist VRS, the UST vent is29 Ref. 6, p. 4-30.

30 Ref. 11, p. 2-3.

31 Ref. 20, p. 60.

32 Ref. 6, p. 4-50.

33 Ref. 6, p. 4-54.

34 Electronic mail c ommunica tion from A . Arnold, EPA Regi on 1, to T. Driscoll, EPA/OAQPS/EMAD. July 29, 2004.
8 required to be equipped with a P/V valve designed to open only if the pressure or vacuum inside the tank increases bey

ond a defined threshold. 29 , 30 Soon, Calif ornia is expected to

require P/V valves on all

UST vents for Stage I c ontrol, including those equipped with vapor balance systems. The V/L

ratio for vapor balance VRS is gener ally 1.0 or less, and the r

atio for vacuum assist is generally

in the range of 0.9 to 2.4. 31 Hybrid vacuum a ssist systems usually have a much lower V/L ratio than traditional vac uum assist. A hybrid VRS has a V/L ratio close to 1.0. Stage II VRS can achieve 95 percent control eff iciency. The

95 percent is a certification control e fficien

cy . The in-u se contr

ol effic iency

achieve d, howeve

r, is aff ected by rule effec tiveness

and rule penetra tion. The i

n-use control eff

iciency accoun ts for rul e effe ctivene ss when various defects/leaks or malfunctions occur w ithin the VRS. In-use control efficiency can be improved through better monitoring of the VRS and more f requent oversight inspections. With more frequent monitoring, malfunctions and defects/leaks can be repaired more quickly

and can be expected to reduce excess emissions. Rule penetration acc ounts for the number of GDF in an are a that ar

e actua lly s ubject to the Stag e II

control r equirements (e. g., GDF s that dispe nse less than 10,000 gallons per month are exempt from Stage I I controls in an area

). The range of in-use control efficiencies for Stage II VRS are 62 to 92 percent depending on the inspection frequency (this is for no exemptions, i.e., 100 percent rule penetration). 32 When rule penetration is accounted for, depending on the exemption level for an a rea, the in-use control efficiency range s from 56 to

90 perce nt. 33 EPA Region 1 indicated that most of their States (Maine, New Hampshire, Vermont, Massachusetts, Connecticut, and Rhode I sland) rely on a n in-use efficiency of 84 per cent for Stage I I VRS in their SI P calcula tions. 3435 Ref. 7, p. 15.
9

2. ORVR contr

ol sy stems . The emissions points from Stage II process operations for a vehicle equipped with ORVR a

re shown in Figu re 3. The emissions p oints inclu

de vehic le refueling emissions at the nozzle/fillpipe interface (these emissions are sig nificantly reduc ed compared to the uncontrolled sy stem), spillage (these emissions are reduce d as well), UST vent breathing and empty

ing (these emissions are comparable to the uncontr olled systems), and fugitiv es.

ORVR-equipped vehicles collect the gasoline vapor displaced from the vehicle fuel tank during filling; the gasoline vapors ar e adsorbed in a canister, and sometime afterwards, are released to the engine. ORVR controls are expected to achieve from 95 to 98 percent reduction of the vehicle refueling emissions (59 FR 16273 and 16279-80; Apr il 6, 1994). For ORVR control only , ORVR doe s not aff ect UST ve

nt breat hing an d empty ing losse s. 35 In 1998, the phase-in period for installing ORVR canisters in cars began; now all new manufactured cars a nd new pick up trucks up to 6000 p ounds gr

oss vehic le weig

ht category

have ORV

R. The pha se-in period for installing ORVR canisters is just beginning in the 2004 model y ear for new pickup trucks a nd sport ut

ility vehicles in the 6001 to 8500 pounds gross vehicle weight ca tegory and will not be

totally phased in

until the 20 06 model y

ear. Th e phase- in period

for hea vy- duty vehicles (8501 to 10,000 pounds gross vehicle weight c ategory ) will begin in the 2005 model year ( 80 percent) and be totally phased in for the 2006 model year. Figure 3. Stage II Process Operation with ORVR-equipped vehicle.36 Ref. 20, p. 36.

37 Ref. 20, pp. 21 and 51.

38 Ref. 20, p. 21.

39 Ref. 20, pp. 20 and 51.

40 Ref. 20, p. 22.

41 Ref. 20, p. 27.
10 3. Combined Sta

ge II VRS a

nd ORVR sy

stems . As ORVR e quipment is being phased in for new vehicles, there is some concern r egarding the compatibility of ORVR controls and Stage II controls. When an ORVR-equipped vehicle refuels at GDF with Stage II

VRS, the amount and composition of the vapor returned to the UST by the Stage II

control system can be impacted. An increase in the amount of air (in lieu of g asoline vapor) returned to the vapor space of the UST

will lead to gasol ine evap oration, or vapor growth , in the UST

and lead to excess emissions from the UST vent. A larger amount of air is returne d to the UST vapor space for some Stage II

vacuum assist VRS when refueling vehicles with ORVR controls, and there fore, the exces s emissions

are gr eater f or some va

cuum assi st sy stems. 36 These excess emissions are referred to in this paper as “incompatibility excess emissions.”

4. P/V valves on the UST vent . The emis sions point s from a Sta ge II VRS w

ith a P/V valve on t he UST ve

nt are shown in Fig

ure 4. I n the past , not all Sta

ge II VRS r

equired P/V valves on the UST ve

nts to meet

the requ ired con trol eff iciencie s; P/V valve s are mor e likely to be install ed on vac

uum assist St

age I I VRS. Several

districts in Califor

nia have require d P/V valves on UST to red

uce empt yin g and br eathing emissions f

or small pr

essure c hange s, 37 and the Californ ia Environmental Pr

otection Agenc y Air Resour

ces Boa rd (CARB ) will req

uire P/V val ves on a ll US T ve nt s as par t o f th eir enh anc ed v apo r re cov ery (E VR) pro gra m fo r St age I. 38 P/V valves have been shown to improve the effectivene ss of Stage I sy stems and to enhance the perfor mance of and/or a re esse ntial to ma

ny St age I I sy stems. 39 The CARB EVR program requires a P/V valve for Stage I , with pressure limits from -8 inches w.c. to +3 inches w.c. 40 The CARB EVR requirements for Stage I I include pressure limits of less than +1.5 inche s w.c. maximum, and

a daily averag e limit of le ss than or equal to 0 .25 inche s w.c; Stage I o peration is excluded from the average. 4142 Ref. 20, pp. 51 and 53.

43 Ref. 20, p. 56.

44 Ref. 20, p. 53.

45 Ref. 20, pp. 27, 53-54.
11 On both vapor balance and vacuum assist VRS, the P/V valve on the UST vent helps reduce UST vent empty

ing and breathing emissions (and also Stage I UST vent emissions). On a vapor balance sy stem, the P/V valve limits air ingestion into the UST through the vent line and vapor growth from the UST. When fuel is dispensed, the sy stem maintains a slight negative pressur e, which actually enhanc es the ef

fective ness of th e vapor b alance sys tem, and s lowly equilibra tes the va por spac e, if the

UST is lea

k-tight

. 42 There are also no significant pre ssurerelated fugitiv e emission s for a va por bala nce sy stem. 43 In a vacuum assist sy stem, the vapor pump colle cts a fixed

volume of

vapor, w hich is re turned to the UST. G asoline e

vaporat ion in the UST vapor space (vapor gr owth) causes a positive pressure in the UST and emissions from the UST vent, depending on the pressure setting of the valve. 44 With a P/V valve, the pressurerelated fugitiv e emission s can be s ignific ant for v acuum as sist sy stems. 45 Figure 4. Con troll ed Sta ge II Pr ocess Opera tion with vapo r recov ery sy stem,

P/V valve, and add-on control device (processor).46 Ref. 20, pp. 8, 54, 56, and 107.

47 Ref. 20, p. 54.

48 Ref. 20, p. 33.

49 Ref. 20, p. 34.

50 Ref. 20.
12 5. Add-on control devices on the UST vent . An add-on air pollution control device (APCD), or processor, may be placed on the UST vent to collect emissions from the UST. The emi ss io ns p oi nt s fr om a St age II VRS wit h a P /V v alv e an d an AP CD a re s how n i n Fi gur e 4. If used, add-on control devices are g enerally use d on vacuum assist Stage II VRS, not on vapor balance sys tems. 46 As mentioned above, vacuum assist sy stems operate at positive pressure and emissions from the UST vent occur when the pressure setting on thevalve is exceeded. The addon device controls vapor growth emissions from the UST vent. Having a control device on the UST vent also allows the UST to be maintained at lower pressures (the pre ssure setting on the valve co uld be low er) without an increase i n emissions

. 47 A lower pressure setting also reduce s pressur e-rela ted fug itive emis sions. 48 The APCD or processor may be a combustion device, refrig eration

unit, car bon bed, or membra

nes. 49

6. Californ

ia Enhanced Vap or Recov ery (EVR) re quireme

nts

. 50 CARB has promulgated a new program in California called EV R. The purpose of the EVR program is to increase the control efficiency

achieved by

Stage II VRS in ozone nonattainment areas. The program includes six main modul es; the fo llowing i s a very brief de scription

of the mod

ule requ irements : a. Module

1 - Stage I va por rec overy . Change s control efficie ncy require ment to 98 percent. Requires P/V valves on all sy stems. Contains additional specifications to vapor adaptor to prevent leaks. b. Module 2 - Stage II

vapor recovery . Improves the certifica tion process. Changes
co nt ro l r eq ui re me nt s t o 9 5 p er ce nt co nt ro l e ff ic ie nc y and

0.38 pounds per 1000 gallons summer fuel throughput. Include s fugitive emissions in calculation of the emission factor. Requires pressur e limit of + 0.25 inch es w.c. d aily averag e and +1 .5 inches

w.c. maximu

m to help minimize pre ssure-r

elated f ugitive emissions. Contains mu ltiple othe

r requir ements re lated to Modul e 2 inc ludi ng: – Static pressure performance – C om pat ib il it y wit h P has e I (S tag e I) – Liqu id remova

l – Nozzle/dis

penser C ompatibili

ty – Unihose multi-product (UMP) configuration – Vapor Pi

ping Req uiremen ts – Liquid Condensate Traps – Leak-ti ght Co nnect ors an d Fitt ings – Dynamic B ackpressure – Balance sy stem Component Pressure Drops51 Ref. 20, p. 36.
13

– Maximum A/L

limits (1.0

for systems witho

ut proce ssors; 1.3 for systems with processors – HAPS limits for processor emissions – Maximum hydrocarbon rate f rom processor c. Module 3 - ORVR compatibility. Requires emissions factor limit of 0.38 pounds per 1000 ga llons and t

he press ure-re lated fu

gitive e missions mus t be less than 50 per cent of t his amount. d. Module 4 - Liquid retention. Requires liquid retention emissions factor of le ss than 100 milliliters per 1000 gallons. Limits nozzle spitting to 1.0 milliliters per nozzle. e. Module 5 - Spillage and Dripless nozzle. Requires spillage emissions factor of 0.24 pound s per 1000

gallons . Hold on a

limit for no zzle drips. f. Module 6 - In-station diag nostics. Provides continuous real-time monitoring of critical emissions-related VRS parameters and components to alert opera tor of problems so corrective action c an be tak

en. Assur

es complia

nce of in stalled va

por bala nce and vacuum a ssist VRS.

E. Stakeholders and Studies Conducted To Date The Northeast States for Coordinated Air Use Manag ement (NESCAUM) and northeastern States have been very interested and active in Stage I I VRS issues. In a

ddition, CARB has been a major stakeholder in the Stage II VRS forum. CARB has conducted several projects to assess the emissions from GDF and vehicles equipped and not e quipped with ORVR. CARB also certifies gasoline dispensing sy stems with the Stage II

VRS equipment. In a recent meeting, CARB announced that the State would probably continue to require Stage II VRS for gas sta tions afte r “wides pread us e” is achieved in

Californ ia. The A merican Petroleu m Inst itute (API) has also been ve

ry eng aged in these issues. The API has conducted several emissions testing projects and has published several reports on: (1) examining widespread use and
co mp ar in g a nn ua l e mi ss io ns un de r d if fe re nt co nt ro l s ce na ri os (e .g ., St ag e II V RS co nt ro ls on ly, ORVR controls only, and combined Stag e II VRS and ORVR controls), and (2) determining incompatibility excess emissions caused by Stage II VRS and ORVR controls. Other engaged stakeholders include other state and local air pollution control ag encies, GDF operators, vendors of gaso line dispe

nsing eq uipment, a

nd vendors of UST ve

nt contro ls.

1. Studies to assess incompatibility excess emissions . Several tests have been conducted to quantif y th e excess e

missions tha

t occur d ue to the i ncompati bility betwee n vacuum a ssist VRS and ORV

R controls . As discu ssed abov e in sect ion I. D, beca

use the va

cuum assi st sy stems return vapor with a higher conce ntration of air (lower vapor concentra tion) to the UST headspace when refueling an ORVR-equipped vehic le, incompatibility excess emissions occur. The quantity and conce

ntration of vapor returned to the UST is a significant fa ctor in the amount of incompatibility excess emissions. The V/L ratio for vacuum assist VRS generally causes the greatest incompatibility

excess emissions due to the larger quantity of dilute vapor returned to the UST. 51 The incompatibility excess emissions are signific antly lower for hybrid VRS and vapor balance VRS; both ha

ve lower V/L r atios. API

and CARB have conducted t esting t o try to quantify the excess emissions from the incompatibility of Stage II

VRS with ORVR-equipped52 CARB. Prelimina ry Draft Te st Report, Total Hydr

ocarbon E

missions fr

om Two Phase II Vacuum Assist Vapor Recovery Systems During Baseline Ope ration and Simulated Refueling of Onboard Refueling Vapor Recovery (ORVR) Equipped Vehicles . June 1999.

53 Lette r from P. Se arles, A

PI to W. L

oscutoff , CARB. June

14, 2002. R

eview of CARB estimate s of Enha

nced Va por Reco very

(EVR) re ductions.

54 API. ORVR Compatibility Study for the Gilbarco Vaporvac VRS . February 2004. Includes Phase 1, Phase 2 - Outside, a nd Phase 2 - SHED.
14 vehicles. The emissions factors for incompatibility excess emissions from several test reports are provided in Table 1 . There

are some differe nces in th e magni

tude of th e incompa

tibility excess emissions f

actors e stimated by A

PI an d CARB: (1 ) in their

2004 study

, API e stimated e

xcess emissions f

rom incomp atibility

to be 0.33 lb/1000 g allons an d accou nted for the decr ease in vehicle fillpipe emissions resulting from the combined Stage I I VRS and ORVR controls; and (2) in their 1999 study, CARB estimates total excess emissions from incompatibility to be 0.86 lb/1000 gallons (and did not account for decrea sed vehicle fillpipe emissions). We are
curren tly e valuatin g their test data and incom

patibility excess em

issions fa ctors. Table 1. Comparison of Test Data for Determining Incompatibility

Excess Emissions Factors

Test Data Incompat ibi li ty Exces s Emis sion s Factor (IEEF), lb/ 1000 gal
Gilbarco
vac uum as si st VRS (Ce rtified V/L rati o is 1.0 t o 1.2) Wa yne-Dresser
vac uum as si st VRS (Ce rtified V/L ratio is 0.9 to 1.1) OR VR - Ve hicle

fuel tank f

il lpi pe savin gs (reduc tion) Ov era ll

(Gil barco)
exces s emi ssi ons factor
CARB T est

1999 52 0.86 a 0.06 a NA 0.86
API an aly si s of

CARB IEEF 53 0.78 b 0.08 b NA 0.78 b

API Report -Phase 1 2004 54 NA NA 0.31 0.55 c

API report - Phase 2 2004 54 0.72 NA 0.39 0.33

a CA RB repo rt pro vides avera ge em issions fo r base line and OR VR -simulate d refue ling; the inco mpa tibility
ex ce ss emi ss io n f

ac to rs we re ca lc ul at ed b y E PA’ s c ont ra ct or f ro m t he se va lu es an d t he per ce nt of ORVR vehi cles si mulat ed; f

or th e Wayne - Dress er s yst em, only the t est wit h th e P/V val ve i ntac t was used. b API us ed a

line arre gr es si on of

th e CA RB t es t r es ul ts to det er mi ne th e e mi ss io n f ac to r a t 1 00 p er ce nt

ORVR vehi cle simu lat ion a nd adju ste d the fac tors for a low er Rei d vapor pr essu re (a ssu med uncon trol led e miss ions of 7.6 lb/1000gal versus 8.4 lb/1000 gal.).

c API calculated 0.55 lb/1000 gal based o n the CARB factor of 0.86 lb/1000 gal. (0.86 – 0.31 = 0.55).
To addre ss the inc ompatibili ty is sue, CARB has also l ooked at “ mini-boot”

equipmen

t, pressur e-sensi ng diaphragm i

n the nozzle , and hy

drocar bon sensin

g techn ology for vac uum assist55 Ref. 20, pp. 60 and 62.

56 Ref. 20, p. 62.

57 Ref. 11.

58 Ref. 12.
15 Stage I I VRS e quipment. 55 These technologies help prevent the ing estion of air to the UST when refueling an ORVR vehicle by adjusting the vapor collection (or V/L ratio). 56 In the

future, it is our unde rstandin g that CA RB plans t

o requir e VRS to be c ompatible

with ORVR c ontrols. A PI testing has shown that the mini-boot reduces the amount of incompatibility excess emissions that occurs due to combined vacuum assist Stage I I VRS and ORVR-equipped vehicles. Testing has also shown that with the mini-boot installed, the emissions from vacuum assist Stage II VRS and
non -ORVR-equipped vehicles may be increased. 54 We believe there are adequate te st data available to determine an excess VOC emissions factor from the incompatibility of vacuum assist Stage II

VRS with ORVR-equipped vehicles. However, we are seeking more information regarding the te sting results from API, CARB, and ARID Technologie s, Inc. (ARI D is a vendor of UST vent controls.) We are also seeking information from other stakeholders who may have also conducted or are planning to conduct source testing at GDF to try to quantify incompatibility excess emissions. CARB and the Western Sta

tes Petro leum Assoc iation (WSPA ) are c urrently planning an emissions test to a ssess pressur e-rela ted fug itive emis sions and U ST vent emi ssions (the test proto col is not p

ublicly available ye

t).

2. Studies to d

efine wi desprea

d use

. 57 , 58 As mentioned above, several studies of GDF control me asures f

or ozone nonattainme

nt area s have be en condu cted by stakehol ders. API conducted some studies that looked at the emissions levels associated with multiple control measures, including: (1) ORVR-equipped vehicles alone , (2) Stage II VRS alone, and (3) combined ORVR and Stage II VRS (with the incompatibility excess emissions), and (4) comb ined ORVR a

nd Stage II VRS (withou

t the inco mpatibility

excess em

issions). I

n these studies, the VOC emissions levels for each control measure were projected over time to see the expected trends. Figure 5 shows example emissions levels that have been pr ojected for 30 y

ears for a hypothe

tical State for each of the four control scena rios (based on the algorithms and ty pe of analyse s conducted by API ).59 Ref. 20, pp. 37-40.
16

The Stag e II

VRS-only

emissions l evels as

shown in F igure 5 for a hy pothetic al State include vehicle refueling emissions and spillage emissions. They do not include UST vent bre ath in g an d em pt ying , an d fu git iv e em is si ons . Th e in -us e co nt rol eff ici enc y for th e St age II VRS used in t

he calc ulations is

85 perce nt. The ve

hicle re fueling

emissions f

actors ( lb/1000 g al) were developed using MOBI LE6 refueling

equations and the emissions were calculated based on gasoline throughput data. Spillage wa s calculated using the EPA procedures in MOB IL E6 (which is based on an AP-42 emissions factor). The ORVR-equipped vehicles-only emissions levels in Figure 5 include vehicle refue ling emissions and spillage emissions. UST vent breathing and empty ing emissions and fugitive emissions are not included. The control efficiency used in this study for ORVR controls was 98 percent and applies to the vehicle refue ling emissions only. Aga in, the vehicle refueling emissions factors (lb/1000 gal) were develope d using MOBIL E6 refueling equations and the emissions were calculated based on ga soline throughput data. Spillage was calculated using MOBI LE6 e quations w

hich appl y 50 percen t lower e missions for spillag e for ORV R use (50 percent of AP-42 emissions factor). 59

For the c ombined O RVR contro ls and Stag e II VRS scena

rio, the in compatib ility

excess emissions were calculated using the “adjusted” CARB incompatibility excess emissions factor of Figure 5. Gene ral em issions tre nds expect ed for refueling emi ssions in future calendar years for a hypothetical State (based on API studies).60 Ref. 20, p. 11.

61 Ref. 11.

62 Ref. 12.

63 Ref. 10.
17 0.78 lb/100 0 gal an

d applied the fac tor to the e stimated p ortion of gallons dispense d to ORVRequipped vehicle s via vac

uum assist V

RS sy stems. Stage II VRS controls have already been implemented in most ozone nonattainment areas; if ORVR were not being implemented, the g eneral trend on Figure 5 is that VOC emissions are expected to continue to increase over time as nationwide g asoline throughput continues to increase (Stage I I controls only

). However, ORVR equipment currently is being phased in for new vehicle s, and, ov er time, n on-ORVR ve

hicles wi ll continue

to be rep laced with ORVR vehic les. The O RVR contro l measure is expecte d to resul

t in a sig nifican t decre ase in emissions over time until all subject vehicle classes are ORVR-equipped. After most vehicle s are ORVR-equipped, VOC emissions are expected to begin to incr ease over time as gasoline through put contin

ues to increase. With the com bined ORV

R and Stag e II

VRS contro l measure s, emissions a

re expected to be l ower tha n with eith er ORVR c ontrols a lone or Sta

ge II VRS controls alone, a nd will decline over time (theoretically until all subject vehicles are ORVR-equ

ipped). H owever , with the c ombined c ontrol mea sures, a n incompa

tibility excess emission occurs where ORVR controls and some Stage I I VRS (vacuum assist) coexist. The emission le

vels with t

he incomp atibility

excess em

issions ar e shown on

Figur e 5. Ther e is a point (see point A on Figure 5) at which emissions from the combined c ontrol measures may actually be high er than t

hey would be w

ith ORVR alo

ne due to t

he incomp atibility

excess emissions. The relative control efficiency used in the calculations for Stage I I VRS affects the emissions levels on the chart. If the in-use c ontrol efficiency for Stage II

is lower than 85 perce nt, the em issions will

be high er and the Stage

II controls only line on the

chart wi ll cross the ORVR on

ly li ne at an e arlier d

ate. I n addition , the comb ined Stag e II VRS and ORV

Requipped controls line on the chart would be higher a nd would also cross the ORVR only line at an earlier date. The relative size of the incompatibility excess emissions is related to: (1) the portion of vacuum assist systems that are use d in an area, (2) the rate of fle et turnover, and (3) the incompat ibility excess em

issions fa ctor. The combined

Stage I I and ORVR incompatibility excess emissions in Figure 5 are based on a hy pothetical area with approximately 50 percent
vacuum a ssist systems. Cal ifornia e stimates that vacuu m assist sy

stems now c ompose approxima

tely 20 perce nt of their VRS. 60 In New Jersey, the estimated percentage of va cuum assist sy stems is 10 p ercent , 61 and in the Houston-Galveston area of Texas, the perce ntage of
vacuum a ssist systems is 64 p ercent

. 62 In an informal study, the Automotive Society of Engineers estimated in 1997 that approximately 47 percent of VRS nationwide are vacuum assist. 63 The incompatibility excess emissions would be large r for those instances where the18

percentage of vac

uum assist VRS in place is greater (such as in Houston-Galveston). If the fleet turnover rate is higher for a pa rticular State, the incompatibility excess emissions will be larg er because there are more O RVR-equipped vehicles in the area.

II. Discussion A. Determine the “Widespread Use” Definition As mentioned above in section I, B ackground, EPA may determine that ORVR control sys tems are

in widespr

ead use t hroughout the motor vehicl e fleet. This issue has seve ral fac ets to it, includi ng: (1)what shou

ld be the d

efinition of widesp

read use , (2) whe

n can it be predi cted to occur, and (3) how can it be demonstrated a nd verified? We know the definition and occurrence of widesp read use is integ ral for S tate and

local air pollution c ontrol ag encies, so they can rev ise their control stra

tegies and upda te their SI Ps. There

have be en sever

al discus sions of wa

ys t o interpret widespread use and some of the potential def initions include: (a) when “x” percent of the vehicles in service a re ORVR-equipped, (b) when “x” percent of the vehicle miles traveled (V MT) are from ORVR-equipped vehicles, (c) when the total VOC emissions from ORVR-equipped vehicles are equal (or equivalent) to the total VOC emissions from Stage I I VRS programs, or (d) when “x” p ercent

of gaso line sold is

dispense d to ORVR-e quipped v ehicles

. Some of the widespread use definitions are simple approache s and some are more complex. I

n each o f these d

efinition s, the re quireme

nt for wha

t perce ntage r eprese nts widespread use would be established first (i.e., 95 perc ent, 90 percent, 85 percent, etc.). The analy sis/comput

ation wou ld then be conducte d based on State-s pecific data, or region -specif

ic data if a larger or smaller a rea than a State would be analy zed. Each of the possible definitions are discussed below, along with the advantag es and disadvantages of eac h. We are seeking y

our comments on these or other definitions of widespread use.

1. Definition (a) - Percentage of ORVR-equipped Vehicles . Definition (a) for widespread use is a simple approach. I n this definition, the analysis would be conducte d based on vehicle registration data, projections of that data into the future, and the phase-in schedule for ORVR. I t is importa

nt to note that while t

he appro ach acc

urately repres ents the v ehicle f

leet, more vehicle miles are traveled for ne wer vehicles, as people tend to drive newer vehicles more often an d for long er trips t

han for o lder veh

icles. Th is approa ch may not refle ct this fa

ct. This approach also may

not address differences in vehicles such as f uel economy (miles pe

r gallon) and useful life.

2. Definition (b) - Percentage of V MT by ORVR-equipped vehic les . This def inition is also a fairly simple a

pproach. Definition (b) would be based on all of the data inputs for definition (a) plus the VMT data by class of vehicle. This approach addresses the VMT by ORVR vehicles issue mentioned under definition (a), that newer vehic les are often driven more miles than older vehicles; an area or State is more likely to reach the criterion in definition (b) before reachi ng the c riterion in definit ion (a) ( i.e., wid

esprea d use woul d occur e arlier w ith64 Ref. 6, p. 4-54.

65 Final Reg

ulatory I mpact Ana lysis: Re

fueling Em ission Reg

ulations for

Light Duty Vehicles and Trucks and Heavy Duty Vehicles . U.S. Environmental Protection Agency , Office of Mobile Sources. January 1994.
19 definition (b)). VMT data are gene rally available

for States and regions. This approach may not address differences in vehicles such a s fuel economy ( miles per gallon) and useful life.

3. Definition (c) - V OC emission s with ORVR c ontrols e qual VOC e missions wit

h Stage I I VRS only . Definition (c) is a slightly more complex approach that would require calculation and comparison of vehicle refue ling emissions based on two different refueling control measures. This definition would require the data inputs for definitions (a) a nd (b) along with data on ambient temperature, Reid vapor pressure, r ule effectiveness, rule penetration, and the perc entage

of GDF w

ith vacuu m assist Sta

ge II VRS (

to deter mine inco mpatibility

excess emissions). Definition (c) is represented by point B on Figure 5. The advantag e of this approach is that it a ddresse s and comp ares em issions lev els direc

tly. A disadva

ntage w ith this approach is that the in-use control efficiency of VRS must be correctly de termined (range was provided a s 56 to 90 percent). 64

4. Definition (d) - Gasoline dispensed to ORVR-equipped vehicles . Definit ion (d) wo

uld require data on the volume o f gasol ine sold in addition to

the data inputs needed for definition (b). One disadvantage with this approach is that g asoline quantities dispensed typ ically are not a vailable on a coun

ty or area basis and must be es timated ba sed on eit her VMT data and fuel ec onomies or

county gasoline sales ( in dollars ). This ap proach d oes addr ess differences in vehicles such as fuel e conomy/ga s mileage for each vehicle ty pe. As part of the Regula tory Impa ct Analy sis (RI A) document deve loped for the ORVR r

egulat ions in January 1994, the widespre ad use an

aly sis conduc

ted was b ased on g asoline d ispensedto ORVRequipped vehicle s. 65

5. Combinations of definitions . Because of uncertainties inhere nt in measuring the VOC emissions from vehicle refueling, a combination of widespre ad use definitions may be be neficial. For examp le, wides

pread us e may

be deter mined to be

when the refuel ing VOC e

missions wit

h St ag e II V RS co nt ro ls on ly e qu al th e r ef ue li ng VO C e mi ss io ns wi th OR VR co nt ro ls on ly and when “X” percent of the vehicle s are equipped with ORVR (for example, 95 percent). This is an example of

a combina

tion of de finitions ( a) and ( c). An a dvantag e of a combination a pproach is that, in theory, decla

ration of widespread use is balanced betwe en two criteria rather than rely ing solely on one fac

tor. The disadvantage is that each of the “ factors” being considered may be interre lated an

yw ay . Another

disadvan tage of the combi

nation ap proach i s that the a

lgorith m is
more com

plex and Sta

tes would b e requir

ed to expen

d more ef fort to de monstrate that the c riteria are met.
6. Use of definition (c) . EPA is currently consider ing use of definition (c) to define when widespre ad use of

ORVR occu

rs. This de finition c onsiders and compa

res emiss ions leve ls directly. EPA would like y our comments on which widespread use definition is appropriate.66 Memorandum from G. Lew, CARB , to J. Guerrero, CARB. April 16, 2002. Updated

ORVR Penetration Ca

lculation s.

67 Ref. 11.
20 B. Uniform, Nationwide Widespread Use Definition There is a question of whether the definition of “widespre ad use” should be the same for all areas or States. We believe that the definition of widespread use should be consistent nationwide. However, we anticipate that the data supplied to the algorithms will be Statespecific. Therefore, when wide spread use will be predicted to occur in eac h State may be different. At a recent NESCAUM meeting, NESCAUM and State representatives pointed out that vehi cle turnover occurs more quickly in the Northeast U.S. (because road salt used in winter on roads deteriorates the vehicle bodies) than in States with less snow and ice . Therefore, they expect a higher rate of vehicle turnove r in the northeastern U.S. than in States with more temperate climates. Conversely , CARB studies indicate that they e xpect vehicles to last longer, thus a lower fleet turnover rate is expected in California. Studies conducted by CARB show widespread use (based on definition b at 90 perce nt VMT) is expected to occur in California after 2020, however studies conducted on some NESCAUM states show widespread use ma y occur sooner, maybe

as soon as 2011 (definition c) or 2013 (definition b at 90 percent VMT). 66 , 67

The MOBIL

E6 equations factor in such variables as VMT (States are now developing their 2002 emissions inventories and will have VMT data soon), fleet turnover ra tes, and temperature of gasoline stored in UST that are “State-specific” data. Thus, we believe use of State -spe cifi c dat

a wil l make

the deter minat ion of wide spre ad us e Sta

te-s peci fic a s wel l. We
curren tly p lan to pro vide def

ault data needed for the e quation va

riables ( i.e., MOB IL

E6 defa ults) for factors where a State may not collect the data needed for MOBI LE6, such as VMT. However, where a State does not ag ree with default values, it will be welcome to collect its own data an d/or c onduc t its own te stin g.
Because the Northeast States are all part of the OTR, they have indicated that a regional application of the widespread use definition may be appropriate for them. We believe a reg ional determination of widespread use is appropriate, althoug h a regional averag e of each of the 11 State’s (plus the District of Columbia) data may be needed. [See discussion in section I.B above for OTR States.] C. Widespr ead Use A

lgorithm Developm ent Our approach to developing the widespre ad use algorithm is to start at the end of the process and work backwards. I n other words, first we plan to define widespread use and then develop t he appro priate a lgorith m for the c alculati ons. We wou ld work “ backwa rds” to determine what data are neede d and/or whether more emissions testing will be needed for the algori thm or to sup

port the d efinition . We will ne ed the involvement of stake holders.21

If we select a

definition of widespread use that requires the calc ulation of emissions, our current thinking is to use the MOBI LE6 model equations to compute the emissions from refueling. The MOBI

LE6 model calculates VOC emissions from all fa cets of mobile vehicle use, including refuel ing and

vehicle operati on. Ther

e are mo dules in th

is model tha

t pertain to automobile refueling – these are the pa rts of the model we will use. Because the MOB IL E6 model and

its assumpt

ions are alread y a ccepte d by

most stake

holders, we will no t need to develop a nd defen d new equ

ations/al gorithm s. We would also use e

missions fa

ctors to e stimate the emissions from spillage, UST vent empty ing and breathing, and fugitive emissions. However, no variable currently exists to account for the excess emissions from the incompatibility of Stage I I VRS and ORVR-equipped vehicles. We will need to dete rmine how to factor these incompatibility excess emissions into the calcula tions. This will require defining an incompatibility excess emissions factor(s). We want to involve stakeholders in this process of developing a workable definition of widespread use and we are a sking for comment on the algorithm, including the use of MOBIL E6 equation s and othe

r emission s factors. We also w ant to esta blish a pr ocess tha t confirm s widespread use is actually achieved when predicted to occur a nd ensure there is no backsliding afterw ards.

D. SIP Credits There are several questions regarding SIP credits re lated to the widespread use date and Stage I I control req

uiremen ts. The questions inc lude how SI P credits might be impacted by: (1) con ti nui ng t o us e St age II con tro ls aft er t he w id esp rea d us e da te, (2) req ui rin g St age II controls in new ar eas, and (3) appl yin g improv ed monitor

ing to Sta ge II control sy

stems to decrease emissions and increase rule effectiveness. Figure 6 show s the relative emissions for several control measures and in-use eff iciencies. The figure shows the full rang e of possible inuse efficiencies and its relation to the ORVR only control (point B versus point B’ depending on the Stage II

control efficiency

). The figure also shows that the combined use of ORVR and Stage II VRS controls results in lower VOC emissions than either control measure alone. On Figur e 5, depe nding on which de finition is

selecte d and the d

ata input s, the wide spread u se definition may be met many years pr ior to point A (for example, at point B on Figure 5, which would satisfy definition (c) a bove); if an area continued to use both control measure s beyond the widespread use date, SI

P credits could be provided for many years. EPA r

equests comments on the SIP credit options discussed below. I f a State applied control measures in its projected emissions b aseline , it could not rece ive addit ional SI P credit f or those s ame mea sures, i. e., to avoid doubl e-coun ting.22

1. Continued

use of Sta

ge II VRS . Section 202(a)(6) provides that EPA may revise or waive the applica tion of the

require ments of se ction 182(

b)(3) of the CAA for “serio

us” or worse ozone nonattainment areas after EPA determines that ORVR control sy stems are in “widespread use” in the motor vehicle fleet. I f EPA decides to revise or waive these require ments, States or areas could decide to repeal re quirements for Stage II VRS, following demonstration of widespread use in the area or State. Under this scenario, there would be many serious, severe, and extre me counti es that c

urrently have Stage II

controls that would

no longe r be req uired to hav e th em a fte r wi des pre ad u se i s ac hi eve d. T he S tat e co ul d al so d eci de t hat th e St age II require ments will r

emain in e ffect. We expect a benefit to retain ing Stag e II

VRS until all vehicles have ORVR. In the OTR, Stag e II or comparable emissions-reducing controls ar e require d under se ction 184( b)(2) of the CAA thr

oughout the State s rega

rdless of their classifications. [See discussion in section I.B above f or OTR States.] EPA may consider providing additional SIP credits where States (non-OTR) retain Stage I I VRS after widesprea

d use occurs. EPA would provide SIP cre dits from the date widespread use occurs (depe nding on the defi nition of w

idespre ad use ch

osen) unt il the time w

hen combi

ned ORVR a

nd Stage II VRS emissions are no longer less than ORVR emissions only (point A on Figure 5). CARB staff plan to retain Stage II

controls after widespread use occurs in California.
If SI P credits can be given when VRS are c ontinued after the widespread use date, the calculation would include emission reductions that reflect combined Stage II and ORVR controls. Essentially, for these counties, there would be no change in the e missions that have Figure 6. Gene ral em issions tre nds expect ed for refueling emi ssions in future ca

lendar ye ars for a hyp othetic al State, no incom patibility excess em issions (based on API studies).68 Ref. 20, pp. 96-97.
23

already been projected for the nonattainment area , if reductions for ORVR are already included in their pr ojection s.
2. SIP option for States to include Stage I I VRS in additional areas . States could require Stage II VRS in areas where they are not currently

required and/or located, even knowing that Stage II VRS may not be required a fter relatively

few ye ars. Under the new 8-hr ozone designations: (1) several MSAs were re vised and additional counties were included in ozone nonattainment areas (see Attachment A), (2) several MSAs that were serious or severe unde r the 1-hour standard are newly classified as moderate under the 8-hour ozone standar d, and (3) seve ral are as have b een new

ly c lassifie d as ozone n

onattain ment are as (adde d to the mod erate nonattainment classification). Where MSAs were revised and c ounties were added and the MSAs were previously c lassified as serious or severe, the added counties a re not likely to have Stage II controls in place. If the State de cides to retain Stage II controls in these MSAs after the widespread use date, States could require these a dded counties to also control Stage I I emissions. In the second scena

rio, a State could require Stage I I in moderate nonattainment are as that have been ne wly added to t

he ozone nonattain

ment are as. State and local agencies may be reluctant to require Stage I I VRS for a limited number of years. H owever, some States may be interested in requiring Stage I I VRS for GDF that are

not currently r

equired to have Stage I

I controls, if adequate SI

P credits are granted. There are a few moderate areas (outside of OTR) that did retain Stag e II controls following the April 1994 promulgation of ORVR controls (e.g., counties in Florida)

. If SI P credits can be g ranted f or requi ring Sta ge II VRS in

additiona l areas , the cre dit calculation would include the emissions reductions that reflect combined Stage II and ORVR controls. For these counties, the emissions from GDF would be aff ected significantly , achieving the reduction from the ORVR only line on F igure 5 to the combined Stage I I and ORVR line (with incompatibility excess emissions). This credit could be taken fr om the implementation of Stage II controls through the date associated with point A on Figur e 5.

3. Impr oved Monit

oring f or Stage II VRS . There are several ty pes of improved
mo ni to rin g be in g co ndu cte d by S tat es t hat res ul t i n i ncr eas ed c ont rol eff ici enc ies of t he S tag e II VRS equipme

nt and increased

emissions r

eduction s. Improved mon itoring may include: (1) oversight inspections, and (2) requireme nts for in-station diagnostics (ISD). California has determined that Stage I I VRS have not achieved the e missions reductions that have been assumed in their SIPs. California assumed in their 1994 SI P that the Stage II

VRS had an in-use control efficie ncy of 90 per cent. 68 However, in 1995 they assumed their in-use control efficiency to be69 Ref. 10.

70 Ref. 20, pp. 96-97.

71 Ref. 20, p. 14.

72 Ref. 6, pp. 6-22 through 32.

73 Ref. 6, p. 4-54.

74 Ref. 6, p. 4-53.

75 Ref. 6, p. 4-50.
24 84.5 per cent, 69 and in 200 0, they

estimate d that the

in-use e fficien

cy was appr oximately 76 perce nt. 70 To improve

their Stage II

in-use e fficien

cy , they implement

ed the EV R progr am. 71 a. Inspections. Oversig

ht inspections of the Stage II VRS at GDF are conducted by area inspectors and generally

focus on Stage II

VRS equipment defects and visual inspection of the nozzles, boots, faceplates, and hoses for cuts, tears or other disrepair (some states require more than visual inspections); checks of the nozzle check valves, nozzle latches, etc.; inspection of the APCD on the UST vent, if any (i.e., the processor); on-site paperwork and re cords; and confirmation that the installed VRS matches the permitted VRS. Some areas have an equipment checklist or an inspection form that inspectors use at each site, while othe rs do not. The inspectio n freque ncy range s from onc e every

5 ye ars to two

to three inspections each y

ear. Some areas have priority

inspection programs, where GDF w ith recurrent problems are inspected more frequently a

nd conscientious GDF are inspected less fre quently, perhaps only once per y

ear. 72 EPA reque sts information on th e Stage II inspection freque

ncy in nonatta

inment ar eas and a lso request s informa

tion on any

leak che ck requi

rements a nd the fr equency f or the le ak checks.
As discuss ed above

in section

I.C, t he in-use control e fficien

cy range s from 56 to 90 perce nt, depen ding on the inspection freq uency and the exemption lev els. 73 After th e VRS equipmen t is installe d, associ ated we ar and te ar, malf unctions, or sy stem prob lems can result in reduction of certified efficiency . While Stage II control systems can a

chieve 95 percent or better control efficiency , in-use efficiency is demonstrated to drop significantly without proper operation and maintenance. 74 Data analy zed during

prepar ation of the EPA’s Technical Guidance Document

indicate that conducting semi-annual inspections provide in-use ef ficiency of 92 percent, annual inspections provide in-use control eff iciency for

Stage II VRS of 86 perce nt, and min

imal or le ss frequent inspe ctions pr ovide 62 p ercent

in-use e fficien

cy (these values assume no exemptions). 75 The in-us e contro l effici ency for Stag e II

is direct ly r elated to the inspection frequency

and subsequent repair of systems. Based on the inspection program conducted by a

n area, SIP credits may

be provided above the ty pical in-use efficiency demonstrated from Stage II VRS operation. Another closely r

elated option for improved monitoring might include a maintenance program for dispenser components. A GDF could implement a program of scheduled76 Ref. 20, p. 66.

77 Ref. 20, p. 67.

78 Ref. 20, p. 67-68.

79 Ref. 20, p. 94.
25 replacement of components that may leak. In this progra

m, each component would be datestamped and replaced on a scheduled basis, re gardless of detected leaks or othe r defects/malfunctions. This maintenance progra m may prevent lea

ks from occurring. b. In-station diagnostics. We believe that be tter (and more frequent) monitoring, coupled with good operation and maintenance prog rams, results in emissions reductions. There are several potential VOC emissions points at GDF other than the refueling interface that are monitored

infrequently , at best. CARB will r equire a n ISD m onitoring sys tem as a p art of the ir EVR program for improved monitoring at GDF . ISD is a progra m that measures operating parameters of the Stage

II VRS and GD F equipme

nt to ensur

e it is oper

ating pr operly . The I SD provides real-time monitoring of critical VRS components and signa ls when failure modes are detecte d. The pa

rameter s monitore d depend

upon the ty

pe of VRS. For vap or balan ce VRS, UST press

ure, pre ssure dr

op acros s hose, no zzle, etc ( to detec t liquid bloc

kage) , and V/L

ratio with a flow meter would be measured. 76 For vac uum assist V

RS, UST pre ssure an

d V/L r atio with a sen sor would

be measu red; if the V/L

ratio is ou

t of limits, t

he vapor pump flow i s adjusted to achieve the correct V/L ratio. 77 If the assist VRS also has an APCD (or proce ssor) on the UST vent, operating parameters of the APCD such as hydroca

rbon concentration, flow rate, flame detection, pressure would be monitored. 78 Californ ia has ind icated that the g oal of the ISD program in their State is to bring the in-use control eff iciency to the 90 pe

rcent efficiency
cu rr en tl y as su me d i n t he in ve nt or y. 79 For other States that adopt ISD prog rams, SIP credits may be provided. There is also a corollary

question concerning the continuation of GDF testing after wides pread u se occu rs. Bec ause m ost o f the cu rrent moni torin g/test ing foc uses o n the r efueli ng, testing of gas stations after widesprea d use of ORVR occurs may be pointless. We are seeking you r commen

ts on the e fficac

y of monitoring

/testing after w idespre ad use oc curs.
c. Other CARB EVR r

equirements. We a sk for comment on a dding UST

vent cont rols as possible SIP control measures after Stage II VRS requirements are removed, for those States or areas that remove Stage I I. The control measure s may include a P/V valve or an add-on control device (processor) or possibly other CARB EVR requirements. We also ask for comment on addition of UST vent controls as possible SIP control measures when a State decides to keep Stage I I VRS r equirements in pla

ce (i.e ., combina

tion of Sta

ge II and ORVR con

trols and UST vent controls). In addition, we ask for comments regarding other EVR re quirements, such as unihose dispensers. E. Ancillary Emissions Issues80 Emissions discussed here include those from breathing and empty ing and do not include emissions from filling (i.e., related to Stage I ).

81 AP-42. Section 5.2, Transportation and Marketing of Petroleum L iquids. January 1995. See http://www.epa.gov/ttn/chief/ap42/ch05/final/c05s02.pdf

82 Membranes, Molecules, and the Science of Permea tion. Tedmund Tiberi. Petroleum Equipment & Tec

hnology . April 1999.

83 CARB. Uncontrolled Vapor Emissions Factor at Gasoline Dispensing Facilities

. January 2000.

84 Ref. 81.

85 Ref. 81.
26 The following dis cussions i nclude a dditional p otential i ssues we have ide ntified. We

ask for y our comme

nts on the s ignific ance of these issu

es.
1. UST vent emptying a

nd breathing emissions . Emissions from an U ST vent co

uld resul t from one or more o f the f ollo wing: 80 (1) normal emptying and breathing emissions expected from the UST vents without any Stag e II controls during refueling (uncontrolled) ; (2) normal empty

ing and breathi ng emiss ions expected from t he UST ve

nts when St

age I I VRS are used during refueling , both vapor balance and vacuum assist systems (controlled); or (3) excess emissions from the UST vent related to vapor growth resulting from the incompatibility of combined Stage I I vacuum assist VRS with ORVR-equipped vehicles during refueling. (

Note : The AP-42 emissions factor for UST vent empty ing and breathing emissions also includes vapor loss between the UST and the gas pump, i.e., f ugitive emissions.) 81 At a recent NESCAUM meeting, a repre sentative of the State of Massachusetts indicated that OPW, a Stage II equipment manufacturer, had conducted some testing of these vents. OPW found that some of the P/V valves on the UST vents staye d open during the entire test, rega rdless of whether vehicles were being ref

ueled and regardless of whe ther ORVR-equipped vehicles were being refuel ed, imply

ing ther e were continuou s VOC emiss ions from t he UST ve

nts. L astly

and as a separa te issue, some studie s sugg est that there ar e signif icant emi ssions from the UST ve nts, other tha n those fr om refue ling veh

icles. 82 We believ e more e missions te sting ma

y be needed to determine whether controls and/or more fre quent monitoring of these vents is warranted. Currently, UST vent emissions are r elatively small compare d to the uncontrolled refuel ing emis sions leve l based on curren t emissions

factor s (rang es from

7.6 pounds of VOC per 1000 gallon s of f

uel d ispen sed [l

b VOC/ 1000 gal] to 11.1 lb VOC/1000 gal for an uncontrolled refueling emissions factor to 1.0 lb VOC/1000 gal for UST vent and fugitive emissions). 83 , 84 However, when ORVR-equipped vehicles ar e in widespread use and refueling emissions are controlled from 95 to 98 percent (i.e., emissions from refueling are much lower), empty

ing and breathing emissions from an UST vent may become a more significant portion of total VOC emissions and may warr

ant a closer look. 85 At that time, EPA and States may want to revisit the issue of requiring controls on the UST vent. In addition, a P/V valv e on the U ST vent is86 Ref. 52.

87 Ref. 54.

88 Ref. 81.
27 currently r

equired in some areas of the country as part of the Stage I

controls or Stage II

vacuum assist VRS. We believ e when or if Stage II is remove d, remova

l of the UST

vent P/V va

lve will have to be reviewed.

2. Fugitive Emissions . Fugitive emissions at a GDF could result from one or more of the following : (1) the n

ormal fug itive emis sions expec

ted from G

DF withou

t any Stage I I controls (uncontrolled refueling operations); (2) the normal fugitive emissions expected from GDF when Stage II VRS is used (controlled); (3) the excess fugitive emissions from the GDF resulting from the incompatibility of combined Stage II Vacuum assist VRS with ORVR-equipped vehicles during refueling; and (4) the pote ntial fugitive emissions from the deterioration and aging of gasoline dispensing equipment. Few studies of potential fug itive emissions from GDF have been conducte d and as su

ch, it is no t clear w

hether t hese emi ssions ar

e signif icant. Al so there

could be fugitive emissions caused by deterioration and aging of e quipment, although this issue has not been studied. Similar to other types of larg er facilities, there is the potential for fugitive emissions from hoses, pipes, flanges, etc. CARB studies sugg est that pressure-related fugitive e missions resulting from lea ks at GDFmay

be signi ficant. Further

more, some testing

by C ARB sug gests that pressure-related fugitive emissions may increase when Stage II

Vacuum assist VRS is used in conjunc

tion with OR

VR-equip ped vehic les. 86 CARB test method pr

ocedure s calcul ate pressur e-rela ted fug itive emis sions base d on press ure mea suremen

ts in the sy

stem. A re cent API study measured f

ugitive emissions simulated in a field laboratory setting and concludes that the CARB cal culation s overes timate fu gitive e missions. 87 Some additional evaluation and emissions testing will probably be

needed to quantify

fugitive emissions under the various uncontrolled and controlled scenarios at GDF.

3. Potential Need to Develop New Emissions Factors for VOC and HAP

. Cu rr en tl y, AP-42 (the repository f

or EPA emissions factors) section 5.2 includes averag e emissions factor information for VOC and also an equation for developing the vehicle refueling emissions factor based on site-specific Reid vapor pressure and te mperature. The averag e VOC emissions factors are: (1) uncontrolled Stage I I refueling

operations (11.0 lb VOC/1000 gal), (2) controlled Stage II refueling operations (1.1 lb VOC/1000 gal), a nd (3) UST vent breathing and empty ing and fugitives (1.0 lb VOC/1000 gal). 88 These average VOC e missions factors, developed from some testing conducted in 1985, are higher in some instances than those shown in the review of recent test data from CARB and API . The cur rent ave rage A P-42 emiss ions fac tor infor mation is almost 20 y

ears old and does not acco unt for th e chang es in ga soline co mposition. T here is a lso some HAP emissions factor information in Volume III: Introduction to Area Source Emission Inventory Development

(Revised Final, January 2001) , Chapter 11, Gasoline Marketing (Stage I89 Volume III is part of a series of documents developed by the Emissions Inventory Improvement Project (EI

IP) that are part of a

cooperative effort between US EPA and State a nd local air pollution control agencies to document direct and c ost-effective methods for developing emissions i

nventori es.

90 Ref. 4.
28 and Stage II) (Revised Final, January 2001)

. 89 Table 11.3-2 in Volume II I, labeled “HAP Perc ent of VOC Emis sions,” includes a species profile f or 8 HAP. 90 We believe more emissions testing may be need ed to deve lop new e

missions fa

ctors, e special ly f

or air toxic s. The list of refueling-related ac tivities that may possibly

need additional emissions factor work or w

here the re are no emission s factors include s: (a) incompat

ibility excess em

issions fr om Stage II vacuum a ssist VRS and ORVRequipped vehicles, which would include breathing a nd emptying e

missions from UST vent and vehicle refueling emissions, as well as fug itive emissions from GDF sy stems and VRS; (b) UST vent br

eathing and empty

ing emis sions fro m UST withou t Stage I I VRS, with and without P/V valves; and (c) fugitive emissions from the UST and dispensing equipment, including equipment lea ks f rom pi pes , ho ses , fl ang es, etc ., f or u nco nt rol led syst ems and for St age II VRS contro ls.A-1 

### Attac hme nt A
8-Hour Oz one Nonatt ainmen t Area s Lis ted b y Ca tegor y/C lassification (Attain men t Da te)*

SEVERE 17 (June 2021) Los Angeles South Coast Air Basin, CA Los A ngeles County (P)[n], Ora

nge Coun ty [n], Riverside

County (P)[n], San B ernard

ino County (P)[n] SERIOUS (June 2013) Riverside Co, (Coachella Valley), CA Riverside County (P)[n]
Sacramento Metro, CA El Dor ado Co unty (P)[n ], Plac er County

(P)[n ], Sacrame

nto County

[n], So lanoCount

y ( P)[n], Sutter County (P)[n], Yolo County [n] San Joaquin Valley, CA Fresno County [n], Kern Co

unty (P)[n], King s County

[n], Madera

County [n], Merce d County [n], San Joaquin County [n], Stanislaus County [n], Tulare County [n] MODERATE (June 2010) Baltimore, MD Anne Arundel Co

unty [n], B altimore ( City

)[n], B altimore C ounty

[n], Ca rrol l Coun

ty [n], Harford County [n], Howard County [n] Boston-Lawrence-Worchester (E. MA), MA Barnstable County

[n], Bristol County [n], Dukes County [n], Essex County [n], Middlesex County [n], Nantucket County

[n], Norfol

k County [n], Ply mouth County

[n], Suffolk C ounty [n], Worcester County [n]

Boston-Manchester-Portsm outh(SE), NH Hillsborough County (P)[n], Merrimack County (P)[n], Rockingham County (P)[n], Strafford County (P)[n]
Cass Co, MI Cass County

Charlott e-Gastonia-Roc k Hill, NC-SC North Carolina – Cabarrus County , Gaston County [m], Ire dell County (P) (Davidson Township, Coddle Creek Township), Lincoln County, Mecklenburg County [m], Rowan County, Union County South Caro lina – Yor

k County (P) Chicago- Gary-L ake County, IL-INA-2

Illinois – Cook County [n], Du Page County [n], Grundy County

(P) [n] (Aux Sable Township, Goose Lake Township), Ka ne County [n], Kendall County (P) [n] (Oswego Township), Lake County [n], McHenry

County [n], Will County [n] Indiana – L ake County [n], Porter County [n]

Clevelan d-Akron-L orain, OH Ashtabula

County [m], Cuyahoga

County [m], Geaug a County

[m], Lak e County [m], Lor ain County [m], Medina Co

unty [m], Portag e County

[m], Summit Count

y [m]

Dallas-F ort Worth, TX Co ll in Co un ty [ n] , D al la s C ou nt y [n ], De nt on Co un ty [ n] , E ll is Co un ty, Jo hn so n C ou nt y, Kaufman County, Parke

r County, Rockwall County, Tarrant County [n]
Detroit-Ann Arbor, MI Lenawee County

, Livingston County

[m], Macomb County [m], Monroe County [m], Oakland County [m], St Clair Cou

nty [m], Washtena

w County [m], Way

ne County

[m] Fredericksburg, VA Fre deri cksburg , Spot sy

lvania Cou

nty , Staf ford Count y [ n]
Greater Connecticut, CT Hartford Count y [ n], L itchf

ield C ounty

[n], Ne w L ondon

Count y [ n], To lland

Count y [ n], Windham County [n]

Houston-G alveston-Brazori a, TX Brazori a County

[n], Chambers County

[n], Fort B end County

[n], Galves ton County

[n], Harris County [n], Liberty

County [n], Montgomery County [n], Waller County [n]
Jefferson Co, NY Jefferson County [n]
Kent and Queen Anne’s Cos, MD Kent County [n], Queen Annes County [n]

La Port e, IN La Por te County

Lanc aster, PA Lancaster County

[n] Los Angeles-San Bernardino Cos(W Mojave),CA Los Angeles County

(P)[n], San Bernardino County (P)[n] Memphis, TN-AR Tenness ee – Shelby Co

unty [m] Arkansa s – Crittenden CountyA-3

Milwaukee-Racine, WI Keno sha Co

unty [n], Mi lwau

kee C ounty

[n], Oz auke e Coun

ty [n], Ra cine Count y [ n], Washington County [n], Waukesha County [n] Muskegon, MI Muskeg on County

[m] New York-N. New Jersey-Long Island,NY-NJ-CT Connecticut – Fairfield County [n], Middlesex County [n], New Haven County [n] New Je rsey – Ber gen Count y [ n], Es sex Cou

nty [n], Hu dson C ounty

[n], Hu nter don Co unty [n], Middlesex County [n], Monmouth County [n], Morris County [n], Passaic County [n], Somerset County [n], Sussex County [n], Union County [n], Warren County [n] New Y ork –

Bron x Count y [ n], Ki ngs C ounty

[n], Na ssau

Count y [ n], Ne w Yor k Coun ty [n], Quee ns Cou nty [n], Ric hmond Count y [ n], Roc

klan d Coun

ty [n], Su ffol

k Coun ty [n], Westchester County [n] Philadelphia-Wilmin-Atlantic City,PA-NJ-MD-DE New Jersey – Atlantic County [n], Burlington County [n], Camden County [n], Cape May County [n], Cumberla

nd County

[n], Glouce ster Count

y [n], M ercer

County [n], Ocean

County [n], Salem County [n] Delaware – Kent County

[n], New Castle County [n], Sussex County [n] Maryland – Cec il County [n] Pennsylvania – Buc

ks County [n], Chester County [n], Delawar e County [n], Montgomery County [n], Philadelphia County [n] Poughkeepsie, NY Dutchess County [n], Orange County [n], Putnam County [n] Providence (All RI), RI Bristol County [n], Kent County [n], Newport County [n], Providence County [n], Washington County [n] Richmond-Petersburg, VA Char les Ci ty Count y [ m], Che ster

fiel d Coun

ty [m], Col onial Hei ghts

[m], Ha nover Coun

ty [m], Henrico County [m], Hopewe ll [m], Peters burg, Pr ince Ge orge Co

unty , Richmond

[m] Sheboygan, WI Sheboy gan Coun ty [m] Springfield (Western MA), MA Berkshire County

[n], Franklin County [n], Hampden County [n], Hampshire County [n]
St Louis, MO-IL Missouri – Franklin Co

unty [m], Jeffers on County

[m], St Charle s County

[m], St Lou

is [m], St Louis County [m] Illinois – Jersey

County [m], Madison Co

unty [m], Monroe C ounty

[m], St Clair Cou

nty [m]A-4

Ventura Co, CA Ventura County (P)[n], that part of Ventura County excluding the Channel I slands of Anacapa and San Nicolas Islands. Washington, DC-MD-VA Entire District of Columbia [n] Mary land – Calv ert County

[n], Charle s County

[n], Frede

rick Coun ty [n], Montgome

ry County [n], Prince George’s County [n] Virginia – Alexandria [n], Arlington County [n], Fairfax [n], Fairfax County [n], Falls Church [n], Loudon County [n], Manassas [n], Manassas Park [n], Prince William County [n] MODERATE EARLY ACTION COMPACT (December 2007) Greensboro-Winston Salem-Highpoint, NC Alamanc e County, Caswell County , Davidson County [m], Davie Co

unty [m], Forsy

th County [m], Guilfor

d County [m], Randolph

County , Rocking

ham County

* Effec tive June 15, 2004 (P) = part of the cou nty n = area has whole or part county or counties i n a current 1-hr Ozone nonattainment area m = area has whole or partcounty or counti es i n a curren t 1-hr Ozone mainte nance area Previously, moderate nonattai nment areas were also required to have Stage II. However, Section 202(a)(6) of the Clea n Air A ct states tha t the Sec tion 18 2(b )(3) re quire men t to ado pt Stag e II co ntrols sh all not ap ply to m ode rate areas af ter t he promulgat ion of onboard r ules. In addit ion, EPA stat ed in t heir Ju ne 23, 1993 memorandum that aft er onboard r efu eli ng vapor recov ery (ORVR) was adopt ed th at moder ate areas coul d remove the ir S tage II c ontr ol requ ireme nt withou t pena lty. Mo st mod erate a reas d id rem ove Stage II con trol req uirem ents.

Also , on A pril 15 , 200 4, the 8 -hour o zon e non attainm ent de signatio ns were pub lished; the se de signatio ns wen t into effect on June 15, 2004. Under the new 8-hour designations, severalareas are classi fied as moderate nonattainment and will st ill have Stage II controls on GDF (they will have Stage II controls because under the 1-hour ozone
nona ttainme nt desig nation s these a reas a re class ified as se rious o r higher .) Th ese ar eas ar e highligh ted ab ove in yel low. For ex ample, areas in EPA Regi on I ( Maine, New Hampshi re, Vermont , Massa chus ett s, Rhode Is land, Connecticut) that

are included as additions t o the new 8-hour moderate nonattainment designati on are areas that were previ ousl y cl assi fi ed as “ seri ous” f or th e 1-h r ozone st andard.

In addi ti on, t

he Cle an Air

Act r equir es al l s tat es i n th e Ozone Trans port Re gion (OTR) to adopt Stag e II or comparabl e meas ures , re gardl ess of t heir cla ssi fi cati on. The OTR Sta tes inc lude: Connect icut , Del aware , Dis tri ct of Columbi a, Main e, Mary land, Massach uset ts, New Hampshi re, New Jers ey, New York, Pennsy lvan ia, Rhode Is la nd, andVer mont . Ne w Ham psh ir e on ly has St age II incer

ta in ar eas . Ne w Ham psh ir e s ubmi tt ed, andEPA approved, a Stage II compa rabilit y SIP revision (64 FR 5243 4; September 29, 19 99). In its comparability SIP revision, New Hampshire relied on reductions fr om its Stage II program (which is implemented in Hillsborough, Merri mack , Roc ki ngh am, and S tr af for d coun ti es) and r educ ti ons fr om it s r ef ormu lat ed ga sol in e (RF G) pro gra m.