1

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

1650 Arch Street

Philadelphia, Pennsylvania 19103

DATE:

SUBJECT: Technical Support Document for the Revisions to the Attainment Plans for the 

Commonwealth of Virginia Portion of the Washington, DC-MD-VA 1990 1-Hour 

and 1997 8-Hour Ozone Nonattainment Areas and the Maintenance Plan for the 

Fredericksburg 1997 8-Hour Ozone Maintenance Area to Remove the Stage II 

Vapor Recovery Program

FROM: Asrah Khadr, Environmental Engineer, EIT /s/

Office of Air Program Planning

TO: File

THRU: Cristina Fernandez, Associate Director /s/

Office of Air Program Planning

I. Introduction

On March 18, 2014, the Commonwealth of Virginia (Virginia) submitted revisions to the 

Virginia State Implementation Plan (SIP) through the Virginia Department of Environmental 

Quality (VADEQ) to amend the SIP-approved ozone attainment plans for the Virginia portion of 

the Washington, DC-MD-VA 1990 1-Hour and 1997 8-Hour Ozone National Ambient Air 

Quality Standard (NAAQS) Nonattainment Areas (Northern Virginia Areas) and the 

maintenance plan for the Fredericksburg 1997 8-Hour Ozone NAAQS Maintenance Area

(Fredericksburg Area) (collectively referred to as the Virginia Areas or Areas). The revisions 

also address the impact on the attainment/maintenance plans due to the removal of Virginia’s 

Stage II vapor recovery equipment from subject gasoline dispensing facilities in the subject 

areas. The SIP revisions contain a demonstration that removal of the Stage II vapor recovery 

program will not interfere with attainment or maintenance of the NAAQS in accordance with 

section 110(l) of the Clean Air Act (CAA). The analysis in these SIP revisions also contains a 

demonstration that meets the requirements of section 184(b)(2) of the CAA which requires areas 

in the Ozone Transport Region (OTR) to implement the Stage II vapor recovery program or a 

comparable measure. 

II. Background 

Stage II Vapor Recovery and Onboard Vapor Recovery Systems

Stage II vapor recovery (hereafter referred to as Stage II) is a means of capturing gasoline vapors 
2

displaced during transfer of gasoline from the gasoline dispensing unit to the motor vehicle fuel 

tank during vehicle refueling at a gasoline dispensing facility (GDF). Stage II vapor recovery 

involves use of special refueling nozzles and coaxial hoses for vapor collection at each gasoline 

pump at a subject GDF. Gasoline vapors belong to a class of pollutants known as volatile 

organic compounds (VOC). Gasoline is made up of a number of toxic compounds, and gasoline 

dispensing operations emit gasoline vapor that contains air toxics (also known as “hazardous air 

pollutants”) that can cause cancer and other serious health effects. These include benzene, 1,3-

butadiene, formaldehyde, acrolein, napththalene, and polycyclic organic matter (POM), all of 

which are gas-phase hydrocarbons that exist in gasoline vapor (except POM, which exists in gas 

and particle phases). 

Stage II gasoline vapor recovery systems have been a required emission control measure in areas 

classified as serious, severe, and extreme for the ozone NAAQS.1 With the amendment of the 

CAA in 1990, Stage II controls were required for moderate ozone areas, under CAA section 

182(b)(3). 

However, under section 202(a)(6) of the CAA, 42 U.S.C. 7521(a)(6), the requirements of section 

182(b)(3) would no longer apply in moderate ozone nonattainment areas after EPA promulgation 

of standards for onboard refueling vapor recovery (ORVR) as part of new motor vehicles’ 

emission control systems,

2

and after EPA determines that ORVR is in widespread use throughout 

the motor vehicle fleet. Under implementation rules issued in 2002 for the 1997 8-Hour Ozone 

standard, EPA retained the Stage II-related requirements under section 182(b)(3) as they applied 

for the 1-Hour Ozone standard (see 40 CFR 51.900(f)(5) and 40 CFR 51.916(a)).

Beginning with model year 1998, ORVR equipment has been phased in for newly manufactured 

light duty passenger cars and trucks, and has been required on nearly all new vehicles since 

2006.3 ORVR is an emission control system contained in the vehicle that captures gasoline 

vapors during refueling. The gas tank and fill pipe are designed to capture refueling-related 

vapors and contain them in an onboard, activated carbon canister. When the vehicle is running 

and warmed up, the vapors are drawn out of the canister and transferred to the engine to be 

combusted as fuel. The ORVR system is very efficient and is monitored by the vehicle’s onboard diagnostic system. Unlike Stage II systems, which are geographically limited to moderate

and above nonattainment areas, ORVR is applicable to all new vehicles everywhere those 

vehicles operate.

Over time, non-ORVR vehicles continue to be replaced by ORVR-equipped vehicles. On May 

16, 2012, EPA issued a final rule determining that ORVR technology was in widespread use 

throughout the U.S. vehicle fleet and waived the requirement for states to implement Stage II 

vapor recovery at GDFs in nonattainment areas classified as serious or above for the ozone 

NAAQS (77 FR 28772). EPA determined that emission reductions from ORVR-equipped 

vehicles are essentially equal to and would soon surpass the emission reductions achieved by 

 

1 See CAA section 182(b)(3), 42 U.S.C. 7511a(b)(3)

2 See 59 FR 16262 (April 6, 1994), codified at 40 CFR Parts 86 (including 86.098-8), 88, and 600. 

3 Under the current regulatory construct, motorcycles and heavy-duty gasoline vehicles not manufactured as a 

complete chassis are not required to install ORVR, so they may be some small percentage of gasoline refueling 

emissions from new vehicles not captured by ORVR controls.
3

Stage II alone. EPA determined that a state previously required to implement a Stage II vapor 

recovery program may take appropriate action to remove the measure from its SIP. 77 FR 

28772. EPA hereafter refers to this action as the “widespread use determination” or the “Stage II 

waiver.”

III. Stage II As A Control Measure in the Attainment/Maintenance Plans 

Stage II vapor recovery was originally required by the CAA in 1990 in two Virginia ozone 

nonattainment areas. Virginia adopted and published its Stage II vapor recovery regulations as 

Rule 4-37 of VR 120-01, entitled “Emission Standards for Petroleum Liquid Storage and 

Transfer Operations” in the November 2, 1992 edition of the Virginia Register of Regulations

(Vol 9, Issue 3), effective January 1, 1993. Virginia’s Stage II rules applied to the Northern 

Virginia and Richmond VOC Emission Control Areas, as defined under 9 VAC 5-40-5200(B)(2) 

and 9 VAC 5-20-206. 

Virginia submitted its Stage II regulation to EPA as a SIP revision on November 5, 1992. EPA 

approved Virginia’s Stage II SIP revision on June 23, 1994 (59 FR 32353). 

Stage II and the Virginia portion of the Washington, DC-MD-VA 1990 and 1997 Ozone 

NAAQS Nonattainment Areas Attainment Plans

Under the 1990 1-Hour Ozone NAAQS, EPA originally designated the OTR portion of Virginia 

as serious nonattainment as a part of the Washington, DC-MD-VA 1990 Ozone NAAQS 

Nonattainment Area. The Virginia portion of the OTR include the following areas: Stafford 

County, Arlington County, Fairfax County, Loudon County, City of Alexandria, City of Falls 

Church, City of Manassas, and City of Manassas Park. On December 19, 1997, the District of 

Columbia, Maryland and Virginia (the three states), submitted an attainment plan for the

Washington, DC-MD-VA 1990 Ozone NAAQS Nonattainment Area. On April 17, 2003 (68 FR 

19106), EPA gave the attainment plan conditional approval. On November 13, 2002 (67 FR 

68805), EPA reclassified the area as severe nonattainment; to meet the requirements of this 

classification, a severe area attainment plan was submitted on February 24, 2004. This 

attainment plan was approved on May 13, 2005 (70 FR 25688). The 1990 ozone NAAQS was 

then revoked on June 15, 2005. 

On July 18, 1997 (62 FR 38856), EPA promulgated the 1997 Ozone NAAQS. On April 30, 

2004 (69 FR 23941), EPA designated the Washington, DC-MD-VA Area as moderate 

nonattainment. The Virginia portion of this area includes Arlington County, Fairfax County, 

Loudon County and Prince William County as well as the City of Alexandria, City of Fairfax, 

City of Falls Church, City of Manassas, and City of Manassas Park. On June 12, 2007, the three 

states submitted an attainment plan which was proposed for approval by EPA on March 20, 2013 

(78 FR 17161). On February 28, 2012 (77 FR 11739), EPA determined that the Washington,

DC-MD-VA area was attaining the 1997 Ozone NAAQS and published a clean data 

determination as well as a determination that the area attained the 1997 Ozone NAAQS by its 

statutory attainment date. The attainment plan was approved by EPA on April 10, 2015 (80 FR 
4

19206). 

Stage II and the Fredericksburg 1997 Ozone Maintenance Area Maintenance Plan

On April 30, 2004 (69 FR 23941), EPA designated Stafford County, Spotsylvania County, and 

the city of Fredericksburg as the Fredericksburg 1997 Ozone Nonattainment Area. Since the air 

quality in the Fredericksburg 1997 Ozone Nonattainment Area met the 1997 ozone NAAQS, a 

redesignation request and maintenance plan were submitted by Virginia on September 28, 2005; 

EPA approved the redesignation request and maintenance plan on December 23, 2005 (70 FR 

76165). 

Even though the 1990 1-Hour Ozone NAAQS was revoked on June 15, 2005, EPA’s subsequent 

implementation rules for the 1997 8-Hour Ozone NAAQS retained the Stage II-related 

requirements under section 182(b)(3), but only as they applied to the Area for the Area’s 

classification for the 1-Hour Ozone NAAQS at designation for the 8-Hour Ozone NAAQS (see 

40 CFR 51.900(f)).4 Therefore the attainment plan for the Washington, DC-MD-VA 1997 Ozone 

NAAQS Nonattainment Area and the maintenance plan for the Fredericksburg 1997 Ozone 

NAAQS Nonattainment Area also contain Stage II as a control measure, in addition to the 

attainment plan for the Washington, DC-MD-VA 1990 Ozone NAAQS Nonattainment Area. 

At the time of the development of the Washington, DC-MD-VA 1990 ozone NAAQS attainment 

plan SIP, Stage II was still a mandatory measure for areas classified as moderate ozone 

nonattainment under section 182(b)(3) of the CAA. Although EPA had adopted ORVR rules for 

light-duty vehicles in April 1994, ORVR vehicles were not introduced for sale until model year 

1998, with nearly all new gasoline-powered vehicles being equipped with ORVR by model year 

2006. Under section 202(a)(6) of the CAA, Stage II requirements for areas classified as 

moderate “shall not apply” upon EPA’s promulgation of ORVR rules, and determination of 

widespread use of ORVR throughout the motor vehicle fleet. Although after ORVR 

promulgation Stage II was no longer a mandatory measure under the CAA, Virginia had relied 

upon reductions from Stage II in its ozone plans. Although Virginia was no longer obligated to 

retain Stage II as a mandatory measure under the CAA, the Commonwealth is required under 

section 110(l) of the CAA to demonstrate that a SIP revision to remove Stage II would not 

interfere with the applicable requirements to attain the NAAQS. 

 

IV. EPA Evaluation of Virginia’s SIP Revisions to Remove Stage II Vapor Recovery

A. Requirements

The removal of Stage II gasoline vapor control programs from the SIP has to meet certain 

requirements. Any SIP revision that may relax the SIP must meet the requirements of section 

110(l) of the Clean Air Act. Section 110(l) requires a demonstration proving that the SIP would 

not be relaxed if the measure in question is removed. Additionally, and specific to the removal 

of Stage II, certain areas must meet the requirements of CAA sections 184(b)(2) and 193. CAA 

 

4 See 69 FR 23966 (April 30, 2004), as amended at 70 FR 30604 (May 26, 2005) and 70 FR 71702 (November 29, 

2005) 
5

section 184(b)(2) applies to areas that are in the Northeast Ozone Transport Region (OTR); these 

areas in the OTR are required to implement Stage II or another program with comparable 

emissions reductions referred to as the “comparable measures” requirement. Additionally, CAA 

section 193, also referred to as the “general savings clause,” requires areas trying to modify 

control measures approved prior to November 15, 1990 to prove that modification of the control 

measure “insures equivalent or greater emissions reductions.” The Area did not have Stage II 

approved into its SIP prior to November 15, 1990, therefore CAA section 193 does not apply. 

The Area is a part of the OTR, therefore CAA section 184(b)(2) does apply. These SIP revisions

demonstrate compliance with CAA sections 110(l) and 184(b)(2). 

B. State Submittal

VADEQ submitted an analysis to satisfy the requirements of CAA sections 110(l) and 184(b)(2). 

VADEQ used the EPA guidance document Guidance on Removing Stage II Gasoline Vapor 

Control Programs from State Implementation Plans and Assessing Comparable Measures in 

developing its analysis to meet the requirements of CAA sections 110(l) and 184(b)(2). 

The EPA guidance document, Guidance on Removing Stage II Gasoline Vapor Control 

Programs from State Implementation Plans and Assessing Comparable Measures provides 

direction to states on the calculations necessary for the analysis of the emissions impact of Stage 

II removal. To analyze the emissions impact of Stage II removal, the area wide impact on the 

VOC inventory must be calculated. As recommended by the guidance document, there are 

several methods that can be used to demonstrate compliance with the requirements of CAA 

section 110(l); the method to be used depends on how the removal of Stage II would affect the 

area in question. The first method replaces Stage II with a new control measure that would offset 

any emissions increases that would result from the removal of Stage II. The second method 

involves substituting Stage II with excess emissions reductions not accounted for in the SIP. In 

the event that the removal of Stage II does cause an emissions increase, reductions in the VOC 

inventory since the previously approved SIP inventory can be used to offset any potential 

emissions increases resulting from the removal of Stage II. The third method does not involve 

substitution for any emissions increases in the event of an increase in VOC emissions from Stage 

II removal; this method allows the Area to provide a phase-out plan that would allow a 

minuscule amount of emissions increases that decreases rapidly as ORVR continues to increase 

in the vehicle fleet. This minuscule amount of emissions increases would be too small to 

interfere with attainment or progress towards attainment. This noninterference can be 

demonstrated in several ways. The area can provide its most recent air quality data showing 

attainment of the NAAQS; if the NAAQS has yet to be attained, air quality projections showing 

attainment can be provided. Additional air quality analyses showing that the removal of Stage II 

does not interfere with attainment or maintenance of the NAAQS will also be considered. To 

meet the requirements of CAA section 184(b)(2) comparability must be demonstrated by the 

State. In removing Stage II and trying to prove comparability, EPA believes that it is reasonable 

for states to demonstrate that the removal of Stage II has no impact on VOC emissions or has de 

minimis (minimal) impact on VOC emissions. EPA has defined de minimis impact as any 

additional incremental control achieved by Stage II beyond ORVR that is less than 10 percent 

(%) of the are wide VOC inventory. 
6

To calculate the area wide VOC inventory impact, two important equations must be used. 

Equation 1, presented below, provides the overall Stage II-ORVR increment. This increment 

provides the percentage impact on the annual area-wide emissions control gain from Stage II as 

ORVR is phased into the vehicle fleet. Equation 2, also presented below, calculates the 

emissions benefits of Stage II on the VOC inventory in tons per year (tpy). Equations 3 and 4 

provide the variables necessary to calculate the Stage II impact on the VOC inventory, these 

equations are also provided below. 

Equation 1: incrementi = (QSII)(1-QORVRi)(ηiuSII) - (QSIIva)(CFi)

Incrementi: The increment percentage impact on the annual area-wide emissions control gain 

from Stage II as ORVR is phased into the vehicle fleet

QSII: Fraction of gasoline throughput covered by Stage II 

QORVRi: Fraction of annual gallons of highway motor gasoline dispensed to ORVR-equipped 

vehicles

ηiuSII: In-use Stage II control efficiency 

QSIIva: Fraction of gasoline throughput covered by Stage II 

CFi: Compatibility factor

Equation 2: Tonsi = (Incrementi)(GCi)(EF)

Tonsi: VOC emissions benefit of Stage II (tons)

Incrementi: The increment percentage impact on the refueling inventory from removing Stage 

II 

GCi: The projected gasoline consumption (gal)

EF: The uncontrolled displacement refueling emissions factor (g/gal) 

Equation 3: EF (g/gal) = exp[-1.2798 - 0.0049(ΔT) + 0.0203(Td) + 0.1315(RVP)]

EF: The uncontrolled displacement refueling emissions factor (g/gal) 

ΔT: Values for this variable are area specific and are located in Appendix A-2 of the EPA 

guidance document (degrees fahrenheit)

Td: Values for this variable are area specific and are located in Appendix A-3 of the EPA 

guidance document (degrees fahrenheit)

RVP: Reid Vapor Pressure of the gasoline used for the area (pounds per square inch (psi))

VA DEQ submitted an analysis quantifying the VOC emissions benefits of Stage II. Equation 1 

was utilized to yield the increments provided in Tables 1 and 2. The calculations in Table 1 

assumed a Stage II control efficiency of 77% while the calculations in Table 2 assumed a Stage 

II control efficiency of 56%. Negative increment values are indicative of when excess emissions 

from non ORVR compatible Stage II systems overwhelm the emissions benefits of implementing 
7

Stage II. Table 1 presents calculated increment values which show that the Area will no longer 

see emissions benefits from Stage II after 2012. Table 2 presents calculated increment values 

which show that the Area will no longer see emissions benefits from Stage II after 2011. 

VADEQ used the more conservative Stage II efficiency estimate of 77% to determine the date 

when there will be no emissions benefits from Stage II; therefore, the Area will no longer see 

emissions benefits from Stage II after 2012. 

Table 1. Increment Calculations for 77% Stage 

II Efficiency

Year Increment 

2008 0.13760

2009 0.10597

2010 0.07168

2011 0.04235

2012 0.01821

2013 -0.00128

2014 -0.01632

2015 -0.02785

2016 -0.03673

2017 -0.04335

2018 -0.04817

2020 -0.05428

2030 -0.06204

Table 2. Increment Calculations for 56% Stage 

II Efficiency

Year Increment 

2008 0.08684

2009 0.06302

2010 0.03732

2011 0.01534

2012 -0.00275

2013 -0.01736

2014 -0.02862

2015 -0.03725

2016 -0.04390

2017 -0.04886

2018 -0.05245

2020 -0.05702

2030 -0.06279
8

The emissions benefits of Stage II were calculated using Equations 2 and 3. Using the more 

conservative increments produced by using the 77% Stage II efficiency estimate, the emissions 

benefits were calculated and the values tabulated in Table 3, below. The calculations also prove 

that there will be no emissions benefits from Stage II implementation past 2012. 

Table 3. Stage II Emissions Reductions in the Area-Wide VOC 

Inventory

Year Emissions Reductions (tpd VOC)

2008 0.58

2009 0.46

2010 0.31

2011 0.19

2012 0.08

2013 -0.01

2014 -0.07

2015 -0.13

2016 -0.17

2017 -0.20

2018 -0.22

2020 -0.24

In addition to increment and area wide VOC inventory calculations, VADEQ submitted 

additional analyses to support its removal of Stage II from the Virginia SIP. VADEQ included 

an analysis which calculated the non-ORVR compatible Stage II benefit on a gasoline basis and 

a vehicle miles travelled (VMT) basis and compared the analysis to the Stage II benefit 

calculated with the use of the Motor Vehicle Emission Simulator (MOVES2010a). This 

comparison is provided below in Table 4, and shows that incompatibility excess emissions, 

which are the emissions that arise from the interaction of a Stage II vapor recovery system (VRS)

with ORVR, exceed Stage II benefits in the 2014 time frame. 

Table 4. Excess and Benefit VOC Emissions Calculations Results

Year

Excess Vent Emissions 

(tpd VOC) Stage II Benefit (tpd 

VOC)

Stage II Benefit with respect to 

ORVR (tpd VOC)

Gasoline 

Basis

VMT 

Basis Gasoline Basis VMT Basis

2008 0.5768 0.5790 1.937 1.360 1.358

2009 0.6218 0.6271 1.616 0.996 0.991

2010 0.6669 0.6696 1.343 0.676 0.673

2011 0.7040 0.7042 1.309 0.605 0.605

2012 0.7496 0.7479 1.072 0.323 0.325
9

2013 0.7755 0.7721 0.885 0.110 0.113

2014 0.7933 0.7883 0.730 -0.063 -0.058

2015 0.8071 0.8008 0.605 -0.202 -0.196

2016 0.8189 0.8115 0.505 -0.313 -0.306

2017 0.8211 0.8129 0.434 -0.388 -0.379

2018 0.8204 0.8113 0.378 -0.442 -0.433

2020 0.8184 0.8081 0.307 -0.511 -0.501

2030 0.8055 0.7926 0.249 -0.556 -0.544

Additionally, VADEQ submitted work completed by the Georgia Institute of Technology 

(Georgia Tech) for the Association for Southeastern Integrated Planning project. Georgia Tech 

completed emissions sensitivity analyses utilizing the Community Multiscale Air Quality 

(CMAQ) model, for the sensitivity of ozone concentrations with respect to NOx and VOC 

emissions. Three sensitivity analyses were conducted to gauge the sensitivity of ozone formation 

with respect to a 30% decrease in anthropogenic VOC, ground level NOx and point source NOx 

in the applicable Virginia areas. It was found that Ozone concentrations were most sensitive to 

decreases in point source NOx. The sensitivity to point source NOx is 100 to 1,000 times greater 

than ozone concentration sensitivity to anthropogenic VOC. The results indicate that NOx has a 

much larger impact on Ozone concentrations than VOC. 

Through the CMAQ modeling utilized for the sensitivity analyses, the effect of Stage II on ozone 

concentrations was calculated at the monitor in the Virginia Areas. Table 5, below, presents the 

Stage II benefit in terms of the change of ozone concentration. The results presented show that 

Stage II has a very minuscule effect on ozone concentrations in the Virginia Areas. 

Table 5. Stage II Effect on Ozone Concentration

Area Monitor

Stage II Benefit to Ozone Concentrations 

(parts per billion (ppb))

Virginia Areas Arlington -1.72x10-4 to -2.87x10-4

C. EPA Evaluation and Conclusion 

EPA thoroughly evaluated the submittal made by Virginia through VADEQ. EPA’s detailed 

review has led EPA to conclude that VADEQ properly addressed the recommended increment 

and VOC inventory calculations which prove when Stage II no longer provides a benefit for the 

Virginia Areas. EPA agrees with VADEQ that withdrawal of the Stage II requirement is 

appropriate on January 1, 2014. EPA also reviewed additional data provided by VADEQ 

showing ozone formation in the Virginia Areas is much more NOx dependent. In conclusion, 

EPA agrees with Virginia’s recommendation that the Stage II requirement be removed on 

January 1, 2014, since at that point in time, the Virginia Areas will no longer see any emissions 

benefits from the implementation of Stage II. Also, at that point in time, the Virginia Areas will 

have met and exceeded the de minimus requirement for removing Stage II. EPA is approving the 
10

removal of Stage II from the attainment and maintenance plans for the Virginia Areas because 

the submitted analysis demonstrates that Stage II removal will not interfere with the attainment 

or maintenance of the NAAQS in accordance with section 110(l) of the CAA and meets the 

requirements of section 184(b)(2) of the CAA.