Onboard Refueling Vapor Recovery Systems Analysis of Widespread Use

By Eric Skelton and Lisa Rector

NESCAUM August 20, 2007

Introduction Beginning in the mid-1970s as states began developi ng ozone attainment plans in response to requirements of the federal Clean Air A ct (CAA), gasoline refueling was identified as a candidate area source category for controlling volatile organic compound (VOC) 1 emissions. Considering that millions of gallons o f gasoline were dispensed daily into motor vehicles, it was readily apparent that gasoline refueling was one of the most significant VOC area source cat egories and therefore one of the highest priority categories to be controlled as par t of an overall ozone attainment

strategy.

Gasoline is a relatively volatile liquid that readi ly vaporizes to saturate air in a confined space, such as the space above the liquid level in a motor vehicle fuel tank. When the fuel tank is subsequently refilled with li quid gasoline, this air-vapor mixture is displaced out of the tank and through th e fill pipe. Without some means of capture, the vapors escape to the ambient air, ulti mately contributing to photochemical processes that form ozone and other o xidants.

Early on, states and the U.S. Environmental Protect ion Agency (EPA) identified two basic conceptual approaches to capturing gasoline v apors. The first approach (Stage II Vapor Recovery, or “Stage II”) was first impleme nted in the late 1970s and ultimately became a requirement under CAA § 182(b)( 3) for areas classified as moderate, serious, severe, and extreme ozone nonatt ainment areas. Stage II allows the vapors to continue to pass through the motor ve hicle fuel tank fill pipe but retains the vapors at the gasoline service station, capturi ng them at the interface between the fill pipe and the dispensing nozzle.

In a typical Stage II installation, a flexible rubb er bellows surrounds the nozzle spout, forming a partial seal around the lip of the fill p ipe. The vapors are forced by displacement through a chamber in the nozzle, into a second hose or into the annular space between dual hoses, and into underground pipi ng connected to the vapor space in the underground storage tank. Once in the under ground tank, the vapors remain in a gaseous state within the tank’s head space where they may partially convert to a liquid phase as the tank re-establishes equilibrium between liquid and vapor phases, or partially escape through the tank vent or leaks in the system. Ultimately, most of the vapors are displaced out of the underground tan k into a cargo tank (Stage I Vapor

1 In the atmosphere, VOCs along with nitrogen oxides in the presence of sunlight and heat promote formation of ozone and other photochemical oxidants. Thus, attainment s trategies for reducing tropospheric ozone levels focus on reducing emissions of VOCs, nitrogen oxides, or a c ombination of the two.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

2 Recovery) and transported to a gasoline terminal, e ither to be condensed into liquid or thermally destroyed. According to data compiled in 2006 by E PA’s Office of Transportation and Air Quality and illustrated in Figure 1 below, there ar e 27 states and the District of Columbia involving 275 counties nationally that have impleme nted various levels of Stage II programs. In some states, Stage II programs are required state-w ide. Other states limit the coverage of their Stage II programs to their ozone nonattainment area s.

Figure 1 – Stage II Vapor Recovery Areas – 275 Coun ties

The second approach (Onboard Refueling Vapor Recove ry, or “ORVR”), also required under CAA § 202(a)(6), began with certain 1998 model year new gasoline-powered light duty motor vehicles (passenger cars and light trucks), with fu ll phase in by model year 2006 for other classes of gasoline powered motor vehicles. 2 The approach involves creating a mechanical or li quid seal around the dispensing nozzle, redirecting the vapor s away from the fuel tank fill pipe, and forcing the vapor stream to pass though a canister filled with activated carbon. The vapors are then adsorbed onto the carbon for temporary storage . Upon engine restart, air is pulled through the canister to purge the vapors from the carbon an d route them to the engine where they are combusted. Approved Stage II and ORVR systems both are certified to be 95 percent efficient in capturing VOC emissions from refueling gasoline pow ered motor vehicles. In theory, the choice of one system type versus the other is emissions ne utral. In practice, there are a number of factors that affect the efficiency of each system t ype.

The decision by Congress to require new motor vehic les to be equipped at some point with ORVR was also a decision ultimately to cease requir ing Stage II at gasoline service stations. As increasing numbers of ORVR-equipped motor vehicles replace the aging fleet of motor vehicles without ORVR, there is a continually diminishing ma ss of displaced gasoline vapors available for capture by Stage II. Using Massachusetts as an example, Figure 2 illustrates how ORVR as a

2 The ORVR requirements apply to light-duty vehicles, lig ht-duty trucks, medium-duty passenger vehicles, and complete heavy-duty vehicles. For specific phase-in dates and d efinitions of vehicle classes, see Appendix A.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

3 stand-alone technology ultimately achieves signific antly greater emissions reductions compared to a hypothetical scenario whereby Stage II is main tained as a stand-alone technology for capturing gasoline refueling vapors (i.e., ORVR nev er implemented). If Stage II were the sole program for controlling emissions from gasoline ref ueling, emissions would continue to increase as gasoline throughput increases. In contrast, the emissions benefits of ORVR as the sole program will extend out until virtually all light-d uty gasoline vehicles (as defined in Appendix A) are ORVR equipped.

Figure 2 – Emissions from ORVR & Stage II as Stand- Alone Programs (Massachusetts)



## 0 2 4 6 8 10 12 14 16 18 20

2001 2006 2011 2016 2021 2026Emissions (tons/summer day) .



### Emissions if only Stage II controls were in place, without ORVR

Emissions with only ORVR requirements, without Stag e II controls

Most Stage II programs will reach a point where the continually diminishing emissions benefit will no longer justify the cost of installing new s ystems or maintaining existing ones. In fact,

there is an eventual emissions disbenefit associate d with continuing to employ many of the Stage II systems. CAA § 202(a)(6) authorizes the EPA Adm inistrator to waive the Stage II requirements for areas classified as serious, sever e, or extreme when the Administrator determines that ORVR systems are in “widespread use ” throughout the motor vehicle fleet. 3 The CAA appears to give the Administrator considerable discretion in defining widespread use.

3 CAA § 202(a)(6) also states that Stage II controls no l onger apply to moderate ozone nonattainment areas after EPA promulgates regulations implementing ORVR. These re gulations were promulgated on April 16, 1994 (59 FR 16262).NESCAUM

ORVR Widespread Use Analysis August 20, 2007

4 However, for purposes of this analysis, it is assum ed pursuant to the anti-backsliding requirements in CAA § 110(l) that EPA would not aut horize a state to discontinue a Stage II program if the result would be to worsen air qualit y in the state or nonattainment area(s) within a state where the Stage II equipment is installed.

Using this approach, a strong argument can be made that ORVR is in “widespread use” when ORVR by itself achieves the same or a better emissi ons benefit compared to maintaining Stage II requirements in the state or applicable nonattainme nt areas, as ORVR-equipped vehicles phase into the fleet. When states are able to project th e year in which ORVR by itself achieves the same or a better emissions benefit as compared to m aintaining Stage II requirements and subsequently submit amendments to their ozone attai nment or maintenance plans to discontinue Stage II programs, such amendments should meet the no-backsliding test.

Stage II Programs in the Ozone Transport Region (OT R) The OTR was created under CAA § 184 to address regi onal transport of ozone and ozone precursors in the northeastern U.S. 4 Among other provisions, § 184(b)(1) prescribed sp ecific control requirements 5 to be incorporated into ozone implementation plans for states in the OTR. Additionally, in accordance with § 184(b)(2), all a reas in the OTR, regardless of their ozone attainment status, had to adopt Stage II or alterna tive measures capable of achieving comparable emissions reductions. The CAA required EPA to compl ete a study identifying such control

measures. 6 States with ozone nonattainment classifications o f serious and above had no other option but to adopt and implement Stage II programs in these areas. However, areas in the OTR

with classifications of moderate or below had the o ption of adopting comparable measures. States in the OTR that are now contemplating discon tinuing Stage II programs at some future date face an additional hurdle of addressing the co mparable measures requirement in § 184(b)(2).

Factors Affecting the ORVR Emissions Benefit There are many factors affecting when the state-wid e or nonattainment area-wide collective emissions benefits achieved with ORVR become superi or to the benefits of a Stage II program and therefore when states may discontinue their Sta ge II programs without adversely affecting air quality. We discuss the principal factors in t he following paragraphs.

In-Use Efficiency of Stage II Programs. Although Stage II programs have been important components of the suite of controls for ozone attai nment purposes, they do not perfectly capture and control gasoline vapors. The in-use efficiency of Stage II as a control technology or strategy varies from station to station and locality to loca lity. These variations affect emissions and

therefore affect when ORVR becomes the better choic e as a stand-alone state-wide or area-wide control strategy. Areas with very effective Stage II programs will continue to benefit from a combination of Stage II and ORVR for several years beyond the point at which areas with less effective Stage II programs determine that a stand- alone ORVR program achieves a better result.

4 The OTR covers the entire states of Connecticut, Delaware, M aine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont, along with the District of Columbia consolidated metropolitan statistical area (CMSA), which includes a portion of northern Virginia.

5 The specific requirements were for enhanced vehicle inspection a nd maintenance programs and reasonably available control technology for all VOC sources covered by control techniques guidelines,

6 Stage II Comparability Study for the Northeast Ozone Tra nsport Region , EPA, January 1995.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

5 The following is a summary of the primary factors w hich influence the effectiveness of Stage II

programs.

1. Rule penetration. Typically, Stage II is not required at every gaso line service station in every state. Many states limit the application of Stage II to ozone nonattainment and maintenance areas as part of their federally approved plans. W ithin these areas, Stage II often is required only at commercial service stations with larger undergro und storage tanks and/or with annual or monthly average gasoline throughputs above specifie d thresholds. Decreased rule penetration within the geographical area where Stage II is requ ired translates into more emissions from Stage II equipment and a nearer date by which ORVR is det ermined to be the superior stand-alone

strategy.

2. Rule effectiveness. Stage II systems, in particular the dispensing no zzles and hoses, require regular and consistent maintenance to optimize emis sion reductions. The best maintained systems typically are inspected regularly by statio n personnel who are able to identify maintenance problems (e.g., damaged bellows or hose s) and expeditiously complete the necessary repairs. The certainty of frequent inspec tions by state and local regulatory personnel tends to deter postponement of critical repairs by station personnel. As is the case with rule penetration, decreased rule effectiveness translate s into more emissions from Stage II and a nearer date for a determination for reliance solely on ORVR.

In its Stage II Technical Guidance, 7 EPA developed in-use efficiency factors for Stage II programs based on a combination of exemption levels (rule penetration) and inspection frequency (rule effectiveness). Table 1 lists the various efficiency factors. The table shows, among other things, that in-use efficiency decrease s significantly from certification levels when the inspection frequency is minimal. In addition, the table shows that even though individual Stage II systems are certified to be 95 percent eff icient, an overall Stage II program likely will not control 95 percent of an affected area’s gasoli ne refueling emissions.

Table 1 – Program In-Use Efficiency Factors (% Effi ciency) Inspection Frequency Minimal Annual Semiannual Certification

Exemption Level (gal/mo)

None 62 86 92 95

2000 61 84 90 93
10,000 60 84 89 92
10,000 & 50,000 56 77 83 86

3. System integrity. The plumbing connecting the gasoline dispenser to the underground storage tank is intended to provide an unrestricted and vap or-tight passage for collecting gasoline vapors. Likewise, other tank plumbing fixtures, such as ven t pipes, pressure vacuum valves, fill pipes, and Stage I Vapor Recovery Systems, are intended to be installed and maintained in a vapor-tight condition and to function properly at all times. I n reality, connections and fixtures do not always

7 Technical Guidance – Stage II Vapor Recovery Systems for Cont rol of Vehicle Refueling Emissions at Gasoline Dispensing Facilities , EPA-450/3-91-022a, November 1991.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

6 function properly or are not always vapor-tight. A dditionally, if the plumbing from the dispenser does not properly slope all the way to the undergro und tank, condensed liquid may collect in low spots, partially or completely obstructing vapor re turn lines, and creating back-pressure in the system. Pressure vacuum valves also may not close completely after venting or may stick in a closed position, forcing pressure to be relieved at weak points in the system. Cargo tank drivers may fail to properly connect vapor return hoses to the Stage I system during tank filling. These are the types of factors, tied to inspection freque ncy, that contribute to the fugitive emissions of gasoline vapors, thereby adversely affecting the ef ficiency of Stage II , relative to ORVR.

4. System type. There are two general types of Stage II systems; balance and vacuum-assist. Typically, both types are in use in any given state program, and the propensity to favor one system type over another varies by state. The bala nce system is the simpler of the two. It relies on the draw-down of gasoline from the underground s torage tank during refueling to create a slight vacuum in the vapor return lines that is suf ficient to draw most of the vapors dispensed from the motor vehicle fuel tank into the vapor ret urn system. The dispensing nozzle bellows and the seal it creates against the lip of the moto r vehicle fill pipe help to maintain the slight vacuum necessary to “balance” the volume of gasolin e vapors displaced from the motor vehicle fuel tank against the volume of liquid extracted fr om the underground tank.

The vacuum-assist type of system employs a mechanic al vacuum pump or a venturi 8 to actively draw the displaced vapors into the Stage II system. Typically, the degree of vacuum is set by adjusting the volume of air drawn into the Stage II system against the volume of liquid dispensed. This setting is known as the Air-to-Liq uid Ratio (A/L). If the A/L is greater than 1, a greater volume of air is drawn into the Stage II sy stem, relative to the volume of liquid drawn from the underground storage tank. Drawing excess air increases the capture of vapors displaced out of the motor vehicle fill pipe. These systems often are more acceptable to consumers because the nozzles look and operate more like thos e from the pre-Stage II era. They are equipped with less bulky reduced-tension bellows or may not be required to have a bellows.

A higher A/L ratio is beneficial only to a point. If too much excess air enters the system, the head space pressure in the underground storage tank may increase. At some point, this pressure may have to be relieved by opening the pressure vac uum valve, allowing vapors to escape to the ambient air. Vapors may also leak to soil, groundw ater, and the atmosphere through plumbing connections that are not leak resistant to pressuri zation. In addition, excess air introduced into the headspace of an underground storage tank upsets the equilibrium at the interface between gas and liquid. To re-establish equilibrium, more liqu id gasoline must convert to a vapor phase and occupy the tank head space. This phenomenon, known as vapor growth, increases pressurization of the Stage II system and increases the mass of va por that is released through the pressure vacuum valve or via system leaks, or requires colle ction by the Stage I system. In theory, greater vacuum at the nozzle, resulting from a higher A/L r atio, also may cause more liquid gasoline, otherwise destined for the motor vehicle fuel tank, to vaporize inside the fill pipe and be captured by the Stage II system.

8 A venturi is a tube with tapered constriction in the mi ddle, designed to cause an increase in the velocity of flow of a fluid and a corresponding decrease in fluid pressure to cr eate a vacuum.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

7 The increased vapor collection efficiency of vacuum -assisted Stage II systems, partially offset by the effects described above of excess air on leakag e and vapor growth, affects overall emissions from Stage II and thereby affects when stand-alone ORVR becomes the more effective choice for controlling emissions. Vacuum-assist Stage II s ystems also exhibit certain incompatibility problems with ORVR. This will be discussed later.

Motor Vehicle Fleet Characteristics. The overall attributes of a motor vehicle fleet, within a state or nonattainment area that utilizes Stage II systems, likewise have a significant effect on refueling emissions. The following is a summary of the primary fleet characteristics which will influence state decisions regarding when to discont inue their Stage II programs.

1. Fleet turnover. At some point, as older vehicles are retired from the fleet and replaced by newer vehicles, virtually all light-duty motor vehi cles will be ORVR-equipped. However, the fleet turnover rate varies from state to state, dep ending on such factors as personal disposable income, weather, road conditions, and accident rate s. As the analysis illustrates later in this report, it is unnecessary for states to wait until 100 percent of the vehicle fleet is ORVRequipped before discontinuing Stage II programs. H owever, states with a higher fleet turnover rate are likely to see stand-alone ORVR effectivene ss surpass Stage II at an earlier date, compared to states with a relatively lower turnover rate.

2. Vehicle type. Differences in consumer preferences for vehicle t ypes also affect ORVR penetration and overall control of refueling emissi ons by Stage II. ORVR was first introduced in lighter light-duty new gasoline vehicles and phased in over time into the fleet of heavier lightduty new vehicles (see Appendix A). If there is a preference by consumers in a particular state for purchasing heavier vehicles, the percentage of ORVR-equipped vehicles registered in that

state will be lower 9 compared to a state where the preference is for li ghter vehicles. The resulting lower ORVR penetration rate tends to post pone the date by which ORVR surpasses Stage II.

3. Fuel efficiency. There is a contributing factor to be considered tha t is associated with a higher percentage of heavier vehicles (e.g., light-duty tr ucks) in the fleet and their concomitant lower fuel efficiency. Consider two hypothetical fleets; one heavier, with an average fuel efficiency of 15 miles per gallon (mpg), and the other considerab ly lighter with an efficiency of 30 mpg. The heavier fleet must consume 100,000 gallons of fuel to travel a collective 1.5 million miles. In contrast, the lighter, more fuel efficient fleet co nsumes only 50,000 gallons of fuel to travel the same distance. Over the span of time in which it t akes to travel the 1.5 million miles, the heavier fleet, upon refueling, displaces 100,000 gallons of a saturated mixture of air and gasoline vapors and the lighter fleet only 50,000 gallons. Assumin g near identical degrees of saturation in the displaced air/fuel mixtures between the two fleets, the heavier fleet displaces twice the mass of gasoline vapor per distance traveled compared to th e lighter fleet. Thus, having a higher percentage of heavier vehicles in a fleet will resu lt in more emissions from gasoline refueling, both from ORVR and Stage II. Depending on the comp arative in-use efficiency between ORVR and Stage II, fleet-wide fuel efficiency could have the effect of either moving forward or postponing the date by which ORVR surpasses Stage I I.

9 This heavier vehicle effect began to diminish in model year 20 06 when ORVR was required for 100 percent of new heavy light-duty trucks, medium-duty passenger vehicles , and complete heavy-duty vehicles.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

8 4. Vehicle miles traveled (VMT). VMT differences from state-to-state depend on a num ber of factors, including population, average commute dist ance to work, availability of transportation alternatives, personal disposable income, severity of traffic congestion, and personal preference. Higher state-wide VMT means more fuel is dispensed and consumed and therefore more emissions per unit of time from gasoline refueling and Stage II systems. Similar to the fuel efficiency concept described above, the effect of h igher VMT on refueling emissions will affect the date for moving to a stand-alone ORVR program.

Other Factors Affecting Refueling Emissions. In addition to Stage II and motor vehicle fleet characteristics, other miscellaneous factors affect VOC concentrations in gasoline vapors and affect refueling emissions. Some of the more signi ficant factors are discussed below.

1. Gasoline volatility. Gasoline is a complex mixture of organic compound s, including lighter species that readily evaporate. The propensity for gasoline to evaporate from motor vehicles and refueling operations is a function of its Reid vapo r pressure (RVP), measured in pounds per square inch (psi). Prior to RVP controls, typical summertime gasoline RVP in the northeast U.S. ranged from 10.8 to 11.7 psi. Phase I RVP controls took effect in 1989, limiting RVP to a range of 9.0 to 10.5 psi, with the most stringent limits applying to ozone nonattainment areas. Phase II RVP controls became effective in 1992, capping summ ertime RVP at 9.0 psi with a more stringent cap of 7.8 psi applying in ozone nonattai nment areas. Further, reformulated gasoline (RFG), required in ozone nonattainment areas, typic ally has much lower summertime RVP levels, on the order of 6.8 psi. Higher RVP will te nd to elevate the VOC concentration in the vapor stream and increase emissions from Stage II s ystems and from ORVR-equipped motor

vehicles.

2. Temperature. Gasoline volatility also is affected by temperatu re. On hot summer days, refueling emissions tend to increase both from ORVR -equipped motor vehicles and from Stage II systems simply because gasoline’s evaporation in creases with temperature. There is an offsetting effect related to the difference in temp erature between the cooler dispensed fuel temperature and the warmer motor vehicle fuel tank. As the cooler dispensed fuel enters the motor vehicle fuel tank, it has a condensing effect in the vapor head space, effectively reducing the mass of vapor to be routed to the carbon adsorb er.

Also, increased sunlight and heat, typically associ ated with elevated ambient temperature events, favor formation of tropospheric ozone and other pho tochemical oxidants. For these reasons, widespread use analyses focus on the hottest days o f the summer or the days in which ozone levels are highest. These factors will of course v ary considerably from one area to another.

3. Refueling Activity . The activity level at gasoline service stations w ith high-volume throughputs tends to minimize the opportunity for the undergrou nd storage tanks and the Stage II system to establish equilibrium conditions. Consequently, pr essure vacuum valves may open and vent to the atmosphere more frequently in response to build -up of pressure in the system. The VOC concentration of the vapor stream also will vary, t hereby affecting the VOC emissions rate during the release event.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

9 Effectiveness of ORVR Systems As previously stated, ORVR systems are certified to be 95 percent efficient in capturing VOC emissions during refueling operations. However, in- use efficiency is influenced by other factors,

as described below.

Reliability and Durability. In concept, an ORVR system is quite simple. Organ ic vapors are displaced during refueling to a sealed canister whe re they adsorb onto activated carbon. Following engine start up, air is pulled through th e canister to purge the vapors, which are then routed to the engine and combusted. The vehicle’s On-Board Diagnostic (OBD) System monitors the function of critical components of the system. However, there are limited in-use data available on the reliability of ORVR systems, particularly systems that have been in operation for many years. The available data have been provided to EPA by automobile

manufacturers.

Figure 3 – ORVR Test Data Submitted to EPA as of Ap ril 2006



# ORVR test results

3 70 146

28

8 11

2 2 1

0 20 40 60 80 100 120 140 16000-0.010.01-0.10.1-0.20.2-0.30.3-11-22-5>5

emission rate (std 0.2)Frequency

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%



## Frequency

Cumulative %

Preliminary information compiled in April 2006 on 2 88 vehicles showed that 24 (8.8 percent of the total) did not meet the standard of 0.20 grams of VOC per gallon of fuel dispensed. 10

10 The 0.20 gram per gallon standard is equivalent to the req uired 95 percent efficiency for ORVR systems.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

10 However, of the vehicles that passed the test, more than 80 percent showed results that were half the standard or less. Therefore, although an 8.8 p ercent failure rate may seem high, the average emission rate overall was well within the standard, suggesting that the ORVR program as a whole achieves better than a 95 percent control eff iciency. In fact, EPA’s MOBILE6 model assumes that ORVR systems are 98 percent efficient in controlling the portion of refueling emissions that does not include spillage. 11 Figure 3 (above) illustrates the frequency of compliance with the standard for this limited data set.

There is no information available regarding the eff ectiveness of OBD systems to detect an ORVR malfunction. Lacking sufficient data, the ass umption in this analysis is that ORVR systems retain the same high degree of effectivenes s for the life of the vehicle.

Gasoline Spillage . Spillage of gasoline during vehicle refueling is a common event, involving both vehicle design and human factors. To account f or spillage, EPA’s ORVR certification includes a requirement that any spillage occurring during the certification test is counted in the emission results. This requirement had the effect o f discouraging use of fill pipe designs prone to cause spitback spillage. Each cubic centimeter of g asoline spilled weighs about 0.67 grams, so spillage of even a small volume of gasoline during the refill, required in the test, likely will resul t in failure to meet the 0.2 gram per gallon refuelin g emission standard. Based on the refueling emission test procedure requirement and the results of the field tests displayed in Figure 3 above, it seems clear that ORVR, in conjunction with fill pipe redesign, has reduced gasoline spillage. The emissions modeling used in the widespread use a nalysis accounts for the reduced spillage benefit by incorporating a spillage emission factor for ORVR which is one-half of that for nonORVR vehicles using conventional nozzles.

Compatibility with Stage II Systems. As previously explained, the ORVR system minimizes or prevents the escape of gasoline vapors from the fil l pipe of the motor vehicle fuel tank by directing the vapors to a canister. Thus, when an ORVR-equipped vehicle is refueled at a gasoline service station equipped with Stage II, th ere is little to no vapor to be captured and routed to the underground storage tank. 12 If the Stage II system is a balance system, the s light negative pressure created during draw-down of liqui d fuel in the underground tank will cause an equivalent volume of fresh air to be drawn into the Stage II system. This air may enter by way of one or more refueling nozzles that are in use at the time but for which the interface between the bellows and the fill pipe is imperfectly sealed . Air also may enter from leaks in the system plumbing or through a defective or missing vacuum v ent valve. If the system is perfectly sealed, a slight negative pressure will be established in t he head space of the underground storage tank. In either circumstance, the gasoline dispensing act ion upsets equilibrium, and liquid gasoline will vaporize at the liquid-vapor interface in the tank until equilibrium is re-established.

If the Stage II system is vacuum-assisted, air in e xcess of the volume of gasoline dispensed is drawn into the system. When fueling an ORVR-equippe d vehicle, this air likely contains no gasoline vapors. If the seal formed in the fill pi pe is a liquid seal, the slight vacuum at the nozzl e may cause some liquid gasoline to vaporize and be d rawn into the Stage II system. The volume

11 Frequently Asked Questions on Mobile6 , EPA, January 16, 2002.

12 This is the case regardless of whether the ORVR system is fu nctioning properly to capture and retain the vapors in

the canister.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

11 of air entering the system in excess of the volume of gasoline dispensed creates a slight positive pressure within the head space of the tank. Since the newly introduced air likely contains little to no gasoline vapor, gasoline inside the underground storage tank converts from liquid to vapor phase (vapor growth) to re-establish equilibrium. Multiple fillings of ORVR-equipped vehicles further increase pressure in the Stage II system, c ausing vapors to escape though system leaks or causing the pressure-vacuum valve to open. Emissio ns created by this interaction between ORVR-equipped vehicles and vacuum-assisted Stage II systems are referred to as Incompatibility Excess Emissions (IEE).

Table 2 – Comparison of Test Data for Determining I EE Factors 13

Incompatibility Excess Emissions Factor (lbs/1000 g al)

Test Data Gilbarco

vacuum-assist VRS (Certified

A/L ratio is 1.0 to 1.2) Wayne-Dresser

vacuum-assist VRS (Certified

A/L ratio is 0.9 to 1.1) ORVR – Vehicle

fuel tank fill pipe savings (reduction) Overall

(Gilbarco) excess

emissions factor

CARB TEST (1999) 0.86 a 0.06 a N/A 0.86

API analysis of

CARB IEE factor 0.78 b 0.08 b N/A 0.78 b

API Phase 1 Report (2004) N/A N/A 0.31 0.55 c

API Phase 2 Report (2004) 0.72 N/A 0.39 0.33

a The CARB report provides average emissions for baseline and ORVR-simulated refueling; the IEE factors were calculated by EPA’s contractor from these values and the percent o f ORVR vehicles simulated; for the WayneDresser system, only the test with the P/V valve intact was used.

b API used a linear regression of the CARB test results to d etermine the emission factor at 100 percent ORVR vehicle simulation and adjusted the factors for a lower Rei d vapor pressure (assumed uncontrolled emissions of 7.6 lbs/1000 gal versus 8.4 lbs/1000 gal).

c API calculated 0.55 lbs/1000 gal based on the CARB factor of 0.86 lbs/1000 gal (0.86 – 0.31 = 0.55).

The magnitude of IEE has been the subject of debate for several years, with the American Petroleum Institute (API) and the California Air Re sources Board (CARB) as primary participants in the debate. API and CARB have each overseen testing projects and have come to different conclusions regarding IEE. Table 2 (abov e) summarizes the results and analyses of data from recent studies involving Stage II systems manufactured by Gilbarco and WayneDresser.

When evaluating emissions during refueling of an OR VR-equipped vehicle with a vacuumassisted gasoline dispensing nozzle, the primary di fference between the CARB and API factors is explained according to how each accounts for emissi ons at the interface between the nozzle and the motor vehicle fill pipe. In arriving at the 0. 86 lbs/1000 gal factor, CARB focused solely on vapor growth due to excess air in the underground t ank. However, API contends there is a significant emissions savings with an ORVR-equipped vehicle because essentially no fugitive vapor emissions occur at the nozzle-fill pipe inter face. API quantified this emissions savings in

13 Stage II Vapor Recovery Systems Issue Paper (and references therein), EPA, August 12, 2004.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

12 its phase I report at 0.31 lbs/1000 gal for a net I EE factor of 0.55 lbs/1000 gal. Further in its phase II report, API arrived at an even lower vapor growth emissions factor (0.72 lbs/1000 gal) and a higher fugitive emissions benefit (0.39 lbs/1 000 gal) for a net factor of 0.33 lbs/1000 gal.

A decision on the most appropriate IEE factor to us e in an analysis will have a significant effect on determining when ORVR surpasses Stage II as the better stand-alone technology. A lower IEE factor, exemplified by the Wayne-Dresser vacuum -assist data (Table 2) and likely related to the reduced A/L ratio, will extend the life of effe ctive Stage II programs. California, for example, now requires all Stage II systems to be OR VR-compatible. Pursuant to the California regulation, balance and vacuum-assist Stage II syst ems are required to meet a VOC emissions standard of 0.38 pounds per 1000 gallons dispensed, based on an uncontrolled emission factor of 7.6 pounds per 1000 gallons gasoline dispensed. As shown by the data in Appendix C, the result of this requirement is to project a continued emiss ions benefit from maintaining Stage II programs in California for more than a decade beyon d what other states are likely to achieve without ORVR-compatible equipment..

For the time being, EPA recommends states use the 0 .86 lbs/1000 gal emission factor for nonORVR compatible equipment when performing widesprea d use analyses. 14 At the same time, EPA affirms that additional emissions monitoring is needed in order to better characterize IEE. Results from subsequent studies ultimately may sugg est using a different emission factor, perhaps closer to what was demonstrated for Wayne-D resser systems, particularly if lower limits are stipulated for A/L ratios. The table in Append ix E, using the metropolitan Atlanta data as an example, illustrates how varying the IEE factor aff ects the date when an ORVR-only program yields a better emissions result, compared to maint aining Stage II in conjunction with ORVR.

Widespread Use Analysis A state’s decision to amend its implementation plan to discontinue Stage II and for ORVR to become the exclusive means for controlling gasoline refueling emissions will be facilitated by findings that when the change occurs, it will be em issions neutral at a minimum, and preferably

achieve an emissions benefit. Emissions-based anal yses for all states, however, may be unnecessary if it is possible to identify surrogate s that reliably project nearly the same timeframe for making the change as what would be projected fr om comparing emissions between the two

programs.

In 2002, API commissioned an independent assessment of the relative importance of the above factors and how, in combination, they affect the ef ficacy of ORVR relative to Stage II. Many of API’s members are responsible for implementing Stag e II and therefore have an economic and regulatory stake in the Stage II program. API cont racted with a consultant to develop a spreadsheet-based model to project emissions and en able comparisons between varying ORVR and Stage II scenarios. API’s consultant modeled e missions scenarios for several states, and API

shared the model and the results with EPA.

In 2004, EPA’s Emissions Monitoring and Analysis Di vision within OAQPS published its Stage II Vapor Recovery Systems Issues Paper as a means t o promote discussion of EPA’s preliminary ideas regarding ORVR widespread use and to solicit comments from stakeholders. The Issues

14 Stage II Vapor Recovery Systems – Options Paper (Draft) , EPA-OAQPS, February 7, 2006.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

13 Paper listed four definitions (labeled (a), (b), (c ), and (d)) under consideration for defining widespread use. In response, API suggested a varia nt of Definition (c), referred to as (c2). 15

The emissions-based definitions of widespread use a re:

• Definition (c): Widespread use of ORVR is achieved when VOC emiss ions (tons per summer day) under an ORVR-only scenario equal VOC e missions under a Stage II-only

scenario.

• Definition (c2): Widespread use of ORVR is achieved when VOC emiss ions (tons per summer day) under a prospective ORVR-only scenario equal VOC emissions under a real world combination scenario in which (1) Stage II co ntrols are in place, (2) both ORVR and non-ORVR equipped vehicles are fueling at Stage II equipped stations, and (3) fueling of the ORVR equipped vehicles is creating i ncompatibility excess emissions (IEE) between the two systems.

The surrogate definitions of widespread use are:

• Definition (a): Widespread use of ORVR is achieved when a specifi ed percentage of the in-use light-duty vehicle fleet is equipped with OR VR systems. The 2005 analysis highlighted 85 percent, 90 percent, and 95 percent scenarios. For comparison purposes, this report also highlights the 80 percent scenario in addition to the other three scenarios.

• Definition (b): Widespread use of ORVR is achieved when a specifi ed percentage of the vehicle miles traveled (VMT) by the in-use light du ty fleet is attributable to ORVR equipped vehicles. The 2005 analysis and this anal ysis highlight 90 percent and 95 percent scenarios.

• Known as Definition (d) , widespread use of ORVR is achieved when a specifi ed percentage of the gasoline throughput is attributab le to ORVR equipped vehicles. The 2005 analysis and this analysis highlight 85 percen t, 90 percent, and 95 percent scenarios.

In 2005, EPA and its own consultant expanded upon t he API analytical tool, building in further assumptions and worked through NESCAUM to gather da ta and perform similar analyses for three of the NESCAUM states: Massachusetts, New Ha mpshire, and Vermont. Stage II is required state-wide in Massachusetts and Vermont an d in the more populous Merrimack Valley and seacoast areas of southern New Hampshire. The r esults of these analyses 16 are in Appendix B and summarized in Table 3. EPA has stated its pr eferred definition is Definition (c2). Therefore, Table 3 shades the Definition (c2) resul ts to identify these as EPA’s preferred emissions-neutral scenario for when Stage II may be discontinued. For comparison purposes, Table 3 has similar shading in the rows for Definit ions (a), (b), and (d) to identify which results under these definitions yield dates that most close ly match the dates derived from EPA’s preferred Definition (c2). For example, under Defi nition (b), the closest match to Definition (c2) occurs when 90 percent of the VMT in each state is by ORVR-equipped vehicles.

15 For a fuller comparison of Definition (c2) versus Defi nition (c), see Appendix D.

16 Source: Stage II Vapor Recovery Systems - Options Paper (Draft) , EPA-OAQPS, February 2006.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

14

Table 3 – Summary of 2005 Analysis for Three NESCAU M States Definition Description Massachusetts

Effective Date New Hampshire

Effective Date Vermont

Effective Date

(c) Emissions from

ORVR-only equal

emissions from Stage II-only 2010 2008 2008

(c2) Emissions from

ORVR-only equal

emissions from

combination of ORVR and Stage II plus IEE 2013 2013 2015

80% of fleet with

ORVR 2013

85% of fleet with

ORVR 2015

90% of fleet with

ORVR 2017 (a)

95% of fleet with

ORVR 2023

85% of VMT from ORVR-equipped

vehicles 2011 2012 2013

90% of VMT from ORVR-equipped

vehicles 2012 2013 2015 (b)

95% of VMT from

ORVR-equipped

vehicles 2015 2016 2019

85% of gasolinedispensed to ORVRequipped vehicles 2011 2012 2013

90% of gasolinedispensed to ORVRequipped vehicles 2013 2014 2016 (d)

95% of gasoline

dispensed to ORVRequipped vehicles 2016 2018 2021

At the same time, EPA recognized that decisions aff ecting determination of widespread use would have national implications. Therefore, it wa s important to have data from similar analyses for states outside of the NESCAUM region to support policy decisions. In 2007, EPA contracted with NESCAUM to perform the expanded analyses. Wit h assistance from the National Association of Clean Air Agencies (NACAA), NESCAUM solicited participation in the expanded study from states outside the NESCAUM regi on. Four states expressed interest and a willingness to provide data (California, Delaware, Georgia, and Pennsylvania) and all were selected to participate. The results of the expande d analysis are in Appendix C and summarized

in Table 4.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

15

Table 4 – Summary of 2007 Analysis for Four Additio nal States Definition Description California 17

Effective Date Delaware

Effective

Date Georgia

Effective

Date Pennsylvania

Effective

Date

(c) Emissions from

ORVR-only equal emissionsfrom Stage IIonly 2012 2011 2010 2009

(c2) Emissions from

ORVR-only equal emissions

from

combination of ORVR and Stage II plus IEE N/A 2013 2012 2013

80% of fleet with

ORVR 2014 2012 2012 2012

85% of fleet with

ORVR 2015 2014 2013 2013

90% of fleet with

ORVR 2018 2016 2015 2015 (a)

95% of fleet with

ORVR 2022 2019 2018 2018

85% of VMT

from ORVRequipped

vehicles 2014 2012 2011 2012

90% of VMT

from ORVRequipped

vehicles 2016 2013 2013 2014 (b)

95% of VMT

from ORVRequipped

vehicles 2022 2016 2016 2017

85% of gasoline dispensed to ORVR-equipped

vehicles 2014 2012 2012 2013

90% of gasoline dispensed to ORVR-equipped

vehicles 2017 2014 2013 2015 (d)

95% of gasoline

dispensed to ORVR-equipped

vehicles 2021 2018 2017 2018

Of the four additional states, Delaware was the onl y one where the analysis addressed a program covering the entire state. The analysis for Califo rnia covered only the South Coast Air Basin

17 Data are for California’s South Coast Air Basin only.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

16 (metropolitan Los Angeles). In Georgia and Pennsylv ania, Stage II programs are only in effect in the major metropolitan areas. These analyses there fore were confined respectively to metropolitan Atlanta and metropolitan Philadelphia. 18 NESCAUM subcontracted with EPA’s consultant from the 2005 study (RTI International) to perform the modeling. Effective dates for California are presented in the table but for reaso ns discussed below, no California dates are highlighted.

Options for Establishing ORVR Widespread Use Dates As indicated previously, CAA § 202(a)(6) authorizes EPA to waive the requirements for Stage II once it is determined that ORVR systems are in wide spread use throughout the motor vehicle fleet. Consistent with EPA’s preferred Definition (c2), it is expected that when ORVR by itself

achieves the same or a better emissions benefit com pared to the benefits achieved in the present situation (i.e., Stage II systems operating in conj unction with ORVR on most light-duty vehicles), Stage II programs can be discontinued wi thout causing refueling emissions to increase. NESCAUM has identified several possible options upo n which to base such decisions. The options are presented in this section.

Require every state to conduct an emissions-based ( Definition (c2)) analysis. This approach

would best ensure that emissions will not increase when Stage II programs are discontinued. However, it is the most complex of the various appr oaches.

Require ORVR-compatible Stage II systems. California adopted a regulation, effective March 1, 2006, requiring all Stage II systems to be ORVR-com patible. With the use of a processor, vacuum-assist systems are able to contain the vapor growth problem discussed above and thereby meet the California standard. As indicated by the graph in Appendix C, the South Coast

Air Basin will continue to realize an emissions ben efit from the ORVR-compatible Stage II requirement until essentially 100 percent of the li ght-duty vehicles in the fleet are equipped with ORVR. Even as late as 2030, the emissions benefit over ORVR as a stand-alone program will be almost 0.8 tons per summer day. Other states could consider requiring Stage II equipment to meet the California certification for ORVR compatib ility, and thereby extend the benefits achieved by Stage II and ORVR programs in tandem fo r many years.

Establish a single national date for authorizing di scontinuation of Stage II programs. According to the analyses conducted for six states (excluding California), Stage II programs could be

discontinued without an emissions increase in five of the states on or before 2013. Vermont was the only state that projected a later date (2015). According to the analysis, if Vermont were to discontinue Stage II in 2013, there would be an emi ssions increase of 0.08 tons per summer day. Based on these results, EPA could establish 2013 as the widespread use date for all states. States that have concerns about potential emissions increa ses associated with removing Stage II in 2013 could delay the change to a later date. Alternative ly, EPA could establish a later date (e.g., 2015) and allow individual states the option of preparing technical analyses to justifying an earlier date.

18 Stage II is also in effect in metropolitan Pittsburgh, Pen nsylvania, but this area was not included in the analyses.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

17 Use ORVR fleet penetration as a surrogate. According to the analyses for four of the states, 19

the Definition (a) date either matches the Definiti on (c2) date or exceeds it by no more than one year when 85 percent of the state fleet of light-du ty vehicles is ORVR-equipped.

Use ORVR VMT penetration as a surrogate. According to the analyses of six states (excludin g California) in five of the six scenarios, the Defin ition (b) date either matches the Definition (c2) date or exceeds it by no more than one year when 90 percent of the vehicle miles traveled (VMT) are attributed to ORVR-equipped light-duty vehicles . In the case of Massachusetts, the Definition (b) date (2012) precedes the Definition (c2) date (2013) by one year. If Massachusetts were to discontinue Stage II in 2012, the analysis indicates that there would be an emissions increase of 0.23 tons per day. In reality, the 201 2 date for Massachusetts reflects an 88 percent VMT threshold, so when the 90 percent threshold is achieved sometime between 2012 the 2013 summer seasons, there is actually a small emissions benefit from discontinuing Stage II.

Use ORVR gasoline throughput penetration as a surro gate. According to the analysis of six states (excluding California), the Definition (d) d ate will match the Definition (c2) date when somewhere between 85 percent and 90 percent of the gasoline is dispensed to ORVR-equipped light-duty vehicles. At 85 percent throughput, the result is the same as projected by Definition (c2) for Georgia and Pennsylvania. At 85 percent t hroughput for the other four states, the Definition (d) date occurs one to two years earlier than the date predicted by Definition (c2), meaning emissions will increase somewhat in those s tates if Stage II is discontinued according to Definition (d). At the 90 percent throughput thres hold, only Massachusetts achieves the same result (2013) under both definitions. The other fi ve states are delayed from one to two years under Definition (d) beyond the Definition (c2) dat e.

Stakeholders Meetings In May 2007, NESCAUM hosted a stakeholders meeting in Manchester, NH, to discuss transitioning from Stage II programs to exclusively ORVR programs. At the meeting, there was general support among the participating states for ensuring that the result of Stage II removal was emissions neutral and would properly address so il and groundwater contamination and the potential for on-going fugitive emissions from disc ontinued Stage II systems. At least one state favored retaining discretion to remove Stage II in advance of a date strictly imposed under the Definition (c2) approach as long as excess emissions were offset by other measures. States also favored having the option to use alternative metric s.

State Workgroup Recommendations There was general agreement among the states that E PA should allow use of alternative metrics for states to establish their widespread use dates. In particular, the states favored the following:

• 85 percent of ORVR fleet penetration (Definition (a ))

• 90 percent of VMT attributed to ORVR-equipped vehic les (Definition (b)) In addition, there was agreement that states should not be precluded from establishing dates other than those predicted by the metrics, provided state s are able to demonstrate through technical analyses that a chosen date does not cause emission s to increase. Further, states may choose to

19 California is excluded because of its ORVR-compatibility req uirements for Stage II. No data on ORVR penetration were generated for Massachusetts or New Hampshire in the 2005 study.NESCAUM

ORVR Widespread Use Analysis August 20, 2007

18 perpetuate their Stage II programs while requiring exclusive use of ORVR compatible equipment in lieu of earlier termination of the program.

Conclusions and Recommendations As increasing numbers of ORVR-equipped motor vehicl es replace those without ORVR, most SIP-approved Stage II programs are approaching a po int where the incremental emissions benefit disappears. When states perform analyses to projec t the year in which this point is attained, they will be poised to prepare amendments to their ozone attainment or maintenance plans to discontinue Stage II programs and at the same time meet the no-backsliding requirements pursuant to the Clean Air Act.

The level of the Incompatibility Excess Emissions ( IEE) factor to use in these analyses will have a significant effect on determining when ORVR surpa sses Stage II as the better stand-alone technology. A lower IEE factor will have the effec t of extending the life of effective Stage II programs. A higher factor will have the opposite e ffect. EPA previously affirmed that additional emissions monitoring was needed to bette r characterize IEE and that the results from subsequent studies may suggest using an emissions f actor that is different from the one used in this analysis. It will be helpful to states that a re soon to embark on preparing SIP amendments to receive updated guidance in the short term from EPA regarding the appropriate IEE factor to use and related guidance on appropriate A/L ratios for vacuum-assist Stage II systems.

States choosing to follow the California example by requiring all Stage II systems to be ORVRcompatible may be able to extend the effective life of their Stage II programs. Alternately, EPA can facilitate the efforts of states choosing to es tablish a closer date for discontinuing their Stage II programs, based on the technology in place, by a llowing use of alternative metrics, such as those based on ORVR fleet penetration or vehicle mi les traveled by ORVR-equipped vehicles. At the same time, EPA may wish to consider allowing states to establish dates other than those predicted by the metrics, provided states are able to demonstrate through technical analyses and possibly substitute control measures that a chosen date for discontinuing Stage II will not result

in an emissions increase.A-1 

### APPENDIX A

ONBOARD REFUELING VAPOR RECOVERY REQUIREMENTS

EXCERPTS FROM THE CODE OF FEDERAL REGULATIONS

40 CFR 86.1810-01(k) (k) Refueling emissions general provisions —(1) Implementation schedules. (i) Tables S01–3, S01–4, and S01–5 in this paragraph (k)(1)(i) give t he minimum percentage of a manufacturer's sales of the applicable model year's gasoline- and methanol-fueled Otto-cycle and petroleumfueled and methanol-fueled diesel-cycle light-duty vehicles, light-duty trucks and complete heavy-duty vehicles which shall be tested under the applicable procedures in subpart B of this part, and shall not exceed the standards described in §§86.1811–01(e), 86.1811–04(e)(3), 86.1812–01(e), 86.1813–01(e), and 86.1816–04(e). Ve hicles waived from the emission standards under the provisions of paragraphs (m) and (n) of t his section shall not be counted in the calculation of the percentage of compliance. Either manufacturer sales or actual production intended for sale in the United States may be used to determine combined volume, at the manufacturer’s option. Tables S01–3, S01–4, and S01 –5 follow:

Table S01–3—Light-Duty Vehicles Model Year Percentage

1998 a 40

1999 a 80

2000 a 100

a Note: This subpart prescribes standards for 2001 and l ater MY vehicles. However, the implementation phase-in periods prior to this date are i ncluded for ease of reference.

Table S01–4—Light Light-Duty Trucks Model Year Percentage

2001 40

2002 80

2003 100

Table S01–5—Heavy Light-Duty Trucks Model Year Percentage

2004 40

2005 80

2006 100A-2

40 CFR 86.1811-04(e) (3) Refueling emission standards. Refueling emissions must not exceed the following s tandards:

(i) For gasoline-fueled, diesel-fueled and methanol -fueled LDVs, LDTs and MDPVs: 0.20 grams hydrocarbon per gallon (0.053 grams per liter) of f uel dispensed.

(ii) For liquefied petroleum gas-fueled LDV, LDTs a nd MDPVs: 0.15 grams hydrocarbon per gallon (0.04 grams per liter) of fuel dispensed.

(iii) Refueling standards for HLDTs are subject to the phase-in requirements found in §86.1810– 01(k). MDPVs must also comply with the phase-in req uirement in §86.1810–01(k) and must be grouped with HLDTs to determine phase-in compliance

.

40 CFR 86.1816-05(e) (e) Refueling emissions —(1) Standards. Refueling emissions from Otto-cycle complete heavyduty vehicles equal to or less than 10,000 pounds G ross Vehicle Weight Rating shall be phased in, in accordance with the schedule in Table S01–5 in §86.1810–01 not to exceed the following

emission standards:

(i) For gasoline-fueled and methanol-fueled vehicle s: 0.20 grams hydrocarbon per gallon (0.053 gram per liter) of fuel dispensed.

(ii) For liquefied petroleum gas-fueled vehicles: 0 .15 grams hydrocarbon per gallon (0.04 gram per liter) of fuel dispensed.

(2) Phase-in. Complete heavy-duty vehicles subject to refueling s tandards must comply with the phase-in requirements found in Table S01–5 in §86.1 810–01, and must be grouped with HLDTs and MDPVs to determine phase-in compliance.

40 CFR 86.1803-01 Definitions. Complete heavy-duty vehicle means any Otto-cycle heavy-duty vehicle of 14,000 p ounds Gross Vehicle Weight Rating or less that has the primary load carrying device or container attached at

the time the vehicle leaves the control of the manu facturer of the engine.

Heavy light-duty truck means any light-duty truck rated greater than 6000 lbs GVWR. The LDT3 and LDT4 classifications comprise the heavy light-d uty truck category.

Light light-duty truck means any light-duty truck rated up through 6000 lb s GVWR. The LDT1 and LDT2 classifications compose the light light-du ty truck category.A-3

Light-duty truck means any motor vehicle rated at 8,500 pounds GVWR or less which has a curb weight of 6,000 pounds or less and which has a basi c vehicle frontal area of 45 square feet or less, which is:

(1) Designed primarily for purposes of transportati on of property or is a derivation of such a vehicle; or

(2) Designed primarily for transportation of person s and has a capacity of more than 12 persons;

or

(3) Available with special features enabling off-st reet or off-highway operation and use.

Light-duty truck 1 (LDT1) means any light light-duty truck up through 3750 lbs loaded vehicle weight.

Light-duty truck 2 (LDT2) means any light light-duty truck greater tha n 3750 lbs loaded vehicle weight.

Light-duty truck 3 (LDT3) means any heavy light-duty truck up through 5750 lbs adjusted loaded vehicle weight.

Light-duty truck 4 (LDT4) means any heavy light-duty truck greater tha n 5750 lbs adjusted loaded vehicle weight.

Light-duty vehicle means a passenger car or passenger car derivative c apable of seating 12 passengers or less.

Medium-duty passenger vehicle (MDPV) means any heavy-duty vehicle (as defined in this subpart) with a gross vehicle weight rating (GVWR) of less than 10,000 pounds that is designed primarily for the transportation of persons. The MD PV definition does not include any vehicle

which:

(1) Is an “incomplete truck” as defined in this sub part; or

(2) Has a seating capacity of more than 12 persons; or

(3) Is designed for more than 9 persons in seating rearward of the driver's seat; or

(4) Is equipped with an open cargo area (for exampl e, a pick-up truck box or bed) of 72.0 inches in interior length or more. A covered box not readi ly accessible from the passenger compartment will be considered an open cargo area for purposes of this definition.

### APPENDIX B

ORVR WIDESPREAD USE ANALYSIS

FOR MASSACHUSETTS, NEW HAMPSHIRE, & VERMONT

(2005 ANALYSIS)MASSACHUSETTS(IEE 0.86)024681012141618202001 2006 2011 2016 2021 2026

Emissions (tons/summer day)0%10%20%30%40%50%60%70%80%90%100% % PenetrationEmissions if only Stage II controls werein place, without ORVREmissions with only ORVRrequirements, without Stage II controlsEmissions with Stage II and ORVR,including "excess emissions" of 0.86lb/1000 gal for Vacuum assistEmissions with Stage II and ORVR,without "excess emissions"ORVR Penetration, option (b) definition,% VMTORVR Penetration, option (d)definition,% fuel dispensed"Widespread use"date under option (c)"Widespread use"date under option(c2)TOTAL REFUELING EMISSIONS –MASSACHUSETTS(Calculations assume all VA have IEE of 0.86, uncorrected)Grams Emitted Per Gallon GasolineTons Per Summer DayCalendarYearStage IIControlsOnlyORVROnlyStage II withORVR, NoIEEStage IIwithORVR,IEE% Decrease fromUncontrolledEmissionsStage IIControlsOnlyORVROnlyStage II withORVR, NoIEEStage II withORVR, IEEExcessEmissions2001 0.682 2.307 0.617 0.649 75% 5.92 20.02 5.35 5.630.282002 0.682 2.147 0.585 0.633 76% 6.01 18.93 5.16 5.580.422003 0.689 2.005 0.556 0.622 77% 6.18 17.97 4.98 5.570.592004 0.690 1.813 0.518 0.602 78% 6.28 16.51 4.72 5.490.772005 0.690 1.599 0.476 0.581 78% 6.38 14.78 4.40 5.370.972006 0.690 1.373 0.432 0.559 79% 6.48 12.90 4.06 5.251.192007 0.690 1.166 0.391 0.538 80% 6.57 11.12 3.73 5.131.402008 0.690 0.982 0.355 0.519 81% 6.67 9.50 3.44 5.031.592009 0.690 0.823 0.324 0.504 81% 6.77 8.08 3.18 4.941.762010 0.690 0.687 0.297 0.490 82% 6.87 6.84 2.96 4.881.922011 0.690 0.578 0.276 0.479 82% 6.97 5.84 2.79 4.842.052012 0.690 0.494 0.259 0.471 83% 7.07 5.06 2.66 4.832.172013 0.690 0.428 0.246 0.464 83% 7.17 4.45 2.56 4.822.262014 0.690 0.378 0.237 0.459 83% 7.27 3.98 2.49 4.842.342015 0.690 0.342 0.230 0.456 83% 7.36 3.65 2.45 4.872.412016 0.690 0.317 0.225 0.453 83% 7.46 3.43 2.43 4.902.472017 0.690 0.299 0.221 0.451 83% 7.56 3.27 2.42 4.952.522018 0.690 0.286 0.219 0.450 83% 7.66 3.17 2.43 5.002.572019 0.690 0.275 0.217 0.449 83% 7.76 3.09 2.44 5.052.622020 0.690 0.267 0.215 0.448 83% 7.86 3.04 2.45 5.102.662021 0.690 0.260 0.214 0.448 83% 7.95 3.00 2.46 5.162.702022 0.690 0.253 0.212 0.447 83% 8.05 2.96 2.48 5.222.742023 0.690 0.249 0.211 0.446 83% 8.15 2.94 2.50 5.272.782024 0.690 0.246 0.211 0.446 83% 8.24 2.94 2.52 5.332.812025 0.690 0.242 0.210 0.446 83% 8.34 2.92 2.54 5.392.852026 0.690 0.241 0.210 0.446 83% 8.43 2.95 2.57 5.452.882027 0.690 0.241 0.210 0.446 83% 8.53 2.98 2.59 5.512.922028 0.690 0.240 0.210 0.446 83% 8.62 3.00 2.62 5.572.952029 0.690 0.239 0.209 0.445 83% 8.71 3.01 2.64 5.632.982030 0.690 0.238 0.209 0.445 83% 8.81 3.04 2.67 5.693.01NEW HAMPSHIRE(IEE 0.86)024681012141618202001 2006 2011 2016 2021 2026

Emissions (tons/summer day)0%10%20%30%40%50%60%70%80%90%100% % PenetrationEmissions if only Stage II controls werein place, without ORVREmissions with only ORVRrequirements, without Stage II controlsEmissions with Stage II and ORVR,including "excess emissions" of 0.86lb/1000 gal for Vacuum AssistEmissions with Stage II and ORVR,without "excess emissions"ORVR Penetration, option (b) definition,% VMTORVR Penetration, option (d) definition,% fuel dispensed"Widespread use" dateunder option (c)"Widespread use" dateunder option (c2)TOTAL REFUELING EMISSIONS- NEW HAMPSHIRE(Calculations assume all VA have IEE of 0.86, uncorrected)Grams Emitted Per Gallon GasolineTons Per Summer DayCalendarYearStage IIControlsOnlyORVROnlyStage II withORVR, NoIEEStage II withORVR, IEE% Decrease fromUncontrolledEmissionsStage IIControlsOnlyORVROnlyStage II withORVR, No IEEStage II withORVR, IEEExcessEmissions2001 1.149 2.604 1.020 1.057 65% 2.41 5.46 2.14 2.22 0.082002 1.149 2.416 0.956 1.011 66% 2.46 5.17 2.05 2.16 0.122003 1.164 2.236 0.895 0.971 68% 2.54 4.88 1.95 2.12 0.172004 1.164 1.998 0.814 0.913 70% 2.59 4.45 1.81 2.03 0.222005 1.164 1.752 0.731 0.854 72% 2.64 3.98 1.66 1.94 0.282006 1.164 1.505 0.647 0.794 74% 2.70 3.49 1.50 1.84 0.342007 1.164 1.299 0.578 0.744 76% 2.75 3.07 1.36 1.76 0.392008 1.164 1.099 0.510 0.696 77%2.812.65 1.23 1.68 0.452009 1.165 0.951 0.460 0.660 78% 2.86 2.34 1.13 1.62 0.492010 1.165 0.817 0.415 0.627 79% 2.92 2.05 1.04 1.57 0.532011 1.164 0.695 0.373 0.598 80% 2.98 1.78 0.95 1.53 0.572012 1.165 0.618 0.347 0.579 81% 3.04 1.61 0.91 1.51 0.612013 1.164 0.538 0.320 0.560 82% 3.101.43 0.851.49 0.642014 1.165 0.481 0.301 0.546 82% 3.16 1.30 0.82 1.48 0.672015 1.165 0.434 0.285 0.535 82% 3.22 1.20 0.79 1.48 0.692016 1.165 0.395 0.272 0.525 83% 3.29 1.12 0.77 1.48 0.722017 1.165 0.368 0.263 0.519 83% 3.36 1.06 0.76 1.49 0.742018 1.165 0.338 0.253 0.512 83% 3.42 0.99 0.74 1.50 0.762019 1.165 0.319 0.246 0.507 83% 3.49 0.96 0.74 1.52 0.782020 1.165 0.304 0.241 0.503 83% 3.56 0.93 0.74 1.54 0.802021 1.165 0.293 0.238 0.501 84% 3.63 0.91 0.74 1.56 0.822022 1.165 0.282 0.234 0.498 84% 3.70 0.90 0.74 1.58 0.842023 1.165 0.273 0.231 0.496 84% 3.78 0.89 0.75 1.61 0.862024 1.165 0.269 0.229 0.495 84% 3.85 0.89 0.76 1.64 0.882025 1.165 0.265 0.228 0.494 84% 3.93 0.89 0.77 1.67 0.902026 1.165 0.261 0.227 0.493 84% 4.01 0.90 0.78 1.70 0.922027 1.165 0.258 0.226 0.492 84% 4.09 0.91 0.79 1.73 0.942028 1.165 0.255 0.225 0.491 84% 4.17 0.91 0.80 1.76 0.962029 1.165 0.250 0.223 0.490 84% 4.26 0.91 0.82 1.79 0.982030 1.165 0.249 0.223 0.490 84% 4.34 0.93 0.83 1.83 1.00VERMONT(IEE 0.86)024681012141618202001 2006 2011 2016 2021 2026

Emissions (tons/summer day)0%10%20%30%40%50%60%70%80%90%100% % PenetrationEmissions if only Stage II controlswere in place, without ORVREmissions with only ORVRrequirements, without Stage II controlsEmissions with Stage II and ORVR,including "incompatibility excessemissions" of 0.86 lb/1000 gal forVacuum AssistEmissions with Stage II and ORVR,without "excess emissionsORVR Penetration, option (a)definition, % of vehiclesORVR Penetration, option (b)definition, % VMTORVR Penetration, option (d)definition, % fuel dispensed"Widespread use" dateunder option (c)"Widespread use"date under option (c2)TOTAL REFUELING EMISSIONS– VERMONT(Calculations assume all VA have IEE of 0.86, uncorrected)Grams Emitted Per Gallon GasolineTons Per Summer DayCalendarYearStage IIControlsOnlyORVROnlyStage II withORVR, NoIEEStage II withORVR, IEE% DecreasefromUncontrolledEmissionsStage IIControls OnlyORVROnlyStage II withORVR, No IEEStage II withORVR, IEEExcessEmissions2001 1.519 3.094 1.349 1.386 61% 1.57 3.19 1.39 1.43 0.042002 1.519 2.899 1.272 1.327 62% 1.59 3.03 1.33 1.39 0.062003 1.519 2.684 1.188 1.261 64% 1.61 2.84 1.26 1.33 0.082004 1.519 2.453 1.097 1.190 66% 1.56 2.52 1.13 1.22 0.102005 1.520 2.195 0.996 1.111 69% 1.65 2.39 1.08 1.21 0.132006 1.520 1.926 0.890 1.029 71% 1.67 2.12 0.98 1.13 0.152007 1.520 1.676 0.792 0.952 73% 1.69 1.87 0.88 1.06 0.182008 1.520 1.454 0.704 0.884 75%1.711.64 0.79 1.00 0.202009 1.520 1.258 0.627 0.824 77% 1.71 1.42 0.71 0.93 0.222010 1.520 1.086 0.560 0.772 78% 1.76 1.25 0.65 0.89 0.242011 1.520 0.942 0.503 0.728 79% 1.78 1.10 0.59 0.85 0.262012 1.520 0.823 0.456 0.691 80% 1.78 0.97 0.54 0.81 0.282013 1.520 0.724 0.417 0.661 81% 1.82 0.87 0.50 0.79 0.292014 1.520 0.644 0.386 0.636 82% 1.84 0.78 0.47 0.77 0.302015 1.520 0.579 0.360 0.616 83% 1.860.71 0.440.75 0.312016 1.520 0.527 0.340 0.601 83% 1.88 0.65 0.42 0.74 0.322017 1.520 0.485 0.324 0.588 83% 1.90 0.61 0.40 0.73 0.332018 1.520 0.452 0.311 0.578 84% 1.92 0.57 0.39 0.73 0.342019 1.520 0.426 0.300 0.570 84% 1.94 0.54 0.38 0.73 0.342020 1.520 0.405 0.292 0.563 84% 1.96 0.52 0.38 0.73 0.352021 1.520 0.386 0.285 0.557 84% 1.98 0.50 0.37 0.73 0.362022 1.520 0.369 0.278 0.552 84% 2.00 0.49 0.37 0.73 0.362023 1.520 0.354 0.272 0.548 85% 2.02 0.47 0.36 0.73 0.372024 1.520 0.343 0.268 0.544 85% 2.05 0.46 0.36 0.73 0.372025 1.520 0.330 0.263 0.540 85% 2.07 0.45 0.36 0.73 0.382026 1.520 0.319 0.258 0.537 85% 2.09 0.44 0.35 0.74 0.382027 1.520 0.311 0.255 0.534 85% 2.11 0.43 0.35 0.74 0.392028 1.520 0.301 0.251 0.531 85% 2.13 0.42 0.35 0.74 0.392029 1.520 0.290 0.247 0.528 85% 2.15 0.41 0.35 0.75 0.402030 1.520 0.286 0.245 0.527 85% 2.17 0.41 0.35 0.75 0.40

### APPENDIX C

ORVR WIDESPREAD USE ANALYSIS

FOR CALIFORNIA, DELAWARE, GEORGIA, & PENNSYLVANIA

(2007 ANALYSIS)Data Summary for 4 States

 Denotes that State-provided data were used for this param eter in the analysis, but the data set is too large to adequately describe here. a In CA SCAQMD, beginning in 2009, the CE: 95% (gi ven); RE: 87.5%; RP: 94.7%; and In-use: 78.7%. Provided Data

Or

MOBILE6 Defaults Used Requested Data CA DE GA PA

Stage II VRS In-Use Effectiveness CE: 95% (given)

RE: 87.5%

RP: 81.6%

In-use: 67.8% a CE: 95% (given)

RE: 90.5%

RP: 98.7%

In-use: 85% CE: 95% (given)

RE: 95%

RP: 90%

In-use: 81% CE: 95% (given)

RE: 80%

RP: 96%

In-use: 73%

Ambient Temperature Data Used 24 hrly avg T

data Min: 69.25oF

Max: 87.35oF Used 24 hrly avg T

data; 2 sets Min: 70.2oF

Max: 87.5oF

In-use RVP of the gasoline used during the summer ozone season, and indicate if the gasoline is RFG 6.8 psia;

Yes 6.81 psia

6.57 psia;

Yes 7.0 psia;

No 6.81 psia;

Yes

Total gasoline usage, gallons/yr for the most recent available CYs and for those years that the states have projected data    

Percentage of GDFs equipped with balance Stage II

VRS 90% 18% 6.7% 20%

Percentage of GDFs equipped with vacuum assist Stage II VRS 10% 82% 93.3% 80%

With Stage I but no Stage II VRS, With Stage I but no P/V valve, With Stage I and with P/V valve 0%

0%

100% 0%

0%

100% 16.5%

0%

83.5% 0%

1%

99%

Balance Stage II VRS but no Stage I, Balance Stage II VRS and Stage I but no P/V valve, Balance Stage II VRS and Stage I with P/V valves 0%

0%

100% 0%

0%

100% 0%

0%

100% 0%

2%

98%

VA Stage II VRS but no Stage I, VA Stage II VRS and Stage I but no P/V valve, VA Stage II VRS and Stage I with P/V valves 0%

0%

100% 0%

0%

100% 0%

0%

100% 0%

1%

99%

Vehicle registration data (defn a)  Gasoline only 

Gasoline only 

Fuel-independent 

Fuel-independent

Vehicle distribution data by vehicle type and age  Gasoline only 

Gasoline only 

Fuel-independent;

Default for HDV8a

class 

Fuel-independent

Vehicle mileage accumulation data, AMAR  Gasoline only Default Default Default

Vehicle miles traveled (VMT) for the most recent calendar year and any years where projected data

are available  Gasoline only 

Fuel-independent 

Fuel-independent 

Fuel-independent

VMT fractional mix (represents the fraction of total highway VMT accumulated by each vehicle type) Estimate from VMT info by vehicle type above 

Fuel-independent 

Fuel-independent Estimate from

VMT info by vehicle type above

Diesel sales fraction data Not needed, as

VMT is Gasoline only Default Default Default

Vehicle fuel economy data  Default Default Default

Anti-Tampering Program data    LOS ANGELES, CA Area - Emissions and ORVR Percentagesfor Merged Data 2001 through 2030051015202530354045502001 2006 2011 2016 2021 2026

Emissions (tons/summer day)0%10%20%30%40%50%60%70%80%90%100% % PenetrationEmissions if only Stage II controls were inplace, without ORVREmissions with only ORVR requirements,without Stage II controlsEmissions with Stage II and ORVR, without"excess emissionsORVR Penetration, option (a) definition, % ofvehiclesORVR Penetration, option (b) definition, %VMTORVR Penetration, option (d) definition, %fuel dispensed"Widespread use" dateunder option (c)TOTAL REFUELING EMISSIONS- California (Los Angeles Area)(Calculations assume all VA have IEE of 0.86, uncorrected)Grams Emitted Per Gallon GasolineTons Per Summer DayCalendarYearStage IIControlsOnlyORVROnlyStage II withORVR, NoIEEStage II withORVR, IEE% DecreasefromUncontrolledEmissionsStage IIControlsOnlyORVR OnlyStage II withORVR, NoIEEStage II withORVR, IEEExcessEmissions2001 1.114 2.330 0.947 0.948 66% 19.29 40.35 16.4016.42 0.022002 1.114 2.166 0.890 0.892 68% 19.68 38.28 15.7315.75 0.032003 1.129 2.055 0.850 0.853 70% 20.72 37.73 15.6115.65 0.052004 1.128 1.894 0.794 0.798 72% 21.81 36.62 15.3515.43 0.072005 1.128 1.716 0.732 0.737 74% 22.22 33.80 14.4214.51 0.102006 1.128 1.511 0.661 0.666 77% 21.57 28.89 12.6312.73 0.102007 1.128 1.307 0.589 0.594 79% 20.89 24.19 10.9111.01 0.092008 1.128 1.124 0.526 0.532 81%21.0721.00 9.82 9.93 0.112009 0.651 0.885 0.303 0.311 89% 12.26 16.67 5.715.86 0.152010 0.651 0.781 0.283 0.291 90% 12.36 14.82 5.375.53 0.162011 0.651 0.699 0.267 0.276 90% 12.47 13.38 5.105.28 0.182012 0.651 0.630 0.253 0.263 91%12.5812.17 4.89 5.08 0.192013 0.651 0.567 0.241 0.251 91% 12.72 11.08 4.704.91 0.212014 0.651 0.511 0.229 0.241 92% 12.82 10.05 4.524.74 0.222015 0.651 0.461 0.220 0.232 92% 12.93 9.16 4.36 4.60 0.242016 0.651 0.420 0.212 0.224 92% 12.99 8.37 4.22 4.47 0.252017 0.651 0.385 0.205 0.218 92% 13.07 7.74 4.11 4.37 0.262018 0.651 0.359 0.200 0.213 93% 13.17 7.26 4.04 4.31 0.272019 0.651 0.338 0.195 0.209 93% 13.28 6.89 3.98 4.27 0.282020 0.651 0.320 0.192 0.206 93% 13.40 6.58 3.95 4.24 0.302021 0.651 0.305 0.189 0.204 93% 13.46 6.30 3.90 4.21 0.302022 0.651 0.285 0.185 0.200 93% 13.54 5.91 3.84 4.16 0.312023 0.651 0.268 0.182 0.197 93% 13.62 5.60 3.80 4.12 0.322024 0.651 0.257 0.180 0.196 93% 13.75 5.43 3.79 4.13 0.342025 0.651 0.240 0.176 0.193 93% 13.88 5.12 3.75 4.11 0.352026 0.651 0.223 0.173 0.190 93% 14.004.79 3.714.08 0.372027 0.651 0.214 0.171 0.188 93% 14.134.63 3.714.09 0.382028 0.651 0.210 0.170 0.188 93% 14.264.60 3.734.12 0.392029 0.651 0.205 0.169 0.188 93% 14.394.53 3.744.15 0.412030 0.651 0.203 0.169 0.188 93% 14.534.54 3.774.19 0.42DELAWARE - Emissions and ORVR Percentages(IEE 0.86)012342001 2006 2011 2016 2021 2026

Emissions (tons/summer day)0%10%20%30%40%50%60%70%80%90%100% % PenetrationEmissions if only Stage II controls were inplace, without ORVREmissions with only ORVR requirements,without Stage II controlsEmissions with Stage II and ORVR, including"incompatibility excess emissions" of 0.86lb/1000 gal for Vacuum AssistEmissions with Stage II and ORVR, without"excess emissionsORVR Penetration, option (a) definition, % ofvehiclesORVR Penetration, option (b) definition, %VMTORVR Penetration, option (d) definition, %fuel dispensed"Widespread use" dateunder option (c)"Widespread use" dateunder option (c2)TOTAL REFUELING EMISSIONS– Delaware(Calculations assume all VA have IEE of 0.86, uncorrected)Grams Emitted Per Gallon GasolineTons Per Summer DayCalendarYearStage IIControlsOnlyORVROnlyStage IIwith ORVR,No IEEStage II withORVR, IEE% DecreasefromUncontrolledEmissionsStage IIControlsOnlyORVROnlyStage II withORVR, NoIEEStage II withORVR, IEEExcessEmissions2001 0.718 2.688 0.656 0.698 77% 0.83 3.09 0.75 0.80 0.052002 0.718 2.500 0.622 0.687 77% 0.85 2.97 0.74 0.82 0.082003 0.725 2.322 0.589 0.681 78% 0.88 2.81 0.71 0.82 0.112004 0.725 2.092 0.548 0.667 78% 0.90 2.61 0.68 0.83 0.152005 0.725 1.840 0.503 0.653 79% 0.93 2.35 0.64 0.83 0.192006 0.725 1.580 0.456 0.637 79% 0.92 2.00 0.58 0.81 0.232007 0.725 1.348 0.414 0.624 80% 0.93 1.73 0.53 0.80 0.272008 0.725 1.149 0.379 0.612 80% 0.95 1.50 0.49 0.80 0.302009 0.725 0.978 0.348 0.602 81% 0.95 1.29 0.46 0.79 0.332010 0.725 0.832 0.322 0.593 81% 0.97 1.12 0.43 0.80 0.362011 0.725 0.715 0.301 0.586 81%0.990.97 0.41 0.80 0.392012 0.725 0.622 0.284 0.581 81% 1.00 0.85 0.39 0.80 0.412013 0.725 0.545 0.270 0.576 81% 1.010.76 0.380.81 0.432014 0.725 0.482 0.259 0.573 81% 1.03 0.68 0.37 0.81 0.442015 0.725 0.431 0.250 0.570 82% 1.04 0.62 0.36 0.82 0.462016 0.725 0.393 0.243 0.568 82% 1.05 0.57 0.35 0.83 0.472017 0.725 0.364 0.238 0.566 82% 1.07 0.54 0.35 0.83 0.482018 0.725 0.344 0.234 0.565 82% 1.08 0.51 0.35 0.84 0.492019 0.725 0.328 0.231 0.564 82% 1.10 0.49 0.35 0.85 0.502020 0.725 0.315 0.229 0.563 82% 1.11 0.48 0.35 0.86 0.512021 0.725 0.305 0.227 0.562 82% 1.12 0.47 0.35 0.87 0.522022 0.725 0.293 0.225 0.562 82% 1.14 0.46 0.35 0.88 0.532023 0.725 0.283 0.223 0.561 82% 1.15 0.45 0.35 0.89 0.542024 0.725 0.277 0.222 0.561 82% 1.16 0.44 0.36 0.90 0.542025 0.725 0.274 0.222 0.561 82% 1.18 0.44 0.36 0.91 0.552026 0.725 0.272 0.221 0.560 82% 1.19 0.45 0.36 0.92 0.562027 0.725 0.271 0.221 0.560 82% 1.20 0.45 0.37 0.93 0.562028 0.725 0.270 0.221 0.560 82% 1.22 0.45 0.37 0.94 0.572029 0.725 0.268 0.220 0.560 82% 1.23 0.45 0.37 0.95 0.582030 0.725 0.267 0.220 0.560 82% 1.24 0.46 0.38 0.96 0.58GEORGIA - Emissions and ORVR Percentages(IEE 0.86)05101520252001 2006 2011 2016 2021 2026

Emissions (tons/summer day)0%10%20%30%40%50%60%70%80%90%100% % PenetrationEmissions if only Stage II controls were inplace, without ORVREmissions with only ORVR requirements,without Stage II controlsEmissions with Stage II and ORVR, including"incompatibility excess emissions" of 0.86lb/1000 gal for Vacuum AssistEmissions with Stage II and ORVR, without"excess emissionsORVR Penetration, option (a) definition, % ofvehiclesORVR Penetration, option (b) definition, %VMTORVR Penetration, option (d) definition, %fuel dispensed"Widespread use" dateunder option (c)"Widespread use"date under option (c2)TOTAL REFUELING EMISSIONS– Georgia(Calculations assume all VA have IEE of 0.86, uncorrected)Grams Emitted Per Gallon GasolineTons Per Summer DayCalendarYearStage IIControlsOnlyORVROnlyStage IIwith ORVR,No IEEStage II withORVR, IEE% DecreasefromUncontrolledEmissionsStage IIControls OnlyORVROnlyStage II withORVR, No IEEStage II withORVR, IEEExcessEmissions2001 0.854 2.856 0.785 0.825 74% 6.35 21.23 5.83 6.14 0.302002 0.854 2.681 0.747 0.810 75% 6.40 20.11 5.60 6.07 0.472003 0.854 2.474 0.702 0.792 75% 6.59 19.11 5.42 6.11 0.692004 0.854 2.239 0.651 0.771 76% 6.70 17.57 5.11 6.05 0.942005 0.854 1.958 0.590 0.746 77% 6.72 15.40 4.64 5.87 1.232006 0.854 1.634 0.520 0.718 77% 6.82 13.05 4.15 5.73 1.582007 0.854 1.348 0.458 0.693 78% 6.97 11.01 3.74 5.66 1.922008 0.854 1.118 0.408 0.673 79% 7.13 9.33 3.41 5.62 2.212009 0.854 0.937 0.369 0.657 79% 7.28 7.99 3.15 5.61 2.462010 0.854 0.797 0.339 0.645 80%7.446.94 2.95 5.62 2.672011 0.854 0.680 0.313 0.636 80% 7.57 6.03 2.78 5.63 2.852012 0.854 0.584 0.293 0.627 80% 7.705.27 2.645.66 3.022013 0.854 0.508 0.276 0.621 80% 7.83 4.66 2.53 5.69 3.162014 0.854 0.452 0.264 0.617 81% 7.96 4.22 2.46 5.75 3.292015 0.854 0.413 0.256 0.614 81% 8.09 3.92 2.42 5.81 3.392016 0.854 0.386 0.250 0.611 81% 8.19 3.71 2.40 5.87 3.472017 0.854 0.365 0.245 0.610 81% 8.30 3.55 2.38 5.93 3.542018 0.854 0.349 0.242 0.609 81% 8.40 3.43 2.38 5.99 3.612019 0.854 0.334 0.239 0.608 81% 8.51 3.33 2.38 6.05 3.682020 0.854 0.324 0.236 0.607 81% 8.61 3.26 2.38 6.12 3.742021 0.854 0.315 0.234 0.607 81% 8.72 3.22 2.39 6.19 3.802022 0.854 0.304 0.232 0.606 81% 8.83 3.14 2.40 6.26 3.862023 0.854 0.294 0.230 0.605 81% 8.93 3.08 2.40 6.33 3.932024 0.854 0.288 0.228 0.605 81% 9.04 3.05 2.42 6.40 3.992025 0.854 0.284 0.228 0.605 81% 9.15 3.04 2.44 6.48 4.042026 0.854 0.280 0.227 0.605 81% 9.28 3.05 2.47 6.57 4.112027 0.854 0.278 0.226 0.605 81% 9.42 3.07 2.50 6.67 4.172028 0.854 0.278 0.226 0.605 81% 9.55 3.11 2.53 6.77 4.242029 0.854 0.278 0.226 0.605 81% 9.69 3.15 2.57 6.86 4.302030 0.854 0.278 0.226 0.605 81% 9.82 3.20 2.60 6.96 4.36PENNSYLVANIA - Emissions and ORVR Percentages(IEE 0.86)0246810122001 2006 2011 2016 2021 2026

Emissions (tons/summer day)0%10%20%30%40%50%60%70%80%90%100% % PenetrationEmissions if only Stage II controls were inplace, without ORVREmissions with only ORVR requirements,without Stage II controlsEmissions with Stage II and ORVR, including"incompatibility excess emissions" of 0.86lb/1000 gal for Vacuum AssistEmissions with Stage II and ORVR, without"excess emissionsORVR Penetration, option (a) definition, % ofvehiclesORVR Penetration, option (b) definition, %VMTORVR Penetration, option (d) definition, %fuel dispensed"Widespread use" dateunder option (c)"Widespread use"date under option (c2)TOTAL REFUELING EMISSIONS– Pennsylvania(Calculations assume all VA have IEE of 0.86, uncorrected)Grams Emitted Per Gallon GasolineTons Per Summer DayCalendarYearStage IIControlsOnlyORVROnlyStage IIwith ORVR,No IEEStage II withORVR, IEE% DecreasefromUncontrolledEmissionsStage IIControls OnlyORVROnlyStage II withORVR, NoIEEStage II withORVR, IEEExcessEmissions2001 1.052 2.691 0.943 0.980 68% 3.68 9.40 3.29 3.43 0.132002 1.052 2.499 0.886 0.943 69% 3.77 8.96 3.18 3.38 0.212003 1.065 2.316 0.831 0.912 71% 3.91 8.51 3.06 3.35 0.292004 1.065 2.088 0.764 0.868 72% 4.01 7.86 2.88 3.27 0.392005 1.065 1.842 0.692 0.821 74% 4.11 7.11 2.67 3.17 0.502006 1.065 1.592 0.618 0.773 75% 4.20 6.28 2.44 3.05 0.612007 1.065 1.368 0.552 0.731 77% 4.30 5.52 2.23 2.95 0.722008 1.065 1.203 0.503 0.700 78% 4.40 4.96 2.08 2.89 0.812009 1.065 1.041 0.455 0.669 79%4.494.39 1.92 2.82 0.902010 1.065 0.896 0.413 0.642 79% 4.59 3.86 1.78 2.77 0.992011 1.065 0.774 0.377 0.620 80% 4.69 3.40 1.66 2.73 1.072012 1.065 0.670 0.346 0.601 81% 4.78 3.01 1.55 2.70 1.142013 1.065 0.584 0.321 0.585 81% 4.882.67 1.472.68 1.212014 1.065 0.516 0.301 0.573 82% 4.97 2.41 1.40 2.67 1.272015 1.065 0.463 0.285 0.563 82% 5.07 2.20 1.36 2.68 1.322016 1.065 0.420 0.272 0.556 82% 5.17 2.03 1.32 2.70 1.382017 1.065 0.384 0.262 0.550 82% 5.26 1.90 1.29 2.72 1.422018 1.065 0.364 0.256 0.547 82% 5.36 1.83 1.29 2.75 1.462019 1.065 0.337 0.248 0.542 83% 5.46 1.73 1.27 2.78 1.512020 1.065 0.314 0.241 0.539 83% 5.55 1.64 1.26 2.81 1.552021 1.065 0.296 0.236 0.536 83% 5.65 1.57 1.25 2.84 1.592022 1.065 0.281 0.232 0.534 83% 5.75 1.52 1.25 2.88 1.632023 1.065 0.271 0.229 0.532 83% 5.84 1.49 1.25 2.92 1.662024 1.065 0.265 0.227 0.532 83% 5.94 1.47 1.26 2.96 1.702025 1.065 0.258 0.225 0.531 83% 6.03 1.46 1.27 3.01 1.732026 1.065 0.253 0.223 0.530 83% 6.13 1.46 1.28 3.05 1.772027 1.065 0.250 0.222 0.530 83% 6.23 1.46 1.30 3.10 1.802028 1.065 0.249 0.222 0.531 83% 6.32 1.48 1.32 3.15 1.832029 1.065 0.246 0.221 0.531 83% 6.42 1.48 1.33 3.20 1.862030 1.065 0.246 0.221 0.531 83% 6.52 1.50 1.35 3.25 1.90D-1 

### Appendix D

ORVR WIDESPREAD USE ANALYSIS

Widespread Use Dates – Definition (c) Versus Defini tion (c2)

The U.S. EPA’s Draft Stage II Vapor Recovery Option s Paper (February 7, 2006) (hereinafter “Options Paper”) outlines a number of possible opti ons for defining when Onboard Refueling Vapor Recovery (ORVR) systems are in widespread use and therefore when states may terminate their Stage II Vapor Recovery Programs. In its Options Paper, EPA has indicated it is likely to settle either on Definition (c) or Defini tion (c2) for widespread use determinations, and of the two, the Definition (c2) approach is EPA’s p referred alternative.

The following provides a short summary of each of t hese definitions:

Definition (c) – Widespread use of ORVR is achieved in a given st ate or nonattainment area when VOC emissions (tons per summer day 1 ) under an ORVR-only scenario equal VOC emissions under a Stage II-only scenario.

Definition (c2) – Widespread use of ORVR is achieved in a given st ate or nonattainment area when VOC emissions (tons per summer day) under a pr ospective ORVR-only scenario equal

VOC emissions under a real world combination scenar io in which (1) Stage II controls are in place, (2) both ORVR and non-ORVR equipped vehicles are fueling at Stage II equipped stations, and (3) fueling of the ORVR equipped vehi cles is creating incompatibility excess emissions (IEE) between the two systems.

As explained below, the widespread use date under D efinition (c2) typically occurs several years after the date under Definition (c).

Explanation of Difference in Dates for Achieving Wi despread Use The EPA Options Paper included an analysis of wides pread use scenarios for three states: Massachusetts, Vermont, and New Hampshire. Appendix C of the Options Paper summarizes the data and presents charts to illustrate the scenario s for the three states. Using the Massachusetts example, widespread use under Definition (c) occurs about the year 2010. In contrast, widespread use under Definition (c2) occurs five ye ars later, about the year 2015. As a first step towards understanding why there is such a differenc e, we provide the following explanation, focused on the Massachusetts chart given on page 6 of Appendix C of the EPA Options Paper.

1 Summer day is selected for two reasons. First, it represen ts the worst case emissions scenario where, due to warmer weather, gasoline vaporization is at a maximum. Second, because Stage II Vapor Recovery is an ozone reduction strategy, it is appropriate to examine the effect of removal of an ozone precursor control measure on a day when ozone is more likely to be at a higher concentration.D-2

Green Line (with Triangles) – Emissions with Stage II, ORVR, and IEE The green line marked with triangles represents the present day real world combination scenario outlined in Definition (c2). At the point Stage II is removed, the green line ceases to exist and

the new real world scenario is the blue line marked with diamonds.

Blue Line (with Diamonds) – Emissions with Only ORV R Requirements in Place Until Stage II is removed, the blue line (diamonds) is not a real world scenario. The present-day

value of the blue line is that it illustrates how a n ORVR program by itself becomes increasingly effective at reducing emissions over time as ORVR-e quipped vehicles replace non-ORVR vehicles in the fleet. As stated above, the blue l ine (diamonds) replaces the green line (triangles) as the real world scenario once Stage II is removed

.

Violet Line (with Squares) – Emissions with Only St age II Controls in Place The violet line marked with squares ceased to repre sent real world conditions back in the 1990s when the first ORVR-equipped vehicles entered the f leet. In the Massachusetts chart, which shows a time span from 2001 out to about 2030, this line never reflects real world conditions. The continual upward slope of the violet line over time illustrates that because gasoline consumption (therefore gasoline throughput from ser vice stations) is continually increasing, emissions from the collective Stage II systems is a lso continually increasing.

Intersection of the Blue and the Violet Lines (Defi nition (c))

This is an intersection of two non-real world scena rios. In one scenario (blue line with diamonds), Stage II controls never existed but inst ead ORVR was implemented. In the opposite scenario (violet line with squares), Stage II contr ols were implemented but ORVR never existed.

Emissions Implications of Definition (c) According to this analysis, when widespread use is achieved and Stage II controls are removed, the green line (triangles) ceases to reflect real w orld conditions, and instead the blue line (diamonds) reflects the real world. In the Massach usetts example, in 2010 (widespread use date under Definition (c)), the blue line emissions (the new real world of ORVR only and no Stage II) are 6.84 tons per summer day. The green line (real world prior to removal of Stage II) emissions in 2010 are 4.08 tons per summer day. Thus, by rem oving Stage II controls in 2010, there is an emissions increase of 2.76 tons of VOC per day. 2 These are the excess emissions caused by refueling the remaining non-ORVR equipped vehicles without Stage II controls. 3

Emissions Implications of Definition (c2) Continuing with the Massachusetts example, in 2015 the blue line (diamonds) emissions are 3.65 tons per summer day and the green line (triangles) emissions are 3.86 tons per summer day. By

2 Removal of Stage II Vapor Recovery as a control measure in an ozone nonattainment area would require EPA approval of a State Implementation Plan (SIP) revision. A ccording to § 110(l) of the Clean Air Act, the Administrator shall not approve a SIP revision if the re vision would interfere with any applicable requirement concerning attainment and reasonable further progress. Ther efore, if removal of Stage II Vapor Recovery resulted in a VOC emissions increase on the order of several tons per day during the ozone season, it may not be an approvable SIP revision.

3 The emissions would actually be slightly higher if not for the benefit achieved by eliminating the incompatibility excess emissions associated with refueling ORVR equipped vehicles with vacuum assisted Stage II Vapor Recovery equipment.D-3

removing Stage II in 2015, there is a net emissions benefit of 0.21 tons per day. At this point, there is a great enough penetration of ORVR equippe d vehicles into the fleet for ORVR to more than offset the emissions benefit from continuing t o utilize Stage II controls for capturing emissions from the relatively small residual popula tion of non-ORVR equipped vehicles.

Conclusion Definition (c2) is based on real world conditions a nd has no emissions consequences associated with the termination of Stage II Programs as compar ed to Definition (c).

### APPENDIX E

EFFECT OF INCOMPATIBILITY EXCESS EMISSIONS FACTOR

ON

ORVR WIDESPREAD USE DATE

FOR METROPOLITAN ATLANTA, GEORGIAMetropolitan Atlanta, GA “Definition c2” Widespread Use Dates - Varying IEE Scenarios Emissions (Tons per Summer Day) Stage II with ORVR with IEE Factor as Indicated Calendar

Year ORVR

Only IEE=0.09 IEE=0.33 IEE=0.42 IEE=0.55 IEE=0.72 IEE=0.86

2010 6.94 3.66 4.27 4.50 4.83 5.27 5.62

2011 6.03 3.54 4.19 4.44 4.79 5.25 5.63

2012 5.27 3.44 4.13 4.39 4.77 5.25 5.66

2013 4.66 3.37 4.10 4.37 4.76 5.27 5.69

2014 4.22 3.34 4.09 4.37 4.78 5.31 5.75

2015 3.92 3.33 4.10 4.39 4.81 5.36 5.81

2016 3.71 3.32 4.12 4.41 4.84 5.41 5.87

2017 3.55 3.33 4.14 4.44 4.88 5.45 5.93

2018 3.43 3.34 4.17 4.48 4.92 5.51 5.99

2019 3.33 3.36 4.20 4.51 4.97 5.56 6.05

c2 Year 2019 2015 2014 2013 2013 2012

Note: According to the supplied inputs, in the met ropolitan Atlanta counties, 93.3 percent of Stage II systems are vacuum-assist and 6.7 percent are balance systems.