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FEDERAL CLEAN AIR ACT SECTION 110(l) DEMONSTRATION

TO SUPPORT AMENDMENTS TO RULE 61.4

EPA Memoranda

In 2006-2007, EPA issued two memoranda authorizing states to eliminate the requirements for 

Phase II vapor recovery at gasoline dispensing facilities (GDFs) that exclusively service rental or 

corporate fleet vehicles if (1) it is demonstrated that On Board Refueling Vapor Recovery 

(ORVR) in these fleets is in widespread use, and (2) eliminating this requirement would not 

interfere with attainment or reasonable further progress or any other requirement of the Clean Air 

Act.

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 EPA also recommended applying these same considerations for refueling flexible fuel 

vehicles at E-85 fuel (85% ethanol-15% gasoline) dispensing pumps.

EPA defined ORVR widespread use as a situation where at least 95% of vehicles refueled at a 

given station have ORVR. Since car rental companies and corporate entities operate mostly late 

model vehicles, they will be able to demonstrate 95% or larger ORVR penetration. EPA also 

stated that States which provide exemptions from the Phase II vapor recovery requirement must 

demonstrate that the widespread use benchmark has been achieved at facilities being exempted

and their eligibility for the exemption is continuously maintained. 

For flexible fuel vehicles operating on E85, EPA did not define a widespread use threshold 

because the majority of such vehicles are already equipped with ORVR and this percentage is

increasing with time. EPA further indicated that the air quality impact of allowing E85 refueling 

facilities to operate without Phase II vapor recovery would likely be minimal, and therefore will 

not interfere with the attainment of the National Ambient Air Quality Standard (NAAQS) for 

ozone.

Rule 61.4 Amendments

San Diego County Air Pollution Control District’s Rule 61.4 (Volatile Organic Compounds 

Transfer into Vehicle Fuel Tanks) requires all facilities that dispense more than 2,000 gallons of 

fuel per month to install and maintain Phase II vapor recovery systems. The rule was last 

amended in 1990 and approved by EPA into the State Implementation Plan (SIP) in 1993.

On March 26, 2008, the San Diego County Air Pollution Control Board amended the rule to 

provide an exemption from the Phase II vapor recovery requirements for non-retail gasoline 

dispensing facilities (GDFs) where at least 95% of vehicles refueled are equipped with ORVR. 

The rule required an owner or operator of a facility qualified for the exemption to maintain 

records of the make, model year, vehicle identification number and any other information 

indicating whether a vehicle is equipped with ORVR. In addition, the same exemption was

provided to facilities or pumps where E-85 is dispensed. 

 

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 “Removal of Stage II Vapor Recovery in Situations Where Widespread Use of Onboard Refueling Vapor Recovery is Determined,” Stephen D. 

Page, Director, Office of Air Quality Planning and Standards, and Margo Tsirigotis Oge, Director, Office of Transportation and Air Quality, 

December 12, 2006; “Removal of Stage II Vapor Recovery from Refueling of Corporate Fleets,” Stephen D. Page and Margo Tsirigotis Oge, 

November 28, 2007.
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Emissions Impact Analysis

The following analysis demonstrates that these amendments to Rule 61.4 will not interfere with 

the attainment of the NAAQS for ozone in San Diego County.

I. Non-retail GDFs that may chose to apply for exemption from Rule 61.4.

There are presently 136 non-retail stations in San Diego County, with 20 of them belonging to 

military establishments. Some of these stations dispense a significant amount of gasoline, more 

than three million gallons per year each. These facilities, while non-retail by definition (they do 

not pay state sales tax), also refuel private vehicles of active military personnel and military 

retirees. Consequently, these sources will not qualify for the exemption from Rule 61.4.1 

because their operators do not control the make or age of vehicles they refuel, and therefore it is 

impossible for them to determine with certainty whether ORVR equipped vehicles are in 

widespread use. The same conditions apply to GDFs at car dealerships (5 GDFs belong to 

those). The remaining 111 facilities with a total annual gasoline throughput of approximately 18 

million gallons may qualify for the exemption.

Accordingly, two scenarios were compared assuming that in the worst case, 111 GDFs will 

actually apply for the exemption and be approved by the District. These stations must also 

remove Phase II vapor recovery equipment as required by the rule. It was further assumed that 

in-use control efficiency of Phase II vapor recovery equipment is 84%,2 the present Phase II 

vapor recovery system is dismantled, and at least 95% of vehicles refueled at each GDF are 

equipped with ORVR. The ARB emission factor of 8.4 lbs VOC/1000 gallons of gasoline was 

used for the uncontrolled refueling system.

Scenario 1. All vehicles that would be subject to the exemption are refueled at GDF’s with 

Phase II VR control in place with 84% in-use control efficiency. The vehicles do not have 

ORVR.

VOC emission reductions = 

= 18,000,000 gal/yr x 8.4 lbs VOC/1000 gal x 0.84 x 1ton /2000 lbs = 63.5 tpy.

Scenario 2. All vehicles that would be subject to the exemption are refueled at GDF’s with no 

Phase II VR, and 95% of vehicles have ORVR systems installed, which control emissions by 

95%. The rest of the vehicles (5%), or approximately 5% of gasoline dispensed will be refueled 

without any VOC control in place, i.e. 

VOC emission reductions from vehicles equipped with ORVR = 

= 18,000,000 gal/yr x 8.4 lbs VOC/1000 gal x 0.95 x 0.95 x 1ton /2000 lbs = 68.2 tpy.

VOC emissions increase from non-controlled refueling of vehicles without ORVR = 

=18,000,000 gal/yr x 0.05 x 8.4 lbs VOC/1000 gal = 3.8 tpy.

 

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 This value is consistent with the methodology for the emission estimates in the 2002 baseline emission inventory and emission forecasts in San 

Diego’s 2007 Eight-Hour Ozone Attainment Plan.
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Overall emission reductions = 68.2-3.8 = 64.4 tpy.

These calculations show that there will be a slight gain in VOC emission reductions (0.9 tpy) if

stations refueling at least 95% ORVR-equipped vehicles remove the Phase II vapor recovery,

due to a higher control efficiency of ORVR, provided that the ORVR works as expected. 

II. Flexible Fuel Vehicles

Presently, there is only one active retail station in San Diego County that refuels flexible fuel 

vehicles servicing approximately 1300 vehicles per month, with monthly E85 throughput 

between 10,000 and 20,000 gallons. The facility has both Phase I and Phase II VR systems 

installed. The Phase I system was recently certified by ARB, whereas the Phase II system is not 

certified.

As stated above, the majority of vehicles fueled on E85 are equipped with ORVR. However, 

according to ARB information some E85 light duty trucks manufactured between 1997 and 2002 

were not equipped with ORVR. ARB staff estimated the possible VOC emission increases from 

removing Phase II vapor recovery at stations that were refueling such trucks. They assume that 

some of these trucks would remain in use by 2015 using survival fraction of vehicles as a 

function of vehicle age. Average age of vehicles not having ORVR in 2005 was four years. The 

estimated statewide emissions from refueling these vehicles at E85 pumps not equipped with 

Phase II VR were approximately 0.10 tons/day (36.5 tons/year) in 2015. ARB staff concluded 

that this emission increase will not impact the attainment of the federal air quality standard for 

ozone. 

Similarly, no impact on ozone attainment is anticipated in San Diego. Based on these statewide 

estimates and the proportion of estimated San Diego County population vs. California population 

in 2015 (8%), the excess of VOC emissions from such vehicles in the county will be 0.10 

tons/day x 0.08 = 0.008 tons/day or 2.9 tons/year.

III. Net Impact

Net VOC emissions change = 2.9 tons/year (increase from stations dispensing E85) - 0.9 ton/year

(decrease from stations refueling 95% ORVR equipped vehicles) = 2 tons/year or 0.0055

tons/day (region-wide VOC emissions increase).

In light of such an insignificant VOC emissions increase, it is reasonable to conclude that the 

proposed exemptions in Rule 61.4 for fleet vehicles and vehicles fueled with E85 at qualified 

fueling stations will not adversely affect the attainment of the NAAQS for ozone in San Diego 

County, or any other requirement of the Clean Air Act.