6.10 Gasoline Filling Station Fueling

6.10.1 Emissions

Introduction

Motor vehicle refueling emissions come from vapors displaced from the automobile tank at gasoline dispensing facilities. The quantity of evaporative emissions depends on gasoline temperature, automobile tank temperature, gasoline RVP and dispensing rate. The control technique for vehicle refueling emissions is Phase II vapor recovery system. The Phase II is equipped with a rubber boot to collect and the route the vapors through the nozzle into a coaxial vapor-liquid hose and to the dispenser and into storage tank.

Methodologies

These categories account for organic emissions at vehicle filling stations during refueling operations. The estimates of gasoline consumption in the Bay Area were provided by California State Board of Equalization, Fuel Taxes Statistics & Reports and Caltrans Transportation Planning Support Information System (TPSIS). These estimates were made by adjustments of Gasoline Dispensing Facility sales, population, number of registered vehicles, and the number of drivers’ license. The throughput for each type of GDF was estimated based on the information contained in the District’s data bank.

The 2011 gasoline consumption in the Bay Area was 7,041 thousand gallons per day. Emission factors were taken from AP-42, Section 4.4. The total emissions for area source categories are determined by multiplying the emission factor, control factor and throughput.

Monthly variation

Monthly variation of emissions was based on gasoline usage data for California by months. The monthly Bay Area gasoline usage was estimated from Board of Equalization Taxable Gasoline Sales monthly report.

County Distribution

Emissions distributed into the nine counties were based on Caltrans Transportation Planning Support Information System’s breakdown.

Table 6.21: County fractions.
category ALA CC MAR NAP SF SM SNC SOL SON
#75 Filling Vehicle Tanks (W/O Phase I & II) 23.1% 13.7% 4.8% 2.0% 5.7% 11.0% 25.2% 7.7% 6.8%
#76 Filling Vehicle Tanks (With Phase I & II) 23.1% 13.7% 4.8% 2.0% 5.7% 11.0% 25.2% 7.7% 6.8%
#77 Filling Vehicle Tanks (With Phase I Only) 23.1% 13.7% 4.8% 2.0% 5.7% 11.0% 25.2% 7.7% 6.8%
#78 Filling Vehicle Tanks (With Phase II Only) 21.6% 13.7% 4.3% 2.1% 12.7% 12.4% 23.5% 4.1% 5.6%