Summary |
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SECTION 4.10 |
EMISSION INVENTORY SOURCE CATEGORY
Petroleum Production and Marketing / Petroleum Marketing |
330-374-1100-0000 | (46532) | Gasoline Dispensing Tanks - Working Losses | |
330-376-1100-0000 | (46557) | Gasoline Dispensing Tanks - Breathing Losses | |
330-378-1100-0000 | (46540) | Vehicle Refueling - Vapor Displacement | |
330-380-1100-0000 | (46565) | Vehicle Refueling - Spillage |
METHOD SUMMARY
These categories include 1997 estimates of organic gas emissions resulting from the storage and transfer operations
at gasoline dispensing facilities. Emissions from storage and transfer operations include the working losses and
breathing losses from underground tanks, vapors displaced through vehicle refueling, and spillage. Gasoline dispensing
facilities consist of gasoline retail outlets and private dispensing facilities.
ACTIVITY DATA SOURCE: The California Department of Transportation issues an annual report, "Travel and Related
Factors," which contains the throughput of gasoline distributed in the state by county. The total gasoline
sales for service stations in the State by County were from the Annual Report from the California State Board of
Equalization. The 1997 calendar year report was used for the 1997 gasoline throughput. These gasoline throughputs
were estimated using several variables which are strongly correlated with gasoline consumption. The variables included
several categories of taxable sales, population, vehicle miles of travel, and the number of registered vehicles.
The weighted average share for all the variables was then computed for each county. The above variables were used
to divide the total gasoline sales in each county into highway sales and non-highway sales. Highway sales are assumed
to be gasoline sales from service stations and non-highway sales are assumed to be gasoline sales from tax exempt
gasoline dispensing facilities. Adjustments were made to account for county-specific factors such as business and
recreational trips. The air basin splits were divided by the ratio of the 1997 population.
EMISSION FACTOR SOURCE: Total organic gas emission factors (uncontrolled and controlled) are based on the CAPCOA
Air Toxics "Hot Spots" Program Gasoline Service Station Industrywide Risk Assessment Guidelines Document
and a June 24, 1994 internal memo from Jim Fries to Dale Shimp estimating the benefits of cleaner burning gasoline.
The use of control factors versus uncontrolled factors is based on all service stations that pump more than 480,000
gallons per year.
Private gasoline dispensing facilities, which account for about two percent of a given county's throughput each
year, are assumed to be exempt from vapor recovery regulations. Since uncontrolled emission factors are up to 20
times as high as controlled factors, these facilities would contribute 15 to 26 percent of the total emissions
TEMPORAL DATA: For underground tank working and breathing losses, the annual, weekly, and daily activities are
all uniform. For vehicle refueling and spillage losses, the annual activity is uniform throughout the year. The
weekly activity is nearly uniform, with slightly lower activity on the weekend. The daily activity follows a pattern,
which peaks during the after-work hours in the evening and bottoms between midnight and 6 a.m.
CHANGES IN METHOD AND EMISSION ESTIMATES: There is a higher activity rate (gasoline throughput) for 1997 than for
1990. With full implementation of the Benzene rule and the introduction of cleaner burning gasoline, emissions
were reduced. Thus, the 1997 statewide emissions are lower than the 1990 emissions. The emission factors are lower
from the previous years due to the reduced vapor pressure of cleaner burning gasoline.
DATE OF THE LAST UPDATE: May 1999
GROWTH PARAMETER: The growth parameters were developed by Pechan and are based on gasoline and oil expenditures
data (in billions of 1992 dollars).
STATEWIDE EMISSIONS SUMMARY (1997 - ANNUAL AVERAGE TONS/DAY)
CES No. TOG
CO
NOX
SOX
PM
46532 10.90
0.00
0.00
0.00
0.00
46540 16.80
0.00
0.00
0.00
0.00
46557 2.16
0.00
0.00
0.00
0.00
46565 7.98
0.00
0.00
0.00
0.00
Total 37.84
0.00
0.00
0.00
0.00
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This page last revised on November 11, 2003 |
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