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2020 National Emissions Inventory Technical
Support Document: Nonpoint Gasoline
Distribution
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EP A-454/R-23 -001 r
March 2023
2020 National Emissions Inventory Technical Support Document: Nonpoint Gasoline
Distribution
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Air Quality Assessment Division
Research Triangle Park, NC
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Contents
List of Tables i
18 Nonpoint Gasoline Distribution 18-1
18.1 Sector Descriptions and Overview 18-1
18.1.1 Stage 1 gasoline distribution 18-1
18.1.2 Aviation gasoline distribution, stage 1 and 2 18-3
18.2 Sources of data 18-3
18.3 EPA-developed estimates 18-4
18.3.1 Activity data 18-6
18.3.2 Allocation procedure 18-8
18.3.3 Emission factors 18-11
18.3.4 Controls 18-13
18.3.5 Emissions 18-13
18.3.6 Point Source Subtraction 18-24
18.3.7 Example calculations 18-24
18.3.8 Improvements/Changes in the 2020 NEI 18-30
18.3.9 Puerto Rico and U.S. Virgin Islands 18-30
18.4 References 18-31
List of Tables
Table 18-1: Nonpoint bulk gasoline terminals, gas stations, and storage and transfer SCCs in the NEI. 18-2
Table 18-2: Nonpoint aviation gasoline distribution SCCs in the NEI 18-3
Table 18-3: Ranges and midpoints for data withheld from state and county business patterns 18-10
Table 18-4: 1998 Post-MACT Control Emissions 18-14
Table 18-5: States by PAD District 18-17
Table 18-6: Assumptions for Bulk Terminals Using Aviation Gasoline 18-22
Table 18-7: Sample calculations for VOC emissions from Stage I Gasoline Distribution - Bulk Terminals
18-24
Table 18-8: Sample calculations for VOC emissions from Stage I Gasoline Distribution - Pipelines 18-25
Table 18-9: Sample calculations for VOC emissions from Stage I Gasoline Distribution - Bulk Plants. 18-25
Table 18-10: Sample calculations for VOC emissions from Stage I Gasoline Distribution - Tank Trucks in
Transit 18-26
Table 18-11: Sample calculations for VOC emissions from Stage I Gasoline Distribution - Underground
Storage Tank (UST) Breathing and Storing 18-26
Table 18-12: Sample calculations for VOC emissions from Stage I Gasoline Distribution - Gasoline Service
Station Unloading 18-27
Table 18-13: Sample Calculations for VOC emissions from Aviation Gasoline Distribution - Stage 1.. 18-29
Table 18-14: Sample Calculations for VOC emissions from Aviation Gasoline Distribution - Stage 2 .. 18-30
l
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ii
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18 Nonpoint Gasoline Distribution
18.1 Sector Descriptions and Overview
This section includes discussion of all nonpoint sources in three EIS sectors: Bulk Gasoline Terminals, Gas
Stations, and Industrial Processes - Storage and Transfer. Many of the sources in these sectors include sources
reported to the point inventory as well; therefore, the EPA nonpoint survey is useful to avoid double-counting
S/L/T-reported point emissions with EPA-estimated nonpoint emissions.
This section is broken into two categories: those sources related to stage 1 gasoline distribution and those
related to aviation gasoline.
18.1.1 Stage 1 gasoline distribution
Stage 1 gasoline distribution is covered by the NEI in both the point and nonpoint data categories. In general
terms, Stage 1 gasoline distribution is the emissions associated with gasoline handling excluding emissions from
refueling activities. Stage I gasoline distribution includes the following gasoline emission points: 1) bulk
terminals; 2) pipeline facilities; 3) bulk plants; 4) tank trucks; and 5) unloading at service stations. Emissions from
Stage I gasoline distribution occur as gasoline vapors are released into the atmosphere. These Stage I processes
are subject to EPA's maximum available control technology (MACT) standards for gasoline distribution [ref 1],
Emissions from gasoline distribution at bulk terminals and bulk plants take place when gasoline is loaded into a
storage tank or tank truck, from working losses (for fixed roof tanks), and from working losses and roof seals (for
floating roof tanks). Working losses consist of both breathing and emptying losses. Breathing losses are the
expulsion of vapor from a tank vapor space that has expanded or contracted because of daily changes in
temperature and barometric pressure; these emissions occur in the absence of any liquid level change in the
tank. Emptying losses occur when the air that is drawn into the tank during liquid removal saturates with
hydrocarbon vapor and expands, thus exceeding the fixed capacity of the vapor space and overflowing through
the pressure vacuum valve [ref 2],
Emissions from tank trucks in transit occur when gasoline vapor evaporates from (1) loaded tank trucks during
transportation of gasoline from bulk terminals/plants to service stations, and (2) empty tank trucks returning
from service stations to bulk terminals/plants [ref 3], Pipeline emissions result from the valves and pumps found
at pipeline pumping stations and from the valves, pumps, and storage tanks at pipeline breakout stations. Stage
I gasoline distribution emissions also occur when gasoline vapors are displaced from storage tanks during
unloading of gasoline from tank trucks at service stations (Gasoline Service Station Unloading) and from gasoline
vapors evaporating from service station storage tanks and from the lines going to the pumps (Underground
Storage Tank Breathing and Emptying).
Table 18-1 shows all non-Aviation Gasoline SCCs in the nonpoint data category for EIS sectors Bulk Gasoline
Terminals, Gas Stations, and Industrial Processes - Storage and Transfer. For Stage 1 Gasoline Distribution, the
nonpoint SCCs covered by the EPA estimates are also noted. The SCC level 2, 3 and 4 SCC descriptions are also
provided. The SCC level 1 description is "Storage and Transport" for all SCCs.
18-1
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Table 18-1: Nonpoint bulk gasoline terminals, gas stations, and storage and transfer SCCs in the
see
Description
Sector
2501050120
Petroleum and Petroleum Product Storage;
Bulk Terminals: All Evaporative Losses;
Gasoline
Bulk Gasoline
Terminals
2501055120
Petroleum and Petroleum Product Storage;
Bulk Plants: All Evaporative Losses; Gasoline
Bulk Gasoline
Terminals
2501060051
Petroleum and Petroleum Product Storage;
Gasoline Service Stations; Stage 1: Submerged
Filling
Gas Stations
2501060052
Petroleum and Petroleum Product Storage;
Gasoline Service Stations; Stage 1: Splash
Filling
Gas Stations
2501060053
Petroleum and Petroleum Product Storage;
Gasoline Service Stations; Stage 1: Balanced
Submerged Filling
Gas Stations
2501060201
Petroleum and Petroleum Product Storage;
Gasoline Service Stations; Underground Tank:
Breathing and Emptying
Gas Stations
2501070053
Petroleum and Petroleum Product Storage;
Diesel Service Stations; Stage 1: Balanced
Submerged Filling
Gas Stations
2501995120
Petroleum and Petroleum Product Storage; All
Storage Types: Working Loss; Gasoline
Industrial Processes
- Storage and
Transfer
2505010000
Petroleum and Petroleum Product Transport;
Rail Tank Car; Total: All Products
Industrial Processes
- Storage and
Transfer
2505020000
Petroleum and Petroleum Product Transport;
Marine Vessel; Total: All Products
Industrial Processes
- Storage and
Transfer
2505020030
Petroleum and Petroleum Product Transport;
Marine Vessel; Crude Oil
Industrial Processes
- Storage and
Transfer
2505020060
Petroleum and Petroleum Product Transport;
Marine Vessel; Residual Oil
Industrial Processes
- Storage and
Transfer
2505020090
Petroleum and Petroleum Product Transport;
Marine Vessel; Distillate Oil
Industrial Processes
- Storage and
Transfer
2505020120
Petroleum and Petroleum Product Transport;
Marine Vessel; Gasoline
Industrial Processes
- Storage and
Transfer
2505020150
Petroleum and Petroleum Product Transport;
Marine Vessel; Jet Naphtha
Industrial Processes
- Storage and
Transfer
18-2
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SCC
Description
Sector
2505020180
Petroleum and Petroleum Product Transport;
Marine Vessel; Kerosene
Industrial Processes
- Storage and
Transfer
2505030120
Petroleum and Petroleum Product Transport;
Truck; Gasoline
Industrial Processes
- Storage and
Transfer
2505040120
Petroleum and Petroleum Product Transport;
Pipeline; Gasoline
Industrial Processes
- Storage and
Transfer
2510000000
Organic Chemical Storage; All Storage Types:
Breathing Loss; Total: All Products
Industrial Processes
- Storage and
Transfer
2520010000
Inorganic Chemical Storage;
Commercial/Industrial: Breathing Loss; Total:
All Products
Industrial Processes
- Storage and
Transfer
18.1.2 Aviation gasoline distribution, stage 1 and 2
Aviation gasoline (also called "AvGas") is the only aviation fuel that contains lead as a knock-out component for
small reciprocating, piston-engine crafts in civil aviation [ref 4], Commercial and military aviation rarely use this
fuel. AvGas is shipped to airports and is filled into bulk terminals, and then into tanker trucks. These processes
fall under the definition of stage 1, displacement vapors during the transfer of gasoline from tank trucks to
storage tanks, and vice versa. Stage 2 involves the transfer of fuel from the tanker trucks into general aviation
aircraft.
Table 18-2 shows, for Aviation Gasoline, the nonpoint SCCs covered by the EPA estimates and by the S/L/T
agencies that submitted data. The SCC level 2, 3 and 4 SCC descriptions are also provided. The SCC level 1
description is "Storage and Transport" for all SCCs.
Table 18-2: Nonpoint aviation gasoline distribution SCCs in the NEI
SCC
Description
Sector
2501080050
Petroleum and Petroleum Product Storage; Airports: Aviation
Gasoline; Stage 1: Total
Gas
Stations
2501080100
Petroleum and Petroleum Product Storage; Airports: Aviation
Gasoline; Stage 2: Total
Gas
Stations
2501080201
Petroleum and Petroleum Product Storage; Airports: Aviation
Gasoline; Underground Tank: Breathing and Emptying
Gas
Stations
18.2 Sources of data
Sources in the EIS sectors for Bulk Gasoline Terminals, Gas Stations, and Industrial Processes - Storage and
Transfer do not focus solely on gasoline; however, for the purposes of developing the NEI, these SCCs are the
only ones that EPA estimates in these sectors. EPA does not develop calculation tools that estimate emissions
from transfer of naphtha, distillate oil, inorganic chemicals, kerosene, residual oil, or crude oil. Therefore, sector
level emissions for these three EIS sectors will include sources not related to gasoline distribution, some from
the point inventory.
18-3
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A list of agencies that submitted emissions for bulk gasoline terminals, aviation gasoline distribution, and Stage 1
gasoline distribution from the gas stations and storage and transport sectors is provided in Section 6.2.3.
18.3 EPA-developed estimates
Bulk Terminals
The calculations for estimating VOC and HAP emissions from bulk terminals involve first multiplying the 1998
national VOC emissions developed in support of the Gasoline Distribution MACT standard by the ratio of the
national volume of wholesale gasoline supplied between 1998 and 2020. Emissions from HAPs are calculated by
multiplying VOC emissions by a national average speciation profile. National VOC and HAP emissions are
allocated to states using data on refinery, bulk terminal, and natural gas plant stocks of motor gasoline in each
state [ref 19]. State-level VOC and HAP emissions are then allocated to each county based on employment at
petroleum bulk stations and terminals from the US Census County Business Patterns data for NAICS 42471
(Petroleum Bulk Stations and Terminals) [ref 10].
Pipelines
The calculations for estimating VOC and HAP emissions from pipelines involve first multiplying the 1998 national
VOC emissions developed in support of the Gasoline Distribution MACT standard by the 2020 to 1998 ratio of
national volume of wholesale gasoline supplied. Emissions from HAPs are calculated by multiplying VOC
emissions by a national average speciation profile. National VOC and HAP emissions are allocated to Petroleum
Administration for Defense (PAD) District using data on the movement of finished motor gasoline in PAD District
[ref 21]. PAD District-level VOC and HAP emissions are then allocated to each county based on employment at
petroleum bulk stations and terminals from the US Census County Business Patterns data for NAICS 42471
(Petroleum Bulk Stations and Terminals) [ref 10].
Bulk Plants
The calculations for estimating VOC and HAP emissions from bulk plants involve first calculating bulk plant
gasoline throughput in the US based on data from the U.S. Energy Information Administration (EIA) [ref 5],
National bulk plant gasoline throughput is then allocated to each county based on the number of petroleum
bulk stations and terminals from the US Census County Business Patterns data for NAICS 42471 [ref 10]. The
number of petroleum bulk stations and terminals by county is multiplied by the emissions factor for VOC to
estimate VOC emissions from bulk plants. County-level benzene speciation profiles are multiplied by VOC
emissions to estimate benzene emissions from bulk plants. National average speciation profiles for all other
HAPs are multiplied by VOC emissions to estimate HAP emissions from bulk plants.
Tank Trucks in Transit
The calculations for estimating VOC and HAP emissions from tank trucks in transit involve first calculating
county-level total gasoline consumption by summing onroad gasoline consumption and nonroad gasoline
consumption in each county. County-level gasoline consumption is multiplied by the emissions factor for VOC to
estimate VOC emissions from tank trucks in transit. County-level benzene speciation profiles are multiplied by
VOC emissions to estimate benzene emissions from tank trucks in transit. National average speciation profiles
for all other HAPs are multiplied by VOC emissions to estimate HAP emissions from tank trucks in transit.
18-4
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Underground Storage Tank (UST) Breathing and Storing
The calculations for estimating VOC and HAP emissions from UST breathing and storing involve first calculating
county-level gasoline consumption by summing onroad gasoline consumption and nonroad gasoline
consumption in each county. County-level gasoline consumption is multiplied by the emissions factor for VOC to
estimate VOC emissions from UST breathing and storing. County-level benzene speciation profiles are multiplied
by VOC emissions to estimate benzene emissions from UST breathing and storing. National average speciation
profiles for all other HAPs are multiplied by VOC emissions to estimate HAP emissions from UST breathing and
storing.
Gasoline Service Station Unloading
The calculations for estimating VOC and HAP emissions from gasoline service station unloading involve first
calculating county-level total gasoline consumption by summing monthly onroad gasoline consumption and
nonroad gasoline consumption in each county by fuel subtype. Monthly county-level gasoline consumption is
then allocated to submerged, splash, and balanced filling technologies based on assumptions about the
percentage of each filling technology used in each county. True vapor pressure is calculated for each county,
month, and fuel subtype. Uncontrolled loading loss of liquid is calculated using true vapor pressure,
temperature, molecular weight, and a saturation factor for the filling technology. Uncontrolled loading loss of
liquid loaded is multiplied by monthly county-level gasoline consumption by fuel type to estimate VOC emissions
from loading loss. Controlled VOC emissions are calculated by multiplying VOC emissions from loading loss by a
control efficiency value. Controlled VOC emissions are subtracted from VOC emissions from loading loss to
estimate monthly county-level VOC emissions by fuel subtype. Total county-level VOC emissions are calculated
by summing monthly county-level VOC emissions by fuel subtype. County-level benzene speciation profiles are
multiplied by VOC emissions to estimate benzene emissions from gasoline service station unloading. National
average speciation profiles for all other HAPs are multiplied by VOC emissions to estimate HAP emissions from
gasoline service station unloading.
Aviation Gasoline Stage 1
The calculations for estimating emissions from stage 1 aviation gasoline distribution involve first estimating the
amount of aviation gasoline consumed in each county, based on state-level aviation gasoline consumption data
from the Energy Information Administration (EIA) [ref 7], State-level aviation gasoline consumption is distributed
to the counties based on the proportion of Landing-Take Offs (LTOs) [ref 11], The total amount of gasoline
consumed is used to estimate non-fugitive and fugitive VOC emissions, as well as hazardous air pollutant (HAP)
emissions.
Aviation Gasoline Stage 2
The calculations for estimating emissions from stage 2 aviation gasoline distribution involve first estimating the
amount of aviation gasoline consumed in each county based on state-level aviation gasoline consumption data
from the Energy Information Administration (EIA) [ref 7], State-level aviation gasoline consumption is distributed
to the counties based on the proportion of Landing-Take Offs (LTOs) [ref 11], The total amount of gasoline
consumed is used to estimate VOC and hazardous air pollutant (HAP) emissions.
18-5
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18.3.1 Activity data
Bulk Terminals and Pipelines
Emissions from bulk terminals and pipelines are calculated by growing the 1998 emissions estimates developed
in support of the Gasoline MACT standard. Therefore, there is no activity data for this source category.
Bulk Plants
The activity data for estimating emissions from bulk plants are national volume of bulk plant gasoline
throughput. The ElA's Petroleum Navigator reports the volume of finished motor gasoline supplied in the U.S
[ref 5], The volume of finished motor gasoline is assumed to be the same as total gasoline consumption, and the
volume of bulk plant gasoline throughput is assumed to be 9 percent of total gasoline consumption [ref 6],
Tank Trucks in Transit
The activity data for tank trucks in transit is county-level total gasoline consumption. State-level onroad motor
gasoline consumption and nonroad gasoline consumption are estimated by splitting total motor gasoline
consumption from ElA's State Energy Data System (SEDS) [ref 7] in to onroad and nonroad gasoline consumption
using state-level MOVES data on onroad and nonroad C02 emissions [ref 8], State-level onroad motor gasoline
consumption is then allocated to the county, month, and fuel subtype using a MOVES-derived ratio of county
onroad C02 to state onroad C02. State-level nonroad motor gasoline consumption is allocated to the county,
month, and fuel subtype using the MOVES-derived ratio of county nonroad C02 to state nonroad C02. County-
level onroad consumption and county-level nonroad consumption are estimated by summing county-level
monthly consumption estimates.
GTus,bp Vus x 0-09
(1)
Where:
GTus, bp
Vus
Bulk plant gasoline throughput in the U.S., in thousand barrels
Volume of finished motor gasoline in the U.S., in thousand barrels
(2)
Where:
Onroad gasoline consumption in county c, in gallons
Onroad gasoline consumption in county cfor month m, in gallons
(3)
Where:
Nonroad gasoline consumption in county c, in gallons
Nonroad gasoline consumption in county c for month m, in gallons
18-6
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County-level tank truck gasoline throughput is estimated by summing county-level onroad and nonroad
estimates, and multiplying the sum by 1.09 to account for gasoline that is transported more than once in a given
area (i.e., transported from bulk terminal to bulk plant and then from bulk plant to service station) [ref 6],
GCCit (fiC0R c + GCNR c) X 1.09
(4)
Where:
GCc
Total gasoline consumption in county c, in gallons
Onroad gasoline consumption in county c, in gallons
Nonroad gasoline consumption in county c, in gallons
Underground Storage Tank (UST) Breathing and Storing
The activity data for underground storage tank breathing and storing is county-level gasoline consumption,
calculated as described above in the tank trucks in transit section.
Gasoline Service Station Unloading
The activity data for gasoline service station unloading is county-level total gasoline consumption for each
month and fuel subtype. State-level onroad motor gasoline consumption and nonroad gasoline consumption are
estimated by splitting total motor gasoline consumption from SEDS [ref 7] into onroad and nonroad
consumption using state-level MOVES data on onroad and nonroad C02 emissions [ref 8], State-level onroad
motor gasoline consumption is then allocated to the county, month, and fuel subtype using a MOVES-derived
ratio of county onroad C02 to state onroad C02. State-level nonroad motor gasoline consumption is allocated to
the county, month, and fuel subtype using the MOVES-derived ratio of county nonroad C02 to state nonroad
C02.
County-level gasoline consumption is estimated by summing onroad gasoline consumption and nonroad
gasoline consumption and multiplying the sum by 1.09 to account for gasoline that is transported more than
once in a given area (i.e., transported from bulk terminal to bulk plant and then from bulk plant to service
station) [ref 6],
GCc,t,m,f = Total gasoline consumption in county c for month m for fuel subtype/, in gallons
GCc, oR,m,f Onroad gasoline consumption in county c for month m for fuel subtype /, in gallons
GCc,NR,m,f = Nonroad gasoline consumption in county c for month m for fuel subtype/, in gallons
The county-level gasoline consumption is allocated to submerged, splash, and balanced filling technologies.
Percentages of each filling technology are derived from the EIIP study [ref 3], State, local, and tribal (SLT)
agencies may submit input templates to update theses default assumptions about the percentage of delivered
fuel by filling technology.
GCc,t,m,f (GCc OR mj GCcjyf> m j) X 1.09
(5)
Where:
GCc,ft,m,f GCCf jn j x PerCftc
(6)
18-7
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Where:
GCc,ft.m,f = Total gasoline consumption in county c for filling technology ft for month m for fuel
subtype/, in gallons
GCc,t,m,f = Total gasoline consumption in county c for month m for fuel subtype/, in gallons
Percft,c = Percentage of filling technology ft in county c
Aviation Gasoline Stage 1 and 2
The activity data for this source category is the amount of aviation gasoline consumed, which is estimated using
data from the ElA's State Energy Data System (SEDS) [ref 7], The SEDS MSN Code AVTCP is used to identify the
total consumption of aviation gasoline in units of thousand barrels. Data are then converted to units of gallons.
ACs=ACBsxA23a"°nybarrel PI
Where:
AGs = Annual consumption of AvGas for state s, in gallons
AGBS = Annual consumption of AvGas for state s, in barrels
18.3.2 Allocation procedure
Bulk Terminals
Emissions from bulk terminals are calculated by growing the 1998 emissions estimates developed in support of
the Gasoline MACT standard [ref 2], The national-level emissions are allocated to the states based on the
fraction of refinery, bulk terminal, and natural gas plant stocks in each state [ref 19]. The state-level emissions
are distributed to the counties based on employment in NAICS 42471 [ref 10].
Pipelines
Emissions from pipelines are calculated by growing the 1998 emissions estimates developed in support of the
Gasoline MACT standard [ref 2], The national-level emissions are allocated to the PAD Districts based on data on
the movement of finished motor gasoline by pipeline between PAD Districts from the EIA [ref 21]. The emissions
in each PAD District are distributed to the counties based on employment in NAICS 42471 [ref 10].
Bulk Plants
The national volume of bulk plant gasoline throughput is allocated to counties using County Business Patterns
employment data for NAICS code 42471 (Petroleum Bulk Stations and Terminals) [ref 10]. The number of
petroleum bulk stations and terminals employees is first summed to the national level.
(8)
Empus = ^ Empc
Where:
Empus = Number of petroleum bulk stations and terminals employees in the U.S.
Empc = Number of petroleum bulk stations and terminals employees in county c
The fraction of petroleum bulk stations and terminals employees by county is calculated by dividing the total
18-8
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number of petroleum bulk stations and terminals employees in each county by the total number of petroleum
bulk stations and terminals employees in the U.S.
EmpFracc =
Empc
Emp
(9)
us
Where:
EmpFracc = Total fraction of petroleum bulk stations and terminals employees in county c
Empc = Number of petroleum bulk stations and terminals employees in county c
Empus = Number of petroleum bulk stations and terminals employees in the U.S.
The county-level volume of bulk plant gasoline throughput is calculated by multiplying the fraction of petroleum
bulk stations and terminals employees in each county by the national volume of bulk plant gasoline throughput.
GTc bp = GTus bp x EmpFracc
(10)
Where:
GTc,bP = Bulk plant gasoline throughput in county c, in thousand barrels
GTus,bP = Bulk plant gasoline throughput in the U.S., in thousand barrels, from equation 1
EmpFracc = Total fraction of petroleum bulk stations and terminals employees in county c
Employment data are obtained from the U.S. Census Bureau's County Business Patterns (CBP) [ref 10]. Due to
concerns with releasing confidential business information, the CBP does not release exact numbers for a given
North American Industrial Classification Standard (NAICS) code if the data can be traced to an individual
business. This is the case if a particular county has 2 or fewer establishments under a given NAICS code. In prior
years, the CBP data reported the counties where data was withheld, along with dataset ranges for the withheld
data (e.g., 20-99 employees). A gap-filling procedure was implemented using state-level data, which did not
feature withheld data, to estimate employment counts in all counties.
Beginning in 2018, the Census Bureau stopped reporting dataset ranges for counties with withheld data. As
such, the prior gap-filling methods required updating. For all post-2017 inventories, year-specific employment
data from the County Business Patterns dataset is used to determine the total amount of withheld data in each
state. The 2017 version of the County Business Patterns is then used to determine the counties for which
withheld data exist and the data ranges for those counties, and it is to these counties that the difference
between the state-level total employment and county-level total employment are allocated. To estimate
employment in counties and states with withheld data, the following procedure is used for NAICS code 42471.
To gap-fill withheld state-level employment data:
a. The 2017 version of CBP is used to determine the states for which data is withheld and the employment
size range in those states.
b. State-level data for states with known employment in NAICS 42471 are summed to the national level.
c. The total sum of state-level known employment from step b is subtracted from the national total
reported employment for NAICS 42471 in the national-level CBP to determine the employment total for
the withheld states.
d. Each of the withheld states is assigned the midpoint of the range code reported for that state. Table
18-3 lists the range codes and midpoints.
e. The midpoints for the states with withheld data are summed to the national level.
18-9
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f. An adjustment factor is created by dividing the number of withheld employees (calculated in step c of
this section) by the sum of the midpoints (step e).
g. For the states with withheld employment data, the midpoint of the range for that state (step d) is
multiplied by the adjustment factor (step f) to calculate the adjusted state-level employment for
landfills.
These same steps are then followed to fill in withheld data in the county-level business patterns.
h. The 2017 version of CBP is used to determine the counties for which data is withheld and the
employment size range in those counties.
i. County-level data for counties with known employment are summed by state.
j. County-level known employment is subtracted from the state total reported in state-level CBP (or, if the
state-level data are withheld, from the state total estimated using the procedure discussed above).
k. Each of the withheld counties is assigned the midpoint of the range code (Table 18-3).
I. The midpoints for the counties with withheld data are summed to the state level.
m. An adjustment factor is created by dividing the number of withheld employees (step i) by the sum of the
midpoints (step k).
n. For counties with withheld employment data, the midpoints (step j) are multiplied by the adjustment
factor (step I) to calculate the adjusted county-level employment for landfills.
Table 18-3: Ranges and midpoints for data withheld from state and county business patterns
Employment
Code
Ranges
Midpoint
A
0-19
10
B
20-99
60
C
100-249
175
E
250-499
375
F
500-999
750
G
1,000-2,499
1,750
H
2,500-4,999
3,750
1
5,000-9,999
7,500
J
10,000-
24,999
17,500
K
25,000-
49,999
37,500
L
50,000-
99,999
75,000
M
100,000+
Tank Trucks in Transit. Underground Storage Tank (UST) Breathing and Storing, and Gasoline Service Station
Unloading
The activity data for these sources is available at the county-level; therefore, county allocation is not needed.
Aviation Gasoline Distribution Stage 1 and 2
State-level gasoline consumption (from equation 7) is allocated to the county-level using the ratio of county-to-
state-level LTOs. State and county LTO data were compiled by the U.S. EPA's Office of Air Quality, Planning and
Standards (OAQPS) [ref 11],
18-10
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Where:
LTOc
RLTOc =
c LTO<
(11)
RLTOc = The ratio of landing-take offs (LTOs) in county c
LTOc = The number of LTOs in county c
LTOs = The number of LTOs in state s
LTO data for turbine-powered airplanes were excluded because turbine-powered planes do not use aviation
gasoline. Additionally, LTOs at airports that do not have aviation gasoline refueling, according to data from FAA
Form 5010, were also excluded [ref 12].
The state-level gasoline consumption values from equation 7 are multiplied by the proportion of LTOs in each
county to estimate the county-level amount of aviation gasoline consumed.
AGC = AGS X RLTOc (12)
Where:
AGC = Annual consumption of AvGas in county c, in gallons
RLTOc = The ratio of landing-take offs (LTOs) in county c
18.3.3 Emission factors
CAP emission factors for all SCCs are provided in the "Wagon Wheel Emission Factor Compendium" on the 2020
NEI Supporting Data and Summaries site. The sources for these emissions factors, and locations of where to
obtain factors to compute HAPs are discussed below.
Bulk Terminals
Emissions from bulk terminals are calculated by growing the 1998 emissions estimates developed in support of
the Gasoline MACT standard. Therefore, there are no activity-based emissions factors for bulk terminals.
HAP emissions are estimated using speciation profiles that are available on the NEI Supporting Data and
Summaries webpage by clicking on "EIS Augmentation Datasets" and selecting the HAP Augmentation Profile file
for nonpoint.
Pipelines
Emissions from pipelines are calculated by growing the 1998 emissions estimates developed in support of the
Gasoline MACT standard. Therefore, there are no activity-based emissions factors for pipelines. HAP emissions
are estimated using speciation profiles available on the NEI Supporting Data and Summaries webpage by clicking
on "EIS Augmentation Datasets" and selecting the HAP Augmentation Profile file for nonpoint.
Bulk Plants
The VOC emissions factor for bulk plants is 8.62 pounds of VOC per 1,000 gallons of gasoline [ref 13], HAP
emissions are available on the NEI Supporting Data and Summaries webpage by clicking on "EIS Augmentation
Datasets" and selecting the HAP Augmentation Profile file for nonpoint. Speciation profiles for benzene
emissions from bulk plants are based on county-specific refueling emissions data from MOVES [ref 8],
18-11
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Tank Trucks in Transit
The VOC emission factor is the sum of the individual emission factors reported in the Gasoline Distribution EIIP
guidance document for gasoline-filled trucks (traveling to service station/bulk plant for delivery) and vapor-filled
trucks (traveling to bulk terminal/plant for reloading) [ref 3],
HAP emissions are calculated using speciation profiles available on the NEI Supporting Data and Summaries
webpage by clicking on "EIS Augmentation Datasets" and selecting the HAP Augmentation Profile file for
nonpoint. Speciation profiles for benzene emissions from bulk plants are based on county-specific refueling
emissions data from MOVES.
Underground Storage Tank (UST) Breathing and Storing
The VOC emissions factor for underground storage tank breathing and storing is 1 pound per 1,000 gallons. The
VOC emissions factor for underground storage tank breathing and storing is recommended by the Gasoline
Distribution EIIP guidance document [ref 3],
HAP emissions are calculated using speciation profiles available on the NEI Supporting Data and Summaries
webpage by clicking on "EIS Augmentation Datasets" and selecting the HAP Augmentation Profile file for
nonpoint. Speciation profiles for benzene emissions from bulk plants are based on county-specific refueling
emissions data from MOVES.
Gasoline Service Station Unloading
To calculate the VOC emissions factor for gasoline service station unloading, first calculate the true vapor
pressure for each county and month using the following equation and data from MOVES [ref 8]:
Geographic-specific information on the temperature of gasoline and the method of loading were obtained from
a Stage I and II gasoline emission inventory study prepared for the EIIP.
The true vapor pressure is calculated using the following equation:
¦,m,f = | 0.7553 - ^
+
413
Tc.m + 459.6
S°-5log10(RVPCimJ)
1.854
1042
2416
Tc.m + 459.6
2.013
logio (RVPc mj) ¦
8742
Tc.m + 459.6
:o.5
(13)
Tc.m + 459.6
+ 15.64
Where:
Pc,m,f = Stock true vapor pressure for county c in month m for fuel subtype/, in pounds per square
inch absolute
TC/m = Stock temperature for county c in month m, in degrees Fahrenheit
RVPc,m,f = Reid vapor pressure for county c in month m for fuel subtype/, in pounds per square inch
5 = Slope of the ASTM distillation curve at 10 percent evaporated, in degrees Fahrenheit per
percent (assumed that S=3.0 for gasoline per Figure 7.1-14a of AP-42) [ref 13]
The following equation is used to calculate the VOC emissions factor for gasoline service station unloading:
LCimJ = 12.46 x Sft x PCimJ x M/T (14)
Where:
18-12
-------
Lc,m,f = Uncontrolled loading loss of liquid loaded, in pounds per thousand gallons
Sft = Saturation factor for filling technology ft
Pc,m,f = True vapor pressure of liquid loaded, in pounds per square inch absolute
M = Molecular weight of vapors, in pounds per pound per mole
T = Temperature of liquid loaded (Rankine) [ref 13]
HAP emissions are calculated using speciation profiles available on the NEI Supporting Data and Summaries
webpage by clicking on "EIS Augmentation Datasets" and selecting the HAP Augmentation Profile file for
nonpoint. Speciation profiles for benzene emissions from bulk plants are based on county-specific refueling
emissions data from MOVES.
Aviation Gasoline Distribution Stage 1
CAP emission factors for stage 1 aviation gasoline distribution are provided in the "Wagon Wheel Emission
Factor Compendium" on the 2020 NEI Supporting Data and Summaries site. The emissions factors for fugitive
and non-fugitive VOC are taken from the TRC report Estimation of Alkylated Lead Emissions, Final Report [ref 4],
The emissions factors for the HAPs are taken from multiple sources: the TRC report; the EPA report Locating and
Estimating Air Emissions from Source of Ethylene Dichloride [ref 14]; a memorandum to EPA/OAQPS [ref 15], and
a personal email between EPA/OAQPS employees [ref 16]. HAP emission factors are available on the NEI
Supporting Data and Summaries webpage by clicking on "EIS Augmentation Datasets" and selecting the HAP
Augmentation Profile file for nonpoint.
Aviation Gasoline Distribution Stage 2
CAP emission factors for stage 2 of aviation gasoline distribution are provided in the "Wagon Wheel Emission
Factor Compendium" on the 2020 NEI Supporting Data and Summaries site. The emissions factors for VOC are
taken from the TRC report Estimation of Alkylated Lead Emissions, Final Report [ref 4]. The emissions factors for
the HAPs are taken from multiple sources: the TRC report; the EPA report Locating and Estimating Air Emissions
from Source of Ethylene Dichloride [ref 14]; a memorandum to EPA/OAQPS [ref 15]; and a personal email
between OAQPS employees [ref 16], HAP emission factors are available on the NEI Supporting Data and
Summaries webpage by clicking on "EIS Augmentation Datasets" and selecting the HAP Augmentation Profile file
for nonpoint.
18.3.4 Controls
There are county-level control efficiencies for service station unloading, including assumptions about the
percentage of gasoline unloaded under different filling technologies: splash, submerged, or balanced. There are
no controls assumed for all other sources.
18.3.5 Emissions
Bulk Terminals
Emissions of VOCs for bulk terminals and pipelines are calculated by multiplying 1998 national emissions
estimates developed in support of the Gasoline Distribution MACT standard (Table 18-4) by the 2020 to 1998
ratio of the national volume of wholesale gasoline supplied [ref 17, ref 18]. Emissions are converted from
megagrams (Mg) to tons.
£*2020 (1^)
Evoc,us,bt = Emact,us,m x 7 x 1-1023 tonper Mg
"1998
18-13
-------
Where:
Evoqusm = Annual national-level emissions of VOC from bulk terminals, in tons
Emact,usm = 1998 national VOC emission estimates developed for Gasoline Distribution MACT standard
from bulk terminals, in Mg
G20120 = National volume of wholesale gasoline supplied in 2020, in thousand barrels per day
G1998 = National volume of wholesale gasoline supplied in 1998, in thousand barrels per day
Table 18-4: 1998 Post-MACT Control Emissions
Emission Point
1998 Post-MACT Control Emissions (Mg)
Reference
Pipelines
79,830
2
Bulk Terminals
137,555
2
National VOC emissions are allocated to states using the fraction of refinery, bulk terminal, and natural gas plant
stocks of motor gasoline in each state [ref 19].
GasFracs = (16)
Mus
Where:
GasFraCs = Fraction of motor gasoline in state s
Ms = Amount of motor gasoline in state s
Mus = Amount of motor gasoline in the U.S.
The fraction of stocks of motor gasoline in each state is then used to distribute the VOC and HAP emissions.
Evoc,bt,s GasFracs x Evoc us bt (17)
Where:
Evoc,bt,s = Annual VOC emissions in state s from bulk terminals, in tons
GasFraCs = Fraction of motor gasoline in state s
Evoqusm = Annual national-level VOC emissions from bulk terminals, in tons
State-level VOC emissions are allocated to counties using the fraction of petroleum bulk stations and terminals
facilities employees in each county from the US Census County Business patterns data for NAICS code 42471 [ref
10].
EmpFracc =
Empc
Emps
(18)
Where:
EmpFracc = Fraction of petroleum bulk stations and terminals facilities employees in county c
Empc = Number of petroleum bulk stations and terminals facilities employees in county c
Emps = Number of petroleum bulk stations and terminals facilities employees in state s
18-14
-------
Due to concerns with releasing confidential business information, the CBP does not release exact numbers for a
given NAICS code if the data can be traced to an individual business. Instead, a series of range codes is used.
Many counties and some smaller states have only one petroleum bulk station and terminal facility, leading to
withheld data in the county and/or state business pattern data. To estimate employment in counties and states
with withheld data, the procedure discussed in Section is used for NAICS code 42471.
The fraction of petroleum bulk stations and terminals facilities employees in each county is then used to
distribute the VOC emissions.
Evoc.bt.c = EmpFracc X EV0CMiS (19)
Where:
Evoc,bt,c = Annual VOC emissions from bulk terminals in county c, in tons
EmpFracc = Fraction of petroleum bulk stations and terminals facilities employees in county c
Evoc,bt,s = Annual VOC emissions from bulk terminals in state s, in tons
Emissions of HAPs are calculated by multiplying emissions of VOCs by a national average speciation profile [ref
20],
Ep,c,bt Eyoc c bt X Sp (20)
Where:
EP,bt = Annual emissions of pollutant p in county c from bulk terminal, in tons
Evocm = Annual VOC emissions in county c from bulk terminals, in tons
Sp = Speciation profile of pollutant p, as a fraction of VOC emissions
Pipelines
Emissions of VOCs for pipelines are calculated by multiplying 1998 national estimates developed in support of
the Gasoline Distribution MACT standard (Table 18-4) by the 2020 to 1998 ratio of the national volume of
wholesale gasoline supplied [ref 17, ref 18]. Emissions are converted to tons.
G2020
Evoc,us,pi = Emact,us.,pi x x 1-1023 tonper Mg
"1998
(21)
Where:
Evoc,us,Pi = Annual national-level emissions of VOC from pipelines, in tons
Emact,us,pi = 1998 national VOC emission estimates developed for Gasoline Distribution MACT standard
from pipelines, in Mg
G2020 = National volume of wholesale gasoline supplied in 2020, in thousand barrels per day
G1998 = National volume of wholesale gasoline supplied in 1998, in thousand barrels per day
National VOC and HAP emissions are allocated to PAD Districts using the fraction of the total amount of finished
motor gasoline that originated in each PAD District in 2020. There are five PAD Districts across the United States.
PAD District 1 comprises seventeen states plus the District of Columbia along the Atlantic Coast; PAD District 2
comprises fifteen states in the Midwest; PAD District 3 comprises six states in South Central U.S.; PAD District 4
comprises five states in the Rocky Mountains; and PAD District 5 comprises seven states along the West Coast.
18-15
-------
These data are reported in Table 37 of Volume 1 of Petroleum Supply Annual [ref 21]. States in each PAD District
are shown in Table 18-5.
Mus
Where:
Mpd (22)
PADDFracpD = 1 '
PADDFracpo = Fraction of motor gasoline in PAD District PD
Mpd = Amount of finished motor gasoline in PAD District PD, in thousand barrels
Mus = Amount of finished motor gasoline in the U.S., in thousand barrels
Evoc,PD,pi PADDFraCpD X EVOc,us,pi (23)
Where:
Evoqpd,pi = Annual VOC emissions from pipelines in PAD District PD, in tons
PADDFracpo = Fraction of motor gasoline in PAD District PD
Evoc,us,Pi = Annual national-level VOC emissions of from pipelines, in tons
Pipeline emissions in each PAD District are allocated to counties based on County Business Patterns employment
data. Because employment data for NAICS code 48691 (Pipeline Transportation of Refined Petroleum Products)
are often withheld due to confidentiality reasons, the number of employees in NAICS code 42471 (Petroleum
Bulk Stations and Terminals) are used for this allocation. To better account for the location of refined petroleum
pipelines, however, no activity is allocated to States which had employees in this NAICS code but did not have
employees in NAICS code 48691 (i.e., District of Columbia, Idaho, Maine, New Hampshire, Vermont, and West
Virginia). To allocate pipeline emissions in each PAD District to counties, first the county level employment data
for NAICS code 42471 is summed to the PAD District.
EmpPD = I Empc
(24)
Where:
EmpPD = Number of petroleum bulk stations and terminals facilities employees in PAD District PD
Empc = Number of petroleum bulk stations and terminals facilities employees in county c
The fraction of petroleum bulk stations and terminals employees in each county is used to allocate the emissions
from the PAD District to counties.
Empc (25)
EmpFracc =
EmpPD
Where:
EmpFracc = Fraction of petroleum bulk stations and terminals facilities employees in county c
Empc = Number of petroleum bulk stations and terminals facilities employees in county c
EmpPD = Number of petroleum bulk stations and terminals facilities employees in PAD District PD
Due to concerns with releasing confidential business information, the CBP does not release exact numbers for a
18-16
-------
given NAICS code if the data can be traced to an individual business. Instead, a series of range codes is used.
Many counties and some smaller states have only one petroleum bulk station and terminal facility, leading to
withheld data in the county and/or state business pattern data. To estimate employment in counties and states
with withheld data, the procedure discussed in Section 18.3.2 is used for NAICS code 42471.
The fraction of petroleum bulk stations and terminals facilities employees in each county is then used to
distribute the VOC emissions.
Evoc,c,pi = EmpFracc X EVOc,pd,pI (26)
Where:
Evoc,c,pi = Annual VOC emissions from pipelines in county c, in tons
EmpFracc = Fraction of petroleum bulk stations and terminals facilities employees in county c
Evoqpd,pi = Annual VOC emissions from pipelines in PAD District PD, in tons
Emissions of HAPs are calculated by multiplying emissions of VOCs by a national average speciation profile [ref
13]. Total VOC emission estimates are used so emissions represent total emissions.
Ep,c,pl Eyoc,c,pl ^ ^p
(27)
Where:
Ep,c,pi = Annual emissions of pollutant p from pipelines in county c, in tons
Evoc,c,pi = Annual VOC emissions from pipelines in county c, in tons
Sp = Speciation profile of pollutant p, as a fraction of VOC emissions
Table 18-5: States by PAD District
PAD District 1
PAD District 2
PAD District 3
PAD District 4
PAD District 5
Connecticut
Illinois
Alabama
Colorado
Alaska
Delaware
Indiana
Arkansas
Idaho
Arizona
Florida
Iowa
Louisiana
Montana
California
Georgia
Kansas
Mississippi
Utah
Hawaii
Maine
Kentucky
New Mexico
Wyoming
Nevada
Maryland
Michigan
Texas
Oregon
Massachusetts
Minnesota
Washington
New Hampshire
Missouri
New Jersey
Nebraska
New York
North Dakota
North Carolina
Ohio
Pennsylvania
Oklahoma
Rhode Island
South Dakota
South Carolina
Tennessee
Vermont
Wisconsin
Virginia
18-17
-------
PAD District 1
PAD District 2
PAD District 3
PAD District 4
PAD District 5
West Virginia
Bulk Plants
VOC emissions from bulk plants are estimated by multiplying the VOC emission factor by county-level volume of
bulk plant gasoline throughput.
EVoc,c,bp = EFVOCibp/1000 gallons x GTc bp x 42 gallons per barrel (28)
Where:
Evoc,c,bP = Annual emissions of VOC from bulk plants in county c, in pounds
EFvoc,bp = Emissions factor for VOC from bulk plants, in pounds per 1,000 gallons
GTc,bP = Gasoline throughput for bulk plants in county c, in thousand barrels
Benzene emissions are estimated by multiplying VOC emissions by county-level speciation profiles from MOVES
[ref 8],
^BZ.c.bp EV0C,c,bp X $BZ,c (29)
Where:
EBz,c,bP = Annual emissions of benzene from bulk plants in county c, in pounds
Evoc,c,bP = Annual emissions of VOC from bulk plants in county c, in pounds
Sbz,c = Speciation profile for benzene for bulk plants in county c, as a fraction of VOC
All other HAPs emissions are estimated by multiplying VOC emissions by the national average speciation profiles.
Ep,c,bp Eyoc,c,bp ^ ^p,c (^^)
Where:
Ep,c,bp = Annual emissions of pollutant p from bulk plants in county c, in pounds
Evoc,c,bP = Annual emissions of VOC from bulk plants in county c, in pounds
Sp,c = Speciation profile for pollutant p for bulk plants in county c, as a fraction of VOC
Tank Trucks in Transit
VOC emissions from tank trucks in transit are calculated by multiplying county-level total gasoline consumption
by the VOC emission factor for tank trucks in transit.
F - FF GC^ (31)
bvoc,c,tt ~ ttvoc,tt X ioo() gaUons
Where:
Evoc,c,tt = Annual emissions of VOC from tank trucks in transit in county c, in pounds
18-18
-------
EFvoc,tt = Emissions factor for VOC from tank trucks in transit, in pounds per 1,000 gallons
GCc,t = Gasoline consumption for tank trucks in transit in county c, gallons
Benzene emissions are estimated by multiplying VOC emissions by county-level speciation profiles from MOVES.
EBZ.c.tt EVOc,c,tt x $bz,c (32)
Where:
Ebz,c,u = Annual emissions of benzene from tank trucks in transit in county c, in pounds
Evoc,c,tt = Annual emissions of VOC from tank trucks in transit in county c, in pounds
Sbz,c = Speciation profile for benzene for tank trucks in transit in county c, as a fraction of VOC
All other HAPs emissions are estimated by multiplying VOC emissions by the national average speciation profiles.
Ep,C,tt EyoC,c,tt X Sp,c (33)
Where:
EP,c,tt = Annual emissions of pollutant p from tank trucks in transit in county c, in pounds
Evoc,c,tt = Annual emissions of VOC from tank trucks in transit in county c, in pounds
Sp,c = Speciation profile for pollutant p for tank trucks in transit in county c, as a fraction of VOC
Underground Storage Tank (UST) Breathing and Storing
VOC emissions from UST breathing and storing are calculated by multiplying county-level total gasoline
consumption by the VOC emission factor for UST breathing and storing.
F - FF GC^ O4)
Evoc,c,ust htvoc,ust x 1000 gaiions
Where:
Evoc,c,ust = Annual emissions of VOC from UST breathing and storing in county c, in pounds
EFvoc,ust = Emissions factor for VOC from UST breathing and storing, in pounds per 1,000 gallons
GCc,t = Gasoline consumption for UST breathing and storing in county c, in gallons
Benzene emissions are estimated by multiplying VOC emissions by county-level speciation profiles from MOVES.
EBZ,c,ust EyoQ c ust X SfiZ c (35)
Where:
Ebz.c.usi = Annual emissions of benzene from UST breathing and storing in county c, in pounds
Evoc,c,ust = Annual emissions of VOC from UST breathing and storing in county c, in pounds
Sbz,c = Speciation profile for benzene for UST breathing and storing in county c, as a fraction of VOC
All other HAPs emissions are estimated by multiplying VOC emissions by the national average speciation profiles.
18-19
-------
F
±-,p,c,ust
EvOC,c,ust ^ Sp,c
(36)
Where:
EP,c,ust = Annual emissions of pollutant p from UST breathing and storing in county c, in pounds
Evoc,c,ust = Annual emissions of VOC from UST breathing and storing in county c, in pounds
Sp,c = Speciation profile for pollutant p for UST breathing and storing in county c, as a fraction of
VOC
Gasoline Service Station Unloading
County-level uncontrolled loading loss of liquid loaded VOC emissions are calculated by multiplying the loading
loss calculated in equation 9 by the total gasoline consumption in each county for each filling technology.
_ (37)
tvoc,c,m,f,ft,ll 1000 gallons X Km,r
Where:
Evoc,c,m,f,ft,n = VOC emissions from loading loss in county cfor month m for filling technology ft and fuel
subtype/, in pounds
GCc,ft,m,f = Total gasoline consumption in county cfor month m for filling technology ft and fuel subtype
f in gallons
Lc,m,f = Uncontrolled loading loss of liquid loaded for county cfor month m and fuel subtype/, in
pounds per thousand gallons
County-level controlled VOC emissions are calculated by multiplying loading loss VOC emissions by a county-
level control efficiency. Emissions are divided by 100 to convert the control efficiency from a percentage.
EvOC,c,m.flftlct EvoC.c.mJJtJl CEc/100 (38)
Where:
Evoc,c,m,fjt,ct = Controlled VOC emissions in county cfor month m for filling technology ft and fuel subtype
/ in pounds
Evoc,c,m,f,ft,n = VOC emissions from loading loss in county c month m for filling technology ft and fuel
subtype/ in pounds
CEc = Control efficiency value for county c, as a percentage
County-level monthly VOC emissions by fuel subtype and filling technology are calculated by subtracting
controlled VOC emissions from VOC emissions from loading loss.
EvOC,c,m,f,ft EvoC,c,m,f,ft,ll EVOC,c,m.f,ft,ct (39)
Where:
Evoc,c,m,f,ft = VOC emissions in from gasoline service station unloading county cfor month m for filling
technology ft and fuel subtype/ in pounds
Evoc,c,m,fjt,ct = Controlled VOC emissions in county cfor month m for filling technology ft and fuel subtype
18-20
-------
/, in pounds
Evoc,c,m,f,ft,n = VOC emissions from loading loss in county c month m for filling technology ft and fuel
subtype/, in pounds
County-level total VOC emissions by filling technology are calculated by summing VOC emissions for each month
and fuel subtype.
r - V F (40)
JVOC,c,ft / cVOC,c,m,f,ft
Where:
Evoc,c,ft = Annual VOC emissions in from filling type ft for gasoline service station unloading for
county c, in pounds
Evoc,c,m,f,ft = VOC emissions in from gasoline service station unloading county cfor month m for filling
technology ft and fuel subtype/, in pounds
Benzene emissions are estimated by multiplying VOC emissions by county-level speciation profiles from MOVES.
EbZ,c,ssu ~ E\/OC,c,ssu * $BZ,c (41)
Where:
Ebz,c,ssu = Annual emissions of benzene from gasoline service station unloading in county c, in pounds
Evoc,c,ssu = Annual emissions of VOC from gasoline service station unloading in county c, in pounds
Sbz,c = Speciation profile for benzene for gasoline service station unloading in county c, as a fraction
of VOC
All other HAPs emissions are estimated by multiplying VOC emissions by the national average speciation profiles.
Ep,c,ust EvoC,c,ust ^ Sp,c (42)
Where:
EP,c,ssu = Annual emissions of pollutant p from gasoline service station unloading in county c, in pounds
Evoc,c,ssu = Annual emissions of VOC from gasoline service station unloading in county c, in pounds
Sp,c = Speciation profile for pollutant p for gasoline service station unloading in county c, as a
fraction of VOC
Aviation Gasoline Distribution Stage 1
The annual aviation gasoline consumed in each county is used with the emissions factors located in the "Wagon
Wheel Emission Factor Compendium" on the 2020 NEI Supporting Data and Summaries site to estimate
emissions. Emissions of non-fugitive VOC from multiple sources, including tank truck filling and storage tank
breathing, are estimated by multiplying gasoline consumed by the emissions. For VOC, emissions are multiplied
by a conversion factor to convert from tons to pounds.
NFEr c = AGC X EFV0Cir -h 2000 lbs/ton (43)
18-21
-------
Where:
NFEr,c = Annual non-fugitive VOC emissions for source r in county c, in tons per year
EFvoc,r = VOC emission factor for source r, units vary based on pollutant.
Fugitive VOC emissions from valves and pumps are estimated by multiplying gasoline consumed by the
emissions factor. Assumptions concerning bulk terminals used in these calculations can be found in Table 18-6.
Table 18-6: Assumptions for Bulk Terminals Using Aviation Gasoline
Parameter
Data
Reference
Number of Bulk Plant Equivalents (U.S.)
2,442 plants
Number of valves per bulk plant
50 valves/plant
4, Table 2-
8
Number of pumps per bulk plant
2 pumps/plant
Number of seals per bulk plant
4 seals/pump
Number of days per year used
300 days
VFEC = BPE X V X EFV0Cr
xDx LT°C!
LTO
us
PFEC = BPE x P x S x EFV0C r
xDx LTOc/
^ 2000lbs/ton
LTOus 2000 lbs/ton
(44)
(45)
Where:
PFEC = Annual fugitive VOC emissions from valves in county c, in tons
VFEC = Annual fugitive VOC emissions from pumps in county c, in tons
BPE = Number of bulk plant equivalents in the U.S.
V = Number of valves per plant in the U.S.
P = Number of pumps per plant in the U.S.
S = Number of seals per plant in the U.S.
D = Number of days used per year
LTOc = The number of LTOs in county c
LTOus = The number of LTOs in the United States
Total Annual VOC emissions in each county are estimated by summing the fugitive emissions (from equations 35
and 36) and all sources of non-fugitive emissions (from equation 34).
Voc,c ^
NFEC + PFEC + VFEC
(46)
Where:
Evocc
Annual VOC emissions in county c, in tons
Emissions of all HAPs, except ethylene dichloride, are estimated by applying speciation factors to the annual
VOC emissions. For HAPs, no conversion factor is needed, and the emissions are reported in tons.
E-h.c E-VOC.c X SFfi
(47)
Where:
18-22
-------
Eh,c
SFh
= Annual emissions of HAP h in county c, in tons per year
= Speciation factor for HAP h, in tons of HAP emissions per ton of VOC emissions
Ethylene dichloride emissions are calculated by multiplying the gasoline consumed in each county (from
equation 33) by the emission factor. For ethylene dichloride, emissions are multiplied by a conversion factor to
convert from to pounds tons.
Ee>c = AGC X EFe X 0.0005 tons/lb (48)
Where:
Ee,c = Annual emissions of ethylene dichloride in county c, in tons
EFe = Emission factor for ethylene dichloride, in lbs. of ethylene dichloride per gallon of AvGas
Aviation Gasoline Distribution Stage 2
The annual aviation gasoline consumed in each county is used with the emissions factors to estimate emissions.
Emissions of VOC are estimated by multiplying gasoline consumed by the emissions factor. For VOC, emissions
are multiplied by a conversion factor to convert from tons to pounds.
Evoc.c = AGc X EFV0C X 0.0005 tons/lb (49)
Where:
Evoqc = Annual VOC emissions in county c, in tons
AGC = Annual consumption of AvGas in county c, in gallons
EFvoc = VOC emission factor, in tons of VOC per gallon of AvGas
Emissions of all HAPs, except ethylene dichloride and lead, are estimated by applying speciation factors to the
annual VOC emissions. For HAPs, no conversion factor is needed, and the emissions are reported in tons.
Eh,c = EVOc,c x SFh (50)
Where:
Eh,c = Annual emissions of HAP h in county c, in tons per year
Evoqc = Annual VOC emissions in county c, in tons
SFh = Speciation factor for HAP h, in tons of HAP emissions per ton of VOC emissions
Ethylene dichloride and lead emissions are calculated by multiplying the gasoline consumed (from equation 12)
by the emission factor. For lead and ethylene dichloride, emissions are multiplied by a conversion factor to
convert from pounds to tons.
EViC = AGC X EFV X 0.0005 tons/lb (51)
Where:
fp,c = Annual emissions of pollutant p in county c, in tons
EFP = Emission factor for pollutant p, in lbs. of pollutant per gallon of AvGas
18-23
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18.3.6 Point Source Subtraction
There are no point source-specific SCCs for stage 1 and stage 2 aviation gasoline distribution; therefore, point
source subtraction is not performed for these sources. However, some stage I gasoline emissions are reported in
the point source inventory. To avoid double counting of emissions, point source emissions are subtracted from
the total emissions from each source category to estimate the nonpoint emissions from each source category.
Point source emissions are mapped to nonpoint source SCCs using the "Gas Distribution" crosswalk in the file
"NEI PT-NP Crosswalk_complete_WagonWheel_August2021.xlsx" available on the 2020 NEI Supplemental
nonpoint data FTP site.
The point source emissions table is also provided as an input template and for 2020, EPA created a "default" set
of point source emission, populating this table with information directly from the 2020 S/L/T Point inventory
submittals. S/L/T agencies could replace these default submittals, and those that did are listed in Section 6.2.2.
A1P EpC/scC Epc,SCC P Epc,SCC (^2)
Where:
NPEP/C,scc = Annual nonpoint source emissions of pollutant p from each SCC in county c
EP,c,scc = Annual total emissions of pollutant p from each SCC in county c
PEP,c,scc = Annual total point source emissions of pollutant p from each SCC in county c
18.3.7 Example calculations
The tables below show sample calculations for estimating VOC for stage I gasoline distribution. The values in
these equations are demonstrating program logic and are not representative of any specific NEI year or county.
Bulk Terminals
The values in these equations are demonstrating program logic and are not representative of any specific NEI
year or county.
Table 18-7: Sample calculations for VOC emissions from Stage 1 Gasoline Distri
Dution - Bulk Terminals
Eq.#
Equation
Values
Result
15
Evoc,us,bt
^ w ^2020
^MACT,US,bt X r
"1998
x 1.1023 ton per Mg
137555 Mg
9327thousand barrels per day
8253 thousand barrels per day
x 1.1023 tonper Mg
171359 tons VOC
emissions in the US
16
Ms
GasFraCt. =
Mus
205 thousand barrels
16798 thousand barrels
.0052
17
Evoc,bt,s GasFracs
x Evoc,us,bt
.0052 x 171359 tons
891.1 tons VOC
emissions in state
18
r Z7 EmPc
EmpFracr =
Emps
6.54 employees
732 employees
.0089
19
Evoc.bt.c = EmpFracc
x EVOc,bt,s
. 0089 x 891.1 tons
7.93 tons VOC
emissions
18-24
-------
Pipelines
The values in these equations are demonstrating program logic and are not representative of any specific NEI
year or county.
Table 18-8: Sample calculations for VOC emissions from Stage I Gasoline Distribution - Pipelines
Eq.#
Equation
Values
Result
21
Evoc,us,pi
^ w ^2020
^MACT,US.,pl X r
"1998
x 1.1023 tonper Mg
137555 Mg
9327 thousand barrels per day
8253 thousand barrels per day
x 1.1023 tonper Mg
171359 tons VOC
emissions in the US
22
Mpo
PADDFracpr, =
Mus
3,856 thousand barrels in district
119,634 gasoline in US
0.32
23
Evoc,PD,pi
= PADDFracPO
x Evoc,us,pi
0.32 x 171359 tons
5,523 tons VOC
emissions in district
24
EmpPD = ^ Empc
2>Pc
10641 employees in
district
25
r, r EmPc
EmpFracr =
EmpPD
6.54 employees
10641 employees
.00061
26
Evoc,c,pi
= EmpFracc x EV0CiPDiPi
. 00061 x 5,523 tons
3.37 tons VOC
emissions
Bulk Plants
The values in these equations are demonstrating program logic and are not representative of any specific NEI
year or county.
Table 18-9: Sample calculations ¦
or VOC emissions from Stage 1 Gasoline Distribution - Bulk Plants
Eq.#
Equation
Values
Result
1
= VlJS X
3404186 thousand barrels x 0.09
306377 thousand
barrels
8
Empus = ^ Empc
73908 employees in
the US
9
r, r EmPc
EmpFracr =
Empus
6.54 employees
73908 employees
.000089
10
GTC = GTUS x EmpFracc
306377 thousand barrels x .000089
27.11 thousand barrels
18-25
-------
Eq.#
Equation
Values
Result
28
Evoc,c,bp
EFVoc,bV w
1000 gallon
x 42 gallons per Mbbl
8.62 pounds per 1,000 gallons
h- 1000 gallons
x 27.11 thousand barrels
x 42 gallons per Mbbl
9.8 pounds VOC
emissions
Tank Trucks in Transit
The values in these equations are demonstrating program logic and are not representative of any specific NEI
year or county.
Table 18-10: Sample calculations for VOC emissions from Stage I Gasoline Distribution - Tank Trucks in Transit
Eq.#
Equation
Values
Result
2
GCoR,c GCoR,m
GCoR,m
44,007,116.5 gallons of
onroad gasoline
consumed
3
GCNr,c = ^ GCNRm
G^NR,m
913,078.6 gallons of
nonroad gasoline
consumed
4
GCc,t = (fiC0Rc
+ gcnr,c)
x 1.09
(44,007,116.5 gallons
+ 913,078.6 gallons')
x 1.09
48,963,012.6 gallons of
gasoline consumed
31
Evoc,c,tt
= (EFV0C tt X GCc t)
/1000 gallons
(. 06 pounds per 1000 gallons
x 48,963,012.6 gallons)
/1000 gallons
2937.7 pounds VOC
emissions
Underground Storage Tank (UST) Breathing and Storing
The values in these equations are demonstrating program logic and are not representative of any specific NEI
year or county.
Table 18-11: Sample calculations for VOC emissions from Stage I Gasoline Distribution - Underground Storage
Tank (UST) Breathing and Storing
Eq.#
Equation
Values
Result
2
GCoR,c GCoR,m
GCoR,m
44,007,116.5 gallons of
onroad gasoline
consumed
3
GCNr,c = ^ GCNRm
913,078.6 gallons of
nonroad gasoline
consumed
18-26
-------
Eq.#
Equation
Values
Result
4
GCc,t = (fiC0Rc
+ gcnr,c)
x 1.09
(4,4007,116.5 gallons
+ 913,078.6 gallons')
x 1.09
48,963,012.6 gallons of
gasoline consumed
34
EvOC,c,ust
{EFvoc.ust x GCc,t)
/1000 gallons
(1 pound per 1000 gallons
x 48,963,012.62 gallons)
/1000 gallons
48,963 pounds VOC
emissions
Gasoline Service Station Unloading
These sample calculations use splash filling as an example, and the equations use fuel subtype 10 and January as
an example. These calculations would need to be repeated using every month and both fuel subtypes to
calculate values for each filling technology (splash, submerged, and balance). The values in these equations are
demonstrating program logic and are not representative of any specific NEI year or county.
Table 18-12: Sample calculations for VOC emissions from Stage I Gasoline Distribution - Gasoline Service Station
Unloading
Eq.
#
Equation
Values
Result
GCc.t.m.f (GCc OR.mJ GCc,NR,m,f) 1-09
(1,650,266.8 gallons
+ 11,985.2 gallons') x 1.09
18,111,854.7
gallons
18,111,854.7 gallons
x 0 % splash filling
0 gallons
splash filling
13
c,m,f
¦{
0.7553
413
Tc.m + 459.6
1042
Tc.m + 459.6
S°-5log10(RVPCimJ)-
so.s
0.7553
413
1.854
+
2416
Trm + 459.6
+
60 + 459.6
1042
60 + 459.6
2416
60 + 459.6
3 loglo(10.61)
3°.5
1.854
5.54 pounds
per square
inch
absolute
- 2.013
+ 15.64
logio (RVPcmf) -
8742
Tc.m + 459.6
- 2.013
+ 15.64
loglo(10.61)
8742
60 + 459.6
14
Lc,m,f 12.46 X Sft X PClm,f x M/T
12.46 x 1.45 saturation factor
x 5.54 pounds per square inch absolute
65.5 pounds per pound per mole
x ¦
12.61
pounds per
1000 gallons
520 Rankine
18-27
-------
Eq.
#
Equation
Values
Result
35
G ^c ,ft
EVOC,c,m,f,ft,ll ~ 1000 gallons X LCimJ
0 gallons splash filling
1000 gallons
x 12.61 pounds per 1000 gallons
0 pounds
VOC
emissions
from
uncontrolled
loading loss
in January
for fueling
subtype 10
for splash
filling
36
EvOC,c,m.flftlct Evoc.c.m.f.ft.ll ^ CEc/100
0 pounds x 0 control efficiency/100
0 pounds
controlled
VOC
emissions in
January for
fueling
subtype 10
for splash
filling
37
EvOC,c,m,f,ft EvoC,c,m,f,ft,ll EVOC,c,m.f,ft,ct
0 pounds 0 pounds
0 pounds
total VOC
emissions in
January for
fueling
subtype 10
for splash
filling
38
EyOC,c,ft = ^ £VoC,c,m,/,/t
EvOC,c,m,f,ft
0 pounds
total VOC
emissions
for splash
filling
Aviation Gasoline Distribution Stage 1
Table 18-13 lists sample calculations to determine the VOC emissions from stage 1 aviation gasoline distribution.
The values in these equations are demonstrating program logic and are not representative of any specific NEI
year or county.
18-28
-------
Table 18-13: Sample Calculations for VOC emissions from Aviation Gasoline Distribution - Stage 1
Eq.#
Equation
Values
Result
7
AGS
= AGBS
gallons/
'barrel
57,000 barrels x 42 9aU°nS/barrei
2,394,000 gallons of
AvGas consumed in the
state
11
LTOc
RLTOc = £
c LTOs
3,064 LTOs in county
689,947 LTOs inAL
0.00444 fraction of LTOs
12
A Gc A Gs x RLTOc
2,394,000 gal AvGas in Al x 4.44
x 10 ~3 fraction
10,633 gallons of AvGas
consumed
43
NFEr c = AGC x EFV0C r -r-
2000 lbs/ton
10,633 gal AvGas in county x 9.02
x 10~3lbs. VOC per gal AvGas
2000 lbs/ton
0.048 tons VOC emissions
from tank filling
10,633 gal AvGas in county x 3.61
x 10~3lbs. VOC per gal AvGas
2000 lbs/ton
0.0192 tons VOC
emissions from storage
tank working
10,633 gal AvGas in county x 1.03
x 10~2lbs. VOC per gal AvGas
2000 lbs/ton
0.0548 tons VOC
emissions from composite
10,633 gal AvGas in county x 1.69
x 10~3lbs. VOC per gal AvGas
2000 lbs/ton
0.00901 tons VOC
emissions from breathing
losses
44
VFEC = BPE xFx
EFVoc r * D X
LTOc /
/LTOus ¦
2000lbs/ton
2,442 plants in US x
cn valves/ v
bU /plantx
0.573 lbs. per valve per day x
300 days x 3'°64/28,353,661 H"
2000 lbs/ton
1.13 tons fugitive VOC
emissions from valves
45
PFEC = BPE x P xS x
EFVoc r * D x
LTOc /
/Lrous
2000 lbs/ton
2,442 plants in US x
pumps, m seals/ x
z /plant X4 /pump x
5.95 Z&s. per seaZ per day x
300 days x 3l064/28,353,661 H"
2000 lbs/ton
1.89 tons fugitive VOC
emissions from pumps
46
Evoc.c = ^ NFEc + PFEC
r
+ VFEC
0.131 tons + 1.13 tons + 1.89 tons
3.15 total annual tons
VOC emissions from
AvGas distribution
Aviation Gasoline Distribution Stage 2
Table 18-14 lists sample calculations to determine the VOC, lead, and ethylene dichloride emissions from stage 2
aviation gasoline distribution in an example county. The values in these equations are demonstrating program
logic and are not representative of any specific NEI year or county.
18-29
-------
Table 18-14: Sample Calculations for VOC emissions from Aviation Gasoline Distribution - Stage 2
Eq.#
Equation
Values
Result
7
AGS
= AGBS
gallons/
'barrel
57,000 barrels x 42 9aU°nS/barrei
2,394,000 gallons of
AvGas consumed in
the state
11
LTOc
RLTOc = £
c LTOs
3,064 LTOs in county
689,947 LTOs in state
0.00444 fraction of
LTOs
12
A Gc A Gs x RLTOc
2,394,000 gal AvGas in state x 4.44
x 10 ~3 fraction
10,633 gallons of
AvGas consumed
49
Evoc.c = AGC X EFVC)c x
0.0005 tons/lb
10,633 gal of AvGas in county x
0.0136 lbs. VOC per gal x 0.0005 tons/lb
0.0723 tons VOC
emissions from AvGas
distribution
18.3.8 Improvements/Changes in the 2020 NEI
There are no significant changes to the methodology used to calculate emissions from aviation gasoline
distribution. Activity data was updated to reflect the most recent, best available data at the time of the NEI.
For stage 1 gasoline distribution, the methodology used to calculate county-level gasoline consumption for tank
trucks in transit and gasoline service station unloading was updated. For the 2017 NEI, national-level motor
gasoline consumption reported by EIA was allocated to onroad and nonroad consumption and then to the
county-level using MOVES data on C02 emissions. For the 2020 NEI, state-level data on total motor gasoline
consumption reported by SEDS is allocated using C02 emissions from MOVES to onroad and nonroad
consumption and then to the county-level. This methodology is explained in more detail in section 18.3.1.
For prior inventory years, the U.S. Census Bureau denoted counties for which County Business Patterns (CBP)
data was withheld and reported an employment size range. A gap-filling procedure was implemented using
state-level data, which was used to estimate the number of employees not reported in the county-level dataset.
An average value for number of employees for each employment size range was used to allocate the difference
to the counties with withheld data. Beginning in reference year 2018, data are still only published for a county
and NAICS code if there are three or more establishments. However, the CBP data no longer includes an
employment size range for counties in which data is withheld for a NAICS code. For the 2020 NEI, the gap-filling
method was updated. 2020 employment data from the CBP dataset is used to determine the total amount of
withheld data in each state. The 2017 version of the CBP is then used to determine the counties for which data
is withheld and the employment size range in those counties. The difference between the state-level total
employment and the county-level total employment is allocated to the counties identified using 2017 CBP.
18.3.9 Puerto Rico and U.S. Virgin Islands
Since insufficient data exists to calculate emissions for the counties in Puerto Rico and the US Virgin Islands,
emissions are based on two proxy counties in Florida: 12011, Broward County for Puerto Rico and 12087,
Monroe County for the US Virgin Islands. The total emissions in pounds for these two Florida counties are
divided by their respective populations creating a pound per capita emission factor. For each Puerto Rico and US
Virgin Island County, the pound per capita emission factor is multiplied by the county population (from the same
year as the inventory's activity data) which serves as the activity data. In these cases, the throughput (activity
data) unit and the emissions denominator unit are "EACH".
18-30
-------
18.4 References
1. U.S. Environmental Protection Agency, "National Emission Standards for Source Categories: Gasoline
Distribution (Stage I), 40 CFR Part 63." Office of Air Quality Planning and Standards, February 28, 1997.
Pages 9087-9093.
2. U.S. Environmental Protection Agency, "Gasoline Distribution Industry (Stage I) - Background
Information for Proposed Standards," EPA-453/R94-002a, Office of Air Quality Planning and Standards,
January 1994.
3. Eastern Research Group, Inc., "Volume III: Chapter 11, Gasoline Marketing (Stage I and Stage II), Revised
Final," prepared for the Emission Inventory Improvement Program, January 2001.
4. TRC Environmental Corporation. 1993. Estimation of Alkylated Lead Emissions, Final Report. Prepared
for the U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards. RTP, NC.
5. U.S. Department of Energy, Energy Information Administration, Petroleum Navigator - Product
Supplied.
6. Cavalier, Julia, MACTEC, Inc., personal communication, "RE: Percentage of Gasoline Transported Twice
By Truck," with Stephen Shedd, U.S. Environmental Protection Agency, Office of Air Quality Planning and
Standards, Emission Standards Division, July 6, 2004.
7. Energy Information Administration. 2022. State Energy Data System (SEDS): 1960-2020 (complete).
Consumption in Physical Units. U.S. Department of Energy. Washington, D.C.
8. 2020 MOVES run results provided by Alison Eyth, U.S. Environmental Protection Agency, Emissions
Inventory and Analysis Group, November, 16, 2022.
9. Pacific Environmental Services, Inc., "Draft Summary of the Analysis of the Emissions Reported in the
1999 NEI for Stage I and Stage II Operations at Gasoline Service Stations," prepared for the U.S.
Environmental Protection Agency and the Emission Inventory Improvement Program, September 2002.
10. U.S. Census Bureau, 2020 County Business Patterns, released April 2022.
11. [2020 Aircraft NEI All Info.xlsx], electronic file from Janice Godfrey, U.S. Environmental Protection
Agency, OAQPS, to U.S. Environmental Protection Agency, OAQPS. Aircraft operations data for 2020
compiled from FAA's Terminal Area Forecasts (TAF) and 5010 Forms.
12. Federal Aviation Administration (FAA). 2017. Form 5010. Airport Data and Contact Information.
13. U.S. Environmental Protection Agency, "Compilation of Air Pollutant Emission Factors, AP 42, Fifth
Edition, Volume I: Stationary Point and Area Sources, Chapter 7: Liquid Storage Tanks," Office of Air
Quality Planning and Standards, Emission Inventory Group, September 1997.
14. U.S. Environmental Protection Agency. 1984. Locating and Estimating Air Emissions from Sources of
Ethylene Dichloride. Table 16, EPA-450/4-84-007d. RTP, NC.
15. Memorandum from Greg LaFlam and Tracy Johnson (PES) to Stephen Shedd (EPA/OAQPS). Speciated
Hazardous Air Pollutants - Baseline Emissions and Emissions Reductions Under the Gasoline Distribution
NESHAP. August 9, 1996.
16. Personal Communication via e-mail from Stephen Shedd (EPA/OAQPS) to Laurel Driver (EPA/OAQPS). E-
mail dated May 29, 2002.
17. U.S. Department of Energy, Energy Information Administration, "U.S. Daily Average Supply and
Distribution of Crude Oil and Petroleum Products," Table 2 in Petroleum Supply Annual 2020, Volume 1.
released August 31, 2021
18. U.S. Department of Energy, Energy Information Administration, "U.S. Daily Average Supply and
Distribution of Crude Oil and Petroleum Products," Table 2 in Petroleum Supply Annual 1998, Volume 1.
released June 1999
19. U.S. Department of Energy, Energy Information Administration, "Refinery, Bulk Terminal, and Natural
Gas Plant Stocks of Selected Petroleum Products by PAD District and State" Table 35 in Petroleum
Supply Annual 2020, Volume 1, released August 31, 2021
20. Hester, Charles, MACTEC, Inc. Memorandum from Charles Hester, MACTEC, Inc., to Stephen Shedd, U.S.
Environmental Protection Agency, Office of Air Quality Planning and Standards, Emission Standards
18-31
-------
Division, "Review of Data on HAP Content in Gasoline," May 18, 2006.
21. U.S. Department of Energy, Energy Information Administration, "Movements of Crude Oil and
Petroleum Products by Pipeline Between PAD Districts," Table 37 in Petroleum Supply Annual 2020,
Volume 1. released August 31, 2021
18-32
-------
United States Office of Air Quality Planning and Standards Publication No. EPA-454/R-23-001r
Environmental Protection Air Quality Assessment Division March 2023
Agency Research Triangle Park, NC
------- |