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AREA SOURCE EMISSION
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US. ENVIRONMENTAL PROTECTION AGENCY
REGION VIII
AIR a HAZARDOUS MATERIALS DIV6ION
DENVER , COLORADO 80295



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Publication No. EPA-908/1-76-006
PEDCo- ENVIRONMENTAL
SUITE 13 • ATKINSON SQUARE
CINCINNATI. OHIO 45246
513 1-7-7 1-4330
WYOMING AQMA AREA SOURCE
EMISSION INVENTORY
Contract No. 68-02-1375
Task Order No. 19
Prepared for
U.S. Environmental Protection Agency
Region VIII, Denver, Colorado
Prepared by
PEDCo-Environmental Specialists, Inc.
Suite 13 - Atkinson Square
Cincinnati, Ohio 45246
June 1975
BRANCH OFFICE!
Suit* 110, Crown Cantar
Kanui City, Mo. 64108
Suit* 104-A, Profaulonal Villaga
Chapal Hill, N.C. 27514
jpaaxDฎ

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This report was furnished to the. U.S. Environmental
Protection Agency by PEDCo-Environmental Specialists, Inc.,
Cincinnati, Ohio, in fulfillment of Contract No. 68-02-1375,
Task Order No. 19. The contents of this report are repro-
duced herein as received from the contractor. The opinions,
findings, and conclusions expressed are those of the author
and not necessarily those of the Environmental Protection
Agency.
Material included in this report was not originally
intended for publication, but to document the data sources
and assumptions made in preparing the area source emission
inventory. Therefore, the text may be sketchy and the
report more useful as a resource document than a general
procedures manual for emission inventories. It should also
be pointed out that the area source emission inventory is
subject to frequent updating so that data presented herein
may soon become obsolete.
Publication No. EPA-908/1-76-006
ii

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SUMMARY
CONTENTS
Page
1
CATEGORIES
1.
Bituminous Coal
2.
Distillate Oil
3.
Residual Oil
4.
Natural Gas
5.
Other Fuels
6.
Open Burning
7.
Highway Vehicles
8.
Off-Highway Vehicles
9.
Railroads
10.
Aircraft
11.
Industrial Processes
12.
Evaporative Losses
13.
Unpaved Roads
14.
Agriculture
15.
Construction
16.
Aggregate Storage Piles
17.
Dust from Paved Roads
REFERENCES
iii
6
10
16
20
23
29
34
47
52
57
60
65
68
76
81
85
88
91

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FIGURES
TABLES
Page
13.1 Distribution of ADT vs percent	7 3
of miles of unpaved roads
Page
1.	Campbell County Base Year and	3
Projected Emissions
2.	Converse County Base Year and	4
Projected Emissions
3.	Sweetwater County Base Year and	5
Projected Emissions
7.1 Projected Annual VMT (10^)	45
13.1 Wyoming Unpaved Roads 1974	69
15.1 Highway Construction in 1974	82
iv

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SUMMARY
This report presents a base year and projected air pollutant
emissions inventory of area sources in the two Wyoming Air
Quality Maintenance Areas (AQMA), The Powder River AQMA en-
compasses Campbell and Converse Counties and is designated
for particulates and photochemical oxidants. The Sweetwater
AQMA includes only Sweetwater County and is designated for
particulates and SO2•
Designation by the Wyoming Department of Environmental
Quality and U.S. Environmental Protection Agency indicates
that there is a possibility that future growth in the AQMA
may cause the National Ambient Air Quality Standards to be
exceeded despite enforcement of source control regulations.
The area source inventory is to be used in a detailed analysis
of each AQMA to better determine the impact of future growth
on air quality.
A base year of 1974 was specified for the inventory in order
that it be consistent with the time frame of the point
source emission inventory also being prepared. At the time
that the inventory was completed, 1974 was the most recent
year for which data could be obtained.
The area source categories used in the inventory include all
conventional source? categories described in APTD-1135, Guide
for Compiling a Comprehensive Emission Inventory, plus some
additional categories of fugitive dust sources. Two of the
conventional categories, incinerators and vessels, were
excluded since these sources are negligible in the AQMA's.
Special consideration was given to the estimation of emissions
from two industrial processes, pipeline compressors and
heater treaters, and from the burning of spilled oil in oil
fields. An attempt was made to develop a particulate emission
factor for the open burning of crude oil in a sump. Also
1

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particulate emissions from mining operations were not in-
cluded in this inventory, since they will be inventoried as
point sources.
The base year and projected annual emissions are shown in
Tables 1 through 3 for Campbell, Converse, and Sweetwater
counties. Each section of this report shows the data and
methodology used to estimate emissions, base year emissions,
and projections for each source category.
The area source categories showing the greatest particulate
emissions are fugitive dust sources. Fugitive dust accounts
for about 98 percent of the area source particulate emissions
in the Powder River Basin AQMA and 98 percent in the Sweet-
water AQMA. Unpaved roads are responsible for most of the
fugitive dust emissions.
Mobile sources account for about 85 percent of the identi-
fied hydrocarbon area source emissions in the Powder River
Basin AQMA, and they also account for about 72 percent of
the SC>2 emissions in the Sweetwater AQMA.
The procedure used to project emissions was to apply growth
factors to the base year emissions for each source category.
Separate growth factors were developed for each category for
1975, 1980, and 1985.
Particulate emissions are shown to increase from 1975 to
1985 by about 139 percent in Campbell County and about 38
percent in Converse and Sweetwater Counties. Hydrocarbon
emissions will remain about the sajme in Campbell County and
decrease about 33 percent in Converse County from 1975 to
1985. SC>2 emissions in Sweetwater County are shown to
remain almost constant for the next ten years.
2

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Table 1. CAMPBELL COUNTY BASE YEAR AND PROJECTED EMISSIONS
Particulates (tons/yr)	Hydrocarbons (tons/yr)
Source Category
1974
1975
1980
1985
1974
1975
1980
1985
Bituminous Coal
98
99
104
109
98
99
104
109
Distillate Oil
25
31
80
103
5
6
16
21
Residual Oil
17
21
53
68
2
3
7
9
Natural Gas
8
10
20
25
7
8
16
20
Other Fuels
5
6
11
14
2
2
5
6
Open Burning
17
17
17
17
-
-
-
-
Highway Vehicles
90
104
145
148
1450
1575
1953
1192
Off-Highway
18
32
41
45
72
90
113
125
Vehicles








Railroads
37
37
176
232
141
141
664
877
Aircraft
-
-
-
-
2
2
3
4
Industrial
255
255
255
255
309
309
309
309
Processes








Evaporative
-
-
-
-
6254
6274
6394
6454
Losses








Unpaved Roads
27836
32669
56628
67944
-
-
-
—
Agriculture
826
826
846
865
-
-
-
-
Construction
1486
2369
2893
3117
-
-
-
-
Aggregate
5
5
5
5
-
-
-
-
Storage








Dust from Paved
676
777
1399
1751
-
—
—
—
Roads
Total
31399 37258 62673 74698
8342 8509 9584 9146

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Table 2. CONVERSE COUNTY BASE YEAR AND PROJECTED EMISSIONS
Particulates (tons/yr)	Hydrocarbons (tons/yr)
Source Category
1974
1975
1980
1985
1974
1975
1980
1985
Bituminous Coal
8
8
8
9
8
8
8
9
Distillate Oil
12
12
18
21
2
2
3
5
Residual Oil
7
7
11
12
1
1
2
2
Natural Gas
4
4
5
5
3
3
4
4
Other Fuels
3
3
4
4
6
6
9
9
Open Burning
62
62
62
62
-
-
-
-
Highway Vehicles
80
82
83
70
1290
1243
1116
552
Off-Highway
17
19
31
19
55
58
73
60
Vehicles








Railroads
9
9
148
206
34
34
558
776
Aircraft
-
-
-
-
2
2
3
4
Industrial
84
84
84
84
85
85
85
85
Processes








Evaporative
-
-
-
-
1374
1375
1397
1401
Losses








Unpaved Roads
15039
15490
21060
22113
-
-
-
-
Agriculture
1045
1045
1055
1065
-
-
-
-
Construction
857
869
925
866
-
-
-
-
Aggregate
8
8
8
8
-
-
-
-
Storage








Dust from Paved
642
655
860
892
-
-
-
-
Roads
Total
17877 18357 24362 25436
2860 2817 3258 2907

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Table 3. SWEETWATER COUNTY BASE YEAR AND PROJECTED EMISSIONS
Particulates (tons/yr)	Sulfer Dioxide (tons/yr)
Source Category
1974
1975
1980
1985
1974
1975
1980
1985
Bituminous Coal
25
24
17
13
24
22
16
12
Distillate Oil
24
27
36
39
70
78
105
111
Residual Oil
11
12
17
18
91
102
137
146
Natural Gas
42
47
63
67
3
3
4
4
Other Fuels
6
7
9
9
2
2
3
3
Open Burning
3
3
3
3
-
-
-
—
Highway Vehicles
368
393
379
335
141
151
184
176
Off-Highway
30
33
44
47
34
37
50
53
Vehicles








Railroads
200
200
200
200
455
455
455
455
Aircraft
4
4
5
6
2
2
3
4
Industrial
53
53
53
53
2
2
2
2
Processes








Unpaved Roads
24588
27000
33678
34975
-
-
-
-
Agriculture
25
25
25
26
-
—
-
-
Construction
8588
9250
11345
11896
-
-
-
—
Aggregate
108
108
108
108
-
-
-
-
Storage








Dust from Paved
2325
2488
2999
3139
-
—
-
—
Roads
Total
36400 39674 48981 50934
824 854 959 966

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1. BITUMINOUS COAL
Data Inventory and Methodology
Coal consumption was determined by two methods: (1) degree-
day heating method for residential and apportioning state
coal consumption totals for commercial; (2) contacting major
county distributors. The distributor's total sales in 1974
for each county are:
Campbell - 9,800 tons (Ref. 32) and (Ref. 34)
Converse - 845 tons (Ref. 34)
Sweetwater - 2,500 tons (Ref. 33)
This data reflects residential customers for Campbell and
Converse, and residential and commercial customers for
Sweetwater.
The following describes the procedure used to determine coal
consumption for residential, commercial-institutional, and
industrial.
Residential:
Residential coal consumption was calculated using the degree-
day heating method (Ref. 11). The general equation is:
RFC = (DU) X (DD) x (HRF) X (R)	(eq. 1)
where RFC - residential fuel consumption, tons
DU - dwelling units
DD - degree-days
HRF - heating requirement factor, tons of coal per
dwelling unit per degree day
R - correction factor for number of rooms per
dwelling unit, average no. of rooms/5.0 rooms
The heating requirement factor for tons of coal burned is
0.0012 tons/dwelling unit/degree day (Ref. 11).
6

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The following is the number of dwelling units and degree-
days for each county and the state, used to calculate coal
consumptions.
1970 dwelling
units using coal
(Ref. 1)
1974 dwelling
units using coal
Average rooms per
dwelling unit
(Ref. 1)
Average annual
1974 heating
degree-days
(Ref. 8)
1974 Residential
coal consumption
(tons/year)
State
3,454
3,592
4.7
7,416
State
avg.
30,047
Campbell
245
255
4.5
7,332
Sheridan
2,019
Converse
61
63
4.8
7,584
Casper
550
Sweetwater
107
80
4.4
7,721
Lander
652
The State of Wyoming and both Campbell and Converse counties
have had a 1% increase per year in coal consumption (Ref. 32).
Sweetwater county had a 25% decrease in coal consumption from
1970 to 1974 (Ref. 33). The degree-days for each county were
determined from the 1974 Climatological Summary of the nearest
National Weather Service (NWS) recording station and indicated
accordingly. The state degree-days were determined by averaging
all NWS stations in the state.
Comparing the calculated coal consumption for residential use
with the distributor's sales for Campbell and Converse indicates
the distributors sales are higher. Since the major distributors
were contacted and their data is considered more accurate, the
distributor's sales were used to calculate emissions.
Sweetwater distributor sales contains both residential and
commercial. Therefore, no comparison is possible.
7

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Commercial-Institutional:
Since the 1974 calculated residential coal consumption of
30,047 tons is greater than the state retail dealers con-
sumer use for 1974 of 24,000 tons (Ref. 4), it was assumed
that there is no commercial-institutional area source coal
consumption. The exception is Sweetwater County where a
total residential and commercial distributor's sales for
1974 was used to calculate emissions.
Industrial:
It was assumed that all industrial coal users burned large
enough quantities to be included as point sources. Thus,
industrial coal combustion area source emissions were
assumed to be negligible.
Base Year Emissions
Since the majority of the coal consumption is residential,
emission factors for hand-fired units were used (Ref. 12):
Particulates = 20 lb/ton
Hydrocarbons = 20 lb/ton
Sulfur dioxide = 38S lb/ton, where
S = percent sulfur, 0.5% average (Ref. 37)
Applying these emission factors to the previously-determined
coal consumption values yields the following annual emissions.
1974 area source
coal consumption
Campbell
9,800
Converse
845
Sweetwater
2,500
1974 emissions
(tons/year)
- particulate
hydrocarbon
sulfur dioxide
98
98
n.d.
8
8
n.d.
25
n.d.
24
n.d. = not determined
8

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Proj ections
Residential and commercial-institutional coal usage in
Sweetwater County is steadily declining at a rate of about 6
percent per year due to home heating conversion to natural
gas, LPG, and electricity. In Campbell and Converse Counties,
the availability of inexpensive coal from strip mining
activity has created an increase in residential coal consump-
tion of 1 percent per year. Based upon these growth rates,
future coal usage and resulting emissions are as follows:
County	Year Coal Usage (tons/yr) Emissions (tons/yr)



PART
so2
HC
GF
Campbell
1975
9,899
99

99
1.01

1980
10,403
104

104
1 . 06

1985
10,934
109

109
1.11
Converse
1975
853
8

8
1.01

1980
897
8

8
1.06

1985
943
9

9
1.11
Sweetwater
1975
2,350
24
22

0.94

1980
1,725
17
16

0.69

1985
1,266
13
12

0. 50
GF = growth factor.
9

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2. DISTILLATE OIL
Data Inventory and Methodology
Distillate oil consumption was determined by two methods:
(1) degree-day heating method for residential and appor-
tioning state distillate oil consumption totals for com-
mercial and industrial; (2) contacting the major distributor
in each county. The distributor's total sales in 1974 for
each county are:
Campbell (Ref. 38)
Converse (Ref. 39)
Sweetwater (Ref. 40)
Distillate Oil (gallons)
Residential	Commercial
20,000 (res.	& comm.)
1,500	n.d.
5,000	733,000
Industrial
n.d.
1,200,000
400,000
n.d. = not determined
The following describes the procedure used to determine
distillate oil consumption for residential, commercial-
institutional, and industrial.
Residential:
Residential distillate oil consumption was calculated using
the degree-day heating method (Ref. 11). The heating requirement
factor for gals of oil burned per dwelling unit per degree-
day is 0.18 (Ref. 11). The following is the number of
dwelling units for each county used to calculate distillate
oil consumption.
State	Campbell Converse Sweetwater
1970 dwelling units
using distillate	3,572	69	44	23
oil (Ref. 1)
1974 dwelling units
using distillate oil 2,500	48	31	12
1974 residential
distillate oil	3,137,000 57,000 40,600	14,700
consumption (gals/yr)
10

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The average rooms per dwelling unit and average annual
degree-days used to calculate consumption are shown in
chapter 1. Campbell County had a 30% decrease in dwelling
units using distillate oil from 1970 to 1974 (Ref. 38), and
it was assumed that Converse County also had the same decrease.
Sweetwater County had a 50% decrease from 1970 to 1974
(Ref. 40), and it was assumed that the state had a 30%
decrease from 1970 to 1974.
Comparing the calculated distillate oil consumption for all
three counties with the major distributor's sales for residential
use, indicates that the calculated total is higher than the
distributor's sales. Since only one distillate oil dis-
tributor per county was contacted, this method only accounts
for part of the total county sales. Therefore, the calculated
values were used for residential distillate oil consumption
for all three counties.
Commercial-Institutional:
Commercial-institutional distillate oil consumption was
calculated by apportioning the state distillate oil com-
mercial consumption by county/state population. State
residential and commercial distillate oil consumption for
area sources was determined from 1973 published data (Ref. 6),
where 1973 data was assumed to be representative of 1974.
Point source contribution for commercial-institutional fuel
usage was assumed to be negligible.
State distillate type	887,000 bbls = 37,254 . 10^ gals
heating oil (Ref. 6)
State distillate usei
by military (Ref. 6)
State kerosene used
for heating (Ref. 6)
3
State distillate used	8,100 bbls = 9,198 . 10 gals
State kerosene used	219,000 bbls = 340 . 103 gals
11

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1974 state residential	46,792 • 10 gals
and commercial distillate
oil consumption
1974 state residential	3,137 • 103 gals
distillate oil consump-
tion (subtract)
3
1974 state commercial-	43,655 • 10 gals
institutional distillate
oil consumption
The following is the apportioned commercial-institutional
distillate oil consumption by county.
State Campbell Converse Sweetwater
1974 Population	359,000 11,900	7,100	25,900
(Ref.3)
1974 commercial-	43,655	1,447	863	3,149
institution distil-
late oil consumption
(103 gallons/year)
Again, the calculated is higher than the distributors sales.
Since all distributors were not contacted, the calculated
consumption was used.
Industrial:
Industrial distillate oil consumption was calculated by
apportioning state industrial distillate oil consumption by
county/state mining, contract construction, and manufac-
turing employees. State industrial distillate oil consump-
tion for point and area sources was determined from the
following 1973 published data, where 1973 data was assumed
to be representative of 1974.
State industrial use (Ref. 6)	448,000 bbls = 18,816 • 103 gals
State oil companies' use 406,000 bbls = 17,052 ฆ 103 gals
(Ref. 6)		
1974 state point & area source	35,868 • 103 gals
industrial distillate oil con-
sumption

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The following is the apportioned industrial distillate oil
consumption by county, assuming the 1973 ratio of county to
state total employees is representative of 1974.
State Campbell Converse Sweetwater
Mining, construction, 27,986 1,430	512	4,435
and manufacturing
employees (Ref. 2)
1974 point and area 35,868 1,833	658	5,684
source industrial
distillate oil con-
sumption (103 gals)
1974 point source
industrial distillate
oil consumption
(103 gals) (Ref. 41)		0	10	5,604
1974 industrial
distillate oil con-
sumption(103 gals/yr)	1,833	648	80
Comparison of calculated consumption with distributor sales in
Converse and Sweetwater Counties shows the sales to be greater
than the calculated. This is attributed to distributor sales
outside the county. Therefore, the calculated industrial
distillate oil consumption was used.
Residential, Commercial-Institutional, Industrial:
The following is the total distillate oil consumption in 1974
used to calculate area source emissions.
1974 Area Source Distillate Oil Consumption (gals/yr)
Campbell - 3,337,000
Converse - 1,551,600
Sweetwater - 3,243,700
13

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Base Year Emissions
The emission factors for distillate fuel oil combustion are as
follows (Ref. 12):
3
Emission Factors (lb/10 gals)
Particulate - 15
Hydrocarbons - 3
Sulfur dioxide - 43 (assume 0.3% sulfur)
Applying these emission factors to the county distillate oil
consumption yields the following emissions:
1974 Emissions (tons/year)
Campbell:
Particulate -
25

Hydrocarbon -
5
Converse:
Particulate -
12

Hydrocarbon -
2
Sweetwater:
Particulate -
24

so2
70
14

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Projections
It is assumed that residential distillate fuel oil consump-
tion from 1974 to 1985 will remain almost constant.
Oil is not a commonly used residential fuel in any of the
AQMA counties (less than 3 percent of all homes) and may be
replaced by other lower cost fuels.
Industrial and commercial-institutional growth factors for
Campbell and Converse Counties were determined from employ-
ment projections of permanent and service workers (Ref. 56).
These employment projections were made for three alternative
futures of industrial development. The intermediate alter-
native future was used to determine the growth factors.
Since there are no current industrial and commercial growth
projections for Sweetwater County, population growth factors
were used (Ref. 57). Wyoming Department of Environmental Plan-
ning & Development (DEPAD) is currently developing growth data
for Sweetwater County, and their data may be incorporated in
the AQMA analysis study when it becomes available.
Applying the growth factors, the resultant emissions are as
follows:
Projected Emissions (tons/year)

Campbell
Converse

Sweetwater

GF
PART
HC
GF
PART
HC
GF
PART
so2
Commercial-









Institutional








1975
1.39
15
3
1.06
7
1
1.12
26
76
1980
3.75
41
8
1.74
11
2
1.50
35
102
1985
4.98
54
11
1.97
13
3
1.60
38
108
Industrial









1975
1.16
16
3
1.02
5
1
1.12
1
2
1980
2.83
39
8
1.41
7
1
1.50
1
3
1985
3.57
49
10
1.56
8
2
1.60
1
3
Total (residential
included)






1975

31
6

12
2

27
78
1980

80
16

18
3

36
105
1985

103
21

21
5

39
111
GF = growth factor
15

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3. RESIDUAL OIL
Data Inventory and Methodology
Residual oil consumption was determined by one method,
apportioning state residual oil totals for commercial and
industrial usage. It was assumed that there is no resi-
dential usage of residual oil in Wyoming, so only commercial
and industrial residual oil consumption was calculated.
Commercial-Institutional:
Commercial-institutional residual oil consumption was cal-
culated by apportioning state commercial-institutional
residual oil by county/state population. State commercial-
institutional consumption for area sources was determined
from 1973 published data (Ref. 6), where 1973 data was
assumed to be representative of 1974. Point source contribution for
commercial-institutional fuel usage was assumed to be negligible.
State residual type heating	318,000 bbls = 13,356 * 10"^ gals
oil (Ref. 6)
State residual used by military
1974 state commercial-	13,356 • 10"* gals
residual oil consumption
(103 gallons/year)
The following is the apportioned commercial-institutional
residual oil consumption by county.
State	Campbell Converse Sweetwater
1974 population	359,000 11,900	7,100	25,900
(Ref. 3)
1974 commercial-	13,356	443	264	964
institutional
residual oil
consumption
(10-3 gals/year)
16

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Distributors for commercial residual oil usage were not
contacted, so calculated consumption was used.
Industrial:
Industrial residual oil consumption was calculated by appor-
tioning state industrial residual oil consumption by
mining, contract construction, and manufacturing employees.
State industrial residual oil consumption for point and area
sources was determined from the following 197 3 published
data, where 1973 data was assumed to be representative of
1974.
State industrial use (Ref. 6)	301,000 bbls = 12,642 • 10^ gals
State oil companies' use	639,000 bbls = 26,838 • 10^ gals
(Ref. 6)
1974 state point and area	39,480 • 10^ gals
source industrial residual
oil consumption(103 gals/yr)
The following is the apportioned industrial residual oil
consumption by county, assuming the 1973 ratio of county/state
employees is representative of 1974.
State Campbell Converse Sweetwater
Mining, construction, 27,986 1,430	512	4,435
and manufacturing
employees (Ref. 2)
1974 point and area	39,480
source industrial
residual oil consump-
tion (103 gals)
1974 point source
industrial residual oil
consumption (103 gals)
1974 industrial residual
oil consumption
(103 gals/year)
2,017	722	6,256
974	367	9,048
1,043	355	(neg)
17

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Since the Sweetwater point source residual oil consumption is
greater than the calculated point and area source total, the
industrial residual oil consumption for Sweetwater County was
assumed to be negligible.
Commercial-Institutional, Industrial:
The following is the total residual oil consumption in 1974
used to calculate emissions.
1974 Area Source Residual Oil Consumption (gals/yr)
Campbell - 1,486,000
Converse - 619,000
Sweetwater - 964,000
Base Year Emissions
The emission factors for residual oil combustion are as
follows (Ref. 12):
3
Emission Factors (lb/10 gals)
Particulate - 23
Hydrocarbon - 3
Sulfur Oxides (SO„) - 188.4 (1.2% sulfur)
(Ref. 41)
Applying these emission factors to the county residual oil
consumption yields the following emissions:
1974 Emissions (tons/year)
Campbell: Particulate - 17
Hydrocarbon - 2
Converse: Particulate - 7
Hydrocarbon - 1
Sweetwater: Particulate - 11
S02 - 91
18

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Projections
The same procedure used in projecting distillate fuel oil
was used for residual fuel oil. The resultant emissions are
as follows:
Projected Emissions (tons/year)

Campbell

Converse
Sweetwater

GF
PART
HC
GF
PART
HC
GF
PART
so2
Commercial-









Institutional








1975
1.39
7
1
1.06
3
—
1.12
12
102
1980
3.75
19
3
1.74
5
1
1.50
17
137
1985
4.98
25
3
1.97
6
1
1.60
18
146
Industrial









1975
1.16
14
2
1.02
4
—
1.12
—
—
1980
2.87
34
4
1.41
6
1
1.50
—
—
1985
3.57
43
6
1.56
6
1
1.60
—
—
Total









1975

21
3

7


12
102
1980

53
7

11
2

17
137
1985

68
9

12
2

18
146
19

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4. NATURAL GAS
Data Inventory and Methodology
The consumption of natural gas in the three counties was best
determined by contact with the natural gas distributors. The
total 1974 residential, commercial-institutional, and industrial
natural gas sales for Campbell County was 1621 MMCF (Ref. 43).
Since there was no point source consumption of natural gas, this
value was used to calculate area source emissions.
The total 1974 residential, commercial-institutional, and
industrial natural gas sales for Converse County was 730 MMCF
(Ref. 43 and 44). The total 1974 point source natural gas
consumption of 32 MMCF in Converse County (Ref. 41) was
subtracted to obtain area source consumption. This value is
698 MMCF.
The total 1974 residential, commercial-institutional, and
industrial natural gas sales for Sweetwater County were 16,08 0
MMCF (Ref. 45). The total 1974 point source industrial natural
gas consumption of 77 04 MMCF in Sweetwater County (Ref. 41) was
subtracted to obtain the total area source consumption. This
value is 8376 MMCF.
Base Year Emissions
The emission factors for natural gas combustion are (Ref. 12):
Emission Factors (lb/MMCF)
Particulate - 10
Hydrocarbon - 8
S02 - 0.6
Applying these factors to the county natural gas consumption
yields the following emissions:
20

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1974 Emissions (tons/year)
Campbell: Particulates - 8.1
Hydrocarbons - 6.5
Converse: Particulates - 3.5
Hydrocarbons	- 2.8
Sweetwater: Particulates - 41.9
SOo	- 2.5
21

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Projections
Since the natural gas distributors did not have projections
of natural gas consumption and they did not provide a
breakdown by residential, commercial, and industrial, future
consumption was paralleled with population growth. For
Campbell and Converse Counties, DEPAD data was used (Ref. 56).
For Sweetwater County, the Wyoming Department of Transportation
planning projections were used (Ref. 57).
Projected Emissions (tons/year)
Campbell
Converse
Sweetwater

GF
PART
HC
GF
PART
HC
GF
PART
S02
1975
1.21
10
8
1.03
4
3
1.12
47
3
1980
2.45
20
16
1.44
5
4
1.50
63
4
1985
3.14
25
20
1.51
5
4
1.60
67
4
22

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5. OTHER FUELS
Data Inventory and Methodology
Two types of other fuels were considered in this area source
category: wood and LPG (liquified petroleum gas). The
procedure used to determine consumption for each fuel type
is discussed below.
(1) Wood
Residential wood consumption was calculated using the degree-
day heating method (Ref. 11). The heating requirement factor
used for the tons of wood burned per dwelling unit per
degree-day is 0.0017 (Ref. 11). The number of dwelling units
and degree-days for each county used to calculate wood
consumption is as follows:
Campbell Converse Sweetwater
197 0 Dwelling units
using wood
(Ref. 1)
1974 Dwelling units
using wood
(assumed same as 1970)
Average rooms per
dwelling unit
(Ref. 1)
Average annual 1974
heating degree-days
(Ref. 8)
Residential wood
consumption for 1974
(tons/year)
4.5
24
24
4.8
7332	7584
(Sheridan) (Casper)
297
25
25
4.4
7721
(Lander)
289
There were no data available to indicate' that wood was consumed
by commercial-institutional or industrial area sources.
Therefore, both were considered to be negligible in this
inventory.
(2) LPG
The combined 1973 State commercial and residential LPG
consumption is 53,467,000 gallons (Ref. 7). It was assumed
23

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that the 1973 consumption is representative of 1974. In order
to disaggregate the state total into residential and commercial,
the natural gas residential to commercial ratio (Ref. 5) was
used. This ratio is 13,868/12,348. Therefore, the 1974
residential LPG consumption is approximately 28,000,000 gallons
and the 1974 commercial LPG consumption is approximately
25,000,000 gallons.
Residential:
Residential LPG consumption was calculated by apportioning the
state LPG consumption by number of dwelling units using LPG.
State Campbell Converse Sweetwater
1970 Dwelling units
using LPG
(Ref. 1)
Growth factor
1974 Dwelling units
using LPG
13,474
1.08
14,570
1205
1.40
1687
332
1.00
332
294
2.34
688
1974 Residential
LPG., consumption
(10 gallons/year)
28,000
3506
690
1322
The increases in LPG usage from 1970 to 1974 (growth factor)
were estimated by LPG distributors (Ref. 35 and 36). State
LPG sales were assumed to increase in proportion to state
population.
One major distributor for the three counties was contacted to
obtain residential LPG sales for 1974. Sales for Converse were
673,652 gallons and for Sweetwater were 640,611 gallons (Ref. 36).
Converse sales closely match the calculated consumption.
Sweetwater sales are below the calculated since other major
distributors were not included. The calculated residential
LPG consumption was used to estimate emissions.
24

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Commercial-Institutional:
Commercial-institutional LPG consumption was calculated by
apportioning the state commercial LPG consumption by
county/state population.
State Campbell Converse Sweetwater
1974 Population 359,000 11,900	7,100	25,900
(Ref. 3)
1974 Commercial-
institutional LPG 25,000	829	494	1,803
consumption
3
(10 gallons/year)
Industrial:
Industrial LPG consumption was calculated by apportioning
state industrial LPG consumption by county/state mining,
contract construction, and manufacturing employees. The
state industrial LPG consumption for 1973 was 10,276,000
gallons (Ref. 7) and was assumed to be representative of
1974. Also, the 1973 ratio of the county to state total
employees in mining, construction, and manufacturing was
assumed to be the same as for 1974.
The following is the apportioned industrial LPG consumption
by county.
State Campbell Converse Sweetwater
Mining, construc-
tion, and manufac- 27,986 1,430	512	4,435
turing employees
(Ref. 2)		 					
1974 Industrial
LPG consumption 10,276	525	188	1,628
3
(10 gallons/year)
25

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Residential, Commercial, Institutional, Industrial:
The total estimated LPG consumption for 1974 for each county
is as follows:
1974 Area Source LPG Consumption (gals/yr?
Campbell - 4,860,000
Converse - 1,372,000
Sweetwater - 4,753,000
Ba3e Year Emissions
Emissions were calculated for the two types of fuels—wood and
LPG.
(1)	Wood
The average emission factors for wood burning in boilers are
(Ref. 12):
Emission Factors (lb/ton)
Particulate - 10
Hydrocarbon - 36
Sulfur Oxides (SC^) - 1.5
Applying these factors to the county wood consumption yields
the following emissions:
1974 Wood Emissions (tons/yr)
Converse:	Particulate - 1.5
Hydrocarbon - 5.3
Sweetwater:	Particulate - 1.4
Sulfur Oxides (S02) - 0.2
(2)	LPG
The emission factors for LPG combustion are (Ref. 12):
26

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3
Emission Factors(lb/10 gals)
Particulate - 1.9
Hydrocarbon - 0.8
Sulfur Oxides (SC^) - 0.9 (10 grains/100 ft^)
Applying these factors to the county total LPG consumption yields
the following emissions:
1974 LPG Emissions (tons/year)
Campbell: Particulate - 4.6
Hydrocarbon - 1.9
Converse: Particulate - 1.3
Hydrocarbon - 0.5
Sweetwater: Particulate - 4.5
S02 - 2.1
27

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Projections
Projected emissions for wood were calculated by applying
population growth factors. Since wood burning exists only
in the residential sector, population would be an acceptable
measure of growth in consumption.
Projected Wood	Emissions (tons/year)
Converse	Sweetwater
GF PART HC	GF PART SC>2
1975 1.03 2 5	1.12 2
1980 1.44 2 8	1.50 2
1985 1.51 2 8	1.60 2
Since base year LPG emissions are small, applying separate
growth factors to residential, commercial, and industrial
categories is not necessary. Therefore, population growth
factors were considered adequate and resulted in the follow-
ing projected emissions:
Projected LPG Emissions (tons/year)
Campbell	Converse	Sweetwater

GF
PART
HC
GF
PART
HC
GF
PART
1975
1.21
6
2
1.03
1
1
1.12
5
1980
2.45
11
5
1.44
2
1
1.50
7
1985
3.14
14
6
1.51
2
1
1.60
7
2
2
3
3
28

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6. OPEN BURNING
Data Inventory and Methodology
There are four classifications of open burning which have
been used in estimating emissions: (]) oil sump burning;
(2) agricultural burning; (3) slash burning, and (4) forest
fires. Oil sump burning is the ignition of oil that has
accumulated in a pit, pond, or creek from small oil spills,
transmission pipeline leaks, or tank overflows. Also included
in this classification are oil well testing and oil tank
bettery fires. Agricultural burning includes all intentional
field burning done by farmers and ranchers. Slash burning
includes waste from logging operations and brush from land
clearing. Forest fires are self-explanatory. Data for each
classification is as follows:
(1) Oil Burning
The following is a summary of the number of barrels of crude
oil burned in each county for tfce year 1974 (Ref.9):
Campbell:	2308 bbls = 96,936 gals
Converse:	8210 bbls = 344,820 gals
Sweetwater:	316 bbls = 13,272 gals
This data was extracted from the Open Burning Log in the
Wyoming Air Quality Division files and multiplied by a
factor of 2 to reflect unreported oil burning in a sump.
Ten barrels of oil burned was assumed if the number of
gallons burned was not recorded in the Log. The range of
the number of barrels burned per site was from 2 to 200
barrels, with the average being approximately 25 barrels.
Also included in the open burning log was natural gas flaring,
which was neglected as a source classification due to the
short periods of burning (one day to two weeks) and the un-
certainty of the amount burned.
29

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(2)	Agricultural Burning
The Wyoming Department of Agriculture was contacted to
determine the number of acres and tons per acre of stubble
burned. It was the opinion of the department that the
number of acres burned was very small and should be
neglected as a pollutant source. The Wyoming AQD concurred.
(3)	Slash Burning
The Open Burning Log is also used to record slash burning
requests by the U.S. Forest Service or private companies.
There were no slash burning requests in the three counties
for the calendar year 1974.
(4)	Forest Fires
The U.S. Forest Service, Rocky Mountain Regional Office, was
contacted to obtain data on the number, location, and acres
of forest fires that occurred in 1974 (Ref. 10). Only one
forest, Medicine Bow, exists in the three counties. It
covers the southwestern portion of Converse County. Two
fires were identified occurring in July and August which
burned a total of 6 non-commercial forest acres. The area
is moderately forested, so it was assumed that 30 tons/acre
of vegetation were burned (Ref. 11). This yields a total of
180 tons of vegetation burned during 197 4.
Base Year Emissions
There are only two open burning classifications with emissions
during 1974: forest fires and oil burning. The emission
factors for open wood burning are 17 lb/ton for particulate
and 4 lb/ton for hydrocarbon. The emissions in 1974 from
forest fires are:
1974 Forest Fire Emissions (tons/year)
Converse
Particulates
1.5
HC
0.4
30

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Since there is no particulate emission factor for oil sump
burning, the following procedure was used to derive an
emission factor. The EPA published particulate emission
factors for orchard heaters (smudge pots) were reviewed.
The factors for each smudge pot type (Ref. 12) are:
lazyflame - .094 lb/6 lb = 15.7 lb/1000 lb
= 113 lb/1000 gals
cone type - .088 lb/8 lb = 11.1 lb/1000 lb
= 80 lb/1000 gals
return stack - .098 lb/11 lb = 8.9 lb/1000 lb
= 54 lb/1000 gals
The average emission factor for orchard heaters is 82 lb/1000 gals.
The particulate emission factor for residual oil in a boiler
is 23 lb/1000 gals. These published factors were compared
to an unpublished emission factor for particulates developed
from the burning of kerosene and gasoline used in fire
drills performed by the Navy. This factor is 943 lb/1000 gal
(Ref. 13) and is considerably higher than the others due to
the low burning temperature and incomplete combustion caused
by water spray. It is estimated that oil sump burning would
have a higher emission factor than controlled combustion in
a boiler, but be lower than the fire drill oil burning.
Therefore, an average of the three emission factors is pro-
posed as the emission factor for oil sump burning—350 lb/1000 gals.
The combustion emission factor for hydrocarbons is negligible,
since nearly all of the hydrocarbon losses are evaporative
(Ref. 12).
31

-------
3
The emission factor for sulfur oxides is 15.7 lb/10 gallons
(Ref. 12), which is based on 0.1 percent sulfur in crude oil
in Sweetwater County (Ref. 17).
Applying these emission factors to the oil burned in each
county yields the following emissions:
1974 Oil Burning Emissions (tons/year)
Campbell: Particulates - 17
Converse: Particulates - 60
Sweetwater: Particulates - 2.6
SO2 - negligible
32

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Projections
Since forest fires vary from year to year, it is impossible
to predict emissions for future years. It was assumed that
these emissions remain the same for 1975, 198Q, and 1985,
since only a small portion of Converse County has a forested
area and base year emissions are small.
It is also difficult to predict future oil spills and pipe-
line leaks. Short term (1974-78) oil and gas production
projections made by DEPAD are shown to be constant (Ref. 58).
Therefore, it is assumed that oil sump burning will remain
the same for 1975, 1980, and 1985.
33

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7. HIGHWAY VEHICLES
Data Inventory and Methodology
The Wyoming State Highway Department was contacted to obtain
traffic data (Ref. 14). Total daily VMT (vehicle-miles of
travel) data for 1974 were obtained for the following highway
system categories: Interstate, Federal Aid Primary (FAP),
Federal Aid Secondary CFAS); and State Highway System.
Three other categories exist in Wyoming: Federal Aid Primary
not on system; County; and City Streets. Data for these
other categories were obtained from unpublished data for the
year 1973 provided by the Highway Department. This analysis
assumes that 1973 VMT data for the three categories are also
representative of 1974. The following is a summary of the
data:
1974 Daily VMT

Campbell
Converse
Sweetwater
Interstate
110,626
168,641
770,923
FAP
144,037
84,448
113,863
FAS
29,990
17,713
83,519
State Highway
—
102
—
FAS not on System
—
1,933
14,388
County
48,991
29,223
77,173
City Streets
8,884
8,540
53,653
Total Annual VMT 125,022,720 113,369,000	406,434,435
Since HC emissions are a function of vehicle speed, it is
necessary to apply an emission correction factor based on
speeds assigned to each highway system category. The Highway
Department provided the following average speeds for the
category groupings:
34

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Category
Speed
HC Speed Correction Factor
Freeway - Interstate	55 MPH	.63
FAP
Arterial - FAS	45 MPH	.63
State Highway
FAS not on system
County
Local - City Streets	25 MPH	.86
In order to disaggregate total VMT into travel by light-duty
vehicles (LDV), heavy-duty vehicles (HDV), and heavy-duty
diesel (HDD), the Wyoming Department of Revenue was contacted
to obtain the percent of commercial vehicles registered in
]974 by weight and by fuel use (Ref. 15). The following
data were provided for all interstate and intrastate com-
mercial vehicles registered:
Commercial Vehicles
Gross
No. of Vehicles Fuel Type	No. of Vehicles Veh. Weight
30,376	gasoline	27,435 (30%) <16,000 lbs.
60,135	diesel	63,704 (70%) >16,000 lbs.
616	LPG
12	other
The percentages of commercial vehicles less than 8,500 lb.
gross weight (LDT) and greater than 8,500 lb. (HDV) could
not be determined from any summaries of registration records.
It was assumed that half of the commercial vehicles less
than 16,000 lbs. are LDT. This assumption seems reasonable
because of the large number of pick-up trucks registered as
commercial vehicles.
To account for commercial vehicles that are actually light-
duty vehicles, 15% of the commercial vehicle VMT in each
35

-------
county were subtracted to get HDV VMT, and the same amount
was added to LDT VMT. Also, the percent of vehicles greater
than 8,500 lbs. using gasoline and diesel were adjusted
to reflect the 15% reduction in HDV VMT. This adjustnent
shows that 19% of the heavy-duty commercial are gasoline
fueled and 81% are diesel fueled.
The 15% reduction was applied to commercial VMT data provided
by the Highway Dept. for Interstate, FAP, FAS, and State
Highways (Ref. 14). The total VMT for the remaining three
categories were factored as follows:
FAS not on system - Ratio of commercial to
total VMT for FAS
County	- Ratio of commercial to total
VMT for State Highways
City Streets	- Assumed to be 3%
The reduced commercial VMT and factored total VMT produces
heavy-duty VMT estimates for both gasoline and diesel vehicles:
Heavy-Duty VMT
Campbell
Converse

VMT
% Total
VMT
% Total
VMT
Interstate
15,064
13.6
21,785
13.0
196,015
FAP
20,635
14.3
9,184
10.8
14,614
FAS
4,989
16.6
1,763
10.0
10,901
State Highway
—
—
8
8.0
—
FAS not on
—
—
193
10.0
1,870
system





County
3,919
8.0
2,337
8.0
6,174
City Streets
266
3.0
256
3.0
1,609
Sweetwater
% Total
25.0
12.8
13.0
13.0
8.0
3.0
36

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The heavy-duty VMT estimates were subtracted from the total
VMT to obtain the total light-duty VMT.
Light-Duty VMT
Interstate
FAP
FAS
State Highway
FAS not on system
County
City Streets
Camobell
—
95,562
123,402
25,001
45,072
8,618
Converse
146,856
75,264
15,950
94
1,740
26,886
8,284
Sweetwater
574,908
99,249
72,618
12,518
70,999
52,044
In order to further disaggregate the heavy-duty VMT into HDV
(using gasoline) and HDD (using diesel) the 19% and 81% factors
were applied to the heavy-duty VMT values shown above.
Heavy Duty VMT
For Gasoline & Diesel
Converse
Sweetwater
Gas
Diesel
Gas
Diesel
Gas
Diesel
Interstate 2,862
12,201
4,139
17,645
37,243
158,772
FAP 3,920
16,714
1,745
7,439
2,777
11,837
FAS 948
4,041
335
1,428
2,071
8,830
State Highway
—
2
6
—
—
FAS not on
—
37
156
355
1,515
system





County 745
3,174
444
1,893
1,173
5,001
City Streets 50
216
49
207
306
1,303
Prior to applying appropriate emission factors and speed
correction factors, the LDV, LDT, HDV, and HDD daily VMT were
grouped according to freeway, arterial, or local traffic and
converted to annual VMT, as shown below.
37

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1974 Annual VMT x 10"^
LDV
LDT
HDV
HDD
Campbell	Converse	Sweetwater
Freeway	77,623	79,079	235,863
Arterial	25,003	16,027	55,769
Local	3,129	3,007	18,892
105,755	98,113	310,524
Freeway 2,299 1,995 10,204
Arterial 574 277 1,220
Local		17		16		104
2,890	2,288	11,528
Freeway 10,554 9,156	62,272
Arterial 2,633 1,271	5,601
Local		79		76	476
13,266	10,503	68,349
Freeway 2,475 2,148 14,607
Arterial 618 299 1,314
Local		18		1ฃ		112
3,111	2,465	16,033
Total	125,022	113,369	406,434
To check the annual VMT, gasoline sales totals for each county
were obtained from the State Department of Revenue for 1974.
Diesel sales could not be obtained because there is no diesel
sales tax in Wyoming. Total VMT calculated by applying an
average vehicle mileage factor of 12.2 miles per gallon (Ref. 11)
to the county gasoline sales are as follows:
Gasoline Sales VMT	LDV, LDT & HDV VMT
Campbell 138,645,509	121,911,000
Converse 72,318,513	110,904,000
Sweetwater 366,949,953	390,401,000
Considering the relative accuracy of the 12.2 miles per gallon
average mileage factor, reasonably good agreement was found
between VMT estimates from the Highway Department and VMT
38

-------
Hydrocarbon emission factors for the year 1974 were calculated
for the four vehicle classes by procedures described in
Supplement 5 to AP-42 (August 1975) (Ref. 12). These emission
factors are a function of vehicle age distribution, ambient
temperature, percent of vehicles operating with a cold engine,
altitude, and average vehicle speed. The following assumptions
were made with respect to the above variables:
. the fraction of travel by each model year is the
same in Wyoming as nationwide
. mean annual temperature = 45ฐ F
. approximately 20 percent of the LDV are operating
in a cold condition (first 500 seconds of operation
after an engine-off period of at least 4 hours) at
any given time
. high altitude emission rates are applicable.
The resulting emission factors for each of the four vehicle
classes and three highway types are summarized below. The
annual HC emissions for Campbell and Converse Counties are
also presented in that summary. The emission estimates were
determined by multiplying annual VMT for each travel category
by the corresponding emission factor.
Vehicle Highway HC Emission Hydrocarbon Emissions (tons/yr)
Class Type Factor, gm/VMT Campbell	Converse
LDV
Freeway
8.75
749
763

Arterial
8.75
241
155

Local
10.96
38
36
LDT
Freeway
11.57
29
25

Arterial
11.57
7
4

Local
14.00
-
-
HDV
Freeway
25.83
300
261

Arterial
25.83
75
36

Local
31.50
3
3
HDD
Freeway
2.34
6
6

Arterial
2.59
2
1

Local
3.66
_
—
Total
1450
1290
39

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computed from gasoline sales. Since the Highway Department
VMT is based on counts of actual traffic volume, these data were
used to estimate emissions.
Base Year Emissions
Emission factors for LDV, LDT, HDV, and HDD for particulates
and sulfur oxides are as follows (Ref. 12).
Emission Factors (gm/mile)
Pollutant
LDV, LDT
HDV
HDD
Particulate



Exhaust
.34
.91
1.30
Tire wear
.20
.27
.27
Brake wear
.02
.03
.03

.56
1.21
1.60
Sulfur Oxides
(S02)	.18	.36 2.8
Since only Sweetwater County has been designated for S02,
sulfur dioxide emissions were not calculated for Converse
and Campbell. County-wide emissions are calculated by
multiplying VMT by the appropriate emission factor for LDV,
LDT, HDV, and HDD.
1974 Particulate and S0o Emissions (tons/yr)
Campbell	Converse	Sweetwater

Particulates
Particulates
Particulates
S02
LDV,
LDT 67.0
62.0
248.8
63.9
HDV
17.7
14.0
91.2
27.1
HDD
5.5
4.3
28.2
49.5
Total
90.2
80.3
368.2
140.5
40

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Projections
According to Supplement 5 of EPA's Compilation of Emission
Factors (August 1975), SO2 emission factors will remain the
same for future model years. Therefore, projected SO2
emissions will vary only with VMT.
However, particulate emission factors will decrease for
future model years due to the use of unleaded fuel. It is
assumed that all model year vehicles beyond 1975 will use
unleaded fuel. Therefore, projected particulate emissions
will vary with model year and VMT.
Since projected VMT for the three counties was not available
from the highway department, alternative methods were examined.
The selected method was to assume that foreign (out-of-
state) travel will remain constant and that the remainder of
the VMT (Wyoming) will increase with county population.
The percent of foreign vehicles was available for two high-
way system types: freeway and arterial. These percentages
for interstate and primary and secondary roads by county are
as follows (Ref. 14).
Percent Foreign Vehicles
Campbell	Converse	Sweetwater
Freeway	.34	.27	.47
(Interstate)
Arterial	.07	.09	.26
(FAP and FAS)
It was assumed that there are no foreign vehicles on local
roads.
Base year VMT was then converted to percentages according to
three categories:
41

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Percent of VMT
Campbell Converse	Sweetwater
Freeway .74 .81	.83
Arterial .23 .16	.13
Local .03 .03	.04
Total base year emissions for each county were subdivided
into the three categories using the above percentages.
Base Year Total Emissions (tons/year)
Campbell	Converse	Sweetwater
PART	PART	PART SO
Freeway
Arterial
Local
Total
67
21
2
90
65
13
2
80
305
48
15
368
2
118
19
	4
141
This method assumes that the ratio of LDV, LDT, HDV, and
HDD will remain the same in future years. These emissions
were multiplied by the percent of in-state vehicles to
obtain those emissions from in-state traffic.
Base Year In-State Traffic Emissions (tons/year)
Campbell	Converse	Sweetwater
PART	PART	PART SO
Freeway
Arterial
Local
44
2Q
2
47
12
2
PART
162
36
14
2
63
14
4
Total
66
61
212
81
These emissions were then multiplied by population growth
factors and added to emissions from foreign traffic.
Particulate emissions were adjusted for those vehicles using
unleaded fuel. The emission factor for unleaded fuel for
LDV and LDT is .05 gm/mile (Supplement 5, AP-42). The ratio
of LDV and LDT VMT to total VMT was calculated for each
42

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county and multiplied by the 1980 and 1985 total emissions
to obtain the emissions from LDV and LDT vehicle types. Only
the emissions from these vehicle types will be affected by
the use of unleaded gas.
An average particulate emission factor for 1980 and 1985 was
calculated with 60 percent and 93 percent of all vehicles using
unleaded fuel by 1980 and 1985, respectively.
For 1980,
EF = (.4) (.34) + (.6) (.05) + (.22) = .39 gm/mi.
For 1985,
EF = (.07) (.34) + (.93) (.05) + (.22) = .29 gm/mi.
where, EF = emission factor
The percent vehicles using unleaded fuel (beyond 1975) was
obtained from the national vehicle age population distribution.
The ratio of the average emission factor to the 1974 emission
factor (.56 gm/mile) was calculated and multiplied by the
emissions from LDV and LDT to determine the 1980 and 1985
loss in emissions from unleaded fuel use. This loss was
subtracted from the 1980 and 1985 projected emissions, therefore
adjusting emissions for those vehicles using unleaded fuel.
Projected Emissions (tons/year)
Campbell
GF PART
GF PART
Converse
Sweetwater
GF PART SO2
In-State Traffic
1975	1.21 80
1980	2.45 126
1985	3.14 133
1.03
1.44
1.51
63
68
58
1.12 237 91
1.50 254 105
1.60 229 102
Foreign Traffic
1975	1.0	24
1.0
19
1.0 156 60
43

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1980	1.0	19	1.0	15 1.0 125 79
1985	1.0	15	1.0	12 1.0 106 74
Total
1975	104	82	393	151
1980	145	83	379	184
1985	148	70	335	176
Since hydrocarbon emission factors vary with each vehicle
model year, Supplement 5 of EPA's Compilation of Emission
Factors (August 1975) was used to calculate these factors
for future years. Therefore, projected HC emissions vary
with both VMT and emission factors.
The method used to project VMT in estimating projected
particulate and SO2 emissions was also used for hydrocarbon
emissions. Projected VMT for each vehicle class and highway
type is shown in Table 7.1.
Projected emission factors for each vehicle class and high-
way type are as follows:
HC Emission Factor
	(gm/VMT)	
Vehicle Class
Highway Type
1975
1980
1985
LDV
Freeway
8.3
5.5
2.1

Arterial
8.3
5.5
2.1

Local
10.4
6.8
2.5
LDT
Freeway
11.0
8.2
4.0

Arterial
11.0
8.2
4.0

Local
13.3
9.8
4.9
HDV
Freeway
24.1
18.0
13.2

Arterial
24.1
18.0
13.2

Local
29.3
21.5
15.4
HDD
Freeway
2.3
2.3
2.3

Arterial
2.6
2.6
2.6

Local
3.7
3.7
3.7
Applying these factors to projected VMT for Campbell and
Converse Counties results in the following projected emissions:
44

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Table 7.1. Projected Annual VMT (103)


Campbell


Converse

Sweetwater

1975
1980
1985
1975
1980
1985
1975
1980
1985
LDV
Freeway
Arterial
Local
89,266
28,753
3,598
160,679
51,756
6,477
201,043
64,758
8,104
80,661
16,347
3, 067
105,966
21,476
4,029
109,920
22,278
4,180
252,373
59,673
20,214
304,263
71,942
24,371
318,415
75,288
25,504
LDT
Freeway
Arterial
Local
2,644
660
20
4,759
1,188
35
5,954
1,487
44
2,035
282
16
2,673
371
21
2,773
385
22
10,918
1,305
111
13,163
1,574
134
13,775
1,647
140
HDV
Freeway
Arterial
Local
12,137
3,028
91
21,846
5,450
163
27,335
6,819
205
9,339
1,296
78
12,269
1,703
102
12,727
1,767
106
66,631
5,993
509
80,331
7,225
614
84,067
7,561
643
HDD
Freeway
Arterial
Local
2,846
711
21
5,123
1,279
37
6,410
1,601
47
2,191
305
18
2,878
401
24
2,986
416
25
15,629
1,406
120
18,843
1,695
144
19,719
1,774
151

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LDV
Freeway
Arterial
Local
LDT
Freeway
Arterial
Local
HDV
Freeway
Arterial
Local
HDD
Freeway
Arterial
Local
Total
Projected Hydrocarbon Emissions (tons/year)
Campbell	Converse
1975 1980 1985	1975 1980	1985
817 974 465	738 642	254
263 314 150	150 130	51
41 49 22	35 30	11
32 43 26	25 24	12
8 11 7	3 3	2
322 433 398
80 108	99
3	4	4
248 243 185
34	34	26
3	2	2
7 13 16
2	4	5
1575 1953 1192
6	7	8
111
1243 1116 552
46

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8. OFF-HIGHWAY VEHICLES
Data Inventory and Methodology
This category includes off-highway sources using: (1) gasoline;
(2) diesel. Typical gasoline fuel users are farm tractors,
construction tractors, compressors, pumps, and small electric
generators. Typical diesel fuel users are farm tractors,
construction tractors, and construction loaders and grader
(1) Gasoline
To calculate gasoline fuel consumption two fuel usage factors
were used (Ref. 11):
tractor gasoline - 1,000 gals/tractor/year
fuel usage factor
population gasoline - 13 gals/person/year
fuel usage factor
The total number of farm tractors (Ref. lo) and population
(Ref. 3) in each county is as follows:
Tractors
Campbell:
Converse:
Sweetwater:
1969
885
648
276
1974
956
700
298
1974 Population
11,900
7,100
25,900
It is assumed that the number of tractors has increased from
1969 to 1974 by 8%, which is proportional to state wide
population growth.
Applying the tractor fuel usage factor to the number of
tractors in each county and assuming that 60% are gasoline
powered (Ref. 11), yields the gasoline consumption by tractors.
47

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Tractor Gasoline Consumption (gals/yr)
Campbell - 573,600
Converse - 420,000
Sweetwater - 178,800
Applying the population fuel usage factor to population in
each county, yields the gasoline consumption by other fuel
users.
Other Gasoline Consumption (gals/yr)
Campbell -	154,700
Converse -	92,300
Sweetwater -	336,700
(2) Diesel
To calculate diesel fuel consumption	two fuel usage factors
were used (Ref. 11).
tractor diesel	- 1,000 gals/tractor/year
fuel usage factor
construction diesel - 5,000 gals/employee/year
fuel usage factor
The total number of non-building construction employees in
1973 (Ref. 2) in each county is as follows:
Non-Building Employees
Campbell - 108
Converse - 140
Sweetwater - 400
Employees for 1973 are assumed to be representative of 1974.
48

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Applying the tractor fuel usage factor to the number of
tractors in each county and assuming that 35% are diesel
powered (Ref. 11), yields the diesel consumption by tractors:
Tractor Diesel Consumption (gals/year)
Campbell - 334,600
Converse - 245,000
Sweetwater - 104,300
Applying the construction fuel usage factor to number of
non-building employees, yields the diesel consumption by
other diesel fuel users.
Other Diesel Consumption (gals/year)
Campbell - 540,000
Converse - 700,000
Sweetwater - 2,000,000
Base Year Emissions
Emission factors for gasoline and diesel farm tractors are as
follows (Ref. 12):
Tractor Emission Factors (lb/10^ gal)
Gasoline	Diesel
Particulate	8.0	45.7
Exhaust HC	125.0	60.7
Crankcase HC	25.1
S02	5.3	31.2
Emission factors for other fuel consumption were obtained by
averaging gasoline and diesel-powered construction equipment
emission factors (Ref. 12).
49

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Other Fuel Consumption Emission Factors (lb/103 gals)
Gasoline
Diesel
Particulate
Exhaust HC
SO.
7.1
136.8
5.3
26.1
29.1
31.2
Applying these emission factors to the tractor and other
fuel consumption for both gasoline and diesel yields the
following emissions:
1974 Emissions (tons/year)
Campbell
Part HC
Converse
Part
HC
Sweetwater
Part S02
Tractor
Gas
Diesel
2
8
43
10
2
6
32
7
1
2
Other
Gas
Diesel
1
7
11
8
6
10
1
26
1
31
Total
18
72
17
55
30
34
50

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Projections
Since off-highway base year emissions were determined by
applying fuel usage factors for tractors, population, and
construction employees, growth in emissions would parallel
projected farm activity, population, and construction.
Farming activity will remain relatively constant in the
three counties (growth factor = 1.0), while population and
construction will both increase.
Construction growth factors were obtained from DEPAD (Ref. 56)
for Campbell and Converse Counties. Construction data were
not available for Sweetwater County, so population growth
factors were used.
Projected Emissions (tons/year)
Campbell	Converse	Sweetwater
GF PART HC	GF PART HC	GF PART S02
Other Gasoline (assumed to increase in proportion


to population)




1975
1.21
1 13 1.03
6
1.12
1
_ _
1980
2.45
2 27 1.44
1 9
1.50
2
1
1985
3.14
3 35 1.51
1 9
1.60
2
1
Other
Diesel
(assumed to increase
in proportion




to construction activity)



1975
2.97
21 24 1.25
11 13
1.12
29
35
1980
4.14
29 33 2.45
22 25
1.50
39
47
1985
4.64
32 37 1.20
10 12
1.60
42
50
Tractor (assumed constant)
1975
1.0
10
53
1.0
8
39
1.0
3
2
1980
1.0
10
53
1.0
8
39
1.0
3
2
1985
1.0
10
53
1.0
8
39
1.0
3
2
Total









1975

32
90

19
58

33
37
1980

41
113

31
73

44
50
1985

45
125

19
60

47
53
51

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9. RAILROADS
Data Inventory and Methodology
The Wyoming Air Quality Division contacted the Wyoming
Public Service Commission to obtain data on miles of track
for each railroad company in the three counties and in the
entire state (Ref. 18). The following is a summary of the
miles of track for each county for 1974:
Campbell	Converse	Sweetwater
Burlington	76	69
Northern
Chicago and	—	70
Northwestern
Union Pacific	--	— 433
U.S. Steel Corp.	--	— 57
TOTAL	76	139 490
The total miles of track for all railroads in the state is
3287 miles. Miles of track include main line, second line,
passing and switching, and yards (abandoned track has been
subtracted).
The total state residual and distillate fuel oil consumed
by railroad locomotives in 1973 was 2.552 x 10^ barrels
(Ref. 6). To calculate the 1974 railroad fuel consumption
for each county, the 1974 statewide fuel consumption was
assumed to be the same as 1973 and the miles of track were
used to apportion fuel to each county. Therefore, using
.023, .042, and .149 for Campbell, Converse, and Sweetwater
counties, respectively, county railroad fuel consumption was
calculated.
Campbell - 2,478 • 10^ gals/yr.
3
Converse - 4,533 • 10 gals/yr.
Sweetwater - 15,975 • 10"^ gals/yr.
52

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The apportioned fuel consumption was checked by contacting
the Burlington Northern (BN), Chicago and Northwestern
(CNW), and Union Pacific (UP). The CNW and BN provided
information on frequency of trains, speeds, and average fuel con-
sumption rate. The BN provided the following data for
Converse and Campbell (Ref. 19):
Converse	Campbell
trains/day 4.0	14.0
locomotive/train 3.0	4.0
fuel consumption 2\ gals/mi/loco. 2h gals/mi/loco,
speed 49 MPH	49 MPH
The CNW provided the following data	for Converse County
(Ref. 20):
trains/day	1.0
fuel consumption	300 gal/hour
speed	4 5 MPH
The BN and CNW indicated that no trains operate on Sunday, therefore,
trains operate	313 days/year. Using the track mileage
reported above, the following fuel usage rates were calculated:
Converse	Campbell
Burlington	583 • 10"*	2,997 • 10"*
Northern
3
Chicago and	146 • 10
Northwestern
TOTAL 729 • 10"* gals/yr.	2,997 • 10"* gals/yr,
UP data for Sweetwater County could not be obtained within
the time constraints of this analysis.
53

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Since the actual fuel consumption is more accurate than
apportioning statewide fuel consumption, the actual fuel
totals were used for Campbell and Converse Counties. Ap-
portioned fuel consumption was used for Sweetwater due to
the lack of actual fuel data.
Base Year Emissions
The following are the emission factors used to calculate
particulate, S02, and hydrocarbon emissions (Ref. 12):
3
Particulate - 25 lb/10 gals
SOj - 57 lb/103 gals (.4% sulfur)
HC - 94 lb/103 gals
The calculated emissions and associated fuel consumptions
are as follows:
1974 Emissions (tons/yr)
3
Campbell: Fuel Consumption - 2,997 . 10 gals/yr
Particulates - 37 tons/yr
Hydrocarbons - 141 tons/yr
3
Fuel Consumption - 729 • 10 gals/yr
Particulates - 9 tons/yr
Hydrocarbons - 34 tons/yr
3
Fuel Consumption - 15,975 • 10 gals/yr
Particulates 200 tons/yr
SO- - 455 tons/yr.
Converse:
Sweetwater:
54

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DEPAD reported that in the Powder River Basin, a transportation
alternative for coal development is to transport coal out of
Wyoming by rail (Ref. 60). This report stated that a 113
mile track connecting Gillette and Douglas could be completed
in two years. It is assumed that this alternative will be
selected since current plans call for six new coal mines
with the three existing coal mines expanding their operation (Ref. 42).
The only new coal users locally will be one coal gasification
plant and expansion of the existing Wyodak power plant.
This new track will carry a maximum of 24 loaded trains per
day (plus 24 empty) in 1980 and 34 loaded trains per day
(plus 34 empty) in 1985. These train frequencies were ob-
tained from the Powder River Basin EIS (Ref. 42).
The 1975 Campbell and Converse County railroad emissions
were estimated to be the same as the 1974 emissions.
An average train will be powered by approximately 5 loco-
motives (Ref. 42). Trains will operate 365 days per year.
It was assumed that half of the trains will service the
coal mines through Gillette and the other half will service
through Douglas. Burlington Northern average fuel consumption
data (2.25 gals/loco./mile) were used to calculate future
emissions. Existing train activity will probably continue
at the same level to 1985 in these two counties.
In Sweetwater County only one new coal mine is known to be
opening. Since most of this new coal will be used to supply
the new units at the Jim Bridger Power Plant, an increase in
railroad activity across the county is not expected. There-
fore, railroad emissions will probably remain constant through
1980 and 1985.
55

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Projected Emissions (tons/year)
Campbell	Converse	Sweetwater

PART
HC
PART
HC
PART
1975
37
141
9
34
200
1980
176
664
148
558
200
1985
232
877
206
776
200
so2
455
455
455
56

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10. AIRCRAFT
Data Inventory and Methodology
Aircraft operations are limited to three general aviation
airports located in Rock Springs, Gillette, and Douglas.
Gillette and Douglas presently have no domestic air carrier
service but are serviced by a third level or commuter air
carrier (Ref. 21). The third level carrier operates ap-
proximately two flights per day into each airport. Rock
Springs is serviced by a domestic carrier with six scheduled
flights per day (Ref. 22). The remainder of the aircraft
operations at the three airports is general aviation.
The type of aircraft used for the domestic carrier is
Convair 580 turboprop. Third level carrier and general
aviation are both comprised of general aviation piston
aircraft.
Annual airport operations (landing and take-off) for each
aircraft type and each	airport in 1974 are summarized below:
Aircraft(engines)	Rock Springs Gillette	Douglas
Air carrier	2,200
turboprop (2)
Business jets (2)	1,000 Neg	Neg
General aviation	3,000 Neg	Neg
turboprop (2)
General aviation
piston
2 engines	16,900 3,650	3,650
1 engine	16,900 3,650	3,650
TOTAL	40,000 7,300	7,300
Rock Spring's annual operations were provided by the Rock
Springs Municipal Airport Manager (Ref 22). The Gillette
and Douglas annual operations were determined by assuming
57

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that each airport had an average daily operation of 20 aircraft
(Ref. 23) and that the business jet and general aviation turbo-
prop traffic was negligible. It was assumed that turboprop and
business jets normally have two engines and that h of the
piston engine aircraft have 2 engines.
Base Year Emissions
The emission factors for a landing and takeoff cycle are as
follows for each aircraft type (Ref. 12):
Emission factor (lb/engine)
Particulate	Hydrocarbon	SQ^
Air carrier turboprop	1.1	2.9	.40
Business jet	.11	3.6	.37
General aviation turboprop	.20	1.1	.18
General aviation piston	.02	.40	.014
Multiplying the emission factor by the number of engines and
annual LTO cycles yields the total emissions for each pollutant
for the year 1974.
1974 Emissions (tons/yr)
Campbell Converse Sweetwater
(Gillette) (Douglas)	(Rk.Sp.)
Part HC Part HC Part S02
Air carrier	— — — — 2.4 0.9
turboprop
Business jets	— — — —	0.1 0.4
General aviation	<—	—	—	—	0.6	0.5
turboprop
General aviation	0.1	2.2	0.1	2.2	0.5	0.4
piston														
TOTAL	0.1 2.2 0.1 2.2 3.6 2.2
58

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Projections
Projections of activity at the Rock Springs airport were
obtained from the Manager of the Rock Springs Municipal
Airport (Ref. 22). It is anticipated that there will be a
60 percent increase in operations by 1985. This gives a
growth factor of 1.3 from 1974 to 1980 and 1.60 from 1974 to
198 5. It is assumed that operations will remain almost
constant from 1974 to 1975.
For Campbell and Converse Counties, it is assumed the
operations will remain the same in 197 5 as in the base year
and increase approximately 100 percent from 1975 to 1985
(Ref. 27) •	Detailed estimates are not warranted because
of the negligible emissions from this source category.
Growth factors from the base year and resultant emissions
are as follows:
Projected Emissions (tons/year)
Campbell	Converse	Sweetwater

GF
PART
HC
GF
PART
HC
GF
PART
Sฐ2
1975
—
.12
2.2
—
.12
2.2
—
3.6
2.2
1980
1.5
.18
3.3
1.5
.18
3.3
1.3
4.7
2.9
1985
2.0
.24
4.4
2 . 0
.24
4.4
1.6
5.8
3.5
59

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11. INDUSTRIAL PROCESSES
Two categories of industrial processes have been considered
as area sources: (1) heater treaters; (2) pipeline compressors.
Each of the categories has been analyzed separately.
Data Inventory and Methodology
(1) Heater Treaters
Heater treaters are used to remove water from the crude oil
being extracted from the wells. Normally, they are placed
on the main line entering the tank battery where the crude
oil is stored before shipping to the refinery. Most heater
treaters burn natural gas that is tapped off the oil well.
Heater treaters range in size from 4 feet to 10 feet in
diameter, and consume from 20 MCF to 2.5 MMCF daily. The
most common sizes are 6-8 feet and the average consumption
rate is 100 MCF per day. Operating time is 24 hours per day
and 9 months per year (there is little moisture during the
summer) (Ref. 24).
In order to determine the number of heater treaters and
their locations in the three counties, it was necessary to
make two assumptions—that there is one heater treater per
tank battery and one tank battery per lease (Ref. 25). The Wyoming
Oil and Gas Commission was contacted to obtain the number of
leases for each oil field for each county and location
(Ref. 26). It was also assumed that only 90% of the heater
treaters would be operating during the entire 9-month period
because the units are not needed full time. Presented below
are the equivalent nujnbere of heater treaters operating in
1974 in each county:
Campbell: 1,104
Converse: 389
Sweetwater: 258
60

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Applying the 100 MCF of natural gas rate for 9 months
(27.375 MMCF) to the number of heater treaters in each
county, the annual natural gas consumption values are
obtained:
Natural Gas Consumption (1Q6 ft-^)
Campbell = 30,222
Converse = 10,063
Sweetwater = 7,063
(2) Compressors
Compressors used in natural gas transmission are powered by
either piston or gas turbine engines. The compressors are
located on the pipelines which transport raw natural gas at
a well site to the refinery or distribute natural gas to the
customer. They burn natural gas as a fuel.
The major companies that operate pipelines in Converse and
Campbell Counties were contacted. Data were obtained by
manufacturer, type of engine, number of units, horsepower
per unit, estimated operating time, and location (Ref. 43,
44, 45, 46, 47). All compressors were determined to have
piston engines ranging in horsepower from 130 to 2000. The
total number of compressors in each county is as follows:
Campbell - 93
Converse - 22
Compressors in Sweetwater County were not inventoried due to
the small number of pipelines transporting natural gas from
wells in this county.
Estimates of fuel consumption per unit were based on data
relating horsepower to natural gas consumption per hour
(Ref. 48).
61

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Estimated Natural Gas Consumption (MMCF/yr)
Campbell - 5508.8
Converse - 352.4
Base Year Emissions
(1) Heater Treaters
Emission factors for natural gas are as follows (Ref. 12).
Emission Factors (Ibs/1Q^ ft3)
Particulates - 15
Sulfur Oxides (SO2) - 0.6
Hydrocarbons - 8
Maximum factors were used for particulates and hydrocarbons
because the natural gas being burned is in a raw state.
1974 Heater Treater Emissions (tons/yr)
Pollutant
Particulates
SO.,
Campbell
227
n.c.
Hydrocarbons
121
Converse
80
n.c.
Sweetwater
53
2
43
n.c.
n.c. = not calculated
(2) Compressors
Particulate emissions were calculated by using the average
emission factor for natural gas combustion in an industrial
process, 10 lb/MMCF (Ref. 12). Hydrocarbon emissions were
calculated by using the non-methane emission factors for
each manufacturer's engine type (Ref. 48) in lb/hour and
multiplying by the number of operational hours per year.
62

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The total emissions of particulates and hydrocarbons are as
follows
1974 Compressor Emissions (tons/year)
Campbell: Particulates - 27.5
Hydrocarbons - 187.6
Converse: Particulates - 4.3
Hydrocarbons - 41.5
63

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Proj ections
DEPAD has projected oil and gas production in the three
counties over the short term (1974-78) (Ref. 58); they
projected that production would be relatively constant. The
two industrial processes, pipeline compressors and heater
treaters, are related to oil and gas production. Therefore, a
change in oil and gas production would be proportional to a
change in industrial process emissions. Since production will
probably remain constant to 1985, it is ausumed that
emissions from this category will be the same for 1975,
1980, and 1985.
64

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12. EVAPORATIVE LOSSES
Two types of evaporative losses were considered in this
source category: (1) oil and gas fields; (2) gasoline
transport.
The major oil and gas field hydrocarbon evaporative loss was
identified as crude oil storage tanks. Additional hydrocarbon
combustion emissions (from heater treaters and pipeline
compressors) are presented in Section 11 of this report.
Emissions from other oil and gas field sources are considered
negligible (Ref. 62, 63).
The major gasoline transport hydrocarbon evaporative loss
was identified as: (1) loading of tank cars and trucks; (2)
loading of underground gasoline storage tanks; (3) filling
motor vehicle gas tanks.
Data Inventory and Methodology
Crude oil pumped from wells is stored in tanks before shipment
to the refinery. The tanks are normally the fixed roof type
with a capacity of 500 barrels and a diameter of 15 feet.
To determine the number of oil field storage tanks in the
two counties, it was assumed that there is one tank per
well.The number of wells per field are given in Reference
64. In some fields, however, a few wells have a high total
production. For these fields the assumption of one tank per
well is unrealistic, therefore the number of tanks was
calculated using 30 turnovers per tank per year (Ref. 65). The
estimated number of tanks in each county is as follows:
Campbell - 2,069
Converse - 564
The 1974 oil production in the two counties is given below (Ref. 64).
Oil Production (lO^bbl)
Campbell - 34,247
Converse - 6,967
65

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For gasoline transport, the 1974 gasoline sales for Campbell
and Converse counties obtained from the Wyoming Department
of Revenue were used to calculate evaporative losses. The
gasoline sales are as follows:
Campbell - 11,364,386 gals
Converse - 5,927,747 gals
Base Year Emissions
Hydrocarbon emissions from fixed roof tanks occur as breathing
losses and working losses. Breathing losses result when
vapor is expelled due to thermal expansion, barometric
pressure changes, and added vaporization of the liquid.
Working losses are when emptying or filling operations cause
hydrocarbon vapor to be expelled from the tank.
The emission factor for breathing losses was adjusted for a
15 ft diameter tank. The emission factors are as follows (Ref.
Oil and Gas Field
Hydrocarbon Emission Factors
Breathing losses - 0.11 lb/day-103 gal storage capacity
Working losses - 7.3 lb/103 gal throughput
Oil and Gas Field
1974 Hydrocarbon Emissions
(tons/yr)
Campbell - 6,123
Converse - 1,306
The emission factors for gasoline transport are as follows (Ref.
Gasoline Transport
Hydrocarbon Emission Factors
Tank Cars/Trucks
(submerged loading) - 4.1 lb/103 gals
Underground Gasoline Storage
(uncontrolled submerged) - 7.3 lb/103 gals
Filling motor vehicle gas tanks
(vapor displacement and liquid spillage) -
11.67 lb/103 gals
Total Emission Factor - 23.07 lb/103 gals
66

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Using the total emission factor and county gasoline sales,
the base year hydrocarbon emissions are as follows:
Gasoline Transport
1974 Hydrocarbon Emissions
(tons/yr)
Campbell - 131
Converse - 6 8
Projections
In Section 11, a rationale for considering oil and gas field
hydrocarbon emissions to be constant from the base year to
1985 was presented. Therefore, hydrocarbon evaporative
losses will be considered constant to 1985.
For gasoline transport, growth factors were determined from
projected VMT for LDV, LDT, and HDV using gasoline in
Section 7. Applying these growth factors to base year
emissions results in projected emissions.
Gasoline Transport
Projected Hydrocarbon Emissions
(tons/yr)
Campbell
Growth	HC
Factor Emissions
Converse
Growth HC
Factor Emissions
1975
1980
1985
1.15
2. 07
2.53
151
271
331
1.02
1.34
1.39
69
91
95
67

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13. UNPAVED ROADS
Data Inventory and Methodology
The Wyoming Department of Highways was contacted to obtain
the following data for unpaved roads in 1974: miles of
unpaved roads, average daily traffic, and average vehicle
speed by surface type (Ref. 27). This data is shown for the
three counties and for each highway system in Table 13.1.
Information on silt content of the road bases was also
needed in order to estimate emissions. Since the average
silt content of gravel roads is known to be 12% (Ref. 28),
it is only necessary to determine parent soil silt content
for bladed and graded and drained roads. Therefore, the
Wyoming State Soil Scientist was contacted to obtain data
for silt content for soils in each county (Ref. 29). Data
was provided for the general soil series by percent con-
tribution of groups of series at a given map location. A
weighted average was then applied to calculate average silt
content at each map location. To arrive at a county-wide
silt content, an average of all locations was determined.
The exception was Sweetwater County, where only 20% of the
county soil series had been analyzed by the Soil Conservation
Service. An average of the existing series was used to
arrive at a county-wide silt content (Ref. 30). The three
county-wide silt content averages were used to represent
both bladed and graded and drained road surface silt content.
Base Year Emissions
Emission factors for dust from unpaved roads were obtained
from a recent EPA publication (Ref. 28). Only the particulates
of less than 30 microns in diameter were assumed to have
impact on a regional scale# so the equation for calculating
the emission rate was modified with a factor of 0.6 to
account for just the sub-30 micron particles (Ref. 28):
68

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Table 13.1. WYOMING UNPAVED ROADS 1974
SURFACE TYPE BY
HIGHWAY SYSTEM
CONVERSE
Miles of % Silt
Road Content
CAMPBELL
Miles of % Silt
Road Content
SWEETWATER
Miles of % Silt
Road Content
ADT
(Estim.)
SPEED
(MPH)
Bladed(B)









County
Federal
Local

106.2
22.7
282.8

28.8
3.7
54.3

31.9
176.0
88.9

5
5
5
30
30
30
TOTAL

411.7
22.6%
86.8
24%
296.8
18%
—
—
Graded & Drained(C)








County
Federal
Local

361.6
15.3
273.0

149.0
95.3

234.2
38.3
100.2

10
10
10
40
40
40
TOTAL

249.0
22.6%
244.3
24%
372.7
18%
—
—
Gravel (E2)









County
Federal
Local

13.8
28.5

788.2
344.1

811.3
20.7
79.2

20
20
20
40
40
40
TOTAL

42.3
12%
1132.3
12%
911.2
12%
—
—
Total miles

1103.0

1463.4

1580.7




-------
E = (0.6) x (0.81) x (s) x (S/30)	(eg. 2)
where	E = emission factor, lb/vehicle-mile
s = silt content, percent
S = average vehicle speed, MPH
Using the data from Table 13.1, the following emission
factors were calculated:
Emission Factors, lb/VMT
Road surface
Bladed
Graded & drained
Gravel
Campbell	Converse	Sweetwater
11.7	11.0	8.7
15.6	14.6	11.7
7.8	7.8	7.8
These emission factors are not corrected for wet days or
days with snow cover on the roads. It is assumed that no
emissions occur on these days. The annual mean number of
days with 0.01 inches or more of precipitation was obtained
from the map of precipitation frequency in the EPA fugitive
dust publication (Ref, 28). The number of days with snow
cover or freezing conditions was estimated from the National
Weather Service 1974 Climatological Summary for the nearest
recording station. The emission factors presented below are
corrected for non-dusting days:
Corrected Emission Factors (lb/VMT)
Campbell
Converse
Sweetwater
Bladed
Graded &
drained
Gravel
Corr.
Fact.
Emis.
Fact.
255/365 8.2
255/365 10.9
255/365 5.4
Corr.
Fact.
243/365
243/365
243/365
Emis.
Fact.
7.3
9.7
5.2
Corr.
Fact.
248/365
248/365
248/365
Emis,
Fact,
5.9
7.9
5.3
70

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To calculate emissions, the annual VMT was determined from
the Highway Department data. Particulate emissions for each
county and for each surface type are:
1974 Particulate Emissions (tons/yr)
Bladed
Graded &
drained
Gravel
TOTAL
Campbell	Converse Sweetwater
Annual	Annual Annual
VMT 106 Emissions	VMT 106 Emissions VMT 106 Emissions
0.16 656	0.75 2,738 0.54	1,593
0.89 4,851	2.37 11,495 1.36	5,372
8.27
9.32
22,329
27,836
0.31
3.43
806
15,039
6.65
8.55
17,623
24,588
71

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Projections
Growth in emissions from unpaved roads is dependent on new
miles of roads and increased average daily traffic (ADT).
Since new industry (mainly new coal mines) will be located
in rural areas with existing unpaved roads, it was assumed
that miles of road will remain constant. New employees will
travel from urban areas to the industrial sites and truck
traffic will increase around each site. It was assumed that
ADT will increase with population.
However, as the traffic volume or ADT increases, some roads
will be paved. In order to incorporate this into the pro-
jected emission calculations, the following procedure was
used:
•	Assume a normal distribution of ADT vs. percent of
total miles of unpaved roads. This distribution
is shown in Figure 13.1.
•	Establish base year ADT at 50 percentile and
determine percent of miles exceeding 250 vehicles
per day (traffic volume at which a road is paved—
Ref. 63).
•	Multiply growth factors by base year ADT to obtain
projected ADT and determine percent of miles
exceeding 250 vehicles per day for future years.
•	Subtract base year percent of miles exceeding 250
ADT from each percent of miles determined for
future years.
•	Multiply this difference by the existing miles of
road to arrive at additional miles of roads
exceeding 250 vehicles per day, or miles which
should be paved far each future year.
. Determine from the distribution the average ADT on
roads to be paved for each future year (slightly
greater than 250).
•	Multiply this ADT by the additional miles of road
exceeding 250 vehicles per day for each future year
to arrive at VMT loss on unpaved roads due to
paving.
•	Multiply total base year VMT on unpaved roads by
growth factors and subtract .VMT loss due to paving.
72

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toto 10
-J
u>
lug 1_
9
8
7
5
4
3
2
10 1

-------
Base year ADT for each county was determined by finding the
weighted average ADT of all road surface types (miles were
used as the weighting factor).
The following calculations and distribution data were used
to project emissions from unpaved roads:
Campbell
Miles of Unpaved Roads	1463.4
Growth Factors
1975	1.21
1980	2.45
1985	3.14
County-Wide ADT
1974	17.45
1975	21.11
1980	42.75
1985	54.79
Percent Miles (distribution)
1974	0.8
1975	1.0
1980 3.0
1985 4.5
Percent Difference
1975	0.2
1980	2.2
1985	3.7
Miles to be Paved
1975	2.9
1980	32.2
1985	54.1
Average ADT on Miles to
be Paved (Distribution)
1975	320
1980	330
1985	330
VMT Loss Due to Paving (annual)
1975
1980
1985
Projected VMT (annual)
1975
1980
1985
338,720
3,874,490
6,516,345
11,277,000
22,834,000
29,265,000
Converse
1103.0
1.03
1.44
1.51
7.68
7.91
11.06
11.60
0.3
0.3
0.4
0.4
0.1
0.1
1.1
1.1
330
340
340
136,510
136,510
3,533,000
4,939,000
5,179,000
Sweetwater
1580.7
1.12
1.50
1.60
14.82
16.60
22.23
23.71
0.6
0.7
1.2
1.4
0.1
0.6
0.8
1.6
9.5
12.6
320
330
330
186,880
1,114,275
1,517,670
9,576,000
12,825,000
13,680,000
74

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(Continued)	Campbell	Converse Sweetwater
VMT with Assumed Paving
1975	10,938,000 3,533,000 9,389,000
1980	18,960,000 4,803,000 11,711,000
1985	22,749,000 5,043,000 12,162,000
Particulate
Emissions without Paving
(tons/year)
1975	33,681	15,490	27,538
1980	68,198	21,656	36,882
1985	87,405	22,709	39,340
Particulate
Emissions with Paving
(tons/year)
1975	32,669	15,490	27,000
1980	56,628	21,060	33,678
1985	67,944	22,113	34,975
75

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14. AGRICULTURE
Data Inventory and Methodology
There are two sources of fugitive dust from agricultural
activity: wind blown dust and dust caused by tilling operations.
The emissions from tilling have not been aonsidered due to
the small number of tractors operating in the three Wyoming
counties during the year. Windblown dust is considered the
greatest contributor to regional emissions.
The Wyoming Department of Agriculture was contacted to
obtain data on acres planted for each crop type in each
county for the years 1972-73 (Ref. 31). Data for 1974 was
not published at the time of this analysis, so an average of
the two years was used for 1974.
The following is a summary of acres planted or harvested by
crop type for each county:
Acres Planted or Harvested
Crop
Campbell
Converge
Sweetwater
Wheat
21,600
2,425
—
Barley
6,550
3,350
600
Oats
4,450
3,600
900
Beans
—
500
—
Sugar Beets
—
375
—
Corn
850
2,100
—
Hay
700
11,950
7,150
Alfalfa
1,900
20,050
11,750
When the number of acres planted was not available, the
average number of acres harvested was uped.
76

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Base Year Emissions
The windblown dust emission factor equation for determining
particulate emissions is (Ref. 28):
E = a I K C L' V'	(eq. 3)
where: E - emission factor, tons/acre/year
a - portion of total wind erosion losses that
would be measured as particulates, estimated
at 0.025
I - soil erodibility, tons/acre/year
K - surface roughness factor
C - climatic factor
L1 - unsheltered field width factor
V' - vegetative cover factor
In the equation, K,C,L', and V' are dimensionless. In the
EPA fugitive dust publication (Ref. 28), the map of major
soil types in the Northern Great Plain states was used to
determine value I. C,K,L', and V' were also obtained from
data presented in the report.
A summary of the factors used to calculate emission factors
by crop type are presented on the next page.
77

-------
Emission Factors (tons/acre)
County and
Crop Type
I
K
C
L'
V'
E
Campbell
86

.40



Wheat

.6

.82
.04
.017
Barley

.6

.82
.07
.030
Oats

.8

.90
.02
.012
Corn

.6

.82
.56
.237
Hay

.8

.90
.02
.012
Alfalfa

1.0

.85
neg
neg
Converse
86

.40



Wheat

. 6

.82
.04
.017
Barley

.6

.82
.07
.030
Oats

.8

.90
.02
.012
Corn

.6

.82
.56
.237
Hay

.8

.90
.02
.012
Alfalfa

1.0

.85
neg
neg
Beans

.5

.66
.74
.210
Sugar Beets

.6

.70
.85
. 307
Sweetwater
86

.20



Barley

.6

.82
.01
.002
Oats

.8

.90
.01
.003
Hay

.8

.90
.01
.003
Alfalfa	1.0	.85 neg	ne9
Emission factors are multiplied by the corresponding acres
to arrive at total annual emissions. The particulate
emissions for each crop type and county are:
78

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1974 Particulate Emissions (tons/year)
Crop type
Campbell
Converse
Sweetwater
Wheat
367
41
—
Barley
197
100
1
Oats
53
43
3
Corn
201
498
—
Hay
8
143
21
Alfalfa
Neg
Neg
Neg
Beans
—
105
—
Sugar Beets
—
115
—
TOTAL
826
1,045
25
79

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Projections
Data on acres planted and harvested for each crop type from
1964 to 1973 was reviewed to determine trends in agricultural
activity (Ref. 61). It was assumed that the trend established
during the last ten years would continue for the next ten
years. For Campbell and Converse Counties, acres of wheat,
oats, beans, sugar beets, corn, and hay should remain almost
constant from 1974 to 1985. Barley should continue to
increase about 20 percent from 1975 to 1985. For Sweetwater
County, acres of barley and oats should decrease about 20
percent from 1975 to 1985 and hay acreage should remain the
same. Therefore, resulting emissions are as follows:
Projected Particulate Emissions (tons/year)
Campbell
Converse
Sweetwater
1975
1980
1985
826
846
865
1045
1055
1065
25
25
26
80

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15. CONSTRUCTION
Data Inventory and Methodology
For purposes of estimating emissions, three different types of
construction were identified: (1) residential, commercial, and
public; (2) highway; (3) industrial. The first type of
construction included residential sites, shopping centers,
commercial lots, schools, hospitals, recreation centers, and
trailer courts. The data for acres of construction was obtained
from building and planning departments in the following towns:
Rock Springs (Ref. 49), Green River (Ref. 50), Gillette (Ref. 50),
and Douglas (Ref. 52).	'
1974 Acres of Building Construction
Residential	Commercial Public
Homes	Trailer Courts	Buildings Buildings

Acres
Mo.
Acres
Mo.
Acres
Mo.
Acres
Mo.
Campbell
11
3
65
12
8
6
19
6
Converse
12
3
—
—
1.5
6
10
4
Sweetwater
58
3
72
12
32
6
22
6
It was estimated that 1/6 acre was exposed during excavation and
regrading of residential sites. It was also estimated that 1/4
acre was exposed for commercial buildings. Acreage for public
buildings and trailer courts was determined for each individual
construction project.
The Wyoming Department of Highways was contacted to obtain data
on highway projects constructed in 1974 (Ref. 53). This data is
summarized in Table 15.1. Acres of highway constructed was
estimated from the miles and width of the project, and by type of
construction (new or reconstruction).
The Wyoming Air Quality Division was contacted to determine which
new industrial sources were under construction in 1974. The
81

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Table 15.1 HIGHWAY CONSTRUCTION IN 1974

Project
Type Construction
Const. Factor
Months
Miles
Width (H)
Total Acres
Campbell:
1-90
New
1.0
4
4.2
150
76.4

1-90
New
1.0
3
3.9
150
70.9

1-90
New
1.0
3
6.0
150
109.1

1-90
New
1.0
6
6.9
150
125.5

1-90
New
1.0
5
6.7
150
121.8

Gillette St.
New and reconst.
.66
4
0.68
30
1.7

WYO. 59
New and reconst.
.66
1
8.6
60
41.2
Converse:
1-25
New
1.0
' 4
18.9
150
343.6

WYO. 59
New and reconst.
.66
5
10.6
60
77.1
Sweetwater:
1-80
Reconst.
.33
7
14.7
150
88.2

1-80
Reconst.
.33
7
15.4
150
92.4

1-80
Reconst.
.33
7
0.1
150
0.6

Blairtown Rd
. New and reconst.
.66
7
4.3
30
5.1

U.S. 30
New
1.0
4
5.5
60
40.0

U.S. 187
Reconst.
.33
5
2.9
60
7.0

WYO. 373
New
1.0
6
25.6
60
186 .2

WYO. 414
New and reconst.
.66
10
5.9
60
28.3

WYO. 530
Reconst.
.33
7
0.1
60
0.2

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following is a summary of the data:
1974 Acres of Industrial Construction
Acres Months
Campbell -
Converse -	3	6
Sweetwater -	320	12
Base Year Emissions
The average particulate emission factor for construction is 1.2
tons per acre per month (Ref. 28). The correction factors to
reflect differences in climate between the test sites used to
develop the emission factors and the three counties in Wyoming
are as follows:
Corrected Emission Factors (tons/acre/month)
Correction Factor	Emission Factor
(PE test)2 (31)2
Campbell &	(PE co.)2 = (50)2 = *384	,46
Converse -
(31)2
Sweetwater -	(33)2 =	1.06
Applying these factors to each county's construction acreage and
multiplying by the number of months yield the following emissions
1974 Particulate Emissions (tons/year)
Campbell - 1485.7
Converse - 856.9
Sweetwater - 8588.4
83

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Projections
Projected construction employment for Campbell and Converse
Counties was obtained from DEPAD (Ref. 56). These data were
converted to growth factors and applied to two classifica-
tions of construction: (1) residential-commercial-public;
and (2) industrial. Since there are currently no construc-
tion projections for Sweetwater County, growth in construc-
tion for these two classifications was assumed to be parallel
to population growth.
Projected highway construction for 1975, 1980, and 1985 was
not available from the State Highway Department. An interim
report by the Highway Department indicated new arterial
roads that were being planned in the Rock Springs area. The
report stated that approximately 96 miles would possibly be
built by 1995 (Ref. 57). In order to maintain an acceptable
level of transportation service, new roads and reconstruction
of old roads will have to keep pace with population growth.
Since the current highway construction is now meeting this
demand, it is assumed that this level of construction will
remain constant to 1985 in all three counties.
The following are the projected emissions for the two classi-
fications, urban and industrial, and total projected emissions
including highway construction.
Projected Emissions (tons/year)
Campbell	Converse	Sweetwater

GF PART
GP
PART
GF
PART
Urban
and Industrial




1975
2.97 1331
1.25
59
1.12
6176
1980
4.14 1855
2.45
115
1.50
8271
1985
4.64 2079
1.20
56
1.60
8822
Total
(includes highway
construction)


1975
2369

869

9250
1980
2893

925

11,345
1985
3117

866

11,896
84

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]6• AGGREGATE STORAGE PILES
Data Inventory and Methodology
Two sources were used to obtain the amount of aggregate
stored in the three counties. The Wyoming State Highway
Department provided the amount of stockpiled aggregate
maintained by the Department for the three counties in 1974.
The Wyoming Air Quality Division permit application files
for 1974 were used to extract those stockpiles maintained by
private industry in the three counties. Following is a
summary of the data obtained for each county:
1974 Aggregate Stockpiled (tons)
Highway Dept.	Industry
Campbell 7,407
Converse 7,407	8,000
Sweetwater 18,734	50,000
Base Year Emissions
The particulate emission factor for estimating the total
amount of dust emissions with drift potential greater than
1000 feet (particles less than 30 microns in diameter) is as
follows (Ref. 28):
E = (0.33) f (PE/100)2	(eq- 4>
where E - emission factor, lbs per ton
PE - Thornthwaite's precipitation-evaporation index
Using the map of PE values for state climatic divisions in
the EPA publication Emission Factors for Fugitive Dust
(Ref. 28), the PE index for Converse and Campbell counties
is 50 and 33 for Sweetwater County. Therefore, the emission
factors calculated for each county are:
85

-------
Particulate Emission
Factor (lbs/ton)
Campbell -	1.32
Converse -	1.32
Sweetwater -	3.14
Applying the emission factors to the tons of aggregate
stored yields the following particulate emissions for 1974:
1974 Particulate Emissions (tons/year)
Campbell - 4.9
Converse - 7.7
Sweetwater - 107.9
86

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Projections
It is difficult to determine how much aggregate will be
stockpiled from year to year. However, it is felt that the
amount does not vary significantly when averaged over the
long term. Therefore, it is estimated that emissions will
remain constant for 1975, 1980, and 1985.
87

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17. DUST FROM PAVED ROADS
Data Inventory and Methodology
Very little information exists on emission rates or procedures
for estimating dust emissions from paved streets and highways.
The American Public Works Association, the New York Interstate
Sanitation Commission, and other groups are currently conducting
studies to obtain data on the air pollution impact of reintrained
dust from roads. PEDCo recently did a particulate emission
inventory of Nashville (Ref. 54) in which it was assumed that
these emissions are directly proportional to the amount of
traffic (VMT).
VMT data for the three AQMA counties have already been generated
to estimate exhaust emissions. The VMT on unpaved roads (also
already estimated) was subtracted from the VMT totals to obtain
VMT on paved roads. These data are summarized below.
1974 Annual VMT x 103
County		Paved Roads	
Campbell	115,702
Converse	109,939
Sweetwater	397,884
In Wyoming, the normal amount of loose material on road surfaces
is increased substantially by the periodic sanding of roads
during the winter for snow and ice control. All roads maintained
by the State Highway Department and major streets in most munic-
ipalities are sanded. It is assumed that sand remains on the
roads after the snow has melted and the pavement has dried
approximately 20 days per year.
Base Year Emissions
The emission factor derived for the Nashville study was 1.75 gm/
VMT (on days with no precipitation). It was based on a single
88

-------
test of a clean paved road in the Seattle area (Ref. 55). An
emission factor of 77 gm/VMT has been used in some previous
emission inventories for estimating emissions from sanded roads.
This value was obtained from a different test site in the same
study in the Seattle area (Ref. 55). If these factors are both
applied in Wyoming, the average emission factors are calculated
as follows:
(255-20) 1.75 + (20) 77
Campbell -	365	= 5.35 gm/VMT
(243-20) 1.75 + (20) 77
Converse -	365	= 5.29 gm/VMT
(248-20) 1.75 + (20) 77
Sweetwater -	365	=5.31 gm/VMT
Due to the relative inaccuracy of these factors, a value of
5.3 gm/VMT is recommended for all three counties. With this
factor and the VMT data presented above, the dust (particulate)
emissions from paved roads are calculated to be:
1974 Dust from Paved Roads (tons/yr)
Campbell: 676
Converse: 642
Sweetwater: 2325
It should be emphasized that the calculations in this section do
not have the same accuracy as those in other sections of this
report, and that the resulting emission estimates are only
order-of-magnitude values.
89

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Projections
The method and growth factors used to project motor vehicle
exhaust VMT were also used to project VMT in estimating
reintrained dust from paved roads. Growth factors and esti-
mated emissions in the future years are summarized below:
Projected Emissions (tons/year)
Year	Campbell
Converse
Sweetwater
GF	PART
GF	PART
GF
1975 1.15	777
1980 2.07 1399
1985 2.59 1751
1.02	655
1.34	860
1.39	892
1.07
1.29
1.35
2488
2999
3139
90

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REFERENCES
1.	U.S. Department of Commerce, Bureau of the Census, 1970
Census of Housing, Wyoming Detailed Housing Characteristics,
Washington, D. C., 1970.
2.	U.S. Department of Commerce, Bureau of the Census,
Wyoming County Business Patterns, Washington, D. C.,
1973.
3.	U.S. Department of Commerce, Bureau of the Census,
Wyoming Current Population Reports, Federal-State
Cooperative Program for Population Estimates,
Series P-26, Washington, D. C., 1974.
4.	U.S. Department of Interior, Bureau of Mines, Mineral
Industrial Surveys, "Bituminous Coal and Lignite Distribution,
Calendar Year 1974," Washington, D. C., 1975.
5.	U.S. Department of Interior, Bureau of Mines, Mineral
Industrial Surveys, "Natural Gas Production and Consumption:
1973, "Washington, D. C., 1974.
6.	U.S. Department of Interior, Bureau of Mines, Mineral
Industrial Surveys, "Sales of Fuel Oil and Kerosene in
1973, "Washington, D. C., 1974.
7.	U.S. Department of Interior, Bureau of Mines, Mineral
Industrial Survey, "Sales of Lignefied Petroleum Gases
and Ethane in 1972, Washington, D. C., 1973.
8.	U.S. Department of Commerce, National Oceanic and Atmospheric
Administration, National Climatic Center, Local Climatological
Data, 1974 Annual Summary with Comparative Data,
Asheville, North Carolina, 1974.
9.	Wyoming Department of Environmental Quality, Air Quality
Division, Open Burning Log, 1974.
10.	U.S. Forest Service, Rocky Mountain Regional Office,
Individual Fire Report Data-Computer Summary, 1974.
11.	U.S. Environmental Protection Agency, Guide for Compiling
a Comprehensive Emission Inventory, APTD 1135, Marcn 1973.
12.	U.S Environmental Protection Agency, Compilation of Air
Pollutant Emission Factors, second edition, AP-42,
April 1973.
91

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13.	Ryckman, Edgerly, Tomlinson and Associates, Inc.,
unpublished file data provided by U.S. Navy.
14.	Wyoming State Highway Department, Planning Division,
Wyoming Traffic, April 1975.
15.	Wyoming Department of Revenue, Commercial Vehicle Section,
Communication with Mr. Zeman, May 1975.
16.	U.S. Department of Commerce, Bureau of the Census,
Census of Agriculture, County Data, Washington, D. C., 1969.
17.	U.S. Geological Survey, Casper, Wyoming. Communication with
Ken Moore, Research Chemist, June 1975.
18.	Public Service Commission of Wyoming, Rate and Tariff
Department, Railroad Track Mileage for Wyoming, Sept. 1969.
19.	Burlington Northern Railroad Company, Denver, Colorado.
Communication with Mr. Edmonds, Transportation Section,
June 1975.
20.	Chicago and Northwestern Railroad, Casper, Wyoming.
Communication with Mr, Dick Fadler, June 1975.
21.	Wyoming Department of Economic Planning and Development,
Study of the Economic Feasibility of Providing Third Level
Air Carrier Service in Wyoming, December 1974.
22.	Rock Springs Municipal Airport. Communication with
Mr. Wachtel, Airport Manager, June 1975.
23.	Gillette Aviation, Antelope Airlines, June 1975.
24.	Continental Oil Company/ Casper, Wyoming. Communication
with Mr. W. C. Blackburn, Production Manager, June, 1975.
25.	Wyoming Oil and Gas Conservation Commission, Casper, Wyoming.
Communication with Mr. Basko, State Oil and Gas Supervisor,
June 1975.
26.	Petroleum Information Corp., Oil and Gas Production Report
Wyoming, 1974.
27.	Wyoming Department of Highways, Traffic Planning Division.
Communication with Paul Joslin, April 1975.
28.	U.S. Environmental Protection Agency, Development of
Emission Factors for Fugitive Dust Sources,
EPA-450/3-74-037, June 1974.
92

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29.	U.S Department of Agriculture, Soil Conservation Service,
Casper, Wyoming. Communication with Clarence J. Fowkes,
Assit. State Soil Scientist, May 1975.
30.	University of Wyoming, Agricultural Experiment Station,
"Characterization Data of Selected Soils from Sweetwater
and Fremont Counties, Wyoming, Science Monograph 13,
August 1968.
31.	Wyoming Department of Agriculture, Wyoming Agricultural
Statistics, 1972-73.
32.	Wyodak Coal Company, Gillette, Wyoming. Communication
with Bud Wester, June 1975.
33.	Sweetwater Coal Yard, Rock Springs, Wyoming. Communication
with Zuezk Coal Distributor, June 1975.
34.	Best Coal Company, Converse County, Wyoming, June 1975.
35.	Petrolane-Wyoming Gas Service, Gillette, Wyoming.
Communication with Don Arensmeyer, Manager, June, 1975.
36.	Standard Oil Company, Douglas, Wyoming. Communication
with Tom Christy, LP Gas distribution manager, June 1975.
37.	U.S. Geological Survey, Laramie, Wyoming. Communication
with Gary Glass, June 1975.
38.	Fulkerson Oil, Gillette, Wyoming. Communication with
Bill Fulkerson, May 1975.
39.	Link Standard Oil, Douglas, Wyoming. Communication with
Mrs. Link, May 1975.
40.	Red Horse Oil, Rock Springs, Wyoming. Communication with
Pete Bunning, June 1975.
41.	Wyoming Department of Environmental Quality, Air Quality
Division, Point Source Air Contaminant Emission Reports,
1974.
42.	Final Environmental Impact Statement. Eastern Powder River
Coal Basin of Wyoming, Department of Interior, October 1974.
43.	McCulloch Interstate Gas Company, Casper, Wyoming.
Communication with Mr. Ouets, Operations Manager, June 1975.
44.	Kansas-Nebraska Natural Gas Company, Inc., Hastings,
Nebraska. Communication with Mr. Drake, Operations,
May 1975.
93

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45.	Mountain Fuel Supply Company, Salt Lake City, Utah.
Communication with Mr. A. J. Marushack, Chief Engineer
of Gas Supply Operations, June 1975.
46.	Atlantic Richfield Company, Rocky Mountain District,
Denver, Colorado. Communication with Mr. W. A. Walther,
District Production and Drilling Superintendent, June 1975.
47.	Phillips Petroleum Company, Casper, Wyoming. Communication
with Mr. F. C. Morgan, Superintendent, June 1975.
48.	Southwest Research Institute, Exhaust Emissions from Piston
and Gas Turbine Engines used iri~Natural Gas Transmission,
prepared for American Gas Association, AR-923, January 1974.
49.	Rock Springs Planning and Development, Rock Springs, Wyoming.
Communication with Bill Banks, Planner, June 1975.
50.	Town of Green River, Wyoming Building Inspector's Office,
June 1975.
51.	Campbell County Planning Office, Gillette, Wyoming.
Communication with Bernie Schnorenberg, City and County
Planner, June 1975.
52.	Town of Douglas, Douglas, Wyoming. Communication with
Joe Keefer, Building Inspector, June 1975.
53.	Wyoming Department of Highways, Wyoming Construction
Bulletin, monthly publication, January-December, 1974.
54.	Particulate Area Source Emission Inventory for Nashville-
Davidson County, Tennessee. PEDCo-Environmental Specialists,
Cincinnati, Ohio, February 1975.
55.	Roberts, J. W. et al. The Measurement, Cost and Control of
Traffic Dust in Seattle's Duwamish Valley. Paper No. AP-72-5.
Presented at the APCA Pacific Northwest Section Annual Meeting,
Eugene, Oregon, November 1972.
56.	Wyoming Department of Economic Planning and Development,
Coal and Uranium Development of the Powder River Basin—
An Impact Analysis, June 1974.
57.	Wyoming Department of Highways, Planning Branch, Interim
Report—Rock Springs Green River Area Transportation
Planning Process, September 1974.
58.	Wyoming Department of Economic Planning and Development,
1974 Wyoming Mineral Yearbook, 1974.
94

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59.	Wyoming Department of Agriculture, Wyoming Agricultural
Statistics f November 197 3.
60.	Wyoming Department of Economic Planning and Development,
Coal Development Alternatives, December 1974.
61.	Wyoming Department of Highways. Communication with Mr.
Jack Warburton, Planning Section, July 1975.
62.	Wyoming Oil and Gas Conservation Commission, Casper, Wyoming.
Communication with Mr. Donald Basko, State Oil and Gas
Supervisor, September 1974.
63.	American Petroleum Institute, Division of Production, Dallas
Texas. Communication with Mr. Lyles, August 1975.
64.	Wyoming Oil and Gas Conservation Commission, Wyoming Oil and
Gas Statistics, 1974.
65.	U.S. Environmental Protection Agency, Office of Air and
Water Programs, Compilation of Air Pollutant Emissions Factors
(second edition with four supplements), Research Triangle
Park, North Carolina, April 1973.
95

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TECHNICAL REPORT DATA
(Please read InUructions on the reverse before completing)
.1. HI PORT NO. 2.
EPA-908/1-76-006
3. RECIPIENT'S ACCESSION"NO.
4. T 1 I LL AND SUBTITLE
Wyoming AQMA Area Source Inventory
5. REPORT DATE
June 1975
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRE8S
PEDCo-Environmental Specialists, Inc,
Suite 13, Atkinson Square
Cincinnati, Ohio 45246
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-02-1375
Task Order No. 19
12. SPONSORING AGENCY NAME AND ADDRESS
U. S. Environmental Protection Agency
Region VIII
1860 Lincoln Street
Denver, Colorado 80203
13 fฅna?F REP0RT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This report contains emission estimates for non point sources of air pollution
in AQMA counties of the State of Wyoming. Estimates for particulates, sulfur
oxides, and hydrocarbon emissions are made for the base year (present), 1980
and 1985. Methodologies and data sources are presented.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Held/Group
Fuel Combustion
Emissions
Mobile Sources
Stationary Sources
Air Quality Data
Dispersion Modeling
A1r Quality Maintenance
Analysis

IS. DISTRIBUTION STATEMENT
Unl imi ted
19. SECURITY aUMS'(This Report)
Unclassified
21. NOg^F PAGES
"•WWfllKmW™""'"
22. PRICE
EPA Form 2220-1 (9-73)

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