EPA-AA-TEB-81-11
Mobile Source Emission Inventory
by
Mark Wolcott
December 1980
Test and Evaluation Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
Office of Air, Noise, and Radiation
U. S. Environmental Protection Agency
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Mobile Source Emission Inventory
Within the Office of Mobile Source Air Pollution Control (OMSAPC), a
Program Assessment Group has been established to. evaluate and direct
mobile source control programs. This paper focuses on one input into
that evaluation, the development of emission inventory estimates for a
variety of mobile pollution sources. Both current (1977) and future (up
to 2005) year inventories are estimated. Eighteen different types of
mobile sources are considered to ascertain the contribution of unregu-
lated as well as presently regulated sources. Virtually all counties in
the United States, and its territories are included for one portion of the
analysis. The majority of the analyses include only those counties that
have the potential to violate the National. Ambient Air Quality Standard
(NAAQS) for carbon monoxide (CO), ozone (03) or nitrogen oxides (NOx).
This paper begins by projecting future baseline emissions and is founded
on a set of assumptions consistent with past air quality analyses. From
this baseline the sensitivity of those estimates to the underlying
assumptions used is examined. Twelve sensitivity scenarios are
considered. In each scenario one of the baseline assumptions is
altered. Then, the result of the alteration is interpreted in terms of
its likely air quality impact.
National Emission Data System
This paper is based on emission inventory estimates from the National
Emission Data System (NEDS) maintained by the Office of Air Quality
Planning and Standards (OAOPS) (Reference 1). NEDS contains emission
estimates for five air pollutants: CO, hydrocarbons (HC), NOx, particu-
lates and sulfur oxides (SOx). The NEDS inventories are available on a
county by county basis. For each county an inventory is constructed from
estimates of emission factors and activity levels for each pollution
source cataloged by OAQPS. For example, light-duty vehicle emission
factors are measured in grams of pollutant emitted per mile of travel and
the activity level is measured as the annual number of miles traveled for
all vehicles. The inventory, then, is the product of the appropriate
emission factor and the activity level. For some categories, such as
farm equipment, another step is required. The emission factors available
for farm equipment are measured in grams of pollutant per hour of use.
Estimates of the tractor population and the annual average number of
hours a tractor is used are also recorded. The activity level is the
product of the tractor population and this usage rate. As before, the
inventory is the product of-the activity level and the emission factor
rate.
Based on the OAOPS nationwide inventory, in 1977 transportation sources
accounted for approximately 85 percent of CO emissions, 46 percent of HC
emissions, 43 percent of NOx emissions, 11 percent of particulate emis-
sions and 3 percent of SOx emissions. Since mobile sources account for
proportionately more CO, HC, and NOx than particulate and SOx emissions,
this report is restricted to these three pollutants.
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There are approximately 3,200 counties in the United States. Each year
OAQPS estimates an emissions inventory for each of these counties. The
latest available inventory is for the 1977 calendar year. For highway
mobile sources that inventory is based primarily on March, 1978, emission
factors and estimates of vehicle miles traveled. (The latter is derived
from county fuel consumption.) For stationary sources the inventory is
based on reports from state air pollution control agencies and other
federal agencies. In NEDS estimates for five major sources ot pollution
are reported. Also included are estimates for many comparatively minor
pollution sources.
The five major po.llution sources are:
1. Fuel combustion
2. Industrial processes
3. Solid waste disposal
4. Transportation
5. Miscellaneous
The transportation category includes:
1. Light duty vehicles
2. Light duty trucks
3. Heavy duty gasoline trucks
4. Heavy duty diesel trucks
5. Gasoline off-highway vehicles
6. Diesel off-highway vehicles
7. Locomotives
8. Vessels
9. Aircraft
The NEDS light duty vehicle category includes motorcycles, automobiles,
and light duty trucks less than 6,000 pounds gross vehicle weight. The
heavy duty gasoline category includes all gasoline trucks greater than
6,000 pounds. The gasoline off-highway category includes farm and
construction equipment as well as industrial equipment, lawn and garden
equipment, snowmobiles, and off-highway motorcycles.
These NEDS categories were adapted to fit the requirements of this study:
namely a more detailed look at both present and future mobile source
emissions than is possible without such adaption (Reference 2). Motor-
cycles were separated from the light-duty vehicle group. Two light-duty
truck categories were created: light-duty trucks less than 6,000 pounds
and light-duty trucks between 6,000 and 8,500 pounds. These categories
correspond to those used by the emission factor computer program,
MOBILE1. The off-highway group was also split into its component parts:
farm equipment, construction equipment, industrial machines, off-highway
motorcycles, lawn and garden equipment, and snowmobiles. Organizing the
mobile source categories to correspond with MOBILE1 categories results in
more precise inventory estimates. Expanding the number of mobile source
categories allows a more detailed study of those that contribute most to
the total emissions burden.
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Basically; to calculate the mobile source inventory under the NEDS
procedure, county fuel consumption is estimated for each vehicle type.
Second, the amount of this consumed fuel is multiplied by national
average fuel efficiencies in miles per gallon (mpg) for each vehicle
type. The results are county by county vehicle miles traveled (VMT)
estimates. (For states in which measured VMT are available, estimated
VMT calculated from fuel use data are adjusted to agree with the total
county measured VMT reported by the State Highway or Transportation
Department.) The estimated VMT's are then multiplied by MOBILE1 emission
factor estimates to produce a highway mobile source emissions inventory.
For non-highway transportation sources the NEDS emissions inventory was
used directly. Stationary source emission inventories were also obtained
directly from NEDS. Together with the transportation sources, stationary
sources account for all estimated emissions. The inventory thus
constructed is consistent with the 1977 NEDS inventory recommended by
OAQPS for air quality analyses and review of the NAAQS. It forms the
basic current year inventory from which the future baseline inventories
are calculated and to which the results from the sensitivity analysis are
compared.
Relative Mobile Source Contribution, 1977 Inventory
Figures 1-3 show the relative contribution of mobile source emissions to
total 1977 county emissions for each of the three pollutants considered
in this report. The horizontal axis in these figures indicates the
percent of total emissions contributed by mobile sources. (The percent
of emissions contributed by stationary sources can be computed as 100
percent minus the percent of emissions contributed by mobile sources.)
The vertical axis indicates the number of counties in the United Stated
and its territories at each mobile source contribution level. As these
figures indicate, mobile sources account for a relatively large share of
emissions in many counties. In 5 percent of the counties, mobile sources
contribute more than 98 percent of the CO, more than 84 percent of the
HC, and more than 96 percent of the NOx. However, most of the 284
counties comprising this 5 percent are in remote areas containing few
stationary emissions sources. The high mobile source contributions for
these counties contrasts with an average contribution of 84 percent for
CO, 5o percent for HC, and 72 percent for NOx.*
In Figure 1, the peak at 95 percent signifies that in 284 out of approxi-
mately 3200 counties, 95 percent of all CO county emissions are due to
mobile sources. At the other end of the horizontal axis, however, there
are a few counties in which mobile sources contribute a small percentage
of total CO emissions. In most of these counties, the dominant sources
*Since stationary sources emit massive amounts of poltutants in
relatively few counties, the average mobile source contribution within
the nation's counties is different from the overall mobile source contri-
bution. For example, in the average county mobile sources account for 75
percent of NOx emitted; for the nation, mobile sources contribute 43
percent of total NOx.
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of emissions are forest wildfires and forest managed burning. .This is
particularly true in Alaska, Idaho, Montana, and Puerto Rico. However,
there are a few counties in the Southwest in which chemical manufacturing
is the dominant source of CO. These counties often contain carbon black
manufacturing plants, which, when uncontrolled, emit large amounts of CO.
As Figure 2 indicates, the degree to which mobile sources account for
total county emissions varies more for hydrocarbons than for carbon
monoxide. While mobile sources contribute 84 percent or more of total
hydrocarbon emissions in a few counties, they contribute substantially
less in the majority of counties. In the counties with the lowest
proportion of mobile source HC emissions there are three dominant types
of sources. The first is a combination of forest wildtires and forest
managed burning. The second is organic solvent evaporation, generally
composed of painting and other types of wood preparation. Petroleum
storage and transport comprise the third type of source found in these
low mobile source contribution counties.
Figure 3 shows the relative contribution of mobile source NOx emissions
to total county emissions. As with the other two pollutants, in a few
counties mobile sources contribute a small percentage of total NOx emis-
sions. A dominant source of emissions in those cmnties is electric
power generated from bituminous coal. However, re idual oil, natural
gas, and lignite are also used.
In order to narrow the focus for further study, a joint set of counties
in which there are definite air quality problems was selected from the
nation's 3200 county total (Reference 2). First, a list of 146 counties
showing violations of the eight hour average National Ambient Air Quality
Standard (NAAQS) for CO (10 mg/m-*) was constructed. To this list were
added 90 counties with at least one annual 1976-1978 mean N02 value
greater than 60 mg/m . Although the current N0£ NAAQS is greater
than this, N02 emissions are anticipated to increase in the years
ahead. Eventually, growth in CO and NMHC pollution sources will dominate
the reduction in per unit emissions from cleaner technology. For NOx,
however, the increase in total emissions is expected sooner than for CO
and NMHC. Since counties now meeting the N02 standard may not meet it
in the future, all counties with at least one annual mean within 60
percent of the NAAQS were included in the N02 list. (The CO and N02
lists have 62 counties in common.) Next, a list of Air Quality Control
Regions (AQCR) with violations of the 0.12 ppm one-hour 03 NAAQS in
1975-1977 was assembled. Generally, AQCR's are used to characterize NMHC
inventories since transport and .precursor reactivity generally occur in
areas larger than counties. However, to be consistent with the other
inventories used in this analysis, the NMHC inventory was constructed on
a county basis. ' Further, since the focus of this paper is the inventory
sensitivity to the assumptions underlying it, the distribution of emis-
sions, among pollution sources is more important than the absolute emis-
sion levels. Since in eight AQCR's sampled the mix of sources is roughly
the same for the AQCR as its most urban county, it was assumed that the
mix of sources would also be approximately the same in the most urban
county as in the whole AQCR. Therefore, in order to keep the joint list
of counties at a manageable size, not all of the counties in each 03
AQCR were included. Instead, a different selection procedure was used.
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Since the 69 AQCR's that registered violations of the 63 NAAQS contain
approximately 500 counties, if an AQCR was represented by at least one
county on the combined CO and N02 list, than no other counties from
that AQCR were added to that list. For an AQCR not represented, one
county within it (usually the one with the largest population) was
chosen. The aim of this selection criterion was to minimize the total
number of counties on the joint list, yet still represent each violation
area. With the exception of the distributional analysis described in the
next three paragraphs, it is this joint list of counties that is
considered throughout the remainder of the paper. (For the distri-
butional analyses, the three individual lists from which the joint set
was constructed are used.) Appendix A contains the state, county and
AQCR codes for each of the included counties. All except the four
Connecticut counties were subsequently used. (NEDS data for Connecticut
were erroneous at the time the analysis was conducted.) Figures 4-6 show
the relative contribution of mobile source emissions to total county
emissions for these counties. The general shape of Figure 4 (146 CO
counties) follows that of Figure 1 (all 3200 counties). However, in
Figure 1 there are several counties represented in which mobile sources
contributed a negligible portion of total CO. Among the 146 counties
representing areas with ambient CO violations, mobile sources contributed
at least 37 percent of total CO emissions in each county.
The distribution of mobile source HC emissions for the 142 worst 03
counties is presented in Figure 5. As in the case of CO, the general
shape of Figure 5 follows that of Figure 2. However, as demonstrated by
Figures 3 and 6, the distribution of mobile source NOx emissions for the
two groups of counties is different. The peak at 90 percent in Figure 3
is absent from Figure 6 indicating that the mobile source contribution
among the 90 counties with the greatest potential to violate the N02
NAAQS varies much more than the mobile source NOx contribution for the
nation as a whole.
Another way to distinguish the differences between the set of all
counties and those counties with the potential to violate the NAAQS is to
calculate and compare the percentiles associated with each distribution.
These percentiles indicate the range of the mobile source contributions
to the county emissions. The 50th percentile is equivalent to the
median. For CO the median mobile source contribution for the nation's
3200 counties is 92 percent. That is, mobile sources contribute more
than 92 percent of total CO emissions in one-half of all counties.
Further, mobile sources contribute more than 40 percent of CO emissions
in 95 percent of all counties (5th percentile). Finally, at the other
extreme, mobile sources contribute more than 98 percent of total emis-
sions in 5 percent of all counties (95th percentile). In other words, in
90 percent of all counties, mobile sources contribute between 40 percent
and 98 percent of CO emissions. These data are listed in Table 1. Table
1 also lists, for all 3200 counties, the 5th, 50th and 95th percentiles
of the mobile source contribution for HC and NOx. In addition, both the
mean and the maximum contribution are included. The 100 percent maximum
contribution indicates that all CO, HC, or NOx emissions are accounted
for by mobile sources in at least one county.
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Table 2 lists these same statistics tor the disjoint set of counties
representing the areas with the potential to violate the NAAQS. For
these selected counties mobile sources generally account for a greater
proportion of CO emissions and a lesser proportion of HC and NOx emis-
sions than in the country as a whole. However, in seven counties (five
percent) mobile sources account for a small proportion of CO emissions.
Two of these counties contain primary metal processing plants, one
contains a chemical manufacturing plant and one contains a solid waste
disposal plant. Most of the low mobile source.HC counties are dominated
by large amounts of solvent evaporation loss. Electric power generating
facilities dominate those counties in which mobile sources contribute a
small proportion of total NOx emissions (Reference 3).
Up until this point the discussion has centered on the 1977 base year
inventory. In order to develop a sound policy of emission control, it is
necessary to know what the future emission inventory is expected to be.
In order to project future year emissions, several assumptions must be
made. The compound annual increase in the activity level . of each
individual source must be estimated for both mobile and stationary
sources. The promulgation of new regulations and the rate at which the
regulated newer technology replaces existing technology must also be
taken into account, as must the deterioration of that existing
technology. The following section of this paper examines the sensitivity
of the future emissions estimates to the underlying assumptions used to
create them. One set of assumptions is used as a baseline with which
twelve other cases are compared.
The future year inventory material is arranged in four parts. The first
part discusses the baseline assumptions. The second part discusses each
sensitivity scenario and how the scenario results differ from the base-
line. Only CO is considered in part two. Parts three and four include
a similar discussion of the results obtained for NMHC and NOx.
Baseline Inventory
For the baseline, mobile sources are expected to grow at a one percent
compound annual rate for all categories except HDG and HDD (Reference 4).
HDG VMT is assumed to decline at an annual rate of two percent; HDD VMT
is assumed to increase at an annual rate of five percent (Reference 5).
These rates are consistent with those used in support of recent air
quality analyses. For highway vehicles these VMT growth rates are
multiplied by the future year MOBILEl emission factor estimates to arrive
at the estimated baseline inventory (Reference 6). For non-highway
mobile sources, such as railroads, aircraft and vessels, NEDS 1977 base
year emissions estimates are assumed to grow at a one percent compound
annual rate.
For the baseline, the stationary source expected growth rates that were
used are also consistent with recent air quality analyses. Table 3 lists
these stationary growth rates for CO (Reference 4). NMHC and NOx
stationary source growth rates are listed in Tables 4 and 5, respectively
(References 7 and 8).
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For both mobile and stationary sources, the level of future year emis-
sions is a function of new regulations, an assumed source deterioration
rate, and the rate at which old technology is retired and replaced by
new, presumably cleaner, technology. For mobile sources all these
factors are incorporated into the future year emission estimates
predicted by MOBILE1. All of the future light duty vehicle emission
factor estimates used in this analysis assume an inspection maintenance
program beginning in 1982. A 30 percent stringency factor is used but no
mechanic training is assumed. To project future emissions from
stationary sources, these factors are applied separately to the
uncontrolled emission estimates.
No assumption is made about stationary source deterioration rates; that
is, no deterioration rate is applied. Instead, old stationary sources
are assumed to retire and be replaced by new sources. These new sources
remain controlled to the levels originally mandated by new source perfor-
mance standards (NSPS). Old sources that have not yet been retired in
areas that are expected to exceed the NAAQS in 1982 are presumed to be
controlled for the remainder of their operation to reasonably available
control technology (RACT) levels. The NSPS and RACT levels are presented
for each pollutant in Tables 3-5.
The following example illustrates how RACT and NSPS controls are
applied. Assume commercial coal facilities in an area that is not
expected to meet the NC>2 NAAQS are to grow at a 1.0 percent compound
annual rate (Table 5). Growth includes both expanded capacity of
existing facilities and construction of new facilities. Emissions from
this increased capacity are expected to be 24 percent less than pre
control levels. In addition, existing coal facilities are assumed to be
retired at a 4.0 percent compound annual rate and be replaced by new
capacity. The emissions from the new capacity are also expected to be
reduced by 24 percent. Emissions from the remaining facilities are
expected to be reduced by 20 percent.
There are potential problems with some of the NSPS and RACT assumptions
represented in Tables 3-5. For example, new petroleum refineries are
controlled to a lesser degree than existing refineries with RACT (Table
4). However, the degree of NSPS and RACT control assumed for the base-
line case in this paper is consistent with that used in air quality
analyses and recommended by OAQPS.
In order to examine the sensitivity of the baseline inventory estimates
to a variation in each input assumption, twelve different scenarios were
constructed. One scenario is used to examine the effect of low ambient
temperatures. Two scenarios relate to the effect of changing the highway
mobile source and stationary source retirement rates. In four scenarios
the effects of changing the driving cycle over which mileage is accumu-
lated are considered. Four scenarios are used to project emissions under
different mobile and stationary source expected growth rate assumptions.
Finally, the effect of changing the degree of stationary source NMHC
control is examined.
Three types of information are presented for each scenario examined.
These are: an inventory for each emissions source; the percentage
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contribution of each source relative to the total mobile or stationary
source portion of the inventory; and the relative contribution of each
source with respect to the total inventory. This information is
presented for the baseline in Tables 6, 7 and 8. Only the counties with
the greatest potential to exceed the CO, 03 and N02 NAAQS are
included.
Table 6 presents the CO emissions inventory for each .mobile and
stationary source. Eighteen mobile sources are used in this analysis.
Those are listed in Table 9 along with the abbreviations as they appear
in subsequent tables. Light duty diesel vehicles and trucks will be
included once they have been incorporated into MOBILE1. The stationary
sources used are listed in Table 10.
As indicated in Table 6 for the baseline case, total CO emissions are
expected to decline from 49,800 thousand tons in 1977 to 18,150 thousand
tons in 2005. During this period the proportion of mobile source CO
emissions from light duty gas vehicles is projected to decline from 64
percent to 41 percent (Table 7). The proportion of total county CO
emissions contributed by all mobile sources is expected to be decline
from 90 percent to 81 percent (Table 8). This overall reduction is
largely the result of cleaner light duty vehicles.
To further illustrate the relative contributions of the various emissions
sources and how these contributions change over time, Figures 7 and 8
have been constructed to graphically present the data. Figure 7 shows
the contribution of both mobile and stationary sources for the base year
and each projection year thereafter. The numbers in this figure are
identical to those in Table 6 under the headings MOBILE TOTAL and STAT
TOTAL. Figure 8 shows the relative contribution of each mobile source
category to total mobile emissions. The numbers in this figure are
identical to those in Table 7.
Immediately apparent from Figure 7 is the relatively large proportion of
CO emissions attributed to mobile sources. Also apparent is the signifi-
cant decline in total future year emissions. Clearly, most of this
decline is the result of the decline in mobile source emissions. Perhaps
more importantly, by 2005 under this scenario, expected growth in both
mobile and stationary sources overcomes the emission reductions that, in
prior years, have resulted from increased control.
Figure 8 shows the relative contribution of each mobile source category
to total mobile source CO emissions. The OTHER category includes high-
way motorcycles as well as all off-highway categories except aircraft,
vessels and locomotives. The increase in the relative contribution of
off-highway vehicles is primarily the result of the reduction in the
light duty vehicle contribution. Nevertheless, by 2005 CO from gas farm
and construction equipment and from gas industrial machinery, taken
together, are projected to match CO emissions from light or heavy duty
gas trucks and to exceed emissions from railroads, vessels and aircraft.
Sensitivity Analysis
Since the estimation of future year inventories is tied so closely to the
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underlying assumptions, twelve different scenarios were constructed to
examine the sensitivity of the baseline inventory estimates to those
assumptions. For each scenario, only one baseline assumption was changed.
The first step in the sensitivity analysis relates to ambient tempera-
ture. A 68°-86°F ambient temperature is assumed for the standard light
duty Federal Test Procedure (FTP) (Reference 6). According to OAQPS, the
average national summertime temperature is 76°F (Reference 1). NEDS
county emissions are estimated by adjusting the standard FTP mobile
source emissions to reflect the average summertime temperature of the
state to which the county belongs. This same adjustment was made for the
baseline inventory discussed previously. For the low temperature
scenario, however, highway mobile source emissions were adjusted to
reflect the average wintertime temperature. On a national scale this
works out to be 40°F. The purpose of examining this scenario is to
estimate an emissions inventory under conditions that approximate winter
month temperature conditions in which CO emissions tend to be greater.
For this scenario in the counties most likely to exceed the NAAQS, total
1977 CO emissions increase six percent, from 49,800 thousand tons to
52,950 thousand tons, over what they are projected to be under conditions
that approximate summertime temperatures. (Since annual VMT was used to
calculate this inventory and not just wintertime VMT, the absolute
tonnage numbers should not be used by themselves but can be compared
relative to the inventories obtained from modifying other baseline
assumptions.) The changes in CO levels for this and other scenarios are
summarized in Table 11. Table 12 summarizes the changes in the mobile
source contribution to total CO emissions for each of the scenarios. The
table indicates that for 1977 decreasing the temperature an average of 47
percent increases by two percent the mobile source contribution to total
county emissions (from 89.6 percent for the baseline case to 91.1 percent
in the low temperature case).
The effect on the inventory of changing the type of driving assumed to
generate the mobile source portion of the inventory is examined in the
second step of the sensitivity analysis. The Federal Highway Administra-
tion (FHwA) estimates VMT on urban and rural roads. To calculate the
emissions inventory from highway vehicles, OAQPS assumes that the average
urban speed is 19.6 mph and that 43 percent of vehicle trips are cold
starts; 57 percent of trips are assumed to be hot starts (Reference 1).
Rural VMT, on the other hand, is assumed to be accumulated at a rate of
45 mph, with all vehicles operating in the hot stabilized condition. For
the baseline case the county inventory is the sum of the weighted urban
and rural portions calculated in the usual fashion; i.e., the urban emis-
sion factor times the urban VMT plus the rural emission factor times the
rural VMT.
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In order to test the sensitivity of mobile source emissions to the type
of driving cycle over which vehicle mileage is accumulated, two other
driving cycle scenarios were considered. In the first of these two
scenarios, designated RURAL in the tables and graphs, all mileage was
assumed to be accumulated under high speed, warmed up operation. In the
second scenario, designated URBAN, all mileage was assumed to be accumu-
lated under FTP speed and vehicle operating conditions. For the baseline
case the speed and operating conditions were set at the levels described
in the previous paragraph.
As expected and as Table 11 indicates, there is a substantial (48
percent) decrease in CO emissions for rural driving conditions.
Conversely, there is a substantial (10 percent) increase in emissions for
urban driving conditions. However, since in most of the counties
examined in this report the majority of the baseline mileage is accumu-
lated under urban driving conditions, the effect of changing the type of
driving to all rural is to reduce CO emissions more than they are
increased by changing to all urban driving. This is due to the urban/-
rural weighting applied to construct the baseline inventory. In most
counties with an air quality problem 80 percent of highway mobile source
emissions is generated along urban roads. Only 20 percent is generated
along rural roads. Although the air quality effects of changing the
baseline assumptions are not estimated, the inference to be drawn from
these two scenarios is that, for CO, which tends to be an urban problem,
the emissions inventory estimates used in past air quality analyses may
be low. However, this is not a serious air quality concern. For air
quality projections the relative inventory change is important, not so
much the level from which that caange occurs. A problem potentially
greater than underestimating the emissions inventory arises if a cycle
other than the FTP better represents driving conditions in areas
characterized by high ambient CO concentrations. New York City is an
example of such a situation. If New York driving is better represented
by a low average speed cycle with many stops and starts (such as the New
York City cycle) than by the FTP, then the inventory for New York City
has been greatly underestimated both in NEDS and in past air quality
analyses. Further, estimates of emission reductions .resulting from the
introduction of cleaner vehicles that have been made in the past will
only be achieved if the emissions from those vehicles are reduced in the
same or greater proportion under uhe New York City cycle as they are
reduced under the FTP.
Four of the twelve scenarios test the sensitivity .of the mobile source
contribution to changes in the annual expected growth of both mobile and
stationary sources. Baseline expected growth rates are consistent with
recent air quality analyses. Generally, for mobile sources the baseline
VMT growth rates are one percent compounded annually. The two exceptions
to this rule are that heavy duty gas truck VMT is assumed to decrease at
an annual rate of two percent while the heavy duty diesel VMT is assumed
to grow at an annual five percent rate. For the sensitivity analysis,
mobile source growth rates are first reduced by one percentage point from
these .levels and next increased by two percentage points. For each of
these cases, stationary source expected growth rates remain unchanged
from the baseline.
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The low mobile source growth rate scenario is probably unrealistic. It
has been included to put a lower bound on the estimates of mobile source
emissions. Since most of the baseline mobile source growth rates are one
percent, the low mobile source growth rate assumption is approximately
equivalent to assuming no mobile source growth. The high mobile source
growth rate, on the other hand, assumes that mobile sources grow at
approximately a three percent annual rate. This is the upper bound of
the range OAQPS recommends be used in air quality analyses.
As Table 11 indicates,, under the low mobile source growth rate scenario,
total CO emissions in 2005 decline 71 percent from 1977 levels. Under
the high mobile source growth rate scenario, total emissions in 2005
decline only 42 percent. For the baseline VMT growth rates, CO emissions
decline 64 percent over this same 28 year span. Perhaps more
importantly, as Table 12 shows, under the low mobile source growth rate
scenario, the proportion of total CO emissions accounted for by mobile
sources declines 14 percentage points from 90 percent in 1977 to 76
percent in 2005. This decline is only 2 percentage points for the high
mobile source growth rate scenario. The proportion of total emissions
accounted for by mobile sources declines 9 percentage points over this
same period for the standard baseline growth rate assumptions.
The effect of the stationary source expected growth rates on the inven-
tory are examined next. The mobile source expected growth rates are held
constant at the baseline level. Stationary source growth rates are first
decreased by two percentage points and then increased by two percentage
points. This wide range has been choosen to put lower and upper bounds
on the growth rates applied to the stationary sources listed in Tables
3-5. It is unlikely that stationary sources would achieve growth rates
at these extremes for the next three decades. Their inclusion, however,
provides a useful insight into the sensitivity of emissions to stationary
source growth.
Under the low stationary source growth rate scenario, total CO emissions
decline 67 percent from 1977 to 2005. Under the high stationary growth
rate scenario, total emissions decline 58 percent for the same period.
This 9 percentage point difference is considerably less than the 39 point
difference under the high and low mobile source growth rate scenarios and
is due to the large proportion of CO emissions contributed by mobile
sources. As seen later in the paper, the effects of mobile and
stationary source growth rates are more equivalent for NMHC and NOx.
Two sensitivity scenarios have been included to reflect the increase in
emissions that are likely to result from acceleration/deceleration rates
greater than those specified by the FTP (Reference 9). The mechanism
used is to increase the baseline light duty vehicle emission factors by
50-percent (designated +50 LDV in the tables and graphs ) and 100 percent
(designated +100 LDV). The baseline factors were taken from the March,
1978 Mobile Source Emission Factor document. Increases of 50 and 100
percent from those factors are used.
Under the +50 LDV emission factor scenario, the 1977 CO inventory
increases 29 percent over the baseline level. Under the +1()0 LDV emis-
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sion factor scenario, the 1977 inventory increases 57 percent. For these
two scenarios emissions in 2005 also increase substantially. However,
the ratio of 2005 to 1977 CO emissions is not much different from the
corresponding baseline ratio. Under the +50 scenario CO emissions
decline 67 percent from 1977 to 2005. Under the +100 emission factor
scenario, the decline is 69 percent. The baseline decline is 64 percent.
Tables 11 and 12 summarize the results associated with all the scenarios
studied in the sensitivity analysis. Table 11 can be used to determine
the extent to which the predicted change in emissions from 1977 to 2005
varies from the baseline among the different scenarios. If there is no
variation in the predicted emission change, then under the currently
utilized ROLLBACK procedure there would be no expected variation in air
quality. However, to the extent that there is a difference in predicted
inventory levels, there will be a corresponding difference in predicted
air quality.
Among the sensitivity scenarios considered, three show no difference from
the baseline level in the CO inventory change from 1977 to 2005. Two of
those are the low and high stationary source retirement scenarios. The
scenario that assumes that all mileage is accumulated under urban driving
conditions also shows no difference in the 1977 to 2005 percent reduction
achieved from the baseline.
Five scenarios show a greater reduction in total CO emissions from 1977
to 2005 than the baseline case shows. These scenarios are the low
temperature, low mobile source growth, low stationary source growth, and
+50% and +100% LDV emission factor scenarios. The greatest difference is
shown in the low mobile source growth scenario which shows a 70 percent
reduction in CO emissions from 1977 to 2005. This contrasts with the 64
percent baseline reduction. If one believes that the low mobile source
growth (essentially no growth) scenario is realistic, then past air
quality analyses have underpredicted the expected improvement in air
quality.
In three of the sensitivity scenarios a reduction in total CO emissions
from 1977 to 2005 smaller than is shown in the baseline case occurs.
These are the rural driving, high mobile source growth and high station-
ary source growth scenarios. The least reduction is 42 percent shown by
the high mobile source growth scenario. If this (essentially three
percent growth) scenario is "realistic, than past air quality analyses
have overpredicted the improvement in air quality by approximately 21
percentage points (34 percent).
A second air quality interpretation can be made from Table 12 relating to
the proportion of CO emissions generated by mobile sources among the
different scenarios. If a smaller proportion of emissions is generated
by mobile sources under the various scenarios than is predicted for the
baseline case, then increase mobile source control would be needed under
the scenario conditions to obtain air quality improvements equal to those
obtained for the baseline.
For five scenarios the mobile source proportion of total emissions is
significantly different from the baseline proportion. Assuming that all
-------
L4
highway mobile source mileage is accumulated under rural driving
conditions results in an 11 percent drop in this proportion (from 90
percent for the baseline to 80 percent in the RURAL case). On the other
hand, the low temperature, URBAN, +50 LDV and +100 LDV scenarios result
in slight increases in the mobile source proportion of total CO emis-
sions. By 2005 the mobile source proportion of total CO emissions
declines somewhat under all scenarios, including the baseline. As one
would expect, the decline is least (two percent) under the high mobile
and low stationary source growth scenarios.
NMHC
Up until now the discussion has been focused on the CO inventory. The
same scenario conditions as described for CO were used to calculate the
sensitivity of the NMHC and NOx inventories to the baseline assumptions.
Figure 9 shows how NMHC emissions are projected to change under the base-
line conditions. As in the case of CO, total NMHC is expected to decline
through 1995. After 1995, growth in the activity levels of NMHC
pollution sources overtakes the reduction in source emissions that result
from cleaner technologies. Figure 10 shows the corresponding proportion
of mobile source emissions allocated to each category. The dominant
trends shown are the reduction in the proportion of light duty vehicle
and heavy duty gas truck emissions and the increase in the heavy duty
diesel truck emissions. Heavy duty diesel emissions are projected to
match the combined emissions from light and heavy duty gas trucks by
2005. Aircraft NMHC emissions are projected to exceed those from heavy
duty gas trucks by the same year. (No aircraft emission control was
assumed in this projection.) Railroad and vessel emissions are also
projected to be significant. In contrast to CO, however, NMHC emissions
from gas farm and construction equipment and from gas industrial
machinery are expected to comprise, in 2005, a small proportion ot total
county emissions. Tables 15-17 present in more detail the same infor-
mation shown in Figures 9 and 10.
Tables 18 and 19 summarize the NMHC scenario results. As in the case of
CO, five scenarios show a NMHC inventory change from the 1977 baseline
level. Under the low temperature scenario emissions are increased
approximately two percent. For the all mileage accumulated under urban
driving conditions scenario, the inventory is increased by four percent.
Under all rural driving conditions the inventory is reduced by 18
percent. For the scenarios' in which highway mooile source emission
factors were increased by 50 and 100 percent, the 1977 emission inventory
increases 10 and 21 percent, respectively.
For most sensitivity scenarios, the reduction in NMHC emissions from 1977
to 2005 is approximately 55 percent. This means that, in terms of ozone
air quality, little difference is seen among the different NMHC
scenarios. However, for the low stationary source growth scenario, NMHC
emissions in 2005 are reduced 66 percent from 1977 levels. In contrast,
under the high mobile and high stationary source growth scenarios, emis-
sions are reduced only 45 and 38 percent, respectively. Making the
simplistic assumption that changes in emissions are directly proportional
to changes in air quality, past air quality analyses have overpredicted
the improvement in ozone air quality by up to 17 percentage points (31
percent), if either of these scenarios is realistic.
-------
15
Another aspect of the sensitivity analysis not yet discussed deals with
the rate at which present stationary sources of emissions are retired or
scrapped. These sources are assumed to be replaced by new, presumably
cleaner, factories, equipment, etc. Three levels of control are assumed
to apply to each type of stationary source. Old sources in areas that
meet the NAAQS have associated with them one level of control.
Areas that are not expected to meet the NAAQS by 1983 must, at that time,
have controls on old sources designated as reasonably available control
technology (RACT). New sources must be controlled to levels specified by
new source performance standards (NSPS).
For the sensitivity analysis changes in the retirement rate assumption
are used to indirectly examine the effect of changing the average level
of control applied to stationary sources. (Since a fixed retirement rate
is assumed for CO stationary sources, this scenario was not discussed in
the previous section.) In the low retirement scenario (designated as LO
RETIR in the tables and graphs), the rate was reduced one percentage
point from the levels indicated in Tables 3-5 (the baseline expected
growth and control assumption tables). The effect of reducing the
retirement rate is to decrease the average level of stationary source
control, since old sources are scrapped at a lower annual rate. In the
high retirement rate scenario (designated as HI RETIR), the rate was
increased by one percentage point. The effect of this change is to
increase the average level of stationary source control. The plus and
minus one percentage point range was arbitrarily chosen. However, as
Table 18 shows, changing the retirement rate has little affect on
projected emissions.
The purpose of including the low stationary source control scenario in
this study is to directly test the sensitivity of emissions to the NSPS
and RACT NMHC assumptions. Neither CO nor NOx were considered for this
scenario, although it would be possible to do so. Only NMHC was chosen
for examination since the degree of stationary source control assumed in
the baseline case is so great. For NMHC scenarios both the NSPS and RACT
controls from -Table 4 were reduced 50 percent. The assumed NSPS control
on petroleum storage, for example, was reduced from 80 percent to 40
percent. Although the choice of 50 percent reduction is completely
arbitrary, if stationary sources are controlled to a lesser degree than
is generally assumed, future air quality will suffer. If this scenario
is realistic, then the improvement in air quality has been overestimated
by 31 percentage points (56 percent).
Table 19 shows the mobile source proportion of total NMHC emission for
each scenario. Under the all rural driving scenario mobile sources
account for a smaller proportion of total emissions. On the other hand, -
under the low temperature and urban driving scenarios mobile sources
account for a slightly greater proportion of NMHC emissions t:han for the
baseline. Also, both of the scenarios in which light duty vehicle emis-
sion factors are increased show mobile sources accounting for a larger
proportion of NMHC emissions.
-------
16
NOx
As Tables 18 and 19 indicate, the trends evident for CO emissions are
also generally evident for NMHC emissions. NOx, however, is somewhat
different. For CO and NMHC base year off-highway sources account for a
small proportion of total county emissions. For NOx, however, railroads,
vessels, aircraft, and diesel industrial machinery and construction
equipment comprise 20 percent of mobile source county emissions. Also,
as Figure 11 shows the projected changes in mobile and stationary NOx
emissions through 2005 are different from the CO and NMHC projected
changes. One difference between NOx and the other two pollutants is that
total emissions begin to increase between 1987 and 1995. By 2005 NOx
emissions are projected to be greater tnan they were in 1977.
Figure 12 shows the distribution of mobile source NOx emissions for each
projection year. The slight increase between 1987 and 1995 in the
projection of mobile source emissions accounted for by light duty
vehicles is an artifact of the data. As Table 20 shows, total mobile
source emissions decline through 1995. Light duty vehicle NOx emissions,
however, decline only through 1987. Since, by 1995, light duty vehicle
NOx emissions are increasing at the same time that total mobile emissions
are declining, the proportion of mobile emissions accounted for by light
duty vehicles increases. By 2005, however, both total mobile and the
light duty proportion of mobile emissions are increasing. The net
effect is that the proportion of mobile emissions accounted for by light
duty vehicles starts a second downward trend by 2005.
By 2005 NOx emissions from diesel construction equipment and industrial
machinery, taken together, are projected to exceed the combined light and
heavy duty gas truck emissions. The same holds true for railroad NOx
emissions by 2005. Tables 21 and 22 present in greater detail the infor-
mation shown in Figures 11 and 12.
The trend differences between NOx and CO and NMHC become more evident in
Tables 23 and 24. Table 23 summarizes the NOx inventory projections for
each sensitivity scenario. Unlike CO and NMHC, NOx emissions are
unaffected by low temperature, since MOBILE1 assumes that NOx emission
factors are constant for all temperatures. Also different is the
relationship between emissions and the assumed driving cycle. NOx
emissions increase under the warmed-up, high speed rural driving cycle
and decline for the cold start, slower driving assumed for the urban
cycle. For CO and NMHC emissions the trend is just the opposite.
In most NOx scenarios the emissions inventory in 2005 is higher than the
1977 inventory. The inventory is as much as 42 percent higher for high
mobile source growth. Only for low stationary source growth are NOx
emissions in 2005 less than 1977 emissions.
Table 24 summarizes the contribution of mobile sources to total NOx emis-
sions for each scenario. The table indicates two NOx trends that are
different from CO and NMHC trends. Under the rural driving scenario the
mobile source portion of total county emissions increases; under the
urban scenario that proportion decreases.
-------
17-
Conclusions
The major conclusions drawn from this analysis are summarized below:
1. In the majority of counties with air quality problems, mobile sources
account for 95 percent of the CO, 51 percent of the HC and 58 percent of
the NOx.
2. Total CO and NMHC emissions are projected to decline through 1995 and
to increase thereafter. Total NOx. emissions are projected to decline
through 1987 and to increase thereafter.
3. By 2005 CO emissions from gas farm and construction equipment and
from gas industrial machinery, taken together, will match CO emissions
from light or heavy duty gas trucks and exceed emissions from railroads,
vessels and aircraft. On the other hand, NMHC and NOx emissions from
these sources will be negligible.
4. Heavy duty diesel NMHC emissions will nearly match the combined emis-
sions from light and heavy duty gas trucks by 2005. Railroad and vessel
emissions will also be significant by that year. Aircraft NMHC emissions
will exceed heavy duty gas truck emissions by 2005.
5. By 2005, NOx emissions from diesel construction equipment and
industrial machinery, taken together, will exceed the combined light and
heavy duty gas truck emissions. Railroad NOx emissions will also be
significant by that year.
6. For all three pollutants the baseline 1977 emission estimates are
sensitive to the assumed driving cycle. Projected inventory changes
between 1977 and 2005, however, are also sensitive to the assumed mobile
and stationary source growtli rates.
7. The average mobile source contribution to total county emissions is
also sensitive to the assumed activity growth rates. For high mobile
source growth, the mobile source contribution will be nearly the same in
2005 as it is in 1977. The average mobile source contribution to total
emissions will be 88 percent for CO, 45 percent for NMHC, and 53 percent
for NOx.
Clearly, mobile sources will account for a large proportion of county
emissions. As this paper has pointed out, the recent downward trend in
total emissions is expected to be reversed. If the quality of air in our
cities is to be improved, emissions from both mobile ana stationary
sources will have to be controlled to a degree greater than is presently
projected.
-------
18
List of Tables
Table 1 Percent of all County-Wide Emissions Contributed by Mobile
Sources - All Counties
Table 2 Percent of all County-Wide Emissions Contributed by Mobile
Sources - Counties with Potential to Violate the NAAQS
Table 3 Baseline Assumptions for CO Stationary Sources
Table 4 Baseline Assumptions for NMHC Stationary Sources
Table 5 Baseline Assumptions for NOx Stationary Sources
Table 6 Baseline CO Inventory Levels
Table 7 Baseline CO Relative Contributions
Table 8 Baseline CO Contributions Relative to Total Inventory
Table 9 Mobile Sources of Pollution
Table 10 Stationary Sources of Pollution
Table 11 Total CO Inventory - Scenario Summary
Table 12 Mobile Source CO Contribution - Scenario Summary
Table 13 Baseline NMHC Inventory Levels
Table 14 Baseline NMHC Relative Contributions
Table 15 Baseline NMHC Contributions Relative to Total Inventory
Table 16 Total NMHC Inventory - Scenario Summary
Table 17 Mobile Source NMHC Contributions - Scenario Summary
Table 18 Baseline NOx Inventory Levels
Table 19 Baseline NOx Relative Contributions
Table 20 Baseline Contributions Relative to Total Inventory
Table 21 Total NOx Inventory - Scenario Summary
Table 22 Mobile Source NOx Contributions - Scenario Summary
-------
19
Table 1
Percent of County-Wide Emissions Contributed by Mobile Sources
All Counties
Percentiles
Pollutant
CO
HC
NOx
Mean
Percent .05(b)
Contribution(a)
84.0
56.4
72.1
.50
40.3(d) 91.9
21.6 57.9
12.0 84.1
Maximum
.95 Percent
Contribution(c)
98.4 100.0
84.0 100.0
96.1 100.0
(a) Average mobile source contribution in percent
(b) Percentile of counties
(c) Maximum mobile source contribution for one county in percent
(d) Mobile source CO contribution, listed in percent, exceeded in 95 percent
of all counties
Table 2
Percent of County-Wide Emissions Contributed by Mobilt Sources
Counties with the Potential to Violate the NAAQS
Percentiles
Pollutant
CO
HC
NOx
Mean
Percent .05(b)
Contribution(a)
Maximum
.50 .95 Percent
ContrioutionCc)
89.2
50.1
58.2
56.9(d)
21.9
16.0
94.6
50.8
58.4
98.7
72.7
88.5
99.7
30.7
93.3
(a) Average mobile source contribution in percent
(b) Percentile of counties
(c) Maximum mobile source contribution for one county, in perce it
(d) Mobile source contribution, listed in percent, exceeded in 95 percent of
all counties
-------
20
Table 3
Baseline Assumptions for CO Stationary Sources
Stationary Expected Compound Annual Degree of Inventory
Source Category Growth Rate (Percent) Control* (Percent) Projection Year
Point
Sources
Area
Sources
2.5
2.5
2.5
2-5
1.0
1.0
1.0
1.0
24
34
50
62
24
34
50
62
1983
1987
1995
2005
1983
1987
1995
2005
* The NSPS, RACT, and the retirement rate are together reflected by this
series. That is why both point and area sources show increased control
over the years. Newer, cleaner sources, are replacing existing sources.
Table 4
Baseline Assumptions for NMHC Stationary Sources
Stationary
Annual
Source
Category
Combustion
Petroleum
Re fineries
Petroleum
Storage
Industrial
Processes
Solvent
Evaporation
Compound Annual
Growth Rate
(Percent)
0
2.0
2.0
3.5
2.0
NSPS Degree RACT
of Control of Control
(Percent) (Percent)
0
85
80
45
80
0
90
80
35
40
Degree Compound
Retirement Rate
(Percent)
2.0
4.0
4.0
2.5
3.0
-------
21
Table 5
Baseline Assumptions for NOx Stationary Sources
Stationary Compound Annual NSPS Degree RACT Degree
Source Growth Rate of Control of Control
Category (Percent) (Percent) (Percent)
Point 2.5 30 25
Sources
Residential 1.0 50 0
Oil and Gas
Commercial 1.0 24 20
Coal
Commercial 1.0 50 40
Oil and Gas
Compound Annua
Retirement Rate
(Percent)
0
0
0
0
Institutional
Coal
Institutional
Oil and Gas
Other Area
Sources
1.0
1.0
] .0
24
50
20
40
-------
TABLE 6
CO
INVENTORY LEVELS
SCENARIO : BASELINE
EMISSIONS (10OO TONS/YEAR)
MOBILE SOURCE CATEGORIES
BASE YR
1977
PROJ YR
1983
1987
1995
2OO5
BASE YR
1977
PROJ YR
1983
1987
1995
2005
BASE YR
1977
PROJ YR
1983
1987
1995
2005
LDV-G
28533. 1
14235.5
7564.9
5460.7
6O31 .7
AIRCRAFT
399.5
422.8
441 .3
478. 1
528. 1
POINT
3568.0
3145.4
3015.2
2782.4
2707 . 4
LDT1-G
3449.7
2562.8
1677. 1
1073. 1
1 184.3
0.0
O.O
0.0
0.0
0.0
AREA
1628.4
1314.5
1187.8
974.0
819.9
LDT2-G
2186. 1
1879.9
1424.4
862.7
663.8
OH-MCYC
29.2
29.4
3O.4
33.2
37.4
O.O
0.0
0.0
0.0
0.0
HOG
7414.5
5976.9
3694.7
2113.3
1558.5
FARM-G
260.7
275.9
287.3
312.9
344.3
0.0
0.0
0.0
0.0
0.0
CYCLES
270.8
149.6
56. 1
32.0
36.6
LAWN
O.O
0.0
O.O
0.0
O.O
STATIONARY
0.0
0.0
O.O
0.0
0.0 '
LDV-D
0.0
0.0
0.0
0.0
O.O
SNOW
12. 1
12.2
13. 0
13.9
15.5
LDT1-D
0.0
O.O
0.0
0.0
0.0
INDMCH-G
692.0
733.8
764.3
827.2
914.7
LDT2-D
0.0
0.0
0.0
0.0
0.0
CONST-G
251 .3
265.2
277.3
300.9
333. 1
HDD
740.3
892.3
1061 .4
1531:3
2495.8
FARM-D
9.2
9.3
9.4
10.0
11 .0
RAILROAD
1 14.2
118.3
125. 1
135.7
151 . 1
INDMCH-D
14.8
14.9
15. 0
15.3
17.7
VESSELS
176.3
185.4
194.4
210. 1
232.7
CONST-D
50. 1
51 . 1
53.6
59.0
66.0
MOBILE
TOTAL
44604 .2
2783O.8
17699.2
13477.6
14625.4
SOURCE CATEGORIES
0.0
O.O
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
STAT
TOTAL
5196.3
4458.7
4201 . 1
3756.4
3524.5
GRAND
TOTAL
498OO.5
32289.4
21900.2
17233.9
18149.9
-------
TABLE 7
CO : RELATIVE CONTRIBUTIONS SCENARIO : BASELINE
PERCENT OF MOBILE/STATIONARY SOURCE CONTRIBUTION
MOBILE SOURCE CATEGORIES
BASE YR
1977
PROJ YR
1983
1987
1995
2005
BASE YR
1977
PROJ YR
1983
1987
1995
2005
BASE YR
1977
PROJ YR
1983
1987
1995
20O5
LDV-G
64.0
51 .2
42.7
40.5
41 .2
AIRCRAFT
0.9
1 .5
2.5
3.5
3.6
POINT
68.7
70.5
71 .8
74. 1
76.8
LDT1-G
7.7
9.2
9.5
8.O
8. 1
0.0
0.0
0.0
0.0
0.0
AREA
31 .3
29.5
28.3
25.9
23.3
LDT2-G
4.9
6.8
8.0
6.4
4.5
OH-MCYC
0. 1
0. 1
0.2
0.2
0.3
0.0
O.O
0.0
0.0
O.O
HDG
16.6
21 .5
20.9
15.7
10.7
FARM-G
O.6.
1 .O
1.6
2.3
2.4
0.0
O.O
0.0
0.0
0.0
CYCLES
0.6
0.5
0.3
0.2
0.3
LAWN
0.0
O.O
0.0
0.0
0.0
STATIONARY
0.0
0.0
0.0
0.0
0.0
LDV-D
0.0
0.0
O.O
0.0
0.0
SNOW
0.0
O.O
0. 1
0. 1
0.1
LDT1-D
0.0
0.0
0.0
0.0
0.0
INDMCH-G
1 .6
2.6
4.3
6. 1
6.3
LDT2-D
0.0
0.0
O.O
0.0
0.0
CONST-G
O.6
1 .0
1 .6
2.2
2.3
HDD
1 .7
3.2
6.0
1 1 .4
17. 1
FARM-D
O.O
0.0
0. 1
0. 1
0. 1
RAILROAD
0.3
0.4
O.7
1.0
1.0
INDMCH-D
0.0
0. 1
0.1
0. 1
0. 1
VESSELS
0.4
0.7
1 . 1
1 .6
1 .6
CONST-D
0. 1
O.2
0.3
0.4
0.5
MOBILE
TOTAL
10O.O
1OO.O
100.0
100.0
100.0
SOURCE CATEGORIES
0.0
O.O
0.0
0.0
0.0
O.O
0.0
0.0
0.0
0.0
0.0
0.0
0.0
O.O
0.0
0.0
0.0
0.0
0.0
0.0
STAT
TOTAL
1OO.O
10O.O
10O.O
100.0
100.0
GRAND
TOTAL
--
--
--
--
--
NJ
U>
-------
TABLE 8
CO : CONTRIBUTIONS RELATIVE TO TOTAL INVENTORY
PERCENT OF TOTAL INVENTORY
SCENARIO : BASELINE
MOBILE SOURCE CATEGORIES
BASE YR
1977
PROJ YR
1983
1987
1995
2OO5
BASE YR
1977
PROJ YR
1983
1987
1995
2O05
BASE YR
1977
PROJ YR
1983
1987
1995
2OO5
LDV-G
57.3
44. 1
34.5
31.7
33.2
AIRCRAFT
0.8
1 .3
2.O
2.8
2.9
POINT
7.2
9.7
13.8
16. 1
14.9
LDT1-G
6.9
7.9
7.7
6.2
6.5
0.0
O.O
0.0
0.0
0.0
AREA
3.3
4. 1
5.4
5.7
4.5
LDT2-G
4 .4
5.8
6.5
5.0
3.7
OH-MCYC
0. 1
0. 1
O. 1
O.2
0.2
0.0
0.0
O.O
0.0
0.0
HDG
14.9
18.5
16.9
12.3
8.6
FARM-G
0.5
0.9
1 .3
1 .8
1 .9
0.0
O.O
0.0
0.0
0.0
CYCLES
0.5
O.5
0.3
0.2
0.2
LAWN
0.0
O.O
0.0
0.0
O.O
STATIONARY
0.0
0.0
0.0
O.O
0.0
LDV-D
0.0
O.O
0.0
0.0
O.O
SNOW
0.0
0.0
0.1
0. 1
O. 1
LDT1-D
0.0
0.0
0.0
0.0
0.0
INDMCH-G
1 .4
2.3
3.5
4.8
5.O
LDT2-D
0.0
0.0
0.0
0.0
0.0
CONST-G
0.5
0.8
1 .3
1 .7
1 .8
HDD
1 .5
2.8
4.8
8.9
13.8
FARM-D
O.O
O.O
0.0
0. 1
0. 1
RAILROAD
0.2
0.4
0.6
0.8
O.8
INDMCH-D
0.0
O.O
0. 1
0.1
O. 1
VESSELS
0.4
0.6
0.9
1.2
1 .3
CONST-D
0. 1
0.2
0.2
0.3
O.4
MOBILE
TOTAL
89.6
86.2
80.8
78.2
8O.6
SOURCE CATEGORIES
0.0
0.0
0.0
0.0
0.0
O.O
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
O.O
O.O
0.0
0.0
0.0
O.O
STAT
TOTAL
10.4
13.8
19.2
21 .8
19.4
GRAND
TOTAL
1OO.O
1OO.O
100.0
10O.O
1OO.O
-------
25
Table 9
Mobile Sources of Pollution
Description
Light duty gas vehicles
Light duty gas trucks less than 6000 pounds
Light duty gas trucks between 6000 and 8500 pounds
Heavy duty gas trucks
Highway motorcycles
Heavy duty diesel trucks
Locomotives
Vessels
Aircraft
Off-highway motorcycles
Gas farm equipment
Lawn and garden equipment
Snowmobiles
Gas industrial machines
Gas construction equipment
Diesel farm equipment
Diesel industrial machines
Diesel construction equipment
Designation
LDV-G
LDT1-G
LDT2-G
HDG
CYCLES
HDD
RAILROAD
VESSELS
AIRCRAFT
OH-MCYC
FARM-G
LAWN
SNOW
INSMCH-G
CONST-G
FARM-D
INDMCH-D
CONST-D
-------
26
Table 10
Stationary Sources of Pollution
Pollutant Description
CO Point sources
Area sources
NMHC Combustion
Petroleum refineries
Petroleum storage
Industrial processes
Solvent evaporation
NOx Point sources
Residential oil and gas
Commercial coal
Commercial oil and gas
Institutional coal
Institutional oil and gas
Other area sources
Table 11
Total CO Inventory - Scenario Summary
Emissions
Inventory Change from
in 1977 Base Case
^cenario (tons) (Percent)
Baseline 49800.5 0
Low temperature 58190.7 +16.8
Low retirement 49800.5 . 0
High retirement 49800.5 0
Rural 25939.4 -47.9
Urban 54878.5 +10.2
Low mobile source growth 49800.5 0
High mobile source growth 49800.5 0
Low stationary source growth 49800.5 0
High stationary source growth 49800.5 0
+50 LDV emission factors 64067.5 +28.6
+100 LDV emission factors 78333.2 +57.3
Designation
POINT
AREA
COMBUST
PETROL
STORAGE
INDUST
SOLVENT
POINT
RES-OIL
COM- COAL
COM-OIL
IND-COAL
IND-OIL
OTHER
ary
Emissions
Inventory
in 2005
(tons)
18149.9
19762.0
18149.9
18149.9
10875.2
19991.0
14603.7
28808.0
16652.2
20691.7
21167.0
24182.4
Change from
1977
(Percent)
-63.6
-66.0
-63.6
-63.6
-58.1
-63.6
-70.7
-42.2
-66.6
-58.5
-67.0
-69.1
-------
27
Table 12
Mobile Source CO Contribution - Scenario Summary
Scenario
Baseline
Low temperature
Low retirement
High retirement
Rural
Urban
Low mobile source growth
High mobile source growth
Low stationary source growth
High stationary source growth
+50 LDV emission factors
+100 LDV emission factors
Mobile
Source
Contribution
in 1977
(Percent)
89.6
91.1
89.6
89.6
80.0
90.5
89.6
89.6
89.6
89.6
91.1
93.4
Change
from
Base
Case
(Percent)
0
+1.7
0
0
-10.7
+1.0
0
0
0
0
+2.6
+4.2
Mobile
Source
Contribution
in 2005
(Percent)
80.6
82.2
80.6
80.6
67.6
82.4
75.9
87.8
87.8
70.7
83.3
85.4
Change
from
1977
(Percent)
-10.0
-9.8
-10.0
-10.0
-15.5
-9.0
-15.3
-2.0
-2.0
-21.1
-9.4
-8.6
-------
TABLE 13
NMHC : INVENTORY LEVELS
SCENARIO : BASELINE
EMISSIONS (1000 TONS/YEAR)
MOBILE SOURCE CATEGORIES
BASE YR
1977
PROJ YR
1983
1987
1995
2OO5
BASE YR
1977
PROd YR
1983
1987
1995
2OO5
BASE YR
1977
PROJ YR
1983
1987
1995
2OO5
LDV-G
3379.8
1578.8
820.7
565.8
625.2
AIRCRAFT
115.8
121.4
127.2
138.2
152.9
O.O
0.0
O.O
O.O
0.0
LDT1-G
386.3
202. 1
128.4
101 .7
112.7
0.0
O.O
0.0
0.0
O.O
0.0
0.0
0.0
0.0
O.O
LDT2-G
311.4
205.8
133.9
79.8
65.4
OH-MCYC
7 . 1
7. 1
7. 1
7.4
8.O
COMBUST
302.5
302.5
302.5
3O2.5
302.5
HDG
737.3
418.5
252.8
158.4
126.2
FARM-G
9.5
9.5
9.6
10.0
11 .O
0.0
0.0
0.0
0.0
0.0
CYCLES
81 .2
33.6
7.7
1 .5
2.0
LAWN
0.0
O.O
O.O
O.O
0.0 .
STATIONARY
PETROL
226.6
29.2
33.4
43.2
55. 1
LDV-D
O.O
O.O
0.0
0.0
O.O
SNOW
6.8
6.8
7. 1
7.8
8.7
LDT1-D
0.0
O.O
0.0
0.0
O.O
INDMCH-G
21 .2
21 .6
22. 1
23.5
27. 0
LDT2-D
0.0
O.O
0.0
0.0
O.O
CONST-G
6.7
6.7
6.8
7. 1
7.7
HDD
1O6.8
137.7
127.5
165.4
258. 1
FARM-D
2.4
2.4
2.5
2.5
2.7
RAILROAD
79.2
81 .7
85.8
94.2
1O4.3
INDMCH-D
3.0
3.O
3.O
3. 1
3.2
VESSELS
59.4
61 .7
64.3
70. 1
78.5
CONST-D
13. 3
13.3
13.3
14.3
16. 1
MOBILE
TOTAL
5327 . 1
2921 .2
1833.5
1457.9
1620.8
SOURCE CATEGORIES
STORAGE
1031 .3
232.0
251 .5
294.6
359. 1
INDUST
429.3
328.0
367. 1
465.7
638.3
SOLVENT
4033.3
2252. 1
2173.4
2084.0
2092 . 5
O.O
0.0
0.0
0.0
0.0
STAT
TOTAL
6022.9
3143.4
3127.0
3 1 90 . 7
3449.4
GRAND
TOTAL
11350.0
6064.6
4960.5
4648.6
5O70 . 1
t-o
00
-------
TABLE 14
NMHC : RELATIVE CONTRIBUTIONS SCENARIO : BASELINE
PERCENT OF MOBILE/STATIONARY SOURCE CONTRIBUTION
LDV-G LDT1-G
BASE YR
1977
PROJ YR
1983
1987
1995
2005
BASE YR
1977
PROJ YR
1983
1987
1995
20O5 .
BASE YR
1977
PROJ YR
1983
1987
1995
2005
63.4
54.0
44 .8
38.8
38.6
AIRCRAFT
2.2
4.2
6.9
9.5
9.4
0.0
0.0
0.0
O.O
0.0
7.3
6.9
7.O
7.0
7.0
O.O
0.0
O.O
0.0
0.0
0.0
0.0
0.0
O.O
0.0
LDT2-G
5.8
7.0
7 .3
5.5
4.0
OH-MCYC
0. 1
0.2
0.4
0.5
.0.5
COMBUST
5.0
9.6
9.7
9.5
8.8
HDG
13.8
14.3
13.8
10.9
7.8
FARM-G
O.2
0.3
0.5
0.7
0.7
0.0
0.0
O.O
0.0
0.0
MOBILE SOURCE CATEGORIES
CYCLES LDV-D LDT1-D
1 .5
1 .2
0.4
0. 1
0. 1
LAWN
0.0
0.0
0.0
0.0
O.O
STATIONARY
PETROL
3.8
0.9
1 . 1
1 .4
1 .6
0.0
0.0
0.0
0.0
0.0
SNOW
0. 1
0.2
0.4
0.5
0.5
0.0
0.0
. O.O
0.0
0.0
INDMCH-G
0.4
O.7
1 .2
1 .6
1 .7
LDT2-D
0.0
0.0
O.O
0.0
0.0
CONST-G
0. 1
0.2
0.4
0.5
0.5
HDD
2.0
4.7
7.0
11.3
15.9
FARM-D
0.0
0. 1
0. 1
0.2
0.2
RAILROAD
1 .5
2.8
4.7
6.5
6.4
INDMCH-D
0. 1
0. 1
0.2
0.2
0.2
VESSELS
1 . 1
2. 1
3.5
4.8
4.8
CONST-D
0.2
0.5
0.7
1 .0
1 .0
MOBILE
TOTAL
1OO.O
100.0
100.0
100.0
1OO.O
SOURCE CATEGORIES
STORAGE
17. 1
7.4
8.0
9.2
10.4
INDUST
7. 1
1O. 4
11.7
14.6
18.5
SOLVENT
67 .0
71 .6
69.5
65.3
60.7
0.0
0.0
0.0
0.0
0.0
STAT
TOTAL
100.0
100.0
100. 0
10O.O
100.0
GRAND
TOTAL.
--
--
--
--
--
-------
TABLE 15
NMHC : CONTRIBUTIONS RELATIVE TO TOTAL INVENTORY
PERCENT OF TOTAL INVENTORY
SCENARIO : BASELINE
LDV-G LDT1-G
BASE YR
1977
PROJ YR
1983
1987
1995
2005
BASE YR
1977
PROJ YR
1983
1987
1995
2005
BASE YR
1977
PROJ YR
1983
1987
1995
2005
29.8
26.0
16.5
12.2 .
12.3
AIRCRAFT
1 .O
2.O
2.6
3.O
3.0
0.0
0.0
0.0
0.0
0.0
3.4
3.3
2.6
2.2
2.2
0.0
0.0
0.0
O.O
O.O
0.0
0.0
0.0
0.0
0.0
LDT2-G
2.7
3.4
2.7
1 .7
1 .3
*
OH-MCYC
0. 1
0. 1
0. 1
0.2
0.2
COMBUST
2.7
5.0
6. 1
6.5
6.0
HOG
6.5
6.9
5. 1
3.4
2.5
FARM-G
O. 1
0.2
0.2
0.2
O.2
0.0
0.0
O.O
O.O
O.O
MOBILE SOURCE CATEGORIES
CYCLES LDV-D LDT1-D
0.7
0.6
0.2
0.0
0.0
LAWN
O.O
0.0
0.0
O.O
O.O
STATIONARY
PETROL
2.0
0.5
0.7
0.9
1 . 1
O.O
0.0
0.0
O.O
O.O
SNOW
O. 1
O. 1
0. 1
0.2
O.2
O.O
0.0
0.0
O.O
0.0
INDMCH-G
0.2
0.4
0.4
0.5
O.5
LDT2-D
O.O
0.0
0.0
0.0
0.0
CONST-G
O. 1
0. 1
0. 1
0.2
O.2
HDD
O.9
2.3
2.6
3.6
5. 1
FARM-D
O.O
0.0
0. 1
0. 1
O. 1
RAILROAD
O.7
1 .3
1 .7
2.0
2. 1
INDMCH-D
0.0
0.0
0. 1
0. 1
0. 1
VESSELS
0.5
1 .O
1 .3
1 .5
1 .5
CONST-D
O. 1
0.2
0.3
0.3
0.3
MOBILE
TOTAL
46.9
48.2
37.0
31 .4
32. O
SOURCE CATEGORIES
STORAGE
9.1
3.8
5. 1
6.3
7. 1
INDUST
3.8
5.4
7.4
10.0
12.6
SOLVENT
35.5
37. 1
43.8
44.8
41 .3
0.0
0.0
0.0
0.0
O.O
STAT
TOTAL
53. 1
51.8
63.0
68.6
68.0
GRAND
TOTAL
100.0
100.0
100.0
100.0
100. 0
-------
31
Table 16
Total NMHC Inventory - Scenario Summary
Scenario
Baseline
Low temperature
Low retirement
High retirement
Rural
Urban
Low mobile source growth
High mobile source growth
Low stationary source growth
High stationary source growth
+50 LDV emission factors
+100 LDV emission factors
Low stationary source control
Emissions
Inventory
in 1977
(Tons)
11350.0
11833.1
11350.0
11350.0
9299.4
11785.0
11350.0
11350.0
11350.0
11350.0
12529.9
13709.1
11350.0
Change
from Base
Case
(Percent)
0
+4.3
0
0
-18.1
+3.8
. 0
0
0
0
+10.4
+20.8
0
Emissions
Inventory
in 2005
(Tons)
5070.1
5230.0
5305.3
4892.7
4308.5
5248.8
4678.1
6251.5
3903.3
7049.4
5349.0
5582.5
8670.1
Change
from 1977
(Percent)
-55.3
-55.8
-53.3
-56.9
-53.7
-55.5
-58.8
-44.9
-65.6
-37.9
-57.3
-59.3
-23.6
-------
32
Table 17
Mobile Source NMHC Contributions - Scenario Summary
Scenario
Baseline
Low temperature
Low retirement
High retirement
Rural
Urban
Low mobile source growth
High mobile source growth
Low stationary source growth
High stationary source growth
+50 LDV emission factors
+100 LDV emission factors
Low stationary source control
Mobile
Source
Contribution
in 1977
46.9
49.1
46.9
46.9
35.2
48 .'9
46.9
46.9
'th 46.9
wth 46.9
51.9
56.1
rol 46.9
Change
from base
Case
(Percent)
0
+2.7
0
0
-24.9
+4.3
0
0
0
0
+ 10.7
+ 19.6
0
Mobile
Source
Contribution
in 2005
32.0
34.0
30.6
33.1
19.9
34.3
26.3
44.8
23.0
23.0
35.5
38.2
18.7
Change
from 1977
(Percent)
-31.8
-30.8
-34.8
-29.4
-43.5
-29.9
-43.9
-4.5
-11.5
-51.0
-31.6
-31.9
-60.1
-------
TABLE 18
NOX
INVENTORY LEVELS
SCENARIO : BASELINE
EMISSIONS (1000 TONS/YEAR)
MOBILE SOURCE CATEGORIES
BASE YR
1977
PROJ YR
1983
1987
1995
2005
BASE YR
1977
PROJ YR
1983
1987
1995
2005
BASE YR
1977
PROJ YR
1983
1987
1995
2005
LDV-G
1536.6
1076.4
951 . 1
974 .4
1076.0
AIRCRAFT
79.6
83.2
87. 1
94.3
1O4.6
POINT
2838.0
2445.9
2685.4
3240.6
4107.9
LDT1-G
202.3
147.7
125.0
1 16.0
129.3
0.0
0.0
0.0
0.0
O.O
0.0
0.0
0.0
0.0
0.0
LDT2-G
158.7
112.4
86. 0
69.8
74.2
OH-MCYC
0.0
O.O
0.0
0.0
0.0
RES-OIL
180.8
184.3
188.7
196.5
208.7
HDG
3OO.6
240.7
185.7
135. 0
115.3
FARM-G
7.9
7.9
7.9
8.4
9.0
COM-COAL
3.7
3.4
3.5
3.6
3.7
CYCLES
0. 1
0.4
0.2
0. 1
0.2
LAWN
0.0
0.0
0.0
0.0
0.0
STATIONARY
COM-OIL
174.3
110.8
114.5
121 .3
133.7
LDV-D
0.0
0.0
0.0
0.0
0.0
SNOW
0.0
0.0
0.0
0.0
0.0
LDT1-D
0.0
0.0
0.0
0.0
0.0
INDMCH-G
16.7
16.9
17.3
18.4
20.8
LDT2-D
0.0
.0.0
O.O
0.0
0.0
CONST-G
6.4
6.4
6.5
6.8
7.4
HDD
523.2
679. 1
552.9
376.5
552.8
FARM-D
26.2
26.6
27.5
29.2
33.2
RAILROAD
325. 1
343.8
359. 1
389.3
429.6
INDMCH-D
71 .4
73.0
77.9
85.0
94.2
VESSELS
62.9
66.2
68.8
75.3
82.7
CONST-D
200.8
211.6
221 .8
240. 0
265. 1
MOBILE
TOTAL
3518.4
31O3. 1
2780.3
2627.4
3003 . 9
SOURCE CATEGORIES
IND-COAL
29. 1
25.3
26.4
27.9
29.8
IND-OIL
113.0
71 .8
74.6
78.0
87.6
OTHER
46.6
47.4
49.8
54.5
61.1
0.0
O.O
0.0
0.0
0.0
STAT
TOTAL
3385.5
2889.8
3143.6
3726.5
4632. 1
GRAND
TOTAL
6903.9
5992.9
5923.9
6353.9
7636. 1
-------
TABLE 19
NOX : RELATIVE CONTRIBUTIONS
SCENARIO : BASELINE
PERCENT OF MOBILE/STATIONARY SOURCE CONTRIBUTION
LDV-G LDT1-G
BASE YR
1977
PROJ YR
1983
1987
1995
2005
BASE YR
1977
PROJ YR
1983
1987
1995
2OO5
BASE YR
1977
PROJ YR
1983
1987
1995
20O5
43.7
34.7
34.2
37. 1
35.8
AIRCRAFT
2.3
2.7
3. 1
3.6
3.5
POINT '
83.8
84.6
85.4
87.0
88.7
5-. 7
4.8
4.5
4.4
4.3
O.O
0.0
0.0
0.0
O.O
0.0
0.0
O.O
0.0
0.0
LDT2-G
4 .5
3.6
3. 1
2.7
2.5
OH-MCYC
O.O
0.0
0.0
0.0
0.0
RES-OIL
5.3
6.4
6.O
5.3
4.5
HOG
8.5
7.8
6.7
5. 1
3.8
FARM-G
O.2
0.3
0.3
0.3
0.3
COM-COAL
O. 1
0. 1
0. 1
0.1
0. 1
MOBILE SOURCE CATEGORIES
CYCLES LDV-D LDT1-D
O.O
0.0
0.0
0.0
0.0
LAWN
O.O
O.O
O.O
0.0
0.0
STATIONARY
COM-OIL
5. 1
3.8
3.6
3.3
2.9
0.0
O.O
0.0
0.0
0.0
SNOW
O.O
0.0
0.0
0.0
O.O
0.0
O.O
0.0
0.0
0.0
INDMCH-G
O.5
0.5
0.6
0.7
0.7
LDT2-D
0.0
O.O
0.0
0.0
0.0
CONST-G
O.2
0.2
0.2
0.3
O.2
HDD
14.9
21 .9
19.9
14.3
18.4
FARM-D
0.7
0.9
1 .0
1 . 1
1 . 1
RAILROAD
9.2
11.1
12.9
14.8
14.3
INDMCH-D
2.O
2.4
2.8
3.2
3. 1
VESSELS
1 .8
2. 1
2.5
2.9
2.8
CONST-D
5.7
6.8
8.O
9. 1
8.8
MOBILE
TOTAL
100.0
10O.O
100.0
100.0
1OO.O
SOURCE CATEGORIES
IND-COAL
0.9
0.9
0.8
0.7
0.6
IND-OIL
3.3
2.5
2.4
2. 1
1 .9
OTHER
1 .4
1 .6
1 .6
1 .5
1 .3
0.0
0.0
0.0
0.0
0.0
STAT
TOTAL
1OO.O
100.0
1OO.O
100.0
100. 0
GRAND
TOTAL
--
--
--
--
-------
TABLE 20
NOX : CONTRIBUTIONS RELATIVE TO TOTAL INVENTORY
PERCENT OF TOTAL INVENTORY
SCENARIO : BASELINE
LDV-G LDT1-G
BASE YR
1977
PROJ YR
1983
1987
1995
2005
BASE YR
1977
PROd YR
1983
1987
1995
2005
BASE YR
1977
PROd YR
1983
1987
1995
2005
22.3
18 .0
16. 1
15.3
14. 1
AIRCRAFT
1 .2
1 .4
1 .5
1 .5
1.4 -
POINT
41.1
40.8
45.3
51.0
53.8
2.9
2.5
2. 1
1 .8
1 .7
O.O
O.O
0.0
0.0
0.0
O.O
0.0
0.0
0.0
0.0
LDT2-G
2.3
1 .9
1 .5
1 . 1
1 .0
OH-MCYC
0.0
O.O
0.0
0.0
0.0
RES-OIL
2.6
3. 1
3.2
3. 1
2.7
HDG
4.4
4.0
3. 1
2. 1
1.5
FARM-G
O. 1
0. 1
0. 1
0. 1
0. 1
COM-COAL
O. 1
0.1
0. 1
0. 1
0.0
MOBILE SOURCE CATEGORIES
CYCLES LDV-D LDT1-D
O.O
0.0
0.0
0.0
0.0
LAWN
O.O
0.0
0.0
0.0
0.0
STATIONARY
COM-OIL
2.5
1 .8
1 .9
1 .9
1 .8
0.0
0.0
0.0
0.0
0.0
SNOW
0.0
0.0
0.0
0.0
0.0
SOURCE
IND-COAL
0.4
0.4
0.4
0.4
O.4
0.0
0.0
0.0
0.0
0.0
INDMCH-G
0.2
0.3
0.3
O.3
0.3
CATEGORIES
IND-OIL
1 .6
1 .2
1 .3
1 .2
1 . 1
LDT2-D
0.0
0.0
0.0
O.O
0.0
CONST-G
0. 1
0. 1
0. 1
0.1
0. 1
OTHER
0.7
0.8
0.8
0.9
O.8
HDD
7.6
11.3
9.3
5.9
7.2
FARM-D
O.4 .
0.4
0.5
0.5
0.4
0.0
0.0
0.0
0.0
0.0
RAILROAD
4 .7
5.7
6. 1
6. 1
5.6
INDMCH-D
1 .0
1 .2
1.3
1 .3
1 .2
STAT
TOTAL
49.0
48.2
53. 1
58.6
60.7
VESSELS
0.9
1 . 1
1 .2
1 .2
1 . 1
CONST-D
2.9
3.5
3.7
3.8
3.5
GRAND
TOTAL
1OO.O
100.0
100.0
100.0
1OO.O
MOBILE
TOTAL
51 .0
51.8
46.9
41.4
39.3
-------
36
Table 21
Total NOx Inventory - Scenario Summary
Scenario
Baseline
Low temperature
Low retirement
High retirement
Rural
Urban
Low mobile source growth
High mobile source growth
Low stationary source growth
High stationary source growth
+50 LDV emission factors
+100 LDV emission factors
Emissions
Inventory
in 1977
(Tons)
6903.9
6903.9
6903.9
6903.9
7103.2
6803.2
6903.9
6903.9
6903.9
6903.9
7672.1
8441.5
Change
from Base
Case
(Percent)
0
0
0
0
+2.9
-0.6
0
0
0
0
+ 11.1
+22.3
Emissions
Inventory
in 2005
(Tons)
7636.1
7636.1
7709.1
7571.6
7894.4
7584.0
6909.4
9816.2
5780.1
10778.3
8174.0
8712.9
Change
from 1977
(Percent)
+ 10.6
+ 10.6
+ 11.8
+9.7
+11.1
+10.5
+0.1
+42.2
-16.3
+56.1
+ 6.5
+3.2
-------
37
Table 22
Mobile Source NOx Contributions - Scenario Summary
Scenario
Baseline
Low temperature
Low retirement
High retirement
Rural
Urban
Low mobile source growth
High mobile source growth
Low stationary source growth
High stationary source growth
+50 LDV emission factors
+100 LDV emission factors
Mobile
Source
in 1977
(Percent)
51.0
51.0
51.0
51.0
52.3
50.7
51.0
51.0
th 51.0
wth 51.0
55.9
59.9
Change
from Base
Case
(Percent)
0
0
0
0
+2.5
-0.6
0
0
0
0
+9.6
+17.5
Mobile
Source
Contribution
in 2005
(Percent)
39.3
39.3
38.9
39.7
41.3
38.9
33.0
52.8
51.9
27.9
43.3
46.8
Change
from 1977
(Percent)
-22.9
-22.9
-23.7
-22.2
-21.0
-23.3
-35.3
+3.5
+ 1.8
-45.3
-22.5
-21.9
-------
38
List of Figures
Figure 1 Distribution of National Mobile Source CO Emissions
Figure 2 Distribution of National Mobile Source HC Emissions
Figure 3 Distribution of National Mobile Source NOx Emissions
Figure 4 Distribution of Mobile Source CO Emissions
Figure 5 Distribution of Mobile Source HC Emissions
Figure 6 Distribution of Mobile Source NOx Emissions
Figure 7 Baseline CO Emissions Inventory
Figure 8 Baseline CO Relative Mobile Source Contributions
Figure 9 Baseline NMHC Emissions Inventory
Figure 10 Baseline NMHC Relative Mobile Source Contributions
Figure 11 Baseline NOx Emissions Inventory
Figure 12 Baseline NOx Relative Mobile Source Contributions
-------
39
FIGURE 1 DISTRIBUTION OF MOBILE SOURCE CO EMISSIONS
320
210
in
UJ
160
DC
UJ
CO
80
10
20
30
PERCENT
OF
40
TOTRL
50
COUNTY
60
CO
70
EMISSIONS
80
90
100
-------
40
FIGURE 2 DISTRIBUTION OF .MOBILE SOURCE HC EMISSIONS
100
80
2 60
a
o
o
cc
UJ
CD
z
Z3
20
10 20 . 30 40 50 60 70 80
PERCENT OF TOTflL COUNTY HC EMISSIONS
90
100
-------
FIGURE 3 DISTRIBUTION OF MOBILE SOURCE NOX EMISSIONS
200
ISO
en
UJ
o
CJ
100
o
oc
CO
2:
SO
10
20 30
PERCENT
OF
40
TOTflL
50
COUNTY
60
NOX
70
EMISSIONS
80
90
100
-------
42
FIGURE H DISTRIBUTION OF MOBILE SOURCE CO EMISSIONS
20
15
tn
LU
10
cc
UJ
CO
10
20
30
PERCENT
HO
OF TOTflL
50
COUNTY
60 70
CO EMISSIONS
80
90
100
-------
43
FIGURE 5 DISTRIBUTION OF MOBILE SOURCE HC EMISSIONS
z
=>
o
o.
oc
Ul
00
10
20
30
PERCENT
40
OF TOTRL
50
COUNTY
60 70
HC EMISSIONS
80
100
-------
44
FIGURE 6 DISTRIBUTION OF MOBILE SOURCE NOX EMISSIONS
«n
UJ
o
o.
oc
UJ
CO
z:
30
PERCENT
OF
50
COUNTT
60
NOX
70
EMISSIONS
90
100
-------
45
80000
75000
70000
65000
_60000
Sssooo
FIGURE 7
CO - BflSELINE
CRTEGORY
£50000
0
i
045000
o
~40000
to
235000
o
0)30000
» i
25000
o
U20000
15000
10000
5000
0
/
5196
44604
/
A
/
/
4458
O"7 (3 q n
/
/
/
/
4201
17699
/
/
/
/
3756
13477
/
f
/
/
3524
14625
/
/
/
STflTIONflRY
MOBILE
1977
1983 1987 1995
PROJECTION TEflR
2005
-------
46
FIGURE 8
CO - BflSELINE
90
80
to
o 70
en
(n
i i
S 60
o
o
uj 50
tt
CO
o
U.
o
I
z
o 30
CE
liJ
Q_
20
10
0
3. 6
T~jr~T
I . I
16.6
4 . 9
7.7
64.0
5.5
21.5
6.8
9.2
51.1
8.5
6 0
20. 9
8.0
9.5
42.7
\
^N
x^
\
\
\
x^
11.9
3.5
1 r
US
11.4
15.7
R U
8.0
4,0.5
\
12. 1
3.6
U-6
17. 1
0.7
Uc
8. 1
41.2
CflTEGORY
OTHER
flIRCRflFT
HDD
HDG
LDT2-G
LDT1-G
LDV-G
1977
1983 1987 1995
PROJECTION YEflR
2005
-------
47
FIGURE 9
NMHC - BflSELINE
CflTEGOflr
15000
14000
13000
i *3 n n i\
I 2000
£11000
cc
|,|
^10000
to
z
o 9000
0
g 8000
* 1
«o 7000
z
o
£ 6000
CO
1-4
5 5000
(_>
= 4000
z
3000
2000
1000
0
/
6022
5327
/
/
/
/ /
/
3143
292 1
/
/
/
/
/ / * / /
/ / / / / /
( (
3126 3UU9
3190
/ '/ /
/ '
1833 1 1(157 1 1620
STflTIONflRY
MOBILE
1977 1983 1987 1995 2005
PROJECTION YEflR
-------
48
FIGURE 10
NMHC - BflSELINE
100
90
80
en
z
o "? n
» «
(O
t «
w 60
o
X
n
z
uj 50
_i
*-
CQ
0
* ^
0
»
I 30
DC
UJ
O_
20
10
0
.
^ . a
2 . 2
1^4
t>' n
c . u
13.8
5.8
70
o
63. H
sN
S\
\\
\
\
\
\
\\
\
\ \
\
\
\
3.6
U 2
"2.1
d. a
1.7
1U.3
7.0
6.9
5U.O
*""*--
\
\\
\\
\
\\
\
\
\
\
v\
\
\
\ \
\
\
1.3
6Q
3. 5
J. 7
7. 0
13.8
7.3
7. 0
41.8
\
\
\
\
\
s
\
\
5 3
9C
1.8
6.5
11.3
1 n Q
1 U o
. 5
7.0
38.8
s
\
"^^
5 3
an
. 4
1. 8
6.1
15.9
~1 fl
1.0
7.0
38.6
CflTEGORY
O T U C Q
flIRCRflFT
VESSELS
RfllLROflD
HOD
HOG
LOT2-G
LDT1-G
LDV-G
1977
1983 1987 1995
PROJECTION YEflfl
2005
-------
49
FIGURE 12
NOX - BHSELJNE
90
80
tn
z
o 70
-------
50
FIGURE n
NOX - BOSELINE
CRTEGORY
1 1000
10500
10000
9500
3000
8500
£ 8000
£ 7500
£ 7000
° 6500
S 6000
o
r 5500
<« 5000
5 4500
01
!C 4000
^ 3500
2 3000
2500
2000
1500
1000
500
0
c
.
.
.
.
/
3335
3518
/
/
/
/
2889
3103
/
/
/
/
3143
2780
/
/
/
/
3726
.2627
/
/
/
/
4632
3003
/
/
/
STflTIONflRY
MOBILE
1977
1983 1987 1995
PROJECTION TEPR
2005
-------
51
Appendix A
Counties with the Potential to Violate the
Current CO, NO and 0 NAAQS
-------
52
COUNTIES WITH THE POTENTIAL TO VIOLATE
CURRENT CO, NO , AND 0 AMBIENT STANDARDS
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
-52
53
State
05
05
05
05
06
06
06
06
06
06
06
06
07
07
07
07
09
10
10
10
11
13
14
14
14
15
15
County
Code
7700
8020
8340
8840
0020
0080
0220
0600
0760
1140
1320
2220
0265
0425
0705
0725
0020
0420
1080
1800
2260
0020
1540
8320
8400
0060
2360
AQCR
030
031
031
028
036
036
036
036
038
036
037
037
042,043
042
042
041
047
050
049
052
056.
064
067
067
073
081
067
County Name
Solano
Stanislaus
Tulafle
Yolo
Adams
Arapahoe
Boulder
Denver
El Paso
Jefferson
Larimer
Weld
Fairfield
Hartford
New Haven
New London
Washington
Broward
Duval
Hillsbourough
Fulton
Ada
Cook
Will
Winnebago
Allen
Lake
State
CA
CA
CA
CA
CO
CO
CO
CO
CO
CO
CO
CO
CT
CT
CT
CT
DC
FL
FL
FL
GA
ID
IL
IL
IL
IN
IN
CO
X
X
X
X
X
X
X
X
X
X
X
X
X
X
;x
X
X
X
X
X
X
X
N02
X
X
X
X
X
X
X
X
X
X
X
X
X
Ozor
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
53
COUNTIES WITH THE POTENTIAL TO VIOLATE
CURRENT CO, NO^ AND Oj AMBIENT STANDARDS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
2.6
State
01
01
01
02
02
03
03
04
05
05
05
05
05
05
05
05
05
05
05
05
05
05
05
05
05
05
County
Code
1980
2400
2480
0060
0180
0440
0620
2220
0060
0960
1620
2820
3480
4200
4400
4600
5440
6420
6600
6680
6820
6880
6960
7120
7220
7260
AQCR
004
005
002
008
009
015
015
016
030
028
030
031
031, 033
024, 033
030
031
024
024, 033
028
024, 033
029, 033
030
031
030
024, 032
030
County Name
Jefferson
Mobile
Montgomery
Anchorage
Fairbanks
Maricopa
Pima
Pulaski
Alameda
Butte
Contra Costa
Fresno
Kern
Los Angeles
Mar in
Merced
Orange
Riverside
Sacramento
San Bernardino
San Diego
San Francisco
San Joaquin
San Mateo
Santa Barbara
Santa Clara
State
AL
AL
AL
AK
AK
AZ
AZ
AR
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CO
X
X
X
X
X
X
X
X
X
X
! x
X
X
X
X
X
X
X
X
X
N02
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Ozon
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
54
COUNTIES WITH THE POTENTIAL TO VIOLATE
CURRENT CO, N02, AND 0^ AMBIENT STANDARDS
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
Z9
80
State
15
15
16
16
16
17
17
18
18
18
18
19
20
20
21
21
21
21
21
21
21
22
22
22
22
23
23
County
Code
2640
3700
2280
3120
3280
0860
3320
0340
0920
1920
2460
0500
0027
0907
0040
0080
0120
0140
1160
1300
1680
0369
1274
1291
1798
2360
2720
AQCR
080
082
088
092
069
095
099
103
077
078
072
022
107
109
113
115
115
115
047
047
113
118
. 121
119
042
125
122
County Name
Marion
St . Joseph
Linn
Polk
Scott
Douglas
Sedgfwick
Boyd
Daviess
Jefferson
McCracken
Caddo
Androscoggin
Penobscot
Allegany
Anne Arundel
Baltimore City
Baltimore County
Montgomery
Prince George's
Washington
Central Mass
Merrimack
Metro Boston
Pioneer Valley
Ingham
Kent
State
IN
IN
IA
IA
IA
KS
KS
KY
KY
KY
KY
LA
ME
ME
MD
MD
MD
MD
MD
MD
MD
MA
MA
MA-
MA
MI
MI
CO N02
X X
X
X X
X
X
X
X
X
X X
X
X
X
\ *
X X
X X
X
X
X
X
X
X
X X
X
X
X
Ozone
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
55
COUNTIES WITH THE POTENTIAL TO VIOLATE
CURRENT CO, N02> AND 03 AMBIENT STANDARDS
81
82
83
84
85
86
87
88
89
90
91
92
93
94
.95
96
97
98
99
100
101
102
103
104
105
106
107
State
23
23
23
23
23
24
24
24
24
26
26
26
27
27
27
28
28
29
29
29
30
30
31
31
31
31
31
County
Code
3140
3980
4780
4620
5320
1480
2660
2940
3260
1860
4280
4300
0220
1100
1720
0780
1520
0080
0100
0540
0140
0300
0080
0660
0300
0740
1380 '
AQCR
123
123
122
125
123
131
128
131
129
139
070
070
141
144
140
085
145
013
148
148
107
121
150
043
045
045
043
County Name
Macomb
Oakland
Saginaw
St. Clair
Wayne
Hennepin
Olmstead
Ramsey
St. Louis
Greene
St. Louis City
St. Louis County
Cascade
Missoula
Yellowstone
Douglas
Lancaster
Clark
Douglas
Washoe
Coos
Hillsborough
Atlantic
Burlington
Bergen
Camden
Essex
State
MI
MI
MI
MI
MI
MN
MN
MN
MN
MO
MO
MO
MT
MT
MT
NB
NB
NV
NV
NV
NH
NH
NJ
NJ
NJ
NJ
NJ
CO N02
X
X
X X
X
X X
X X
X
X X
X
X
X X
X
X
I'X
X X
X
X
X
X X
X
X
X
X
X
X X
X X
Ozon
X
X
X
X
X
X
X
X
X
X
X
X
-------
COUNTIES WITH THE POTENTIAL TO VIOLATE
CURRENT CO, N02> AND 03 AMBIENT STANDARDS
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
033
134
135
State
31
31
31
31
31
31
31
31
31
32
32
32
32
32
33
33
33
33
33
33
33
33
34
34
34
34
36
36
County
Code
1760
2240
3060
3180
3260
3900
4120
5020
5440
0140
0200
0340
1000
1060
0600
2000
3440
4380
4520
4660
5660
6040
0480
1560
1860
2580
0900
1600
AQCR
045
043
043
043
043
150
043
043
043
152
155
153
014
157.
043
162
043
160
043
043
043
161
171
167
171
167
079
174
County Name
Gloucester
Hudson
Middlesex
M0nmouth
Morris
Ocean
Passaic
Somerset
Union
Bemalillo
Chaves
Dona Ana
San Juan
Santa Fe
Bronx
Erie
Kings
Monroe
Nassau
New York
Queens
Schenectady
Buncombe
Gaston
Haywood
Mecklenburg
Butler
Cuyahoga
State
NJ
NJ
NJ
NJ
NJ
NJ
NJ
NJ
NJ
.NM'
NM
NM
NM
NM
NY
NY
NY
NY
NY
NY
NY
NY
NC
NC
NC
NC
OH
OH
CO N02
X
X X
X
X
X
X
X
X
X X
X
X
X
X
X
ix x
X
X X
X
X X
X
X
X
X
X
X
X
X X
Ozone
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
57
COUNTIES WITH THE POTENTIAL TO VIOLATE
CURRENT CO, N02, AND 0^ AMBIENT STANDARDS
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
461
162
State
36
36
36 .
36
36
36
36
36
36
37
37
38
38
38
39
39
39
39
39
39
39
39
39
41
42
42
44
County
Code
1640
2220
2720
3160
3720
3820
4500
6500
6700
2180
3020
1020
1140
1240
0100
0560
1300
4640
4700
4940
5220
6580
7160
0320
0560
1900
0700
AQCR
173
176
079
181
124
178
173
174
178
184
186
193
193
193
197
197
195
151
196
151
151
151
045
120
199
200
208
County Name
0arke
Franklin
Hamilton
Jefferson
Lucas
Mahoning
Montgomery
Summit
Trumbull
Oklahoma
Tulsa
Lane
Marion
Multnomah
Allegheny
Beaver
Cambria
Lackawanna
Lancaster
Lehigh
Luzerne
Northampton
Philadelphia
Providence
Charleston
Richland
Davidson
State
CO
N02
Ozone
OH
OH
OH
OH
OH
OH
OH
OH
OH
OK
OK
OR
OR
OR
PA
PA
PA
PA
PA
PA
PA
PA
PA
RI
SC
sc
TN
X
X
X
X
X
X
X
X
X
X
X
: ix
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
58.
COUNTIES WITH THE POTENTIAL TO VIOLATE
CURRENT CO, N02> AND Oj AMBIENT STANDARDS
County
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
-L88
189
State
44
44
44
45
45
45
45
45
45
45
46
46
46
46
47
48
48
48
48
48
48
48
49
49
49
49
51
Code
1280
1720
3080
0420
1320
1710
2330
2760
5070
5210
0220
0900
1220
1340
0180
0080
0200
1060
1440
2140
2680
2720
0980
1560
2060
2460
2220
AQCR
055
207
018
217
215
153
216
106
215
212
220
220
220
220
159
047
047
047
223
223
225
226
229
229
062
230
239
County Na
Hamilton
Knox
Shelby
Bexar
Dallas
El Paso
Harris
Jefferson
Tarrant .
Travis
Davis
Salt Lake
Utah
Weber
Chittenden
Alexandria
Arlington
Fairfax
Hampton
Norfolk
Richmond
Roanoke
King
Pierce
Spokane
Yakima
Milwaukee
Jtate
TN
TN
TN
TX
TX
TX
TX
TX
TX
TX
UT
UT
UT
UT
VT
VA
VA
VA
VA
VA
VA
VA
WA
WA
Wa
WA
WI
CO
X
X
X
X
X
X
X
X
X
jx
X
X
X
X
X
X
X
X
X
X
N02
X
X
X
X
X
X
X
X
X
X
X
Ozone
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
59
References
1. AEROS, Volume II, EPA-450/2-76-029, U. S. Environmental Protection Agency,
Research Triangle Park, North Carolina, 1976.
2. Mobile Source Emission Inventory Draft Report, Energy and Environmental
Analysis, Inc., Arlington, Virginia, April 1980.
3. National Emissions Data System County Emissions Report, U. S. Environ-
mental Protection Agency, Research Triangle Park, North Carolina, February
1980.
4. Modified Rollback Computer Program User's Manual, U. S. Environmental
Protection Agency, Research Triangle Park, June 1979.
5. Regulatory Analysis and Environmental Impact of Final Emission Regulations
for 1984 and Later Model Year Heavy Duty Engines, U. S. Environmental
Protection Agency, Ann Arbor, Michigan, December 1979.
6. Mobile Source Emission Factors: Final Document, EPA-400/9-78-006, U. S.
Environmental Protection Agency, Washington, D.C., March 1978.
7. Cost and Economic Impact Assessment for Alternative Levels of the National
Ambient Air Quality Standards for Ozone, EPA-450/5-79-002, U. S. Environ-
mental Protection Agency, Research Triangle Park, North Carolina, February
1979.
8. "Data Base for Air Quality Impact Assessment of Proposed Heavy-Duty
Vehicle Emission Standards", Memorandum from Warren Freas, U. S. Environ-
mental Protection Agency, Research Triangle Park, North Carolina, March
20, 1980.
9. Emission Modeling and Sensitivity Study, EPA-460/3-79-005, U. S. Environ-
mental Protection Agency, Ann Arbor, Michigan, April 1979.
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