United States
Environmental Protection
Agency
Air and Energy
Engineering Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S7-88/022 Mar. 1989
x°/ERA Project Summary
Anthropogenic Emissions
Data for the 1985
NAPAP Inventory
David Zimmerman, Wienke Tax, Mark Smith, Janice Demmy, and
Rebecca Battye
This report documents develop-
ment of the anthropogenic emissions
estimates to be used in the 1985
National Acid Precipitation Assess-
ment Program (NAPAP) Emissions
Inventory. Point and area source
data, spanning the contiguous U.S.,
focus on the NAPAP high priority
pollutants S<>2, NOX, and VOC.
Detailed point source data, provided
by the states, were obtained for over
9000 plants, and area source data
were obtained for more than 100 area
source categories. Quality control
was conducted at all levels of
inventory development. This effort
was the first national emissions
inventory In which the data were
actually returned to the responsible
agencies for their comments and
corrections. As a result, the quality
of this annual inventory is better than
that of any previously developed
national inventory. Data are sum-
marized at various levels of
aggregation including nation, state,
and source category. Emissions data
are also analyzed by plant size, stack
height, and general source type.
This Project Summary was devel-
oped by EPA's Air and Energy
Engineering Research Laboratory,
Research Triangle Park, NC, to an-
nounce key findings of the research
project that Is fully documented In a
separate report of the same title (see
Project Report ordering Information at
back).
Background
The National Acid Precipitation
Assessment Program (NAPAP) was
established by Congress in 1980 (Title
VII of P.L. 96-294) to coordinate and
expand research on problems posed by
acid deposition in and around the U.S. A
fundamental objective of the NAPAP
research program is the investigation of
emissions sources that may contribute to
acid deposition in order to: assess the
impact of various source types and
characteristics on the emissions of these
precursors; investigate and verify
atmosphere process models that
simulate source/receptor relationships;
and assess historic trends in emissions.
Among contributors to acid deposition,
anthropogenic emissions sources are
believed to be of primary importance.
This report covers U.S. anthropogenic
emissions of acid deposition precursors
for calendar year 1985 as contained in
the 1985 NAPAP Emissions Inventory.
This inventory is divided into two major
categories, point and area sources.
Points are stationary sources with precise
location data and typically emit at least
100 tons per year (TPY) of a criteria
pollutant (S02, NOX, VOC, PM, or CO).
Area sources consist of both mobile
sources and stationary sources too small
(less than 100 TPY) and too numerous to
inventory individually. The 1985 NAPAP
Emissions Inventory has focused
attention on the three criteria pollutants of
most concern to the NAPAP research
community: SO2, NOX, and VOC. The
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report discusses the methodology and
implementation of the ioventory effort,
and summarizes the emissions data.
Methodology
Point source data were supplied to
EPA through the National Emissions Data
System (NEDS) by state agencies in an
essentially bottom-up collection
strategy. The area source emissions
estimates were calculated by EPA using
a series of computer programs. This is
primarily a top-down strategy which
allocates emissions estimates to state
and county levels.
The data collection efforts for 1985
point source data were prioritized to
reflect the needs of the NAPAP research
and assessment programs. Estimates of
SC>2, NOX, and VOC emissions were
given highest priority. In addition, the
effort concentrated on facilities emitting
at least 1000 TPY of the three priority
pollutants because they represent 97, 90,
and 61% of the point source SOa, NOX,
and VOC emissions, respectively. Of the
50 data elements in a NEDS record, the
data collection effort focused on the 14
that are most important for the NAPAP
community. These priority items
include: the annual emissions estimates
for SOa, NOX, and VOC; the maximum
design and annual operating rates: the
Source and Standard Industrial
Classification codes (SCC and SIC);
emissions control equipment and
efficiencies; fuel characteristics, stack
parameters; location data; and operating
schedules.
Quality control procedures consisting
of manual and computerized checking
were specifically designed for the 1985
NAPAP Emissions Inventory and
involved State and EPA personnel at all
levels of inventory development. These
procedures were designed to ensure that
the quality of the data met the
requirements of the NAPAP community
as closely as possible, given the
resource constraints of the inventory
effort. As a result, the quality of this
annual inventory is better than that of any
previously developed national inventory.
Summaries and Analyses of
Data
Results of the 1985 NAPAP Emissions
Inventory are based on more than 9300
plants in the point source inventory with
over 111,000 individual stationary points
reporting 1985 emissions and operating
data in the contiguous U.S., as well as
emissions data for about 100 area source
categories for each U.S. county. These
results for the three pollutants of most
concern (SOa. NOX, and VOC) show
three distinct patterns (Figure 1). About
90% of the SOa emissions are from point
sources, while NOX emissions are almost
equally split between point and area
sources, and area sources contribute
about 90% of the total anthropogenic
VOC emissions. Breakdowns by major
category are presented in Figure 2 (point
sources) and Figure 3 (area sources).
Examination of the distribution of
emissions among categories indicates
the major sources of each of the three
pollutants (Figure 4). SOa omissions are
predominantly from electric utilities;
utilities contribute about 70% of total
SOa emissions and represent 76% of
point source SOa. The utilities also emit
about 30% of the total NOX or 70% of the
point source NOX, while mobile sources
account for 43% of the total NOX or 80'
of the area source NOX. VOC emissioi
are principally contributed by area SOUK
categories, with mobile source
representing 33% of the total and 37%
the area source VOC emissions.
The analysis of point source emissior
categories was extended to include pla
size (emissions) and the relationsh
between emissions magnitude and sta<
height. The distribution of point sourt
emissions by plant size reveals that 81'
of emissions are from facilities emitting
least 10,000 tons per year. Tries
facilities are primarily utilities an
smelters. For NOX, only 60% <
emissions are from facilities emitting
least 10,000 tons per year. Again, thes
facilities are primarily utilities and larc
industrial sources. For VOCs, tti
distribution according to source size is f.
24
22-
20-
18-
16-
I MJ
10-
8 -
6-
4-
2-
I
/vo,
VOC
|\M Area Source
Figure 1.
Pollutant
V /I Point Source
1 ton = 907 kg
Camparison of point and area source SO2, /VOĢ, and VOC emissions.
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more uniform: VOC point source
emissions originate in a wide variety of
industrial processes and locations.
Regarding the relationship between
point source emissions and stack height,
utility emissions of SOg and NOX
predominate the point source category;
these boilers are typically associated
with tall stacks. Most point source VOC
emissions, however, are contributed by
industrial processes which typically vent
emissions near ground level.
The total anthropogenic emissions of
SO2, NOX, and VOC as well as point and
area source emissions of these pollutants
are included in the report for each state.
The 1985 NAPAP Emissions Inventory
also includes emissions of PM, CO, and
four non-criteria pollutants deemed
important to acid deposition research
(hydrogen chloride, hydrogen fluoride,
primary sulfate, and ammonia).
/vo.
Pollutant
VOC
F7I uc
OC
OTH
UC = Utility Combustion
1C = Industrial Combustion
IP = Industrial Processes
1 ton = 907kg
Figure 2. U.S. anthropogenic point source emissions.
OC = Other Combustion
OTH = Other Sources
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177! THAN E3 IP
Pollutant
1C
OC
OTH
OC = Other Combustion
OTH = Other Sources
TRAN - Transportation
IP - Industrial Processes"
1C = Industrial Combustion
*For this analysis, some Miscellaneous and Additional area source categories
have been included under Industrial Processes; this is not a NEDS area source
category
1 ton = 907 kg
Figure 3. U.S. anthropogenic area source emissions.
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SO2
Other Comb. (2.5%)
Indus. Process (12.5%)
Indus. Comb. (10.8%)
Transport (3.8%)
Other (0.2%)
NO,
Other Comb. (3.5%)
Indus. Process (4.4%)
Indus. Comb. (15.2%)
Utility (70.2%)
.Utility (32.9%)
Other (1.1%)
Transport (42.9%)
VOC
Other Comb. (10.8%)
Utility (0.3%)
Indus. Process (37.4%)
Indus. Comb. (0.92%)
Figure 4. Distribution of 1985 SOz, /VO,, and VOC emissions by major category.
Other (17.9%)
Transport (32.7%)
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David Zimmerman, Wienke Tax, Mark Smith, Janice Demmy, and Rebecca Batfye
are with Alliance Technologies Corporation, Chapel Hill, NC 27514.
Robert C. Lagemann is the EPA Project Officer (see below).
The complete report, entitled, "Anthropogenic Emissions Data for the 1985 NAPAP
Inventory," (Order No. PB 89-151 419JAS; Cost: $28.95, subject to change) will
be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S7-88/022
0000329 PS
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