United States Office of Pollution Prevention
Environmental Protection and Toxics
Agency Washington, DC 20460 June 1999
&EPA Estimates of Stack Heights
and Exit Gas Velocities for
TRI Facilities in
OPPT's Risk-Screening
Environmental Indicators
Model
-------
Estimates of Stack Heights and Exit Gas Velocities
ForTRI Facilities in OPPT's Risk-Screening
Environmental Indicators Model
Nicolaas W. Bouwes, Sr., Ph.D.
Steven M. Hassur, Ph.D.
Economics, Exposure, and Technology Division
Office of Pollution Prevention and Toxics
United States Environmental Protection Agency
June 1999
-------
ACKNOWLEDGMENTS
This report, which describes the methods used to estimate stack heights and exit gas velocities
for TRI facilities, is one of many products of the Office of Pollution Prevention and Toxics' (OPPT' s)
Risk-Screening Environmental Indicators Model Project. This project, initiated in 1991, has resulted
in the Risk-Screening Environmental Indicators Model, a unique and powerful analytical tool for risk-
related analysis and communication. The Indicators Model has the potential to make a significant
contribution to environmental improvement. We wish to thank our contractor, Abt Associates Inc.,
for their support and creativity throughout the development of this project.
We also want to thank several persons at State agencies who were very helpful in providing
data and information for the analyses described in this report. These include Mr. Tom Gentile and
Mr. Eric Wade of the New York State Department of Environmental Conservation; Mr. Christopher
Nguyen of the California Environmental Protection Agency's Air Resources Board; Mr. Orlando
Cabrera of the Wisconsin Department of Natural Resources; and, Mr. Greg Stella of EPA's Office
of Air Quality Planning and Standards.
Project Managers: Nicolaas W. Bouwes, Sr., Ph.D.
Steven M. Hassur, Ph.D.
Abt Associates
Project Staff: Elizabeth Fechner Levy, Project Manager
Brad Firlie, Deputy Project Manager
Rob Sartain, Senior Analyst
Cindy Gould, Research Assistant
Molly Hillis, Research Assistant
-------
EXECUTIVE SUMMARY
In July 1997, EPA's Science Advisory Board (SAB) reviewed and commented on the
methodology used in the Risk-Screening Environmental Indicators Model developed by EPA's Office
of Pollution Prevention and Toxics (OPPT). In response to one of SAB's comments, EPA sought
to improve the estimate of facility stack height used in modeling air emissions of Toxics Release
Inventory (TRI) chemicals. The sensitivity analysis of the air emission modeling used in the
Indicators Model demonstrated that stack height has the greatest impact on predicted concentrations
of air pollutants. At the time of SAB's review, all stacks in the Indicators Model were assumed to be
10 meters high. Also at that time, all exit gas velocities, which represent the second most important
variable impacting air emissions modeling, were assumed to be 0.01 m/sec. As EPA began improving
the accuracy of stack height estimates, it determined that it could also readily improve the estimation
of exit gas velocities. This report describes the Agency's improvements to the accuracy of the
Indicators Model through two types of changes: 1) the incorporation of facility-specific median stack
heights and median exit gas velocities where available; and, 2) the estimation of median values for
stack heights and exit gas velocities by Standard Industrial Classification (SIC) codes. These
estimates are then assigned to facilities without facility-specific data.
To obtain facility-specific stack heights and exit gas velocities as well as estimates of stack
heights and exit gas velocities by SIC code, the Agency relied on the AIRS Facility Subsystem (AFS)
database within the Aerometric Information Retrieval System (AIRS); the National Emission Trends
Database (NET); and databases from three states (California, New York, and Wisconsin).
From AFS and the three State databases, EPA was able to obtain stack height data specific
to facilities which report to TRI. For the 421 California, New York, and Wisconsin facilities which
report to TRI and the 1,209 facilities in common to the TRI and AFS databases, a representative
stack height for each facility was estimated by calculating the median height for all of a facility's
stacks with non-zero height. After identifying facilities in common between TRI and these data
sources, EPA began investigating ways of estimating stack heights for TRI facilities not in AFS or
in the three State databases. In the course of analysis of available data, the Agency noticed
substantial variability in stack height across primary SIC codes of facilities, and chose to calculate and
analyze a median stack height for each 2-digit, 3-digit, and 4-digit SIC code applicable to TRI
reporters, i.e., in the 2-digit SIC code range of 20 to 39. To use the data in AFS and NET, however,
EPA had to investigate the possibility that stack height may vary on the basis of whether the stack
emitted possible TRI chemicals or not. For the TRI facilities with non-zero stack releases for which
facility-specific data were not available, stack heights were estimated from AFS and NET based on
facility 3-digit SIC codes and statistical analyses of height differences between stacks emitting TRI
chemicals and stacks not emitting TRI chemicals.
For stack height, the estimation approaches used for the 13,204 TRI facilities with non-zero
stack air releases reported in 1995 included: 1,209 facilities estimated directly from AFS; 69 facilities
estimated from California State data; 192 facilities estimated from New York State data; 37 facilities
estimated from Wisconsin State data; and 11,514 estimated based on the facilities' 3-digit SIC code.
-------
The remaining 183 facilities (13,204 facilities minus 13,021 facilities) reported 3-digit SIC codes
outside the range of 201 to 399, or reported no SIC code. For these 183 facilities, a stack height was
assigned based on either the 2-digit SIC code (if a valid one was available) or on the median stack
heightforall 108,590 unique stacks in AFS and NET. The median stack height for all 108,590 stacks
from AFS and NET is 10.67 m (35.0 ft), virtually the same as the previously used default value of 10
m for TRI facilities.
At the same time that EPA obtained stack height data, it also obtained exit gas velocity data.
EPA was able to obtain exit gas velocity data specific to TRI facilities from AFS and two of the three
State databases. For a given facility, the exit gas velocity was estimated as the median for all the
stacks. This facility-specific analysis could be conducted for 850 facilities from AFS; 192 facilities
from New York State data; and 24 facilities from Wisconsin State data. Of the 13,204 TRI facilities
with non-zero stack air releases reported in 1995, exit gas velocities were estimated for 11,950
facilities based on the facilities' 3-digit SIC code. The remaining 188 facilities (13,204 facilities minus
13,016 facilities) reported 3-digit SIC codes outside the range of 201 to 399, or reported no SIC
code. For these facilities, an exit gas velocity was assigned based on either the 2-digit SIC code (if
a valid one was available) or on the median exit gas velocity for all 108,590 unique stacks in AFS and
NET. The median exit gas velocity for all 108,590 stacks from AFS and NET is 8.80 m/sec (28.9
ft/sec), considerably larger than the previously used default value of 0.01 m/sec for TRI facilities.
in
-------
TABLE OF CONTENTS
ACKNOWLEDGMENTS i
EXECUTIVE SUMMARY ii
TABLE OF CONTENTS iv
1. INTRODUCTION 1
2. AFS OVERVIEW 2
2.1 INTRODUCTION TO AFS 2
2.2 POLLUTANTS INCLUDED IN AFS 2
2.3 EMISSION AND STACK HEIGHT DATA IN AFS 3
3. OVERVIEW OF STACK HEIGHT DATA IN NET AND STATE DATABASES 4
3.1 NATIONAL EMISSION TRENDS DATABASE 4
3.2 STATE DATA 4
4. ANALYSES OF STACK HEIGHT DATA IN AFS 4
4.1 IDENTIFICATION OF FACILITIES IN COMMON TO BOTH TRI AND AFS . . 4
4.2 ANALYSIS OF STACK HEIGHT DATA BY CHEMICALS EMITTED AND
SIC CODE 5
4.3 ANALYSIS OF OTHER FACILITY CHARACTERISTICS IN TRI
USING AFS DATA 6
5. ANALYSES OF STACK HEIGHT DATA IN NET 7
6. IMPLEMENTATION OF RESULTS OF STATISTICAL ANALYSES IN
THE INDICATORS MODEL 7
6.1 FACILITY-SPECIFIC STACK HEIGHTS 7
6.2 ESTIMATED STACK HEIGHTS 7
6.3 COMPARISON TO PRIOR ASSUMPTION OF 10 m STACK HEIGHT 10
6.4 ESTIMATION OF STACK HEIGHTS FOR TRI FACILITIES WITH
MISSING OR INVALID 3-DIGIT SIC CODES 11
7. ANALYSES OF EXIT GAS VELOCITIES 11
7.1 FACILITY-SPECIFIC EXIT GAS VELOCITIES 11
7.2 ESTIMATED EXIT GAS VELOCITIES 12
7.3 COMPARISON TO PRIOR ASSUMPTION OF 0.01 m/sec
EXIT GAS VELOCITY 13
7.4 ESTIMATION OF EXIT GAS VELOCITIES FOR TRI FACILITIES WITH
MISSING OR INVALID 3-DIGIT SIC CODES 13
8. REFERENCES 14
APPENDIX A 15
iv
-------
1. INTRODUCTION
In July 1997, the EPA Science Advisory Board (SAB) reviewed and commented on the
methodology used in the Risk-Screening Environmental Indicators Model developed by EPA's Office
of Pollution Prevention and Toxics (OPPT). In response to one of SAB's comments, EPA sought
to improve the estimate of facility stack height used in modeling air emissions of Toxics Release
Inventory (TRI) chemicals. At the time of SAB's review, all stacks in the Indicators Model were
assumed to be ten meters (32.8 feet) high. This report describes the Agency's efforts to improve the
accuracy of the Indicators Model by incorporating facility-specific stack heights where available, or
by estimating stack height by facility characteristics, such as the Standard Industrial Classification
(SIC) code.
In response to another SAB comment, the Agency conducted a "ground-truthing" analysis
of the air pathway component of the Indicators Model (Bouwes and Hassur, 1998). In the course
of this analysis, the Agency determined that the accuracy of the model could be further improved by
also incorporating facility-specific exit gas velocities where available, or by estimating exit gas
velocity by facility characteristics, such as the SIC code.
There are a number of possible data sources to use for both facility-specific stack heights and
exit gas velocities and estimates of stack heights and exit gas velocities by facility characteristics.
These data sources include EPA's AIRS Facility Subsystem (AFS) database within the Aerometric
Information Retrieval System (AIRS); EPA's National Emission Trends Database (NET); and
databases from individual States, such as California, New York, and Wisconsin. This report
documents the Agency's effort to analyze the appropriateness of the AFS and NET stack height and
exit gas velocity data for use in the Indicators Model and presents the way in which the AFS and NET
data and additional data from individual States are used in the model.
In Section 2 of this memo, AFS and the data elements it can provide to estimate stack heights
are described. In Section 3, overviews of NET and State data are provided, including a description
of how stack height data for facilities present in both NET and AFS are treated to prevent double-
counting. Sections 4 and 5 present statistical analyses of the stack height data in AFS and NET,
respectively. Section 6 describes the way in which facility-specific data, obtained from both AFS and
States, and the results of the statistical analyses of stack heights are implemented in the Indicators
Model. Finally, Section 7 presents the analyses of exit gas velocity data and describes the way these
results are implemented in the Indicators Model.
-------
2. AFS OVERVIEW
2.1 INTRODUCTION TO AFS
AFS is a component of AIRS, which is administered by EPA's Office of Air Quality Planning
and Standards (OAQPS). AIRS, which is a computerized database management system for airborne
pollution in the United States, consists of four subsystems. Each subsystem addresses a different (but
in many cases related) aspect of the regulatory requirements of the Clean Air Act. AFS contains
emissions, compliance, and enforcement data on stationary sources of air pollution. Included sources
cover the spectrum from large industrial facilities to relatively small operations such as dry cleaners,
although facilities must meet certain threshold requirements to be included in AFS. These threshold
requirements vary by pollutant and are discussed below.
In general, facilities collect emissions data in compliance with their permits and send the data
to their State environmental agencies. Some emissions data are based on actual measurements; others
are based on estimation methods. Sometimes inspectors collect emissions data. Most facilities
prepare emissions inventories once every five years. Each year, States consolidate the data received
from facilities reporting in that year and send the data to the EPA Regional Offices, which enter the
data into AFS. At the time of this analysis, the most recent data for a given facility could be from any
year between 1993 to 1997.
2.2 POLLUTANTS INCLUDED IN AFS
AFS includes data on a total of 52 specific pollutants or pollutant classes (not counting
fugitive emissions, visible emissions, coke oven emissions, fugitive dust, odors, and other). These
data include release estimates for the following five air pollutants:
•D paniculate matter smaller than ten microns (PM10);
• sulfur oxides, with sulfur dioxide (SO2) as a marker for all SOX;
•D nitrogen oxides, with nitrogen dioxide (NO2) as a marker for all NOX;
•D carbon monoxide (CO); and
•D lead (Pb).
These are the "criteria" pollutants for which EPA's OAQPS has set National Ambient Air Quality
Standards. (Although PM10 is the current particulate criterion pollutant, total particulate mass (PT)
was the previous criterion for particulates. Depending upon the vintage of a given facility's data, PT
may be listed in place of PM10.)
The thresholds for including emissions data in AFS are 1,000 tons per year of CO; five tons
per year of Pb; and 100 tons per year for each of the other pollutants, including PM10, SO2, and NO2
Even when a facility exceeds threshold emissions of one pollutant, it might not exceed the threshold
and hence not report for another pollutant. For example, if a facility estimates annual releases of 150
-------
tons of SO2 and 500 tons of CO, AFS will list the facility's estimated SO2 emissions but not its CO
emissions.
The 39 pollutant and pollutant classes in AFS that are either TRI chemicals or likely to contain
TRI chemicals are presented in Table 1.
Table 1
Pollutant and Pollutant Classes in AFS which are TRI Chemicals or Assumed to
Include TRI Chemicals
acetylenes
aldehydes
ammonia
antimony compounds *
aromatics
arsenic
arsenic compounds *
asbestos *
barium compounds
benzene *
beryllium
beryllium compounds *
cadmium
cadmium compounds *
chlorofluorocarbons
chlorophenols
chromium compounds *
cobalt compounds *
copper compounds
cyanide compounds *
fluorides
glycol ethers *
hydrochloric acid *
hydrofluoric acid *
ketones
lead
lead compounds *
manganese compounds *
mercury
mercury compounds *
nickel compounds *
olefins
organic acids
polybrominated biphenyls
polynuclear aromatics
selenium compounds *
vinyl chloride *
VOCs
zinc
2.3
* indicates that chemical or chemical class is classified as a Hazardous Air Pollutant (HAP).
EMISSION AND STACK HEIGHT DATA IN AFS
APS tracks data in a hierarchy with four levels: (1) facilities; (2) stacks, the locations at which
emissions are introduced into the atmosphere; (3) points, the processes that produce pollutant
emissions; and (4) segments, which are components of the processes. For the criteria pollutants,
estimated emissions are available in pounds per year at the facility level. For the HAPs, emissions
may be estimated using "emissions factors" for specific production processes at the segment level.
These processes are categorized by Source Classification Codes (SCCs), six-character identifications
of the specific production processes.
Each facility in AFS has a primary SIC code, recorded at the four-digit level. The primary
SIC code reflects the principal product or service generated by the facility. Within a facility, each
stack is assigned a stack identification number. For each stack, the rate of emission in mass per time
-------
of each stack pollutant (identified by CAS number or other chemical identification number) is
provided, along with the non-zero height of the stack measured in feet.
3. OVERVIEW OF STACK HEIGHT DATA IN NET AND STATE DATABASES
3.1 NATIONAL EMISSION TRENDS DATABASE
EPA's National Emission Trends (NET) database became available to OPPT early in 1998,
well after relevant data for the project were obtained from AFS. EPA decided to use stack height
data from NET to augment the AFS data because some States not included in AFS were included in
NET. The NET database provides information on stack height measured in feet, and the annual
emission rates of five criteria pollutants: VOCs, NOX, CO, SO2, and PM10. To prevent double-
counting of stacks from facilities in both AFS and NET, facilities present in both databases were
identified based on the AFS ID. (From NET, EPA took the State Federal Information Processing
Standard (FIPS) code, county FIPS code, and plant ID and concatenated them to form an
identification number equivalent to an AFS ID.) If stack height data for a given AFS ID were present
in both databases, the data in AFS were kept for further analyses, and the data in NET were removed
from further consideration. The NET database does not include an EPA ID for facilities, and thus
specific facilities in common to TRI and NET cannot be identified, nor can the number of facilities
in common be estimated.
3.2 STATE DATA
For three States not included in AFS (California, New York, and Wisconsin), EPA was able
to obtain facility-specific data on stack heights. For California, 98 facilities matched TRI facilities;
for New York, 279 facilities matched TRI facilities; and for Wisconsin, 44 facilities matched TRI
facilities. Not all of these facilities contributed stack height data to the analysis, however, as not all
facilities reported non-zero stack air releases for 1995. Again, note that although these facilities may
also be present in the NET database, they cannot be identified as TRI facilities in NET because NET
does not include an EPA ID for facilities.
4. ANALYSES OF STACK HEIGHT DATA IN AFS
4.1 IDENTIFICATION OF FACILITIES IN COMMON TO BOTH TRI AND AFS
To use facility-specific stack height data in the Indicators Model wherever possible, the
Agency attempted to identify TRI facilities in AFS for those States that reported to AFS. The match
was performed as follows. For the reporting facilities, the AFS database includes an EPA ID, the
only facility identifier common to both the TRI and AFS databases. On a TRI Form R, a facility is
asked to report up to four EPA IDs associated with the facility. EPA identified TRI forms with non-
zero stack releases, obtained all EPA IDs reported by those facilities on their forms, and matched the
TRI facilities with the AFS facilities by EPA ID. For the 1995 TRI reporting year, which, at the onset
-------
of this analysis, was the most recent year with TRI data available, there are 41,528 Forms R with non-
zero stack releases, submitted by 13,204 facilities. These 13,204 facilities map to 12,106 EPA IDs.
(Some TRI facilities do not have or do not report an EPA ID; others have more than one EPA ID.
It is also possible for one EPA ID to match to more than one TRI ID.)
EPA identified 4,813 facilities in AFS that have primary 4-digit SIC codes in the range 2011
through 3999, not including Federal facilities, and that have stacks with non-zero stack height. EPA
was able to link the 12,106 TRI EPA IDs to 1,231 AFS EPA IDs, albeit with some overlap, due to
some TRI facilities having more than one EPA ID, and other TRI facilities sharing EPA IDs. After
completing this analysis, EPA found 1,212 EPA IDs which represent 1,209 unique TRI facilities with
non-zero stack heights in common to both AFS and TRI. In other words, about a quarter of the AFS
facilities in the SIC code range required to report to TRI and with non-zero stack height can be found
in TRI. Only about nine percent of TRI facilities with non-zero stack releases (1,209 of 13,204) are
found in AFS with non-zero stack height. The low percent of matches can be explained by the
following reasons:
•D AFS data are not fully representative of all States;
•D AFS reporting thresholds may exceed the threshold for reporting to TRI; and,
•D AFS only covers 39 pollutant and pollutant classes that are either TRI chemicals or likely to
contain TRI chemicals.
4.2 ANALYSIS OF STACK HEIGHT DATA BY CHEMICALS EMITTED AND SIC
CODE
After identifying facilities in common to both AFS and TRI, EPA began investigating ways
of estimating stack heights for TRI facilities not in AFS or in the three State databases. First, EPA
identified 37,390 unique stacks in AFS associated with the 4,813 facilities listing their primary facility
SIC code in the range 2011 through 3999, not including Federal facilities. The mean height of these
stacks is 46.7 feet (14.2 meters). Based on the pollutants recorded in AFS as being emitted from
these stacks, the Agency classified each of the 37,390 stacks as either "emitting a possible TRI
chemical" or "not emitting a possible TRI chemical." The set of AFS pollutants that are classified
as possible TRI chemicals for the purpose of this analysis are shown in Table 1. (It is important to
note that the VOCs and other chemical classes may contain more than just TRI chemicals.) If at least
one pollutant emitted from a stack was considered a possible TRI chemical, then the stack was
designated as "emitting a possible TRI chemical". If none of the emitted pollutants were considered
possible TRI chemicals, then the stack was designated as "not emitting a possible TRI chemical".
EPA then investigated the possibility that stack height varied by whether the stack emitted
possible TRI chemicals or not. If stacks that do not emit possible TRI chemicals have different
heights than stacks emitting possible TRI chemicals, then to include stacks that do not emit possible
TRI chemicals in further analyses could bias the stack height results. Of the 37,390 stacks present,
16,889 (45.2%) emit pollutants considered as possible TRI chemicals. The remaining 20,501 emit
only chemicals that are not considered as possible TRI chemicals from the AFS database. The mean
-------
height of those stacks emitting possible TRI chemicals is 46.9 feet (14.3 meters), with a standard
deviation of 41.4 feet (12.6 meters). The mean height of the remaining stacks is 46.5 feet (14.2
meters), with a standard deviation of 35.4 feet (10.8 meters). The difference in the mean heights of
these two groups of stacks is not statistically significant, as determined by using a Student's t-test to
compare the means. (The Agency compared means, rather than medians, because the test of means
is a more powerful statistical test than the test of medians. The more powerful test is better able to
differentiate dissimilar groups.)
In the course of the above analysis, the Agency noticed substantial variability in stack height
across primary SIC codes of facilities in AFS. Thus consideration was given to estimating stack
height as a function of the SIC code of the facility. For 2-digit, 3-digit, and 4-digit SIC codes, EPA
evaluated the mean stack heights for the two groups of stacks — those emitting possible TRI
chemicals and those that do not — by testing the equality of the means by using a Student's t-test at
the five percent level of significance. (The significance level refers to the probability of rejecting the
null hypothesis that the means are equal when actually it should not be rej ected; this is the probability
of committing a Type I error.) For each SIC group, EPA used an F-test to check whether the
variances of the two stack groups were different. If the variances were equal, EPA assumed the two
groups were drawn from the same population, and a Student's t-test was used to compare the means.
If the variances were not equal, EPA assumed the two groups were from two different populations,
and therefore used a modified Student's t-test, accounting for the unequal variances, to compare the
means. At the two-digit SIC code level, 14 SIC code groups indicated significant height differences
between the two groups of stacks and six did not. At the 3-digit level, 55 SIC code groups indicated
significant height differences between the two groups of stacks and 74 did not. At the four-digit
level, 109 SIC groups indicated significant height differences between the two groups of stacks and
303 did not.
4.3 ANALYSIS OF OTHER FACILITY CHARACTERISTICS IN TRI USING AFS
DATA
The Agency also tried to determine if certain facility characteristics tracked in TRI affect stack
height. If stack heights vary in systematic ways with information available in TRI, that information
could be used to refine estimates of stack height in the Indicators Model. Specifically, EPA examined
the potential impact on stack height of TRI stack air release volumes and number of stacks present
at the facility. The key hypothesis being tested was that facilities with larger TRI stack air releases
or greater numbers of stacks would have taller stacks.
Eighteen ordinary least squares regressions were run, one for each two-digit SIC code in the
range of 20 to 39. Eighteen regressions were estimated, instead of twenty, because there are no
facilities with non-zero TRI stack air releases present in both TRI and AFS in SIC codes 21 and 23.
The dependent variable was facility stack height, estimated as the median height of all stacks present
at AFS facilities that could be linked to TRI facilities. Coefficients for two independent variables (and
an intercept term) were estimated. The independent variables were: (a) stack air release volumes
summed over all TRI chemicals at the facility; and (b) number of stacks indicated for the facility in
-------
AFS. Of the eighteen regressions estimated, only two (SIC codes 30 and 37) had stack air release
coefficients statistically different from zero at the five percent level of significance. Based on the fact
that most regressions resulted in no significant differences, the Agency concluded that the volume of
TRI stack air releases and the total number of stacks at a facility are not significant determinants of
stack height.
5. ANALYSES OF STACK HEIGHT DATA IN NET
As with AFS, EPA evaluated the possibility that stack heights within NET varied by whether
the stack emitted possible TRI chemicals. Unlike AFS, NET does not record specific pollutants
emitted from each stack. NET does, however, record annual VOC emissions from each stack. EPA
identified 90,167 unique stacks in NET associated with 16,682 facilities listing their primary facility
SIC code in the range 2011 through 3999, not including Federal facilities. The mean height of these
stacks is 49.9 feet (15.2 meters). For the purposes of this analysis, the Agency labeled any stack with
non-zero VOC emissions as a stack emitting possible TRI chemicals. Based on this definition, of the
90,167 stacks used in the analysis, 62,245 (69.0%) are classified as emitting possible TRI chemicals.
The mean stack height of those stacks emitting possible TRI chemicals is 46.7 feet (14.2 meters), with
a standard deviation of 47.8 feet (14.6 meters). The mean height of the remaining stacks is 57.0 feet
(17.4 meters), with a standard deviation of 51.0 feet (15.6 meters). The difference in the mean
heights of these two groups of stacks is statistically significant, as determined by using a Student's
t-test to compare the means. (Recall that for AFS data, the comparable analysis found that the
difference in the mean heights of the two groups of stacks was not statistically significant.)
6. IMPLEMENTATION OF RESULTS OF STATISTICAL ANALYSES IN THE
INDICATORS MODEL
6.1 FACILITY-SPECIFIC STACK HEIGHTS
For the 421 California, New York, and Wisconsin facilities and the 1,209 facilities in common
to the TRI and AFS databases, a representative stack height for each facility was estimated by
calculating the median height for all of a facility's stacks with non-zero height. The median stack
height was chosen rather than the mean because stack heights may not be normally distributed. No
matter how the stack heights are distributed, the median is the appropriate measure of central
tendency. For a facility with symmetrically-distributed stack heights, the median equals the mean.
Therefore, for a given facility, the median of its stack heights was used as that facility's stack height
in the Indicators Model.
6.2 ESTIMATED STACK HEIGHTS
For the remaining TRI facilities with non-zero stack releases for which facility-specific data
were not available, stack heights were estimated from AFS and NET based on facility SIC codes.
-------
EPA decided that the 3-digit SIC code was the appropriate level at which to analyze and use stack
height data. At the 2-digit level, differences between stacks emitting TRI chemicals and stacks not
emitting TRI chemicals are often masked because the variance in each population is so large. From
a practical standpoint, 2-digit SIC codes represent too gross a level of aggregation for purposes of
estimating stack height. At the other extreme, 4-digit SIC codes offer too fine a level of
disaggregation; not only might one not expect much difference in stack height between, say, a facility
manufacturing creamery butter and a facility manufacturing natural, processed, and imitation cheese,
but the number of observations at the 4-digit level are often too few to make a meaningful
comparison of the two stack groups. Thus, the remaining TRI facilities were classified into 3-digit
SIC code groups by the assigned primary SIC code in the TRI database (i.e., the leading three digits
of the first 4-digit SIC code listed). Of the 13,204 TRI facilities reporting non-zero air releases in
1995, 84% reported only one unique 3-digit SIC code; 12% reported two unique 3-digit SIC codes;
3% reported three, 0.8% reported four, and 0.2% reported five.
EPA determined that of the 37,390 stacks being analyzed from AFS and the 90,167 stacks
being analyzed from NET, there were 18,967 stacks in common to the two databases. To avoid
double-counting these stacks in the analysis, the Agency used the stack height data from AFS for
these stacks, and removed the corresponding NET data from further consideration. Augmenting the
stacks from AFS with the non-duplicative stacks from NET resulted in a total of 108,590 stacks
(37,390 from AFS and 71,200 from NET).
Each TRI facility within a 3-digit SIC code group was assigned the median stack height of
the AFS and NET stacks within that 3-digit SIC group according to the following hierarchy:
1. If the combined AFS and NET stack height data for that 3-digit SIC code group
indicated no statistically significant difference between the mean height of stacks emitting
possible TRI chemicals and the mean height of stacks emitting non-TRI chemicals, then the
median was estimated over all stacks in that group, regardless of whether the stack emitted
possible TRI chemicals. This median height was then used as the estimated stack height for
all TRI facilities in the 3-digit SIC code group that did not have facility-specific data in AFS
or in the three State databases.
2. If the AFS and NET stack height data for that 3-digit SIC code group did indicate a
statistically significant difference between the mean height of stacks emitting possible TRI
chemicals and the mean height of stacks emitting non-TRI chemicals, then the median for only
those stacks emitting possible TRI chemicals was used as the estimated stack height for all
TRI facilities in that 3-digit SIC code group.
In both approaches, the stack heights of facilities that occur in both TRI and AFS (i.e.,
facility-specific data) are included in the calculation of the median height of their 3-digit SIC code
groups. State data are not included in these analyses because of the potential of double-counting with
NET data, which includes data from California, New York, and Wisconsin. (Recall that NET
facilities cannot be matched to TRI facilities because there is no facility identifier in common.) Table
-------
2 presents the number of 3-digit SIC codes with median stack heights falling in particular stack height
ranges for 139 of the 140 unique 3-digit SIC codes in the range 201 to 399. (No estimates of stack
heights were available for facilities in SIC code 316, luggage manufacturing.) Note that the majority
of SIC codes have median stack heights between 9.0 and 11.9m; only one SIC code falls into each
of the two highest ranges of stack heights.
Table A-l in Appendix A indicates each 3-digit SIC code group in the range 201 to 399, the
median stack height as estimated from the AFS and NET data, the estimation technique used
(whether the median was calculated over all stacks or only those emitting possible TRI chemicals),
and the number of 1995 TRI facilities using that value. Table A-l also presents the median stack
heights and the estimation technique used for 2-digit and 4-digit SIC codes within the ranges of 20
to 39 and 2011 to 3999, respectively.
-------
Table 2
Median Stack Heights by SIC Code
Range of Stack Heights (meters)
6.0 to 6. 9m
7.0 to 7. 9m
8.0 to 8. 9m
9.0 to 9. 9m
10.0 to 10.9m
ll.Oto 11.9m
12.0 to 12.9m
13.0 to 13.9m
14.0 to 14.9m
15.0 to 15.9m
16.0 to 16.9m
17.0 to 17.9m
18.0 to 18.9m
19.0 to 19.9m
20.0 to 24.9 m
25.0 to 29. 9m
30.0 to 39. 9m
TOTAL: 6.0 to 39.9 m
Number of 3-Digit SIC Codes with Median
Stack Height in Range
7
13
13
37
25
11
14
2
2
3
2
0
2
2
4
1
1
139
6.3 COMPARISON TO PRIOR ASSUMPTION OF 10 m STACK HEIGHT
In contrast to the previously assumed value often meters (32.8 feet), this modified approach
using AFS, NET, and State data concludes that 6,173 facilities are estimated to have stack heights
above ten meters, and 7,031 facilities are estimated to have stack heights below ten meters. The
mean stack height for all TRI facilities reporting non-zero stack air releases is estimated to be 11.1
meters (36.5 feet), with a standard deviation of 5.00 meters (16.4 feet), and a median height of 9.14
10
-------
meters (30.0) feet. Note that these stack heights are not very different than the previously assumed
value of ten meters.
6.4 ESTIMATION OF STACK HEIGHTS FOR TRI FACILITIES WITH MISSING OR
INVALID 3-DIGIT SIC CODES
Of the 13,204 TRI facilities with non-zero stack air releases reported in 1995, stack heights
were estimated as described above for 13,021 facilities. The estimation approaches used included:
1,209 facilities estimated directly from AFS; 69 facilities estimated from California State data; 192
facilities estimated from New York State data; 37 facilities estimated from Wisconsin State data; and
11,514 estimated based on the facilities' 3-digit SIC code. The remaining 183 facilities (13,204
facilities minus 13,021 facilities) reported SIC codes outside the range of 201 to 399, at the 3-digit
level, or reported no SIC code. (As noted previously, not all data provided by California, New York
and Wisconsin were useable, because not all facilities reported non-zero stack air releases in 1995.)
For these 183 facilities, a stack height was assigned based on either the 2-digit SIC code (if a valid
one was available) or on the median stack height for all 108,590 stacks from AFS and NET. The
median stack height for all 108,590 stacks from AFS and NET is 10.67 m (35.0 ft). This median
stack height of 10.67 m for stacks should not be confused with the median height of 9.14 m for all
TRI facilities, which is based on AFS, NET, and State data, as described in Section 6.3. The median
stack height at the 2-digit SIC code level was calculated according to the hierarchy used for the 3-
digit SIC code analysis, presented in Section 6.2. Stack heights were estimated at the 2-digit SIC
code level for 27 facilities. The stack heights for the remaining 156 facilities were estimated using
the median stack height of all 108,590 stacks (10.67 m). Two significant figures are used for all stack
heights in the Indicators Model.
7. ANALYSES OF EXIT GAS VELOCITIES
7.1 FACILITY-SPECIFIC EXIT GAS VELOCITIES
An analysis similar to that performed for stack heights was conducted for exit gas velocities.
Exit gas velocity data were available from AFS, NET, and the New York and Wisconsin databases.
(Data from California did not include exit gas velocities.) For the 216 New York and Wisconsin
facilities and the 850 facilities in common to the TRI and AFS databases with non-zero exit gas
velocities, a representative exit gas velocity for each facility was estimated by calculating the median
exit gas velocity for all of a facility's stacks with non-zero height and non-zero exit gas velocity. As
was done for stack heights, the median exit gas velocity was chosen rather than the mean because exit
gas velocities may not be normally distributed. No matter how the exit gas velocities are distributed,
the median is the appropriate measure of central tendency. Therefore, for a given facility, the median
of its exit gas velocities was used as that facility's exit gas velocity in the Indicators Model. As with
the stack height analysis, not all facilities provided by New York and Wisconsin could be matched
to TRI facilities with non-zero stack air releases.
11
-------
7.2 ESTIMATED EXIT GAS VELOCITIES
For the remaining TRI facilities with non-zero stack releases and non-zero stack heights for
which facility-specific data were not available, exit gas velocities were estimated from AFS and NET
based on facility 3-digit SIC codes. As previously mentioned, EPA determined that of the 37,390
stacks being analyzed from AFS and the 90,167 stacks being analyzed from NET, there were 18,967
stacks in common to the two databases. To avoid double-counting these stacks in the analysis, the
Agency used the exit gas velocity data from AFS for these stacks and removed the exit gas velocity
data in NET from further consideration. Therefore, augmenting the stacks from AFS with the non-
duplicative stacks from NET resulted in 108,590 stacks (37,390 from AFS and 71,200 from NET).
Each TRI facility within a 3-digit SIC code group was assigned the median exit gas velocity
of the AFS and NET stacks within that 3-digit SIC group according to the following hierarchy:
1. If the combined AFS and NET stack height data for that 3-digit SIC code group
indicated no statistically significant difference between the mean exit gas velocity of stacks
emitting possible TRI chemicals and the mean exit gas velocity of stacks emitting non-TRI
chemicals, then the median was estimated over all stacks in that group, regardless of whether
the stack emitted possible TRI chemicals. This median exit gas velocity was then used as the
estimated exit gas velocity for all TRI facilities in the 3-digit SIC code group that did not have
facility-specific data in AFS or in the New York and Wisconsin databases.
2. If the AFS and NET exit gas velocity data for that 3-digit SIC code group did indicate
a statistically significant difference between the mean exit gas velocity of stacks emitting
possible TRI chemicals and the mean exit gas velocity of stacks emitting non-TRI chemicals,
then the median for only those stacks emitting possible TRI chemicals was used as the
estimated exit gas velocity for all TRI facilities in that 3-digit SIC code group.
In both approaches, the exit gas velocities of facilities that occur in both TRI and AFS (i.e.,
facility-specific data) are included in the calculation of the median exit gas velocity of their 3-digit SIC
code groups. State data are not included in these analyses because of the potential of double-
counting with NET data, which includes data from New York and Wisconsin. (Recall that NET
facilities cannot be matched to TRI facilities because there is no facility identifier in common.) Table
3 presents the number of 3-digit SIC codes with median exit gas velocities falling in a particular exit
gas velocity range for 137 of the 140 unique 3-digit SIC codes reported in TRI. (No estimates of exit
gas velocities were available for facilities in SIC codes 23 6 (girls', children's, and infants' outerwear),
316 (luggage manufacturing), and 317 (handbags and other personal leather goods).) Note that for
all 3-digit SIC codes in the range of 201 to 399, the median exit gas velocity is greater than or equal
to 4.0 m/sec.
12
-------
Table 3
Median Exit Gas Velocities by SIC Code
Range of Exit Gas Velocities (m/sec)
4.0 to 4.9 m/sec
5.0 to 5. 9 m/sec
6.0 to 6.9 m/sec
7.0 to 7.9 m/sec
8.0 to 8.9 m/sec
9.0 to 9.9 m/sec
10.0 to 10. 9 m/sec
11.0 to 11. 9 m/sec
12.0 to 12.9 m/sec
13.0 to 13. 9 m/sec
14.0 to 14.9 m/sec
TOTAL:
Number of 3-Digit SIC Codes with Median
Exit Gas Velocity in Range
3
4
4
12
44
26
26
8
7
1
2
137
7.3 COMPARISON TO PRIOR ASSUMPTION OF 0.01 m/sec EXIT GAS VELOCITY
The mean exit gas velocity for all TRI facilities reporting non-zero stack air releases is
estimated to be 9.92 meters per second (32.5 feet per second), with a standard deviation of 11.0
meters per second (36.0 feet per second), and a median exit gas velocity of 8.90 meters per second
(29.2 feet per second). Note that these exit gas velocities are quite different than the previously
assumed value of 0.01 meters per second. Of the 13,204 TRI facilities with non-zero stack air
releases in 1995,13,192 are estimated to have exit gas velocities above 0.01 meters per second. Only
twelve facilities are estimated to have exit gas velocities less than or equal to 0.01 meters per second.
7.4 ESTIMATION OF EXIT GAS VELOCITIES
MISSING OR INVALID 3-DIGIT SIC CODES
FOR TRI FACILITIES WITH
Of the 13,204 TRI facilities with non-zero stack air releases reported in 1995, exit gas
velocities were estimated for 13,016 facilities. The estimation approaches used included: 850
facilities estimated directly from AFS; 192 facilities estimated from New York State data; 24 facilities
estimated from Wisconsin State data; and 11,950 estimated based on the facilities' 3-digit SIC code.
13
-------
The remaining 188 facilities (13,204 facilities minus 13,016 facilities) reported SIC codes outside the
range of 201 to 399, at the 3-digit level, or reported no SIC code. For these facilities, an exit gas
velocity was assigned based on either the 2-digit SIC code (if a valid one was available) or on the
median exit gas velocity for all 108,590 stacks. The median exit gas velocity for all 108,590 stacks
from AFS and NET is 8.80 m/sec (28.9 ft/sec). This median exit gas velocity of 8.80 m/sec for stacks
should not be confused with the median exit gas velocity of 8.90 m/sec for all TRI facilities,
described in Section 7.3. The median exit gas velocity at the 2-digit SIC code level was calculated
according to the hierarchy used for the 3-digit SIC code analysis, presented in Section 7.2. Table A-2
in Appendix A indicates each 3-digit SIC code group present in TRI, the median exit gas velocity as
estimated from the AFS and NET data, the estimation technique used (whether the median was
calculated over all stacks or only those emitting possible TRI chemicals), and the number of 1995 TRI
facilities using that value. Table A-2 also presents the median exit gas velocities and the estimation
technique used for 2-digit and 4-digit SIC codes, within the ranges of 20 to 39 and 2011 to 3999,
respectively. Two significant figures are used for all exit gas velocities in the Indicators Model.
8. REFERENCES
Bouwes, Sr., N.W., and S.M. Hassur. 1998. Ground-Truthing of the Air Pathway Component of
OPPT's Risk-Screening Environmental Indicators Model. U.S. EPA, Office of Pollution
Prevention and Toxics, Economics, Exposure, and Technology Division. October. Draft.
14
-------
APPENDIX A
15
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 20
SIC 201
SIC 2011
SIC 2013
SIC 2015
SIC 2017
SIC 202
SIC 2021
SIC 2022
SIC 2023
SIC 2024
SIC 2026
SIC 203
SIC 2032
SIC 2033
SIC 2034
SIC 2035
SIC 2037
SIC 2038
SIC 204
SIC 2041
SIC 2042
SIC 2043
SIC 2044
SIC 2045
SIC 2046
SIC 2047
SIC 2048
SIC 205
SIC 2051
SIC 2052
SIC 206
SIC 2061
SIC 2062
SIC 2063
SIC 2064
SIC 2065
SIC 2066
SIC 2067
SIC 2068
TRI
Chemicals
Number of
Stacks
2837
307
153
108
46
213
15
72
103
1
22
232
6
142
2
10
59
13
501
58
105
11
135
44
148
355
286
69
284
77
50
67
16
1
19
25
29
Median Non-TRI Median
(meters) Chemicals (meters)
Number of
Stacks
13.72
11.28
11.28
12.19
9.91
14.94
12.19
14.33
18.29
12.19
12.80
12.19
11.89
12.19
18.29
7.62
16.76
8.53
17.07
16.31
22.56
10.67
27.43
12.19
10.36
11.58
10.97
11.89
19.81
22.86
39.62
19.81
13.26
17.37
14.33
13.11
8.84
5034
67
35
19
12
1
147
9
51
63
5
19
150
3
67
11
64
5
2795
480
5
666
16
28
846
159
595
211
131
80
463
41
83
81
86
1
69
79
23
15.54
9.75
9.14
10.67
11.13
9.14
13.72
15.24
13.72
18.29
10.06
9.75
12.19
6.10
11.58
12.19
12.19
11.89
18.29
20.12
9.14
23.77
22.86
12.19
18.29
15.24
12.19
11.89
10.06
15.39
17.07
23.16
20.73
18.29
9.60
2.13
13.72
18.90
9.14
Equal
Stack
Pop.
Means? *
Unequal
Equal
Equal
Equal
Equal
N/A***
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
N/A***
Equal
Equal
Equal
Equal
Equal
N/A***
Equal
N/A***
Equal
Equal
Unequal
Equal
Unequal
Equal
Unequal
Equal
Unequal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Median
Height
for SIC
code
13.72
10.97
10.67
12.19
10.06
14.63
12.80
14.02
18.29
12.19
10.36
12.19
11.58
11.89
18.29
11.58
12.19
10.82
18.29
20.12
23.47
12.19
18.29
12.19
12.19
11.58
10.97
11.89
18.29
22.86
22.86
18.90
11.13
17.37
13.87
13.11
9.14
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
2837
374
188
127
58
360
24
123
166
1
41
382
9
209
2
21
123
18
3296
538
771
39
981
44
743
355
417
69
747
77
133
148
102
1
88
104
52
code**
34
17
18
86
17
34
See notes at end of table.
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 207
SIC 2074
SIC 2075
SIC 2076
SIC 2077
SIC 2079
SIC 208
SIC 2082
SIC 2083
SIC 2084
SIC 2085
SIC 2086
SIC 2087
SIC 209
SIC 2091
SIC 2092
SIC 2095
SIC 2096
SIC 2098
SIC 2099
SIC 21
SIC 211
SIC 2111
SIC 212
SIC 2121
SIC 213
SIC 2131
SIC 214
SIC 2141
SIC 22
SIC 221
SIC 2211
SIC 222
SIC 2221
TRI
Chemicals
Number of
Stacks
209
11
100
13
63
22
437
275
12
6
102
21
21
299
33
8
55
19
6
178
160
101
101
9
9
15
15
35
35
1049
101
101
74
74
Median
(meters)
13.72
12.19
15.24
18.29
12.19
14.78
17.98
21.34
24.54
11.73
17.98
9.14
10.36
12.19
12.80
12.19
18.29
15.24
9.14
11.43
18.14
20.73
20.73
10.97
10.97
12.19
12.19
15.24
15.24
11.89
15.24
15.24
11.73
11.73
Non-TRI
Chemicals
Number of
Stacks
570
23
482
17
30
18
273
144
51
2
26
13
37
358
12
1
105
17
11
212
48
23
23
11
11
8
8
6
6
247
28
28
15
15
Median
(meters)
15.24
12.19
15.24
12.19
11.89
17.53
15.24
15.54
18.29
15.24
35.81
10.67
10.06
12.19
15.85
12.19
18.29
17.68
12.80
10.67
9.14
15.85
15.85
9.14
9.14
8.99
8.99
9.75
9.75
18.29
20.73
20.73
10.36
10.36
Equal
Stack
Pop.
Means? '
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Unequal
Unequal
Equal
Equal
Median
Height
for SIC
code
15.24
12.19
15.24
12.19
12.19
15.70
16.46
18.59
19.51
12.95
17.98
9.45
10.06
12.19
13.11
12.19
18.29
15.24
9.14
10.67
17.98
19.96
19.96
9.14
9.14
10.67
10.67
15.24
15.24
11.89
15.24
15.24
10.67
10.67
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
779
34
582
30
93
40
710
419
63
8
102
34
58
657
45
8
160
36
6
390
208
124
124
20
20
23
23
41
41
1049
101
101
89
89
code**
85
30
22
20
1
1
4
20
13
See notes at end of table.
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 223
SIC 2231
SIC 224
SIC 2241
SIC 225
SIC 2251
SIC 2252
SIC 2253
SIC 2254
SIC 2257
SIC 2258
SIC 2259
SIC 226
SIC 2261
SIC 2262
SIC 2269
SIC 227
SIC 2273
SIC 228
SIC 2281
SIC 2282
SIC 2284
SIC 229
SIC 2291
SIC 2295
SIC 2296
SIC 2298
SIC 2297
SIC 2299
SIC 23
SIC 231
SIC 2311
SIC 232
SIC 2321
TRI
Chemicals
Number of
Stacks
38
38
15
15
86
7
46
2
18
12
1
323
133
137
53
18
18
105
25
5
75
289
3
156
27
68
11
24
138
3
3
28
6
Median
(meters)
10.52
10.52
11.89
11.89
9.14
12.19
9.14
17.07
5.79
8.69
12.80
12.19
11.58
12.19
12.19
8.38
8.38
7.62
12.19
15.24
5.49
11.58
10.97
11.58
18.59
15.70
10.36
11.58
9.75
8.84
8.84
11.73
12.19
Non-TRI
Chemicals
Number of
Stacks
12
12
3
3
26
3
2
7
1
9
4
59
19
25
15
23
23
36
29
1
6
45
4
19
3
13
1
5
31
7
1
Median
(meters)
21.95
21.95
21.03
21.03
12.34
2.74
3.81
10.36
42.67
15.24
15.24
20.73
22.86
20.73
20.73
25.91
25.91
17.53
15.85
13.72
25.30
14.63
7.62
14.63
22.56
9.75
27.13
20.73
9.14
9.14
15.24
Equal
Stack
Pop.
Means? '
Unequal
Unequal
Unequal
Unequal
Equal
Equal
N/A***
Equal
Unequal
N/A***
Unequal
Unequal
Unequal
Unequal
Equal
Unequal
Unequal
Unequal
Unequal
Equal
Unequal
Unequal
Unequal
Equal
Unequal
Equal
Equal
Unequal
Equal
Equal
N/A***
N/A***
Equal
Unequal
Median
Height
for SIC
code
10.52
10.52
11.89
11.89
10.67
10.67
10.36
17.07
5.79
8.69
12.80
12.19
11.58
12.80
12.19
8.38
8.38
7.62
15.24
15.24
5.49
11.58
9.75
11.58
18.59
12.50
10.36
12.80
9.14
8.84
8.84
10.67
12.19
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
code**
38
15
112
38
15
10
53
2
18
12
1
323
133
162
53
18
105
18
54
5
75
289
7
156
30
81
11
29
169
14
70
26
15
67
35
See notes at end of table.
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 2322
SIC 2325
SIC 2326
SIC 2329
SIC 233
SIC 2335
SIC 2337
SIC 2339
SIC 234
SIC 2341
SIC 2342
SIC 235
SIC 2353
SIC 236
SIC 2369
SIC 237
SIC 2371
SIC 238
SIC 2384
SIC 2385
SIC 2387
SIC 239
SIC 2391
SIC 2392
SIC 2394
SIC 2396
SIC 2399
SIC 24
SIC 241
SIC 2411
SIC 242
SIC 2421
SIC 2426
SIC 2429
TRI
Chemicals
Number of
Stacks
8
7
2
5
19
10
1
8
8
6
2
21
21
3
3
1
1
7
6
1
48
13
2
29
4
1771
6
6
463
342
115
6
Median Non-TRI Median
(meters) Chemicals (meters)
Number of
Stacks
14.63
12.19
11.28
10.67
10.97
10.97
3.66
6.86
7.77
8.99
6.86
6.40
6.40
6.10
6.10
6.10
6.10
7.92
8.08
7.92
10.82
27.43
11.28
8.84
6.86
10.97
8.08
8.08
13.72
14.94
11.58
22.10
3
3
3
3
3
3
1
1
17
1
11
3
2
1076
5
5
303
233
62
8
9.14
9.14
10.97
10.97
15.24
15.24
5.79
5.79
9.14
4.88
9.14
9.14
6.55
11.89
12.19
12.19
12.19
12.19
11.43
16.61
Equal
Stack
Pop.
Means? *
Equal
N/A***
N/A***
Equal
Equal
N/A***
N/A***
Unequal
N/A***
N/A***
N/A***
Equal
Equal
N/A***
N/A***
N/A***
N/A***
Equal
N/A***
N/A***
N/A***
Equal
N/A***
Equal
N/A***
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Median
Height
for SIC
code
10.67
12.19
11.28
9.75
10.97
10.97
3.66
6.86
111
8.99
6.86
7.16
7.16
6.10
6.10
6.10
6.10
7.77
8.08
7.92
9.14
11.58
11.28
9.14
6.71
10.97
10.06
10.06
13.11
13.72
11.58
17.68
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
11
7
2
8
22
10
1
8
8
6
2
24
24
3
3
1
1
8
6
1
65
24
2
32
6
2847
11
11
766
575
177
14
code**
1
0
5
0
0
6
11
0
17
See notes at end of table.
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 243
SIC 2431
SIC 2434
SIC 2435
SIC 2436
SIC 2439
SIC 244
SIC 2441
SIC 2448
SIC 2449
SIC 245
SIC 2451
SIC 2452
SIC 249
SIC 2491
SIC 2493
SIC 2499
SIC 25
SIC 251
SIC 2511
SIC 2512
SIC 2514
SIC 2515
SIC 2517
SIC 2519
SIC 252
SIC 2521
SIC 2522
SIC 253
SIC 2531
SIC 254
SIC 2541
SIC 2542
SIC 259
SIC 2591
TRI
Chemicals
Number of
Stacks
728
171
302
78
163
14
24
3
8
13
22
20
2
528
66
158
304
2355
1454
1087
170
95
11
43
48
364
174
190
157
157
216
99
117
164
40
Median
(meters)
9.45
9.14
8.23
13.72
14.63
14.94
12.04
23.77
11.43
12.19
8.38
7.62
10.67
11.13
9.30
14.94
9.14
9.14
9.14
9.75
9.14
8.23
6.10
7.62
6.10
10.21
10.06
10.67
9.45
9.45
9.14
7.92
9.14
8.53
7.62
Non-TRI
Chemicals
Number of
Stacks
371
111
57
39
158
6
18
3
6
9
9
8
1
370
31
242
97
922
375
285
39
30
2
15
4
255
97
158
106
106
95
34
61
91
17
Median
(meters)
10.67
10.67
9.14
9.14
12.19
19.05
7.32
7.32
6.71
8.53
4.88
4.88
0.30
12.19
9.75
13.72
10.67
9.45
9.14
9.14
10.67
8.84
11.58
4.57
19.20
11.58
12.19
10.97
9.45
9.45
7.62
7.62
7.62
7.62
7.62
Equal
Stack
Pop.
Means? '
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Unequal
Equal
Equal
Equal
Equal
Equal
Median
Height
for SIC
code
10.06
9.45
8.53
12.19
13.72
16.00
9.14
8.69
10.06
9.14
7.01
6.86
10.67
11.89
9.45
14.02
9.75
9.14
9.14
9.14
9.45
8.53
11.58
6.71
6.55
10.97
11.58
10.97
9.45
9.45
8.23
7.92
9.14
8.23
7.62
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
1099
282
359
117
321
20
42
6
14
22
31
28
2
898
97
400
401
3277
1829
1372
209
125
13
58
52
619
271
348
157
157
311
133
178
255
57
code**
142
1
3
254
249
66
23
43
32
See notes at end of table.
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
TRI
Chemicals
Median
(meters)
Number of
Stacks
SIC 2599
SIC 26
SIC 261
SIC 2611
SIC 262
SIC 2621
SIC 263
SIC 2631
SIC 264
SIC 2641
SIC 2646
SIC 2647
SIC 2649
SIC 265
SIC 2651
SIC 2652
SIC 2653
SIC 2655
SIC 2656
SIC 2657
SIC 267
SIC 2671
SIC 2672
SIC 2673
SIC 2674
SIC 2675
SIC 2676
SIC 2677
SIC 2678
SIC 2679
SIC 27
SIC 271
SIC 2711
SIC 272
SIC 2721
2858
284
952
262
47
443
870
2348
83
52
124
284
952
262
38
4
2
3
19
175
38
84
127
351
188
108
30
20
31
14
10
118
83
52
8.
14.02
42.98
42.
23.77
23.
28.96
28.
13.72
14.
13.
27.
8.
9.75
10.
10.
9.
10.
9.
9.14
9.
10.
7.
7.
15.
12.
7.
5.
10.
9.14
14.94
14.
10.21
10.
53
98
77
96
02
72
43
23
97
67
14
06
14
14
06
92
92
70
80
92
79
06
94
21
Non-TRI
Chemicals
Number of
Stacks
74
1153
195
195
385
385
180
180
1
1
124
2
69
10
15
28
268
100
60
11
7
1
16
2
1
70
364
2
2
17
17
Median
(meters)
18.90
35,
22
27,
10,
10,
10,
10.67
18,
12,
7.
.05
35.
.86
22.
.43
27.
.67
10.
.52
13.
10.
8.
9.
14.
.67
10.
9.
7.
9.
5.
10.
9.
6.
14.
.75
18.
.19
12.
77
05
86
43
67
87
67
08
75
94
67
14
62
14
79
67
14
40
63
75
19
Equal
Stack
Pop.
Means? '
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
N/A***
N/A***
N/A***
Unequal
Equal
Equal
Equal
Equal
Equal
Unequal
Unequal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Unequal
Equal
Unequal
Equal
Equal
Unequal
Unequal
Median
Height
for SIC
code
8.53
14.02
38.10
38.10
23.47
23.47
28.96
28.96
13.41
14.02
13.72
27.43
8.23
10.06
11.28
10.67
9.14
10.06
9.14
9.14
9.14
9.75
7.62
7.92
15.70
12.50
9.14
5.79
11.89
9.14
14.94
14.94
10.21
10.21
Number of
Stacks
for SIC
code
198
2858
479
479
1337
1337
442
442
48
38
4
2
3
567
21
244
48
99
127
870
451
248
119
37
20
47
16
10
188
2348
85
85
52
52
Number of TRI
Facilities Using
Median Height
of their SIC
code**
86
89
42
25
126
See notes at end of table.
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 273
SIC 2731
SIC 2732
SIC 274
SIC 2741
SIC 275
SIC 2751
SIC 2752
SIC 2754
SIC 2759
SIC 276
SIC 2761
SIC 277
SIC 2771
SIC 278
SIC 2782
SIC 2789
SIC 279
SIC 2791
SIC 2796
SIC 28
SIC 281
SIC 2812
SIC 2813
SIC 2816
SIC 2819
SIC 282
SIC 2821
SIC 2822
SIC 2823
SIC 2824
SIC 283
SIC 2831
SIC 2833
TRI
Chemicals
Number of
Stacks
248
74
174
25
25
1796
30
841
409
516
52
52
39
39
26
16
10
27
3
24
20449
1306
187
190
71
858
3553
2450
732
38
333
1029
361
Median Non-TRI Median
(meters) Chemicals (meters)
Number of
Stacks
11.58
11.58
11.58
8.84
8.84
9.14
9.60
9.75
9.14
8.84
10.36
10.36
7.62
7.62
9.45
10.06
9.14
7.62
7.92
7.32
9.14
13.11
15.24
9.14
21.34
13.72
11.89
12.19
8.69
12.19
18.29
13.11
15.24
81
7
74
6
6
231
6
111
58
56
11
11
3
2
1
13
10
3
6914
1544
116
61
301
1066
877
735
40
12
90
584
3
164
14.63
9.14
15.24
10.36
10.36
10.06
8.23
10.67
11.13
7.62
7.32
7.32
12.19
9.60
18.29
7.92
7.92
7.32
13.72
16.46
14.63
13.41
18.29
16.76
14.63
13.72
14.94
12.50
18.14
11.28
12.19
10.67
Equal
Stack
Pop.
Means? *
Unequal
Equal
Unequal
Equal
Equal
Unequal
Equal
Unequal
Unequal
Equal
Equal
Equal
N/A***
N/A***
Equal
Equal
Unequal
Equal
Equal
Equal
Unequal
Unequal
Equal
Unequal
Equal
Unequal
Unequal
Unequal
Unequal
Equal
Equal
Equal
N/A***
Equal
Median
Height
for SIC
code
11.58
10.97
11.58
8.84
8.84
9.14
9.14
9.75
9.14
8.53
9.14
9.14
7.62
7.62
9.75
10.06
9.14
7.77
7.92
7.32
9.14
13.11
14.63
9.14
18.29
13.72
11.89
12.19
8.69
12.19
18.29
12.19
13.72
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
248
81
174
31
31
1796
36
841
409
572
63
63
39
39
29
18
10
40
13
27
20449
1306
303
190
372
858
3553
2450
732
50
423
1613
525
code**
4
0
139
3
1
1
23
366
389
145
See notes at end of table.
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 2834
SIC 2835
SIC 2836
SIC 284
SIC 2841
SIC 2842
SIC 2843
SIC 2844
SIC 285
SIC 2851
SIC 286
SIC 2861
SIC 2865
SIC 2869
SIC 287
SIC 2873
SIC 2874
SIC 2875
SIC 2879
SIC 289
SIC 2891
SIC 2892
SIC 2893
SIC 2895
SIC 2899
SIC 29
SIC 291
SIC 2911
SIC 295
SIC 2951
SIC 2952
SIC 299
SIC 2992
SIC 2999
TRI
Chemicals
Number of
Stacks
664
3
1
502
184
45
205
68
702
702
11353
122
462
10769
736
249
104
9
374
1268
227
172
77
106
686
8960
7373
7373
1423
1078
345
164
71
93
Median Non-TRI Median
(meters) Chemicals (meters)
Number of
Stacks
12.19
10.67
5.18
7.92
13.11
9.14
4.88
9.14
8.84
8.84
7.62
14.02
12.19
7.62
12.19
18.29
11.89
10.67
9.14
7.62
10.06
15.24
7.92
24.99
6.10
12.19
12.19
12.19
9.14
9.14
7.62
10.67
7.62
13.11
414
1
2
417
317
29
48
23
257
257
1815
35
202
1578
625
237
222
17
149
795
142
130
21
222
280
2247
1320
1320
846
699
147
81
20
61
11.73
9.45
12.50
16.46
19.81
10.36
4.72
11.28
9.14
9.14
12.19
14.63
13.11
12.19
21.34
23.47
26.67
6.10
11.89
12.50
10.97
14.78
10.67
21.34
10.82
13.72
30.18
30.18
9.14
9.14
10.67
13.41
9.75
14.63
Equal
Stack
Pop.
Means? *
Equal
Unequal
Unequal
Unequal
Equal
Equal
Equal
Unequal
Unequal
Unequal
Unequal
Equal
Equal
Unequal
Unequal
Unequal
Unequal
Equal
Equal
Unequal
Equal
Equal
Unequal
Equal
Unequal
Unequal
Unequal
Unequal
Unequal
Equal
Unequal
Unequal
Equal
Unequal
Median
Height
for SIC
code
12.19
10.67
5.18
7.92
17.98
9.14
4.88
9.14
8.84
8.84
7.62
14.02
12.19
7.62
12.19
18.29
11.89
9.60
9.45
7.62
10.67
15.24
7.92
24.08
6.10
12.19
12.19
12.19
9.14
9.14
7.62
10.67
8.84
13.11
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
1078
3
1
502
501
74
253
68
702
702
11353
157
664
10769
736
249
104
26
523
1268
369
302
77
328
686
8960
7373
7373
1423
1777
345
164
91
93
code**
180
400
428
205
397
146
30
64
SIC 30
2738
9.14
1251
9.75
Unequal
9.14
2738
See notes at end of table.
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 301
SIC 3011
SIC 302
SIC 3021
SIC 304
SIC 3041
SIC 305
SIC 3052
SIC 3053
SIC 306
SIC 3061
SIC 3069
SIC 307
SIC 3079
SIC 308
SIC 3081
SIC 3082
SIC 3083
SIC 3084
SIC 3085
SIC 3086
SIC 3087
SIC 3088
SIC 3089
SIC 31
SIC 311
SIC 3111
SIC 313
SIC 3131
SIC 314
SIC 3143
SIC 3144
SIC 3149
TRI
Chemicals
Number of
Stacks
228
228
10
10
8
8
142
45
97
546
21
525
106
106
1698
204
26
80
8
235
209
125
46
765
272
158
158
16
16
90
65
7
18
Median Non-TRI Median
(meters) Chemicals (meters)
Number of
Stacks
9.75
9.75
8.08
8.08
7.62
7.62
8.23
6.40
9.14
9.14
9.14
9.14
7.92
7.92
9.14
10.36
8.53
9.14
5.33
10.36
9.14
9.45
7.62
9.14
10.06
12.19
12.19
6.10
6.10
6.40
7.32
6.10
4.88
187
187
61
13
48
283
27
256
69
69
651
33
2
13
8
46
83
134
5
327
116
49
49
1
1
64
46
18
10.67
10.67
9.75
9.75
9.75
9.14
10.97
9.14
9.14
9.14
9.14
7.62
7.47
9.14
9.14
17.83
8.84
9.75
7.62
9.14
8.38
16.46
16.46
7.32
7.32
7.32
7.32
7.01
Equal
Stack
Pop.
Means? *
Unequal
Unequal
N/A***
N/A***
N/A***
N/A***
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Unequal
Unequal
Equal
Unequal
Equal
Equal
N/A***
Equal
Median
Height
for SIC
code
9.75
9.75
8.08
8.08
7.62
7.62
8.23
7.32
9.14
9.14
10.67
9.14
8.23
8.23
9.14
9.14
8.53
9.14
6.10
10.36
8.84
9.45
7.62
9.14
9.75
12.19
12.19
6.10
6.10
7.16
7.32
6.10
6.86
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
228
228
10
10
8
8
142
58
145
829
48
781
175
175
2349
237
28
93
16
235
292
259
51
1092
388
158
158
17
16
154
111
7
36
code**
55
4
3
60
178
53
765
23
1
17
See notes at end of table.
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code TRI
Chemicals
Number of
Stacks
SIC 315 1
SIC 3151
SIC 317 1
SIC 3172
SIC 319 6
SIC 3199
SIC 32 2006
SIC 321 60
SIC 3211
SIC 322 300
SIC 3221
SIC 3229
SIC 323 95
SIC 3231
SIC 324 117
SIC 3241
SIC 325 261
SIC 3251
SIC 3253
SIC 3255
SIC 3259
SIC 326 119
SIC 3261
SIC 3262
SIC 3263
SIC 3264
SIC 3269
SIC 327 420
SIC 3271
SIC 3272
SIC 3273
SIC 3274
SIC 3275
1
1
6
60
154
146
95
117
111
55
92
3
16
1
82
20
26
75
103
65
151
Median Non-TRI Median
(meters) Chemicals (meters)
Number of
Stacks
6.71
6.71
19.51
19.51
6.40
6.40
12.19
20.57
20.57
22.86
23.32
19.66
9.14
9.14
32.00
32.00
9.75
9.14
12.50
10.67
11.58
10.67
8.08
4.88
12.50
8.38
12.04
7.16
6.10
9.14
21.95
15.24
2
2
4639
68
68
190
107
83
37
37
1198
1198
380
70
93
196
21
94
19
1
27
47
1416
44
184
556
307
325
12.19
12.19
12.19
9.91
9.91
17.22
15.24
21.34
10.36
10.36
19.81
19.81
9.14
9.14
10.06
9.14
2.13
9.14
9.14
9.14
13.41
7.32
11.13
7.16
11.58
9.45
12.50
15.85
Equal
Stack
Pop.
Means? *
Equal
Unequal
N/A***
N/A***
N/A***
N/A***
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
N/A***
N/A***
Unequal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Median
Height
for SIC
code
6.71
6.71
19.51
19.51
6.40
6.40
12.19
12.80
12.80
20.42
20.12
21.34
9.91
9.91
21.34
21.34
9.14
9.14
10.67
9.14
4.88
9.45
8.23
4.88
12.50
7.62
11.58
7.16
6.10
9.45
15.24
15.85
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
3
1
1
1
6
6
6645
128
128
490
261
229
132
132
1315
1315
641
181
148
288
24
213
35
1
82
67
1836
70
75
659
372
476
code**
0
1
0
7
57
23
48
70
27
12
See notes at end of table.
10
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 328
SIC 3281
SIC 329
SIC 3291
SIC 3292
SIC 3293
SIC 3295
SIC 3296
SIC 3297
SIC 3299
SIC 33
SIC 331
SIC 3312
SIC 3313
SIC 3315
SIC 3316
SIC 3317
SIC 332
SIC 3321
SIC 3322
SIC 3324
SIC 3325
SIC 333
SIC 3331
SIC 3334
SIC 3339
SIC 334
SIC 3341
SIC 335
SIC 3351
SIC 3353
SIC 3354
SIC 3355
SIC 3356
SIC 3357
SIC 336
SIC 3361
SIC 3362
TRI
Chemicals
Number of
Stacks
19
19
615
88
36
6
179
193
70
43
3909
1152
912
13
57
59
111
925
733
18
12
162
414
43
307
64
305
305
624
74
227
99
23
16
185
305
5
6
Median Non-TRI Median
(meters) Chemicals (meters)
Number of
Stacks
6.71
6.71
12.19
10.52
11.73
10.67
12.19
13.72
12.19
7.62
13.11
24.38
30.48
23.47
11.58
17.07
7.62
11.58
11.89
10.97
8.23
10.67
16.15
12.19
17.68
10.97
12.19
12.19
12.50
12.50
14.33
11.89
14.33
11.89
10.97
9.14
9.14
9.60
26
26
1230
107
53
2
780
153
104
31
5112
1377
1128
43
59
89
58
1778
1352
157
54
215
570
72
404
94
380
380
384
80
84
44
16
70
90
355
17
16
6.10
6.10
12.19
9.14
18.29
12.80
12.19
14.02
9.14
21.95
12.19
22.25
24.99
12.19
10.67
11.28
9.75
10.67
10.97
12.19
7.92
9.14
16.46
14.48
17.68
15.09
11.28
11.28
12.19
10.67
14.63
8.53
16.31
14.17
10.67
8.53
7.32
7.77
Equal
Stack
Pop.
Means? *
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Unequal
Equal
Equal
Equal
Equal
Median
Height
for SIC
code
6.10
6.10
12.19
9.45
11.73
10.67
12.19
13.72
10.67
7.62
12.50
22.86
26.82
12.19
10.97
13.72
9.14
10.97
11.58
10.97
7.92
9.75
16.31
13.72
17.68
12.34
12.19
12.19
12.19
11.13
14.63
10.67
14.33
11.89
10.97
9.14
7.32
8.08
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
45
45
1845
195
36
8
959
346
174
43
9021
2529
2040
56
116
148
169
2703
2085
18
66
377
984
115
711
158
685
685
1008
154
311
143
23
16
275
660
22
22
code**
8
123
228
222
55
138
220
213
See notes at end of table.
11
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 3363
SIC 3364
SIC 3365
SIC 3366
SIC 3369
SIC 339
SIC 3398
SIC 3399
SIC 34
SIC 341
SIC 3411
SIC 3412
SIC 342
SIC 3421
SIC 3423
SIC 3425
SIC 3429
SIC 343
SIC 3431
SIC 3432
SIC 3433
SIC 344
SIC 3441
SIC 3442
SIC 3443
SIC 3444
SIC 3446
SIC 3448
SIC 3449
SIC 345
SIC 3451
SIC 3452
SIC 346
SIC 3462
SIC 3463
SIC 3465
SIC 3466
SIC 3469
TRI
Chemicals
Number of
Stacks
114
8
111
18
43
184
86
98
4406
776
609
167
266
19
77
7
163
70
4
19
47
615
96
139
89
148
36
52
55
97
26
71
422
54
10
79
39
240
Median Non-TRI Median
(meters) Chemicals (meters)
Number of
Stacks
9.30
9.60
10.67
7.92
6.10
9.45
9.14
9.45
9.45
12.19
12.80
9.14
8.99
11.89
7.92
10.67
9.14
9.14
18.44
9.14
8.84
9.14
11.28
9.14
7.62
9.60
10.06
9.60
9.45
9.14
7.92
9.14
10.36
10.67
8.08
10.97
10.06
9.91
99
10
112
57
44
268
112
156
2209
168
131
37
227
73
2
152
91
29
46
16
251
53
38
59
67
8
18
8
97
14
83
288
133
6
40
19
90
12.19
8.53
7.62
7.62
11.28
9.14
8.84
9.14
9.14
11.58
11.58
9.14
7.62
6.10
21.64
7.92
9.14
10.67
9.14
11.58
9.14
7.92
8.99
8.23
10.36
7.62
10.67
5.94
9.14
9.91
8.84
12.19
12.19
9.14
12.19
9.75
10.67
Equal
Stack
Pop.
Means? *
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
N/A***
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Unequal
Median
Height
for SIC
code
9.30
8.84
8.53
7.92
7.62
9.14
8.84
9.14
9.14
11.89
12.19
9.14
7.92
11.89
7.62
10.67
7.92
9.14
10.67
9.14
9.14
9.14
9.14
9.14
7.92
10.06
9.75
10.36
9.14
9.14
8.69
9.14
10.36
12.19
8.69
11.28
9.75
9.91
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
114
18
223
75
87
452
198
254
6615
944
740
204
493
19
150
7
315
161
33
65
63
866
149
139
148
215
44
70
63
194
40
154
422
187
16
119
58
240
code**
111
185
70
36
181
45
150
See notes at end of table.
12
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 347
SIC 3471
SIC 3479
SIC 348
SIC 3482
SIC 3483
SIC 3484
SIC 3489
SIC 349
SIC 3491
SIC 3492
SIC 3493
SIC 3494
SIC 3495
SIC 3496
SIC 3497
SIC 3498
SIC 3499
SIC 35
SIC 351
SIC 3511
SIC 3519
SIC 352
SIC 3523
SIC 3524
SIC 353
SIC 3531
SIC 3532
SIC 3533
SIC 3534
SIC 3535
SIC 3536
SIC 3537
SIC 354
SIC 3541
SIC 3542
SIC 3543
SIC 3544
TRI
Chemicals
Number of
Stacks
1275
411
864
222
13
100
18
91
663
33
14
26
46
14
59
15
42
414
2250
269
48
221
258
217
41
401
156
34
63
43
48
30
27
176
55
20
5
18
Median
(meters)
9.14
9.14
9.14
10.52
10.06
9.14
10.21
12.19
9.14
9.14
9.14
7.01
7.62
10.67
9.14
15.24
6.10
9.45
9.75
11.28
11.58
10.97
10.36
10.67
9.14
10.06
12.95
9.30
6.10
10.36
7.77
9.30
12.50
9.14
10.97
10.36
7.32
8.38
Non-TRI
Chemicals
Number of
Stacks
711
437
274
43
2
19
1
21
333
14
12
35
16
16
44
2
18
176
1393
131
13
118
135
104
31
195
114
14
31
7
8
11
10
316
62
17
11
29
Median
(meters)
7.92
7.92
7.92
9.14
3.66
11.89
8.23
8.23
8.23
9.14
9.14
6.40
8.23
6.71
10.36
16.92
6.55
8.23
9.14
10.67
11.89
10.36
9.14
9.14
9.14
9.75
10.36
9.45
6.10
11.58
9.30
7.32
11.28
9.14
9.14
10.67
10.06
8.53
Equal
Stack
Pop.
Means? '
Equal
Equal
Equal
Equal
Equal
Unequal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Median
Height
for SIC
code
8.53
8.53
8.84
10.06
8.53
9.14
10.21
10.67
9.14
9.14
9.14
6.40
8.08
7.47
9.14
15.24
6.10
9.14
9.14
10.97
11.58
10.67
10.06
10.36
9.14
10.06
12.19
9.45
6.10
11.13
8.53
9.14
12.19
9.14
9.14
10.67
8.69
8.53
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
1986
848
1138
265
15
100
18
112
996
47
26
61
62
30
103
17
60
590
3643
400
48
339
393
321
72
596
270
48
94
50
56
41
37
492
117
37
16
47
code**
479
26
305
30
74
86
60
See notes at end of table.
13
-------
Table A-1
Summary of Median Stack Height by SIC Code
5IC Code TRI
Chemicals
Number of
Stacks
SIC 3545
SIC 3546
SIC 3547
SIC 3548
SIC 3549
SIC 355
SIC 3552
SIC 3553
SIC 3554
SIC 3555
SIC 3556
SIC 3559
SIC 356
SIC 3561
SIC 3562
SIC 3563
SIC 3564
SIC 3565
SIC 3566
SIC 3567
SIC 3568
SIC 3469
SIC 357
SIC 3571
SIC 3572
SIC 3573
SIC 3575
SIC 3577
SIC 3579
SIC 358
SIC 3581
SIC 3582
SIC 3585
SIC 3586
SIC 3589
SIC 359
SIC 3592
SIC 3593
SIC 3594
SIC 3596
SIC 3599
33
22
3
11
9
178
24
3
17
44
19
71
324
64
53
29
28
2
15
23
46
64
227
73
16
2
25
41
70
303
7
5
237
30
24
114
36
4
4
6
64
Median Non-TRI
(meters) Chemicals
Number of
Stacks
10.06
9.14
13.72
8.84
9.75
9.75
11.43
9.14
10.97
8.53
9.14
10.67
9.14
7.92
10.06
9.45
10.21
7.32
7.62
10.06
8.53
9.60
10.67
10.36
13.87
7.62
14.94
9.14
10.21
9.14
12.19
7.92
9.14
8.53
9.14
7.92
8.23
5.94
7.47
7.77
7.92
130
44
9
5
9
148
61
13
6
15
23
30
191
55
33
2
16
1
20
39
25
94
18
1
8
9
58
83
5
60
3
15
100
56
2
1
41
Median
(meters)
9.75
9.14
5.49
17.07
9.14
8.23
7.32
9.14
7.16
8.53
9.14
7.92
7.92
7.92
10.67
9.30
9.14
3.35
7.47
7.32
7.01
9.30
10.36
12.80
10.06
6.71
9.30
9.14
12.19
9.14
12.19
12.50
6.10
1.68
11.28
6.10
7.62
Equal
Stack
Pop.
Means? *
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
N/A***
Unequal
Equal
Equal
Equal
Equal
Equal
N/A***
Unequal
Equal
Equal
Equal
Equal
N/A***
Equal
Equal
Equal
Equal
Equal
Equal
N/A***
Equal
Unequal
Equal
Median
Height
for SIC
code
9.75
9.14
8.84
8.84
9.14
9.14
8.53
9.14
10.67
8.53
9.14
9.14
8.84
7.92
10.36
9.45
9.75
7.32
7.62
9.14
7.32
9.14
10.36
10.36
13.87
7.62
14.94
7.92
9.75
9.14
12.19
11.43
9.14
8.53
10.67
7.32
4.57
5.94
7.47
7.77
7.62
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
163
66
12
11
18
326
85
16
23
59
19
101
515
119
86
31
44
2
15
43
85
89
321
91
16
2
33
50
128
386
7
10
297
33
39
214
92
4
6
6
105
code**
42
90
21
91
35
See notes at end of table.
14
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 36
SIC 361
SIC 3612
SIC 3613
SIC 362
SIC 3621
SIC 3622
SIC 3624
SIC 3625
SIC 3629
SIC 363
SIC 3631
SIC 3632
SIC 3633
SIC 3634
SIC 3635
SIC 3639
SIC 364
SIC 3641
SIC 3643
SIC 3644
SIC 3645
SIC 3646
SIC 3647
SIC 3648
SIC 365
SIC 3651
SIC 3652
SIC 366
SIC 3661
SIC 3662
SIC 3663
SIC 3669
SIC 367
SIC 3671
SIC 3672
SIC 3674
SIC 3675
TRI
Chemicals
Number of
Stacks
3004
244
209
35
494
312
1
54
93
34
257
55
68
19
61
2
52
275
59
48
31
50
38
26
23
65
52
13
289
180
1
63
45
1208
123
84
422
32
Median
(meters)
9.60
11.43
12.19
9.14
8.99
8.53
7.62
15.85
9.14
10.06
10.36
10.97
12.19
11.28
8.23
10.06
10.21
11.58
12.19
10.67
11.58
9.14
11.89
10.67
12.19
9.75
9.75
11.58
9.14
9.60
6.40
9.75
7.01
9.14
7.62
8.69
10.06
9.14
Non-TRI
Chemicals
Number of
Stacks
1330
135
80
55
213
81
6
58
38
30
153
70
36
14
13
3
17
126
21
23
17
19
7
32
7
14
12
2
75
48
2
16
9
405
37
102
127
2
Median
(meters)
9.14
9.14
9.91
7.62
8.53
7.92
7.16
12.65
9.91
8.23
9.14
7.62
10.82
10.82
9.75
5.49
12.19
7.92
10.67
7.92
6.10
14.02
12.80
6.10
20.73
12.19
13.72
11.43
10.67
10.67
9.91
15.24
10.97
8.53
6.71
9.75
8.23
4.88
Equal
Stack
Pop.
Means? '
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Unequal
Equal
Equal
Equal
Unequal
Equal
Unequal
Unequal
Unequal
Equal
Equal
Equal
Equal
Equal
Median
Height
for SIC
code
9.14
10.36
11.89
111
8.84
8.53
7.62
15.24
9.14
9.14
10.06
9.14
12.04
10.97
8.23
8.53
10.67
10.97
12.19
8.53
10.06
9.14
12.19
6.40
12.19
10.67
9.75
11.58
9.14
9.75
6.40
9.75
7.01
9.14
7.62
9.14
9.75
8.84
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
4334
379
289
90
707
393
1
112
131
64
410
125
104
33
74
5
69
401
80
71
48
50
45
58
23
79
64
15
289
228
1
63
45
1613
160
186
549
34
code**
45
96
45
86
10
21
365
See notes at end of table.
15
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 3676
SIC 3677
SIC 3678
SIC 3679
SIC 369
SIC 3691
SIC 3692
SIC 3694
SIC 3695
SIC 3699
SIC 37
SIC 371
SIC 3711
SIC 3713
SIC 3714
SIC 3715
SIC 3716
SIC 372
SIC 3721
SIC 3724
SIC 3728
SIC 373
SIC 3731
SIC 3732
SIC 374
SIC 3743
SIC 375
SIC 3751
SIC 376
SIC 3761
SIC 3764
SIC 3769
SIC 379
SIC 3792
SIC 3795
SIC 3799
TRI
Chemicals
Number of
Stacks
16
6
8
517
172
26
17
93
4
32
4500
2586
910
192
1353
89
42
1094
532
320
242
395
210
185
157
157
47
47
100
69
28
3
121
62
24
35
Median Non-TRI Median
(meters) Chemicals (meters)
Number of
Stacks
5.79
6.55
12.34
9.14
9.14
7.01
8.53
9.14
10.67
7.47
11.28
11.89
18.59
9.14
10.67
9.14
8.84
11.28
10.97
12.19
9.14
9.14
9.14
9.45
11.89
11.89
10.67
10.67
12.19
12.19
7.32
9.14
8.23
7.16
9.14
9.14
12
4
121
209
109
8
71
5
16
4944
4391
1584
83
2702
3
19
229
59
99
71
131
24
107
67
67
39
39
36
24
12
51
10
9
32
6.86
6.25
8.84
9.75
9.14
11.58
11.89
33.53
6.10
12.80
13.41
23.77
12.19
11.28
6.10
9.14
9.75
11.89
13.72
7.62
9.14
9.14
9.14
11.58
11.58
10.67
10.67
10.67
14.78
8.38
10.67
6.55
15.24
11.58
Equal
Stack
Pop.
Means? *
Equal
Equal
N/A***
Equal
Equal
Equal
Equal
Unequal
Unequal
Equal
Unequal
Unequal
Unequal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
N/A***
Unequal
Equal
Unequal
Unequal
Median
Height
for SIC
code
6.10
6.25
12.34
9.14
9.14
9.14
9.14
9.14
10.67
6.71
11.28
11.89
18.59
10.06
10.97
9.14
9.14
11.28
10.97
12.80
8.53
9.14
9.14
9.14
11.89
11.89
10.67
10.67
12.04
12.19
7.47
9.14
8.23
7.16
9.14
9.14
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
28
10
8
638
381
135
25
93
4
48
4500
2586
910
275
4055
92
61
1323
532
419
313
526
234
292
224
224
86
86
136
93
40
3
121
72
24
35
code**
138
449
151
125
28
6
22
40
See notes at end of table.
16
-------
Table A-1
Summary of Median Stack Height by SIC Code
SIC Code
SIC 38
SIC 381
SIC 3811
SIC 3812
SIC 382
SIC 3821
SIC 3822
SIC 3823
SIC 3824
SIC 3825
SIC 3826
SIC 3827
SIC 3829
SIC 384
SIC 3841
SIC 3842
SIC 3843
SIC 3844
SIC 3845
SIC 385
SIC 3851
SIC 386
SIC 3861
SIC 387
SIC 3873
SIC 39
SIC 391
SIC 3911
SIC 3914
SIC 3915
SIC 393
SIC 3931
SIC 394
SIC 3942
SIC 3944
TRI
Chemicals
Number of
Stacks
955
258
2
256
198
10
37
30
7
33
47
17
17
190
110
43
7
22
8
14
14
292
292
3
3
1870
22
4
17
1
56
56
158
3
57
Median
(meters)
10.06
10.06
5.18
10.06
6.55
7.32
10.06
6.55
5.49
6.10
6.40
9.14
9.14
9.14
9.75
9.14
6.71
9.75
6.10
7.92
7.92
12.19
12.19
24.38
24.38
9.75
12.80
14.78
10.97
17.07
9.14
9.14
9.14
15.85
10.97
Non-TRI
Chemicals
Number of
Stacks
273
47
29
18
82
3
12
19
1
1
31
8
7
76
43
8
16
8
1
9
9
52
52
7
7
452
1
1
13
13
53
1
43
Median
(meters)
8.23
7.62
6.10
7.62
6.55
8.23
9.75
6.10
7.62
8.53
6.10
6.71
4.88
9.14
8.84
9.91
6.10
12.19
9.14
9.14
9.14
13.11
13.11
8.23
8.23
9.30
10.97
10.97
8.84
8.84
11.28
4.88
11.28
Equal
Stack
Pop.
Means? '
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
N/A***
Unequal
N/A***
Equal
Equal
Equal
Unequal
Unequal
Median
Height
for SIC
code
9.14
9.75
6.10
10.06
6.55
7.62
10.06
6.40
5.49
6.10
6.10
7.92
9.14
9.14
9.75
9.14
6.10
10.36
6.10
9.14
9.14
12.19
12.19
8.38
8.38
9.75
12.50
14.78
10.97
17.07
9.14
9.14
9.14
15.85
10.97
Number of Number of TRI
Stacks Facilities Using
for SIC Median Height
code of their SIC
1228
305
31
274
280
13
49
49
7
33
78
25
24
266
153
51
23
30
8
23
23
344
344
10
10
2322
23
4
17
1
69
69
211
3
57
code**
12
59
80
11
33
2
14
12
43
See notes at end of table.
17
-------
SIC Code
Table A-1
Summary of Median Stack Height by SIC Code
TRI
Chemicals
Number of
Stacks
Median
(meters)
Non-TRI
Chemicals
Number of
Stacks
Median
(meters)
Equal
Stack
Pop.
Means? *
Median
Height
for SIC
code
Number of
Stacks
for SIC
code
Number of TRI
Facilities Using
Median Height
of their SIC
code**
SIC 3949
98
9.14
9.14 Equal
9.14
107
SIC 395
SIC 3951
SIC 3952
SIC 3955
SIC 396
SIC 3961
SIC 3965
59
20
12
29
18
12
9.14
12.65
7.92
9.14
9.14
9.91
7.01
30
4
20
6
5
2
3
9.45
10.06
9.14
9.45
21.34
22.71
21.34
Equal
Equal
Equal
Equal
Unequal
Equal
Unequal
9.14
12.19
9.14
9.14
9.14
11.13
7.01
89
14
20
16
49
24
10
12
18
SIC 399
SIC 3991
SIC 3993
SIC 3995
SIC 3996
SIC 3999
1555
8
119
98
16
1314
9.75
9.14
7.92
9.45
13.72
10.06
350
6
21
28
20
275
9.14
4.88
8.23
9.14
15.24
9.45
Equal
Equal
Equal
Equal
Equal
Equal
9.75
8.38
7.92
9.14
15.24
10.06
1905
14
140
126
36
1589
116
*ls mean height of TRI chemical emitting stacks equal to mean height of non-TRI chemical emitting stacks? If unequal, use data
from stacks emitting TRI chemicals.
^Approximately 87% of TRI facilities use heights based on their 3-digit SIC codes.
***Stack height data unavailable for one or both stack categories (emitting TRI chemicals and emitting only non-TRI chemicals).
See notes at end of table.
18
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
SIC 20
SIC 201
SIC 2011
SIC 2013
SIC 2015
SIC 202
SIC 2021
SIC 2022
SIC 2023
SIC 2024
SIC 2026
SIC 203
SIC 2032
SIC 2033
SIC 2035
SIC 2037
SIC 2038
SIC 204
SIC 2041
SIC 2043
SIC 2044
SIC 2045
SIC 2046
SIC 2047
SIC 2048
SIC 205
SIC 2051
SIC 2052
SIC 206
SIC 2061
SIC 2062
SIC 2063
SIC 2064
SIC 2065
SIC 2066
SIC 2067
SIC 2068
SIC 207
SIC 2074
SIC 2075
SIC 2076
TRI
Chemicals
Number of
Stacks
2175
223
128
62
33
70
1
16
40
1
12
150
4
77
5
57
7
414
48
96
7
106
40
117
298
234
64
238
65
47
66
14
1
7
25
13
178
11
85
9
Median
(mis)
7.92
7.00
6.21
8.96
7.00
10.01
6.46
10.84
10.06
3.60
7.50
6.80
13.43
8.41
5.97
0.43
9.08
9.32
8.31
11.45
6.18
11.22
8.04
7.95
7.93
7.93
7.62
8.75
0.84
10.67
9.75
6.31
274.32
6.07
12.97
6.00
10.79
8.31
11.26
10.85
Non-TRI
Chemicals
Number of
Stacks
4099
60
32
17
11
103
5
33
51
5
9
80
3
43
11
22
1
2320
401
587
16
26
659
133
498
174
111
63
404
32
64
72
82
1
59
79
15
466
9
397
13
Median
(mis)
11.94
8.17
9.44
4.57
8.31
8.31
6.46
8.94
8.62
4.91
13.01
4.04
0.06
7.16
15.09
0.21
10.12
12.53
13.42
12.80
6.74
14.74
14.66
12.62
11.73
7.19
7.18
8.38
9.11
8.28
9.57
12.94
13.14
188.37
6.95
9.69
7.92
13.61
15.24
14.81
8.34
Equal
Stack
Pop.
Means? *
Unequal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Unequal
Equal
Unequal
Equal
Equal
Equal
N/A***
Unequal
Equal
Unequal
Equal
Equal
Equal
Equal
Unequal
Unequal
Equal
Equal
Unequal
Unequal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Median
Exit Gas
Velocity
for SIC
code
7.92
7.28
6.64
7.59
7.68
9.18
6.46
9.47
9.18
3.60
12.44
5.97
13.26
8.31
5.97
0.31
9.08
11.94
13.42
12.80
6.18
13.98
8.04
10.89
7.65
7.83
7.62
8.75
0.84
10.67
10.12
6.31
274.32
6.95
9.97
7.62
10.79
15.24
13.98
9.60
Number of
Stacks
for SIC
code
2175
283
160
79
44
173
1
49
91
1
21
230
7
120
5
79
7
2734
449
683
7
765
40
615
472
345
127
238
65
111
138
14
1
66
104
28
178
20
482
22
Number of TRI
Facilities Using
Median Exit Gas
Velocity of their SIC
code**
34
17
19
88
18
34
91
See notes at end of table.
19
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
SIC 2077
SIC 2079
SIC 208
SIC 2082
SIC 2083
SIC 2084
SIC 2085
SIC 2086
SIC 2087
SIC 209
SIC 2091
SIC 2092
SIC 2095
SIC 2096
SIC 2098
SIC 2099
SIC 21
SIC 211
SIC 2111
SIC 212
SIC 2121
SIC 213
SIC 2131
SIC 214
SIC 2141
SIC 22
SIC 221
SIC 2211
SIC 222
SIC 2221
SIC 223
SIC 2231
SIC 224
SIC 2241
SIC 225
SIC 2251
SIC 2253
TRI
Chemicals
Number of
Stacks
51
364
240
141
88
3
15
35
849
97
64
26
15
62
22
246
1
6
87
11
13
23
4
48
9
6
150
88
3
15
35
97
64
26
15
6
38
Median Non-TRI
(mis) Chemicals
Number of
Stacks
10.95 30
8.
6.55
6.
67.
12.
7.
4.
3.
7.29
6.
7.
12.
3.
8.
6.
12.41
12.41
12.
219.46
219.
11.73
11.
12.95
12.
10.44
11.98
11.
11.11
11.
9.18
9.
9.14
9.
10.47
5.
10.
17
19
51
41
88
00
11
10
77
19
73
31
92
41
46
73
95
98
11
18
14
42
33
17
182
104
19
12
11
36
310
11
1
84
13
11
190
29
8
8
7
7
8
8
6
6
189
23
23
6
6
9
9
3
3
21
7
Median Equal
(mis) Stack
Pop.
Means? *
6.73 Equal
11
8.
7.44
10
2.
5.
9.
9.08
9.
8.
9.
8.
8.90
.43
11.71
11.13
13.42
7.62
12.80
63
9.18
15.24
7.92
10.91
4.27
10.15
.30
10.30
04
2.04
75
5.75
14
9.14
08
9.08
45
8.45
18
9.18
00
8.00
8.31
9.08
Unequal
Unequal
Equal
Unequal
N/A***
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
N/A***
Equal
Median
Exit Gas
Velocity
for SIC
code
9.00
8.17
6.55
6.55
67.51
12.41
7.88
4.37
9.51
8.26
6.61
7.77
8.38
9.38
6.58
6.92
12.41
12.41
12.41
7.50
7.50
8.31
8.31
12.77
12.77
10.15
11.26
11.26
10.72
10.72
9.18
9.18
9.13
9.13
9.18
5.42
9.14
Number of
Stacks
for SIC
code
81
364
550
170
96
10
23
41
1038
120
70
35
18
83
22
350
1
6
99
22
49
34
4
132
22
17
150
96
10
23
41
120
70
35
18
6
45
Number of TRI
Facilities Using
Median Exit Gas
Velocity of their SIC
code**
31
23
20
20
13
14
See notes at end of table.
20
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
SIC 2254
SIC 2257
SIC 2258
SIC 2259
SIC 226
SIC 2261
SIC 2262
SIC 2269
SIC 227
SIC 2273
SIC 228
SIC 2281
SIC 2282
SIC 2284
SIC 229
SIC 2291
SIC 2295
SIC 2296
SIC 2298
SIC 2297
SIC 2299
SIC 23
SIC 231
SIC 2311
SIC 232
SIC 2321
SIC 2322
SIC 2325
SIC 2326
SIC 2329
SIC 233
SIC 2335
SIC 2337
SIC 2339
SIC 234
SIC 2341
SIC 2342
SIC 235
SIC 2353
TRI
Chemicals
Number of
Stacks
2
6
9
1
266
117
97
52
18
18
62
24
5
33
239
3
116
26
61
11
22
120
2
2
23
4
8
5
2
4
17
9
1
7
6
5
1
19
19
Median
(mis)
138.16
10.48
14.01
11.13
10.66
10.65
12.01
9.18
9.04
9.04
10.66
9.18
10.67
11.26
10.43
5.73
10.43
10.52
9.57
10.52
10.34
10.58
13.72
13.72
11.22
44.07
14.54
6.71
13.25
9.82
8.00
28.75
3.05
6.10
12.97
12.97
9.14
9.14
9.14
Non-TRI
Chemicals
Number of
Stacks
1
9
4
57
19
23
15
21
21
8
3
1
4
41
4
16
2
13
1
5
28
6
1
2
3
3
3
3
3
Median
(mis)
9.18
6.83
10.18
9.18
9.18
10.21
8.31
9.18
9.18
10.72
10.72
3.72
10.72
7.59
5.11
6.70
8.12
7.59
1.00
8.31
10.97
10.74
1.22
11.00
10.97
6.00
6.00
13.00
13.00
Equal
Stack
Pop.
Means? *
Unequal
N/A***
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
N/A***
N/A***
Equal
Unequal
Equal
N/A***
N/A***
Equal
Equal
N/A***
N/A***
Equal
N/A***
N/A***
N/A***
Equal
Equal
Median
Exit Gas
Velocity
for SIC
code
138.16
10.48
9.13
11.13
10.43
10.43
10.72
8.49
9.18
9.18
10.72
9.18
10.67
10.76
9.57
5.73
10.43
10.52
9.57
10.52
9.18
10.97
13.72
13.72
10.97
44.07
14.54
6.71
13.25
10.97
6.95
28.75
3.05
6.10
12.97
12.97
9.14
9.14
9.14
Number of Number of TRI
Stacks Facilities Using
for SIC Median Exit Gas
code Velocity of their SIC
code**
2
6
18
1
323
136
120
67
39
70
39
27
5
37
280
7
132
28
74
11
27
148
29
20
22
4
10
5
2
7
9
1
10
22
70
26
16
74
See notes at end of table.
21
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
TRI
Chemicals
Median
(mis)
Number of
Stacks
SIC 237
SIC 2371
SIC 238
SIC 2384
SIC 2385
SIC 2387
SIC 239
SIC 2392
SIC 2394
SIC 2396
SIC 2399
SIC 24
SIC 241
SIC 2411
SIC 242
SIC 2421
SIC 2426
SIC 2429
SIC 243
SIC 2431
SIC 2434
SIC 2435
SIC 2436
SIC 2439
SIC 244
SIC 2441
SIC 2448
SIC 2449
SIC 245
SIC 2451
SIC 2452
SIC 249
SIC 2491
SIC 2493
SIC 2499
SIC 25
SIC 251
SIC 2511
1
7
45
1271
3
348
511
10
11
388
1855
1170
1
6
1
13
2
26
4
3
259
87
2
101
223
42
135
10
1
4
5
9
2
48
135
205
900
4.00
4.
7.26
7.
7.
11.49
6.
11.
16.
11.
10.53
1.51
1.
10.53
10.
10.
5.
10.53
9.
10.
10.
10.
13.
8.91
7.
10.
8.
10.03
10.
6.
10.91
10.
12.
10.
10.45
10.67
10.
00
36
26
10
39
96
86
51
53
53
29
93
53
53
91
71
50
53
37
09
02
18
80
44
72
Non-TRI
Chemicals
Number of
Stacks
1
1
15
11
3
1
607
4
4
163
123
35
5
202
43
40
14
100
5
12
3
4
5
3
3
223
29
151
43
611
216
155
Median
(mis)
12
11
9.14
10
10
7.
11
15
8.
10.21
11
.25
12.
.09
11.
10.
14.
.85
10.
.53
10.
10.
3.
91
11.
6.
7.
5.
25.
.90
16.
15.
4.
.12
15.
56
6.
9.
8.
.37
12.
25
09
97
90
85
53
53
05
00
87
80
18
30
95
35
63
12
10
60
60
62
Equal
Stack
Pop.
Means? *
N/A***
N/A***
Equal
N/A***
N/A***
N/A***
Equal
Unequal
N/A***
Equal
Unequal
Equal
Equal
Equal
Unequal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Unequal
Equal
N/A***
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Median
Exit Gas
Velocity
for SIC
code
4.00
4.00
7.76
7.36
7.26
11.49
6.10
11.39
15.91
11.86
10.53
7.16
7.16
10.53
10.53
10.53
3.05
10.00
9.98
10.18
9.91
9.14
14.01
10.26
7.50
10.53
8.19
10.03
10.09
6.02
10.53
7.84
12.04
9.89
10.42
10.72
10.72
Number of
Stacks
for SIC
code
1
1
8
6
1
60
13
2
29
4
1878
7
7
348
259
122
7
713
144
263
56
235
15
22
1
8
10
11
12
2
611
77
286
248
2466
1386
900
Number of TRI
Facilities Using
Median Exit Gas
Velocity of their SIC
code**
11
18
151
258
262
See notes at end of table.
22
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
SIC 2512
SIC 2514
SIC 2515
SIC 2517
SIC 2519
SIC 252
SIC 2521
SIC 2522
SIC 253
SIC 2531
SIC 254
SIC 2541
SIC 2542
SIC 259
SIC 2591
SIC 2599
SIC 26
SIC 261
SIC 2611
SIC 262
SIC 2621
SIC 263
SIC 2631
SIC 264
SIC 2647
SIC 2649
SIC 265
SIC 2652
SIC 2653
SIC 2655
SIC 2656
SIC 2657
SIC 267
SIC 2671
SIC 2672
SIC 2673
SIC 2674
SIC 2675
TRI
Chemicals
Number of
Stacks
114
92
5
33
26
272
127
145
129
129
181
73
108
103
30
73
2128
232
232
708
708
222
222
4
1
3
341
19
107
31
80
104
621
257
139
60
30
18
Median Non-TRI
(mis) Chemicals
Number of
Stacks
12.34
10.12
4.57
10.15
13.47
10.18
10.76
10.00
8.55
8.55
8.83
9.00
8.43
8.55
9.69
8.55
10.44
10.63
10.63
10.00
10.00
11.15
11.15
24.51
5.18
35.17
8.41
11.87
8.60
9.04
6.19
9.75
10.76
11.00
10.67
12.36
11.28
7.10
20
26
13
2
202
75
127
49
49
82
27
55
62
17
45
840
144
144
257
257
118
118
1
1
104
2
57
10
10
25
216
87
49
1
4
1
Median Equal
(mis) Stack
Pop.
Means? *
7.78
7.83
11.80
5.73
9.65
8.29
10.18
9.69
9.69
9.24
8.37
9.39
11.06
9.91
13.69
9.18
12.47
12.47
9.41
9.41
10.15
10.15
80.01
80.01
6.16
6.26
5.36
7.23
2.15
8.31
8.30
9.08
11.26
10.79
3.55
12.68
Equal
Equal
N/A***
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Unequal
Unequal
Equal
Unequal
Equal
Unequal
Unequal
Equal
Equal
Equal
Equal
Unequal
N/A***
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Unequal
Median
Exit Gas
Velocity
for SIC
code
11.49
9.75
4.57
10.60
13.47
10.16
10.26
10.15
9.60
9.60
8.83
8.87
8.43
8.55
9.69
8.55
10.09
10.63
10.63
10.00
10.00
10.74
10.74
24.51
5.18
35.17
8.10
11.01
7.98
8.03
6.10
9.18
10.15
10.44
11.01
12.36
11.26
7.10
Number of Number of TRI
Stacks Facilities Using
for SIC Median Exit Gas
code Velocity of their SIC
134
118
5
46
28
474
202
272
178
178
181
100
108
103
47
73
2968
232
232
965
965
340
340
4
1
3
445
21
164
41
90
129
837
344
188
60
34
18
code**
72
23
45
34
88
92
43
7
27
135
See notes at end of table.
23
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
SIC 2676
SIC 2677
SIC 2678
SIC 2679
SIC 27
SIC 271
SIC 2711
SIC 272
SIC 2721
SIC 273
SIC 2731
SIC 2732
SIC 274
SIC 2741
SIC 275
SIC 2751
SIC 2752
SIC 2754
SIC 2759
SIC 276
SIC 2761
SIC 277
SIC 2771
SIC 278
SIC 2782
SIC 2789
SIC 279
SIC 2791
SIC 2796
SIC 28
SIC 281
SIC 2812
SIC 2813
SIC 2816
SIC 2819
SIC 282
SIC 2821
TRI
Chemicals
Number of
Stacks
18
8
10
81
1769
75
75
41
41
132
41
91
14
14
1398
20
646
346
386
47
47
21
21
18
14
4
23
3
20
10267
889
98
131
66
594
2290
1641
Median
(mis)
8.37
11.08
11.18
8.03
10.97
6.71
6.71
12.01
12.01
11.13
7.53
11.87
10.47
10.47
11.20
3.20
10.47
11.67
11.36
8.03
8.03
11.21
11.21
8.61
9.83
6.16
8.10
12.19
6.61
7.03
9.08
8.44
9.14
9.99
8.96
8.31
8.03
Non-TRI
Chemicals
Number of
Stacks
14
2
1
57
264
1
1
17
17
21
7
14
1
1
202
5
102
51
44
8
8
1
1
13
10
3
5076
1209
104
36
241
828
675
600
Median
(mis)
2.07
13.21
3.23
6.40
7.54
2.74
2.74
22.43
22.43
6.00
5.00
7.97
5.46
5.46
7.13
5.06
7.13
6.00
8.93
3.52
3.52
8.37
8.37
10.12
10.12
5.12
10.09
11.28
14.36
14.97
11.19
11.28
9.02
9.13
Equal
Stack
Pop.
Means? *
Equal
Equal
Unequal
Equal
Equal
Equal
Unequal
Unequal
Unequal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
N/A***
N/A***
Equal
Unequal
N/A***
Unequal
Equal
Equal
Unequal
Unequal
Equal
Unequal
Unequal
Unequal
Equal
Equal
Median
Exit Gas
Velocity
for SIC
code
8.05
11.08
11.18
7.01
10.18
6.71
6.71
12.01
12.01
9.85
6.26
10.76
9.08
10.47
10.44
3.66
9.75
11.28
11.25
8.03
8.03
11.21
11.21
8.37
9.83
6.16
8.10
10.12
5.12
7.03
9.08
10.09
9.14
9.99
8.96
8.35
8.31
Number of Number of TRI
Stacks Facilities Using
for SIC Median Exit Gas
code Velocity of their SIC
code**
32
10
10
138
2033
76
41
75
41
153
48
105
15
14
1600
25
748
397
430
55
21
19
23
10267
889
55
21
14
4
13
23
202
131
66
594
2965
2241
149
23
378
402
See notes at end of table.
24
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
SIC 2822
SIC 2823
SIC 2824
SIC 283
SIC 2831
SIC 2833
SIC 2834
SIC 2835
SIC 2836
SIC 284
SIC 2841
SIC 2842
SIC 2843
SIC 2844
SIC 285
SIC 2851
SIC 286
SIC 2861
SIC 2865
SIC 2869
SIC 287
SIC 2873
SIC 2874
SIC 2875
SIC 2879
SIC 289
SIC 2891
SIC 2892
SIC 2893
SIC 2895
SIC 2899
SIC 29
SIC 291
SIC 2911
SIC 295
SIC 2951
SIC 2952
SIC 299
SIC 2992
TRI
Chemicals
Number of
Stacks
343
38
268
732
220
509
2
1
259
126
43
28
62
512
512
4354
94
377
3883
512
213
80
6
213
719
205
49
67
92
306
4399
3265
3265
1015
775
240
119
45
Median
(mis)
7.01
13.50
9.14
7.03
7.03
7.25
11.98
10.37
6.34
7.03
8.65
3.81
5.74
5.56
5.56
5.61
9.00
6.55
5.46
8.90
14.23
0.97
2.01
7.62
8.00
7.44
7.03
5.15
13.87
7.14
5.49
4.51
4.51
14.14
15.46
6.82
3.35
5.74
Non-TRI
Chemicals
Number of
Stacks
33
11
31
453
3
134
313
1
2
241
185
27
9
20
169
169
1289
15
174
1100
405
208
70
16
111
635
75
127
17
201
215
1797
1057
1057
670
558
112
70
18
Median
(mis)
9.18
8.29
4.00
9.70
256.03
7.03
11.89
5.49
9.62
9.70
11.28
5.79
10.33
9.18
6.71
6.71
8.72
9.06
10.24
8.52
12.47
15.24
9.01
13.41
10.36
10.45
6.47
16.15
7.10
11.28
10.42
7.83
5.73
5.73
13.78
15.46
6.40
12.97
7.54
Equal
Stack
Pop.
Means? *
Equal
Equal
Equal
Unequal
N/A***
Unequal
Unequal
Unequal
Unequal
Equal
Equal
Equal
Unequal
Equal
Unequal
Unequal
Unequal
Equal
Unequal
Unequal
Equal
Equal
Unequal
Equal
Unequal
Unequal
Equal
Unequal
Equal
Equal
Unequal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Median
Exit Gas
Velocity
for SIC
code
7.04
12.41
9.09
7.03
7.03
7.25
11.98
10.37
8.03
9.42
8.03
3.81
5.74
5.56
5.56
5.61
9.00
6.55
5.46
10.43
14.65
0.97
11.67
7.62
8.00
7.22
7.03
5.53
12.62
7.14
5.49
4.94
4.94
14.02
15.46
6.82
8.31
6.43
Number of Number of TRI
Stacks Facilities Using
for SIC Median Exit Gas
code Velocity of their SIC
code**
376
49
299
732
150
220
509
2
1
500
183
311
70
28
82
512
512
4354
109
377
3883
917
414
434
209
421
80
22
213
719
407
4399
280
49
84
293
306
4322
4322
1685
1333
352
189
157
30
65
63
See notes at end of table.
25
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
TRI
Median
Chemicals
(mis)
Number of
Stacks
SIC 2999
SIC 30
SIC 301
SIC 3011
SIC 302
SIC 3021
SIC 305
SIC 3052
SIC 3053
SIC 306
SIC 3061
SIC 3069
SIC 307
SIC 3079
SIC 308
SIC 3081
SIC 3082
SIC 3083
SIC 3084
SIC 3085
SIC 3086
SIC 3087
SIC 3088
SIC 3089
SIC 31
SIC 311
SIC 3111
SIC 313
SIC 3131
SIC 314
SIC 3143
SIC 3144
SIC 3149
SIC 315
SIC 3151
SIC 319
SIC 3199
1859
186
8
118
339
24
1184
222
129
10
81
1
1
74
186
8
37
81
15
324
24
149
22
64
6
178
166
52
36
511
129
10
62
6
13
1
1
10.09
10
9.
8.
9.
10
10
9.08
9.
6.
8.
4.
12
3.
.62
10.
77
9.
27
10.
7.
18
8.
9.
.09
10.
.52
10.
11.
6.
11.
11.
9.
11.
11.
10.
12
9.
59
6.
10
8.
8.
2.
70
4.
.01
12.
18
62
77
45
10
14
27
09
67
39
85
25
40
13
30
81
43
12
59
37
55
62
70
01
Non-TRI
Chemicals
Number of
Stacks
52
865
171
171
49
12
37
172
2
170
50
50
423
30
1
11
7
30
69
51
4
220
100
43
43
1
1
54
41
13
2
2
Median
(mis)
13.
9.60
13.66
13.
4.91
9.
3.
7.71
12.
7.
10.09
10.
9.08
9.
5.
9.
36.
13.
8.
15.
15.
8.
8.45
9.08
9.
8.31
8.
7.48
5.
9.
0.91
0.
91
66
13
00
19
71
09
91
33
08
09
70
08
09
74
53
08
31
88
28
91
Equal
Stack
Pop.
Means? *
Equal
Equal
Unequal
Unequal
N/A***
N/A***
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Unequal
Unequal
Equal
Equal
Unequal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
N/A***
Unequal
Unequal
Unequal
N/A***
N/A***
Median
Exit Gas
Velocity
for SIC
code
10.70
10.01
10.62
10.62
9.77
9.77
7.84
10.01
5.24
8.90
8.14
9.07
10.09
10.09
10.01
10.67
11.39
7.01
13.87
11.40
8.31
11.30
11.81
9.48
8.80
9.12
9.12
7.18
6.59
7.84
7.50
8.55
2.62
4.70
4.70
12.01
12.01
Number of
Stacks
for SIC
code
126
2724
186
186
8
8
167
49
118
511
15
494
74
74
1607
149
22
75
13
178
235
52
40
731
322
172
172
11
10
135
103
6
13
1
1
1
1
Number of TRI
Facilities Using
Median Exit Gas
Velocity of their SIC
code**
57
63
186
53
801
26
17
See notes at end of table.
26
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
TRI
Chemicals
Median
(mis)
Number of
Stacks
SIC 32
SIC 321
SIC 3211
SIC 322
SIC 3221
SIC 3229
SIC 323
SIC 3231
SIC 324
SIC 3241
SIC 325
SIC 3251
SIC 3253
SIC 3255
SIC 3259
SIC 326
SIC 3261
SIC 3262
SIC 3263
SIC 3264
SIC 3269
SIC 327
SIC 3271
SIC 3272
SIC 3273
SIC 3274
SIC 3275
SIC 328
SIC 3281
SIC 329
SIC 3291
SIC 3292
SIC 3293
SIC 3295
SIC 3296
SIC 3297
SIC 3299
SIC 33
SIC 331
1593
46
237
64
90
214
109
287
17
529
2641
912
46
122
115
64
90
83
52
76
3
14
1
80
14
21
45
59
60
102
17
84
34
1
152
165
58
35
10.76
11.53
11.
11.26
10.
13.
8.37
8.
12.19
12.
9.33
12.
4.
9.
11.
9.28
9.
14.
8.
4.
8.31
8.
5.
8.
12.
7.
11.49
11.
12.13
8.
10.
53.
16.
14.
11.
10.
9.30
8.90
53
01
01
37
19
94
15
05
16
61
30
75
02
31
13
31
39
90
49
83
24
34
43
16
71
33
Non-TRI
Chemicals
Number of
Stacks
3298
56
56
157
79
78
36
36
942
942
308
59
74
162
13
84
15
1
25
43
1060
32
150
457
246
175
13
13
642
90
52
2
305
96
68
29
3707
1049
Median
(mis)
12.01
11
9.
13
15
12
9.
7.
8.
12
10.45
8.
.11
11.
18
8.
9.
.35
13.
.42
15.
.94
15.
5.
12.
14.
80
15.
14.
12.
6.
65
4.
6.
7.
12.
13.
87
8.
.80
8.
12.
11.
14.
13.
12.
11.
31
11
26
31
35
42
24
07
94
89
51
36
95
31
00
00
65
76
66
87
31
77
87
39
01
94
49
Equal
Stack
Pop.
Means? *
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Unequal
Unequal
Equal
Equal
Unequal
Equal
Equal
Equal
N/A***
N/A***
Unequal
Equal
Equal
Equal
Unequal
Equal
Equal
Unequal
Equal
Equal
Unequal
Unequal
Equal
Unequal
Unequal
Equal
Unequal
Equal
Equal
Unequal
Median
Exit Gas
Velocity
for SIC
code
10.76
11.17
11.17
10.87
10.00
11.83
10.53
10.53
12.19
12.19
9.33
12.94
4.95
9.05
14.89
9.28
9.92
14.30
8.75
6.31
7.65
4.60
5.13
7.65
12.68
7.90
9.69
9.69
12.13
8.83
11.26
53.34
16.43
13.44
11.71
10.74
10.03
8.90
Number of
Stacks
for SIC
code
1593
102
102
394
201
193
100
100
90
90
214
142
126
76
16
193
29
1
80
57
1347
53
45
516
306
102
30
30
529
84
86
1
152
261
58
64
6348
912
Number of TRI
Facilities Using
Median Exit Gas
Velocity of their SIC
code**
7
58
23
50
70
27
13
123
238
See notes at end of table.
27
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
SIC 3312
SIC 3313
SIC 3315
SIC 3316
SIC 3317
SIC 332
SIC 3321
SIC 3322
SIC 3324
SIC 3325
SIC 333
SIC 3331
SIC 3334
SIC 3339
SIC 334
SIC 3341
SIC 335
SIC 3351
SIC 3353
SIC 3354
SIC 3355
SIC 3356
SIC 3357
SIC 336
SIC 3361
SIC 3362
SIC 3363
SIC 3364
SIC 3365
SIC 3366
SIC 3369
SIC 339
SIC 3398
SIC 3399
SIC 34
SIC 341
SIC 3411
SIC 3412
SIC 342
SIC 3421
TRI
Chemicals
Number of
Stacks
751
13
46
37
65
451
361
7
9
74
305
36
230
39
213
213
499
47
196
84
20
15
137
132
3
5
53
1
46
4
20
129
40
89
3304 i.
716
558
158
187
14
Median Non-TRI
(mis) Chemicals
Number of
Stacks
8.37
27.60
10.13
7.37
9.14
11.49
11.61
24.23
10.17
10.50
11.28
10.21
13.46
10.06
9.30
9.30
9.14
11.22
9.22
9.00
7.04
13.78
9.08
8.12
7.25
5.97
4.15
8.87
10.80
10.55
8.98
7.83
10.18
7.83
3.90
8.31
8.31
8.31
8.40
8.38
837
42
52
67
51
1205
883
148
35
139
397
49
281
67
315
315
309
59
81
41
16
64
48
239
6
16
68
7
59
48
35
193
67
126
1679 i.
148
112
36
174
Median Equal
(mis) Stack
Pop.
Means? *
7.77
20.95
8.53
9.57
8.23
14.30
14.57
11.16
13.23
13.44
11.26
13.75
10.61
11.37
9.91
9.91
8.39
13.38
5.03
6.31
5.03
3.41
13.58
8.26
3.89
13.14
5.15
2.44
9.30
14.36
5.49
9.51
9.36
10.04
3.93
4.60
4.11
7.03
9.69
Equal
Equal
Equal
Unequal
Equal
Unequal
Unequal
Equal
Unequal
Unequal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Unequal
Unequal
Unequal
Unequal
Equal
Unequal
N/A***
Median
Exit Gas
Velocity
for SIC
code
8.09
21.01
9.81
7.37
9.10
11.49
11.61
11.40
10.17
10.50
11.27
11.28
11.50
10.06
9.30
9.30
9.00
11.22
8.37
9.00
5.55
5.27
9.92
8.19
5.64
5.97
4.85
8.87
10.38
14.36
5.74
8.69
9.36
7.83
8.90
8.31
8.31
8.14
8.40
8.38
Number of Number of TRI
Stacks Facilities Using
for SIC Median Exit Gas
code Velocity of their SIC
1588
55
98
37
116
451
361
155
9
74
702
85
511
39
528
528
808
47
277
125
36
79
185
371
9
5
121
1
105
52
55
322
107
89
3304
716
558
194
187
14
code**
233
57
142
233
221
115
198
72
See notes at end of table.
28
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
5IC Code
SIC 3423
SIC 3425
SIC 3429
SIC 343
SIC 3431
SIC 3432
SIC 3433
SIC 344
SIC 3441
SIC 3442
SIC 3443
SIC 3444
SIC 3446
SIC 3448
SIC 3449
SIC 345
SIC 3451
SIC 3452
SIC 346
SIC 3462
SIC 3463
SIC 3465
SIC 3466
SIC 3469
SIC 347
SIC 3471
SIC 3479
SIC 348
SIC 3482
SIC 3483
SIC 3484
SIC 3489
SIC 349
SIC 3491
SIC 3492
SIC 3493
SIC 3494
SIC 3495
SIC 3496
SIC 3497
SIC 3498
TRI
Chemicals
Number of
Stacks
47
7
119
47
4
11
32
438
71
107
59
99
25
40
37
53
21
32
308
33
4
59
37
175
960
322
638
135
5
36
11
83
460
26
11
22
27
11
45
10
22
Median
(mis)
8.40
10.76
8.31
8.59
0.33
8.90
8.75
9.14
11.10
9.60
9.00
7.95
6.10
10.44
10.00
6.40
3.78
8.47
8.96
8.10
12.42
10.06
9.14
8.90
8.90
8.40
9.02
10.58
9.84
8.90
9.18
14.63
8.90
7.95
5.76
9.86
8.96
7.37
10.76
5.00
5.46
Non-TRI
Chemicals
Number of
Stacks
58
2
114
83
25
44
14
191
29
32
42
60
8
16
4
82
11
71
177
68
1
27
6
75
586
360
226
29
2
16
11
209
4
11
21
11
9
39
1
10
Median
(mis)
11.43
13.07
9.54
12.41
12.41
15.64
5.11
7.28
8.32
5.46
9.53
6.64
5.00
14.75
6.46
8.60
7.30
8.93
8.31
6.94
8.11
9.27
10.65
8.08
9.89
9.71
10.06
9.18
11.23
8.11
13.01
8.69
6.27
10.06
17.86
9.08
17.22
7.10
7.32
13.47
Equal
Stack
Pop.
Means? *
Unequal
Unequal
Equal
Unequal
Unequal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Unequal
Unequal
Equal
Equal
Equal
Equal
N/A***
Equal
Equal
Equal
Unequal
Equal
Equal
Unequal
Equal
Unequal
Equal
Median
Exit Gas
Velocity
for SIC
code
8.40
10.76
8.90
8.59
0.33
8.90
7.99
8.63
10.98
8.60
9.14
7.95
6.10
10.44
10.00
8.17
3.89
8.93
8.37
7.86
12.42
9.27
9.69
8.36
8.90
8.40
9.17
10.12
9.84
8.65
9.18
14.32
8.90
7.95
5.76
13.38
9.02
7.37
8.95
5.00
7.74
Number of
Stacks
for SIC
code
47
7
233
47
4
11
46
629
100
139
101
159
33
40
41
135
32
103
485
101
4
86
43
250
960
322
864
164
7
52
11
94
669
30
11
43
38
11
84
10
32
Number of TRI
Facilities Using
Median Exit Gas
Velocity of their SIC
code**
37
183
45
156
493
26
317
See notes at end of table.
29
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
SIC 3499
SIC 35
SIC 351
SIC 3511
SIC 3519
SIC 352
SIC 3523
SIC 3524
SIC 353
SIC 3531
SIC 3532
SIC 3533
SIC 3534
SIC 3535
SIC 3536
SIC 3537
SIC 354
SIC 3541
SIC 3542
SIC 3543
SIC 3544
SIC 3545
SIC 3546
SIC 3547
SIC 3548
SIC 3549
SIC 355
SIC 3552
SIC 3553
SIC 3554
SIC 3555
SIC 3556
SIC 3559
SIC 356
SIC 3561
SIC 3562
SIC 3563
SIC 3564
SIC 3565
SIC 3566
SIC 3567
SIC 3568
TRI
Chemicals
Number of
Stacks
286
1500
141
38
103
131
116
15
297
128
22
37
26
42
26
16
124
39
16
3
18
32
5
3
1
7
131
20
3
7
41
4
56
182
41
24
22
24
2
11
18
8
Median
(mis)
9.04
9.11
9.14
9.04
9.14
11.10
11.10
10.42
10.03
11.05
10.77
9.14
9.33
9.01
9.11
11.49
8.53
7.95
8.85
8.84
12.16
8.10
10.00
6.22
10.76
8.69
7.89
9.85
11.10
8.29
8.37
8.15
7.01
8.37
8.44
8.85
1.67
7.89
10.90
8.37
7.85
8.86
Non-TRI
Chemicals
Number of
Stacks
103
1095 i.
105
13
92
114
94
20
162
106
10
20
3
7
11
5
285
53
15
8
28
119
44
9
3
6
131
61
13
3
15
12
27
118
50
13
12
1
20
8
Median
(mis)
7.80
3.60
9.11
12.01
8.66
8.19
7.92
9.51
10.73
11.61
9.39
8.84
10.52
13.05
10.67
9.18
5.73
7.25
3.51
0.94
9.69
8.11
2.47
2.07
3.32
15.76
9.69
12.25
6.40
11.80
12.10
5.20
3.00
9.57
9.81
5.15
8.61
11.03
13.20
5.99
Equal
Stack
Pop.
Means? *
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Unequal
Unequal
Equal
N/A***
Equal
N/A***
Unequal
Unequal
Equal
Median
Exit Gas
Velocity
for SIC
code
8.80
9.00
9.11
9.18
9.11
9.60
9.49
10.42
10.15
11.20
10.77
9.14
9.66
9.01
9.33
11.10
7.25
7.95
6.04
5.36
10.42
8.10
2.87
2.48
10.76
9.45
8.37
9.85
6.40
10.04
9.60
6.16
5.74
8.37
8.44
8.80
1.67
7.89
10.90
8.37
7.85
8.82
Number of
Stacks
for SIC
code
389
2595
246
51
195
245
210
35
459
234
32
57
29
42
37
21
409
39
31
11
46
151
49
12
1
13
262
20
16
10
56
16
83
182
41
37
22
36
2
11
18
16
Number of TRI
Facilities Using
Median Exit Gas
Velocity of their SIC
code**
34
74
88
61
43
93
See notes at end of table.
30
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
SIC 3469
SIC 357
SIC 3571
SIC 3572
SIC 3573
SIC 3575
SIC 3577
SIC 3579
SIC 358
SIC 3581
SIC 3582
SIC 3585
SIC 3586
SIC 3589
SIC 359
SIC 3592
SIC 3593
SIC 3594
SIC 3596
SIC 3599
SIC 36
SIC 361
SIC 3612
SIC 3613
SIC 362
SIC 3621
SIC 3622
SIC 3624
SIC 3625
SIC 3629
SIC 363
SIC 3631
SIC 3632
SIC 3633
SIC 3634
SIC 3635
SIC 3639
SIC 364
SIC 3641
SIC 3643
SIC 3644
TRI
Chemicals
Number of
Stacks
32
180
58
15
25
38
44
221
4
3
179
14
21
93
27
3
6
57
2324 i.
192
163
29
355
208
1
54
63
29
183
53
40
11
40
2
37
217
55
41
21
Median
(mis)
10.84
9.18
8.25
4.21
10.18
9.10
10.01
8.59
11.73
7.95
8.70
7.99
8.59
10.18
9.45
24.23
8.55
11.26
3.90
9.64
10.06
7.35
9.00
8.49
7.68
9.45
8.80
8.90
8.80
8.80
8.58
10.03
8.24
9.38
10.54
9.00
9.59
9.08
10.76
Non-TRI
Chemicals
Number of
Stacks
14
83
11
1
8
9
54
49
5
30
14
48
9
2
1
36
1033
121
71
50
150
54
6
28
34
28
133
58
34
12
10
2
17
77
18
21
5
Median
(mis)
6.87
9.02
7.30
6.31
8.70
2.07
9.21
8.60
8.84
6.80
12.88
8.14
10.42
27.52
5.09
7.42
7.89
8.00
7.23
10.18
9.08
8.31
43.83
8.00
11.06
9.18
10.58
10.59
11.00
17.82
11.17
5.39
5.67
8.23
10.48
9.08
8.31
Equal
Stack
Pop.
Means? *
Equal
Equal
Equal
N/A***
N/A***
Equal
Equal
Equal
Equal
N/A***
Equal
Equal
N/A***
Unequal
Equal
Equal
N/A***
Equal
Unequal
Equal
Unequal
Equal
Equal
Unequal
Unequal
Unequal
Unequal
Equal
Equal
Equal
Unequal
Equal
Unequal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Median
Exit Gas
Velocity
for SIC
code
10.45
9.12
8.10
4.21
10.18
8.56
9.28
8.59
11.73
8.11
8.55
7.99
8.59
9.18
9.80
24.23
8.55
9.00
8.90
9.18
9.18
7.35
9.00
8.49
7.68
9.45
8.91
8.90
8.80
9.05
8.58
10.03
8.34
8.17
10.53
8.90
9.69
9.08
10.76
Number of Number of TRI
Stacks Facilities Using
for SIC Median Exit Gas
code Velocity of their SIC
code**
46
263
2324
69
15
33
47
98
270
209
14
21
141
36
5
6
93
313
234
29
355
208
1
82
97
57
183
111
40
11
50
4
54
294
73
62
26
22
95
36
45
103
48
88
See notes at end of table.
31
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
SIC 3645
SIC 3646
SIC 3647
SIC 3648
SIC 365
SIC 3651
SIC 3652
SIC 366
SIC 3661
SIC 3662
SIC 3663
SIC 3669
SIC 367
SIC 3671
SIC 3672
SIC 3674
SIC 3675
SIC 3676
SIC 3677
SIC 3678
SIC 3679
SIC 369
SIC 3691
SIC 3692
SIC 3694
SIC 3695
SIC 3699
SIC 37
SIC 371
SIC 3711
SIC 3713
SIC 3714
SIC 3715
SIC 3716
SIC 372
SIC 3721
SIC 3724
SIC 3728
SIC 373
SIC 3731
SIC 3732
TRI
Chemicals
Number of
Stacks
43
23
11
23
42
38
4
271
173
1
59
38
972
101
53
375
26
13
4
8
392
92
17
3
58
4
10
3368
2108
800
130
1103
66
9
651
407
94
150
281
134
147
Median Non-TRI Median Equal
(mis) Chemicals (mis) Stack
Number of Pop.
Stacks Means? *
7.84
7.95
7.95
9.17
8.80
8.80
8.87
8.90
9.75
7.25
10.06
4.65
8.44
7.84
7.89
8.90
8.90
5.06
10.47
4.83
8.17
8.85
9.09
22.30
8.80
11.49
5.58
9.17
9.85
11.08
10.52
9.05
9.75
11.49
7.74
7.74
8.10
7.92
8.55
7.95
10.76
19
7
7
7
7
69
45
15
9
341
30
90
100
1
4
116
135
92
4
19
5
15
3589 11
3243
1375
51
1817
127
54
26
47
67
17
50
5.55
7.71
5.00
8.05
8.05
6.00
5.73
8.08
6.00
6.18
3.00
6.72
7.28
1.98
11.17
5.32
8.47
8.21
0.98
9.00
8.09
9.08
.05
11.43
12.19
12.92
10.06
6.10
2.26
5.97
7.62
7.89
10.33
7.89
Equal
Equal
N/A***
Equal
Equal
Equal
N/A***
Equal
Equal
N/A***
Equal
Equal
Unequal
Equal
Equal
Equal
Unequal
N/A***
Equal
N/A***
Unequal
Equal
Equal
Equal
Equal
Equal
Unequal
Unequal
Equal
Equal
Equal
Equal
N/A***
N/A***
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Median
Exit Gas
Velocity
for SIC
code
7.84
7.95
7.95
8.31
8.80
8.80
8.87
8.34
8.93
7.25
9.04
5.00
8.44
7.62
7.65
8.84
8.90
5.06
10.47
4.83
8.17
8.75
8.47
15.01
8.87
9.31
5.58
9.17
10.76
11.89
11.10
9.72
9.75
11.49
7.62
7.62
7.90
7.62
8.10
7.95
8.31
Number of Number of TRI
Stacks Facilities Using
for SIC Median Exit Gas
code Velocity of their SIC
62
30
11
30
49
45
4
340
218
1
74
47
972
131
143
475
26
13
8
8
392
227
109
7
77
9
10
3368
5351
2175
181
2920
66
9
778
461
120
197
348
151
197
code**
10
21
387
144
481
159
127
See notes at end of table.
32
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
SIC 374
SIC 3743
SIC 375
SIC 3751
SIC 376
SIC 3761
SIC 3764
SIC 3769
SIC 379
SIC 3792
SIC 3795
SIC 3799
SIC 38
SIC 381
SIC 3811
SIC 3812
SIC 382
SIC 3821
SIC 3822
SIC 3823
SIC 3824
SIC 3825
SIC 3826
SIC 3827
SIC 3829
SIC 384
SIC 3841
SIC 3842
SIC 3843
SIC 3844
SIC 3845
SIC 385
SIC 3851
SIC 386
SIC 3861
SIC 387
SIC 3873
TRI
Chemicals
Number of
Stacks
140
140
31
31
95
65
27
3
62
20
23
19
851 i.
251
251
153
10
27
26
7
25
34
7
17
147
94
28
7
13
5
14
14
283
283
3
3
Median
(mis)
9.81
9.81
8.31
8.31
10.44
11.49
3.66
8.90
11.10
11.49
9.00
13.32
3.00
6.71
6.71
6.22
7.53
7.95
4.42
6.00
7.10
6.68
4.00
5.07
8.03
8.07
5.78
5.74
6.71
10.67
6.92
6.92
9.30
9.30
14.54
14.54
Non-TRI
Chemicals
Number of
Stacks
59
59
20
20
34
23
11
39
1
8
30
203 i.
16
1
15
58
3
11
4
1
27
8
4
66
35
8
16
6
1
9
9
47
47
7
7
Median
(mis)
10.97
10.97
8.05
8.05
4.00
4.00
8.31
16.15
36.27
10.00
16.15
3.00
7.03
15.67
6.89
3.00
3.00
5.96
3.60
6.61
0.61
13.31
4.00
8.31
8.31
11.54
8.58
4.21
11.89
8.00
8.00
9.18
9.18
135.33
135.33
Equal
Stack
Pop.
Means? *
Equal
Equal
Equal
Equal
Equal
Equal
Equal
N/A***
Equal
Unequal
Equal
Equal
Equal
Equal
N/A***
Equal
Equal
Equal
Equal
Equal
N/A***
Unequal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Unequal
Unequal
Median
Exit Gas
Velocity
for SIC
code
10.00
10.00
8.26
8.26
8.90
9.40
5.47
8.90
11.49
11.49
9.66
16.15
8.00
6.74
15.67
6.72
5.64
5.74
7.61
4.26
6.00
7.10
3.08
4.00
5.00
8.10
8.31
7.12
8.26
5.21
10.67
8.00
8.00
9.18
9.18
14.54
14.54
Number of
Stacks
for SIC
code
199
199
51
51
129
88
38
3
101
20
31
49
1054
267
1
266
211
13
38
30
7
25
61
7
21
213
129
36
23
19
5
23
23
330
330
3
3
Number of TRI
Facilities Using
Median Exit Gas
Velocity of their SIC
code**
28
23
46
13
62
81
11
34
See notes at end of table.
33
-------
Table A-2
Summary of Exit Gas Velocity by SIC Code
SIC Code
SIC 39
SIC 391
SIC
SIC
SIC
3911
3914
3915
TRI
Chemicals
Number of
Stacks
537
22
4
17
1
Median
(mis)
9.20
8.
7.
8.
8.
50
51
90
10
Non-TRI
Chemicals
Number of
Stacks
181 !
1
1
Median
(mis)
3.00
11.26
11.26
Equal
Stack
Pop.
Means? *
Equal
Equal
N/A***
Unequal
N/A***
Median
Exit Gas
Velocity
for SIC
code
8.90
8.90
7.51
8.90
8.10
Number of
Stacks
for SIC
code
718
23
4
17
1
SIC 393
SIC 3931
SIC 394
SIC 3942
SIC 3944
SIC 3949
SIC 395
SIC 3951
SIC 3952
SIC 3955
SIC 396
SIC 3961
SIC 3965
SIC 399
SIC 3991
SIC 3993
SIC 3995
SIC 3996
SIC 3999
35
109
48
18
35
3
46
60
7
29
12
10
305
82
65
16
134
7.77
7.77
9.18
10.76
10.30
9.13
8.63
8.27
8.00
9.79
9.21
10.74
8.90
10.18
9.31
11.04
10.78
11.00
8.50
9.18
9.18
49
1
43
5
15
3
7
5
5
2
3
103
6
17
4
20
56
8.31
5.61
8.60
2.19
9.08
8.31
9.08
9.18
2.41
4.75
2.41
6.43
7.25
3.00
1.80
7.50
7.65
Equal
Equal
Equal
Unequal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
Equal
8.08
8.08
8.60
10.76
8.60
8.10
8.66
8.31
8.54
9.18
8.90
9.95
8.90
9.04
8.08
9.72
10.18
8.00
8.34
43
158
63
23
408
Number of TRI
Facilities Using
Median Exit Gas
Velocity of their SIC
code**
14
43
3
89
65
10
36
17
10
13
14
99
69
36
190
13
46
14
18
123
*ls mean exit gas velocity of TRI chemical emitting stacks equal to mean exit gas velocity of non-TRI chemical emitting stacks? If
unequal, use data from stacks emitting TRI chemicals.
**Approximately 91% of TRI facilities use exit gas velocities based on their 3-digit SIC codes.
***Stack exit gas velocity data unavailable for one or both both stack categories (emitting TRI chemicals and emitting only non-TRI
chemicals).
See notes at end of table.
34
------- |