United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park, NC 27711
EPA-454/B-94-023
(Revises EPA-450/4-90-013)
July 1994
Air
& EPA
USER'S GUIDE TO TSCREEN
A Model for Screening Toxic Air
Pollutant Concentrations (Revised)
-------
EPA-454/B-94-023
(Revises EPA-450/4-90-013)
July 1994
USER'S GUIDE
TO
TSCREEN
A Model for Screening Toxic Air
Pollutant Concentrations
(Revised)
Office of Air Quality Planning and Standards
Office of Air and Radiation
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
July 1994
-------
This report has been reviewed by the Office of Air Quality
Planning and Standards, US EPA, and has been approved for
publication. Mention of trade names or commercial products is
not intended to constitute endorsement or recommendation for use.
Copies of this report are available, for a fee, from the National
Technical Services, 5285 Port Royal Road, Springfield, VA 22161.
11
-------
PREFACE
This revised document illustrates how to setup and use the
TSCREEN model. The release scenarios and methods in TSCREEN are
described in "Workbook of Screening Techniques for Assessing
Impacts of Toxic Air Pollutants (Revised)", EPA-454/R-92-024.
111
-------
ACKNOWLEDGEMENTS
The report was prepared by Pacific Environmental Services,
Inc., under EPA Contract No. 68D30032, with Mr. Jawad S. Touma as
the Work Assignment Manager.
IV
-------
CONTENTS
1. Introduction 1
2. Getting Started 1
3. Example Scenario 4
4. Scenario Selection 19
5. Determining Maximum Short-Term Ground Level
Concentration 21
6. Enter/Edit Scenario Data 21
7. Help System 30
8. Error Handling 34
9. Backing Up Data 35
10. Notes on Compiling the Source Code 36
11. References 37
v
-------
1. Introduction
To correctly analyze toxic emissions and their subsequent
dispersion from one of many different types of possible releases,
the computer program TSCREEN, A Model for Screening Toxic Air
Pollutant Concentrations, should be used in conjunction with the
"Workbook of Screening Techniques for Assessing Impacts of Toxic
Air Pollutants (Revised)" (EPA, 1992a). With the use of these
tools one can determine the type of release and the steps to be
followed to simulate the release via an applicable computer
model. Then, the dispersion characteristics and pollutant
concentrations of the resulting plume can be calculated. The air
toxics dispersion screening models imbedded in TSCREEN that are
used for the various scenarios are SCREEN2, RVD, PUFF, and the
Britter-McQuaid model. Using TSCREEN, a particular release
scenario is selected via input parameters, and TSCREEN
automatically selects and executes the appropriate dispersion
model to simulate that scenario. The model to be used and the
worst case meteorological conditions are automatically selected
based on criteria given in the workbook. TSCREEN has a front-end
control program to the models that also provides, by use of
interactive menus and data entry screen, the same steps as the
workbook. The correct release scenario and associated
characteristics of a toxic emissions release are selected with
the help of on-screen text and graphics and data input is
performed in a full-screen edit mode. TSCREEN saves the input
data for each release scenario to a file that can be retrieved
and later edited or executed. TSCREEN also provides a method of
easily viewing and saving the modeling results for each modeled
scenario.
2. Getting Started
Hardware Requirements
TSCREEN is an IBM PC-based software application written and
compiled in FoxPro™, a software application development system,
Microsoft™ C Version 5.1, Microsoft™ FORTRAN, and BASIC. The
program requires 500 kilobytes (KB) of free Random Access Memory
(RAM). Although TSCREEN may operate with certain memory resident
programs installed, no attempt has been made to test its
operation against all memory resident programs available today.
If problems occur while TSCREEN and memory resident programs are
running simultaneously, try removing the memory resident programs
from memory and re-executing TSCREEN. The TSCREEN program files
occupy about 2.2 megabytes (MB) of disk space. As data from
scenario runs are saved, the hard disk space needed will
increase. To install TSCREEN on hard disk systems, make sure
there is at least 2.5 MB of free disk space available to load and
execute the program. The time required to run the dispersion
models will be greatly reduced if the computer has a math co-
-------
processor.
The computer running TSCREEN must be booted with the CONFIG.SYS
file in the root directory of the boot up disk containing the
following parameters:
Files = 30
Buffers = 22
If the CONFIG.SYS file already has these statements with higher
values assigned, then no modification is necessary, otherwise
either add the needed statements or increase their value to that
of the example and reboot the computer.
Software requirements
The files required to run TSCREEN are as follows:
BMTS.EXE - The Britter & McQuaid model
CHEMBASE.DBF - The chemical database
CHEMBASE.IDX - The chemical database index file
DISPLAY.DBF - File used to display file lists
ERHANDLE.EXE - The error handling program
ERMSG.DAT - Error message file
FOXSWAP.COM - FoxPro memory management program
FOXUSER.DBF - FoxPro database
FOXPRO.ESL - FoxPro run-time library
FOXPRO.ESO - FoxPro run-time library
FOXUSER.FPT - FoxPro database
GRAPH.EXE - The graphics generation program
OLDRUNS.DBF - Database that contains previously entered data
OUTPUT.DBF - File used to display model output
PIPERES.EXE - Program that performs calculations for the
scenarios involving gas leaks from a pipe attached to a reservoir
PUFFTS.EXE - The PUFF model
RVDTS.EXE - The RVD model
SCREENTS.EXE - The SCREEN2 model
TSCREEN.EXE - The main program
TSHELP.DBF - The help database
TSHELP.FPT - File containing help text
TSMACRO.FKY - FoxPro macro file
VFONT101.FNT - The graph font file
Installing TSCREEN
Because of the size of the TSCREEN program, TSCREEN is separated
into four separate zipped (compressed) files:
-------
File Size(K)
TSCREEN1.ZIP 520
TSCREEN2.ZIP 175
TSCREEN3.ZIP 378
TSCREEN4.ZIP 181
TSCREEN1.ZIP contains the FoxPro runtime program, FOXPRO.ESO, and
TSCREEN2.ZIP contains the FoxPro runtime program, FOXPRO.ESL, and
the FoxPro memory manager FOXSWAP.COM.
To unzip (decompress) the files, you will need to have a copy of
the PKUNZIP.EXE file, version 2.04g or higher. PKUNZIP.EXE is
available on the Technology Transfer Network's SCRAM Bulletin
Board Systems, along with the TSCREEN model.
Please refer to your DOS manual for the relevant commands for
creating sub-directories and copying files if the following
instructions are unclear.
TSCREEN must be installed on a hard disk in order to run. To
install TSCREEN on a hard disk, check the available disk space
by running the DOS program CHKDSK. To check to see if the DOS
programs are accessible from the PATH setting simply type:
PATH
If the DOS sub-directory or sub-directories containing the DOS
files is listed the type:
CHKDSK
at the hard disk prompt where TSCREEN is to be installed. If
not, read your DOS manual to understand what you have to do to
run CHKDSK. Check to make sure there is at least 2.5 MB of
available disk space. If there is enough free disk space, then
create a TSCREEN sub-directory from the root directory of the
hard drive on which TSCREEN will be installed. The command to
create a TSCREEN sub-directory off the main or root directory is:
CD\
MD TSCREEN
Once the sub-directory is created, insert the first TSCREEN
diskette in the high-density drive of the computer (usually the A
drive on IBM AT-type machines) and copy the files from the
diskette to the sub-directory by typing the command:
COPY A:*.* X:\TSCREEN
where X is the letter designation of the drive which TSCREEN is
3
-------
to be installed (where the sub-directory was created). Repeat
the command above for the other diskettes. Also, copy the
PKUNZIP.EXE file to your TSCREEN sub-directory. While in the
TSCREEN sub-directory,decompress the TSCREEN zip files by typing
following command:
PKUNZIP TSCREEN1.ZIP
Repeat the command for the other three TSCREEN zip files
replacing TSCREEN1.ZIP with the other file names: TSCREEN2.ZIP,
TSCREEN3.ZIP, TSCREEN4.ZIP. Once the files are unzipped
(decompressed), the installation is complete. Type the following
command :
TSCREEN
to start the program.
3. Example Scenario
An example TSCREEN session is demonstrated in this section.
For more information on the scenarios in TSCREEN, see Sections 4
and 5 of this workbook.
Title Screen
Upon starting the program a title screen will appear as shown
in Figure 1.
-------
Figure 1. Title Screen
T S C R E E N
A Model for Screening Air Toxic Pollutant Concentrations
(Dated 94133) May 1994
For Questions Contact:
Jawad S. Touma, Project Officer
US EPA, OAQPS, TSD (MD - 14)
Source Receptor Analysis Branch
Research Triangle Park, NC 27711
(919) 541-5381
Developed by:
Pacific Environmental Services, Inc
5001 So. Miami Blvd, Suite 300
P.O. Box 12077
Research Triangle Park, NC 27709
(919) 941-0333
j
Selection Windows
After the reference pages, the main menu bar appears across
the top of the screen, and a list available keys appears across
the bottom of the screen as shown in Figure 2. From this menu
the user can select:
• File - to retrieve previously entered data, previously
saved model printed output, or previously saved model
graphic output
• Initial Form of Release - to select a form of release and
enter a new scenario
• Chemical Database - to view or edit the Chemical Database
• Quit - to exit TSCREEN.
Figure 2. Main Menu
File
Initial Form of Release
Chemical Database
Quit
Help /Scrol 1 Vertical Menus <-<->/<-->Scrol 1 Horizontal Menu
/Letter=Select Menu Item Exit Current Menu Exit All Menus
-------
Menu selections in TSCREEN can be made by clicking a mouse,
by moving the highlight bar with the arrow keys and pressing
, or by pressing the letter of a menu item that is a
different color. To enter data for this scenario, select
'Initial Form of Release' from the menu bar. The pull-down menu
shown in Figure 3 will appear.
Figure 3. Initial Form of Release
File
Initial Form of Release
- Initial Form of Release
Chemical Database
Quit
Participate Matter Release Type
Gaseous Release Type
Liquid Release Type
Superfund Release Type
Help /Scrol 1 Vertical Menus <-<->/<-->Scrol 1 Horizontal Menu
/Letter=Select Menu Item Exit Current Menu Exit All Menus
TSCREEN has help available at each point in the system,
activated by pressing the key. Even the selection windows
have help pages associated with them. An example of pressing the
key from the first menu item in the 'Initial Form of
Release' menu is shown in Figure 4. (See Section 7 for a
detailed discussion on the use of the help system.)
-------
Figure 4. Help Window
File Initial Form of Release Chemical Database Quit
Help
« Topics »
< Next >
< Previous >
< Look Up >
See Also
Particulate Matter Release Type
A Particulate Matter type release is a release of any solid
material such as particulates, dust, or ash.
See Also: Release Definition
Help /Scrol 1 Vertical Menus <-<->/<-->Scrol 1 Horizontal Menu
/Letter=Select Menu Item Exit Current Menu Exit All Menus
Next select 'Particulate Matter Release Type' from the
'Initial Form of Release' menu. Then the menu in Figure 5 will
appear.
Figure 5. Particulate Matter Release Type Menu
Initial Form of Release Chemical Database Quit
— Initial Form of Release ,
File
Particulate Matter Release Typej
Ga | Particulate Matter Release Type
Li
Su
Workbook Scenario
Stacks,Vents - 1.1
Fugitive/Windblown Dust Emissions - 1.2
Ducting/Connector Failures - 1.3
Help /Scrol 1 Vertical Menus <-<->/<-->Scrol 1 Horizontal Menu
/Letter=Select Menu Item Exit Current Menu Exit All Menus
The second menu of release types that appears lists only the
scenarios specific to the Initial Form of Release selected from
the first selection menu (See Section 4 for a complete list of
the scenario selection menus). The user can return to previous
menus or data entry windows by pressing the key. Pressing
from a menu item or from the data entry windows that follow
7
-------
will cause the user to return to the main menu bar.
Data Entry Screens
Once the scenario has been selected, unique data entry
screens will appear for that scenario. These screens will guide
the user through calculations that will select the appropriate
dispersion model based on the data entered. For example, some of
the screens calculate gas densities and others help calculate
emission rates. Data entry screens for this example are shown in
Figures 6 through 8. Note that in this example there is no
scenario input section since the scenario has already been
determined. Thus, the user is taken directly to the model input
section.
Figure 6. Data Entry Screen
i Continuous Particulate Releases from Stacks, Vents - Scenario 1.1 ,
Based on user input, SCREEN2 model has been selected.
SCREEN2 MODEL INPUTS - Page 1 of 7
Enter a unique title for this data's model run:
Particulate Stack Release
RELEASE PARAMETERS
Emission Rate (Qm) -> 9.3E-4 g/s
Exit Velocity (ExitV)-> 17.8 m/s
Release Height above Ground (Hs) -> 16 m
Diameter at Release Point (D) -> .15 m
Temperature of the Material Released (Ts) -> 298 °K
AMBIENT PARAMETER
Ambient Temperature (Ta) -> 298 °K
Edit Previous Screen Next Screen Abort
Figure 7. Data Entry Screen
Continuous Particulate Releases from Stacks, Vents - Scenario 1.1
SCREEN2 MODEL INPUTS - Page 2 of 7
BUILDING PARAMETERS
Building Height (enter 0 if no building) -> 19 m
Building Minimum Horizontal Dimension -> 19 m
Building Maximum Horizontal Dimension -> 19 m
URBAN/RURAL CLASSIFICATION
Enter U for Urban - R for Rural -> R
FENCELINE DISTANCE
Enter the distance from the base of the stack
to the plant fenceline -> 100 m
-------
Help Calculator Previous Screen Abort
I 1
Figure 8. Data Entry Screen
Continuous Particulate Releases from Stacks, Vents - Scenario 1.1
SCREEN2 MODEL INPUTS - Page 3 of 7
TERRAIN TYPE
Is this a FLAT or SIMPLE TERRAIN evaluation (Y/N) -> Y
SIMPLE TERRAIN
Are receptors above stack-base (Y/N) -> N
FLAT TERRAIN
Do you have specific locations where you would like
pollutant concentrations to be calculated (Y/N) -> Y
Do you have receptors above ground level
(i.e. Flag Pole Receptors) (Y/N) -> N
Edit Previous Screen Next Screen Abort
Based on user input, the SCREEN2 model has been selected
with Flat terrain only. Note that the program automatically
calculates concentrations for many receptors. If the user
selects "Y" to enter discrete receptors, pressing will
advance TSCREEN to the next page (see Figure 9) and allow the
user to enter specified distances of interest that will be added
to the automatic receptors.
If the user enters "N" for discrete receptors, SCREEN2 is
executed with only the automated receptor distances, which extend
from the fenceline distance out to 50,000 meters.
Figure 9. Data Entry Screen for Discrete Receptors
Continuous Particulate Releases from Stacks, Vents - Scenario 1.1
SCREEN2 MODEL INPUTS - Page 4 of 7
RECEPTOR LOCATIONS: Enter (up to 30) distances from
the source at which concentrations should be calculated.
Enter a blank after the last distance to stop input.
Distance from Distance from Distance from
source (meters) source (meters) source (meters)
1 100 fence 11 21
2 12 22
3 13 23
4 14 24
5 15 25
-------
6
7
8
9
10
16
17
18
19
20
26
27
28
29
30
Edit
Previous Screen
Run Model
Abort
In Figure 9, the first distance is the fenceline distance
specified on the previous page. It will appear automatically.
All subsequent distances entered must be greater than the
fenceline. will execute the SCREEN2 model. As the program
executes the user is shown what percent of the program is
complete.
Parts Per Million
After the SCREEN2 model has run, the data entry window in
Figure 10 appears. The user can choose to have the maximum
concentrations displayed in parts per million (ppm) in addition
to ug/m3. "N" is entered in this example. If "Y" had been
entered the user would then be required to enter the appropriate
molecular weight and the concentration in ppm would be calculated
using the following formula:
concentration(ppm) = concentration(ug/m
where: Mw = molecular weight (g/g-mole)
Figure 10. Parts Per Million
3, 0.0245
M.
Do you want maximum concentrations
in parts per million (ppm) (Y/N) ->
Help Up Down Exit/No ppm calculation
Averaging Times
The default averaging time in the SCREEN2 model is 1 hour.
If the SCREEN2 model is used, the maximum concentration can be
calculated for additional averaging times selected from the menu
shown in Figure 11. Since we are only interested in 1-hour
averages for this example, we will not select any of the
10
-------
additional averaging periods.
Figure 11. Averaging Times
Averaging Time
The default averaging time is 1 hour
select one or more from below. . .
15 Minutes
30 Minutes
3 Hours
8 Hours
24 Hours
Annual
Up Down
/ Mark/Unmark Time
Select Marked Times
Abort Without Selection
Averaging times can be selected by pressing the key
or the Space bar to mark the averaging time with an asterisk.
After all of the desired averaging times have been selected,
press to proceed. If additional averaging times were
selected, the estimated concentrations for the new averaging
times would appear at the end of the model output.
Model Output
When the model has completed execution, the output will be
presented on the screen. A portion of the model's output as it
would appear on the screen is shown in Figure 12. A complete
listing of the model's output is shown in Figure 13. The user
can scroll through the output with the / or /
keys. A complete list of the SCREEN2 model output is shown in
Figure 13. The user can scroll through the output using the
various keys shown. The user can also graph, print or save the
entire output to a file. The instructions for the keys used in
viewing the model output are explained in Section 6 of this
appendix.
The SCREEN2 model output begins with the time and date that
the model was run. Next, there is the model name and version
number. Following the model name is the run's title and the user
input. Next, the output contains a summary of results showing
the maximum concentration and the distance to the maximum. Next,
there is a list of concentrations for SCREEN2's automated
distances. Finally, there is a listing of the cavity
concentrations since the effects of building downwash are being
considered. If additional averaging times had been selected,
these results would appear at the end of the model output.
11
-------
Figure 12. Model Output on the Screen
Continuous Particulate Releases from Stacks and Vents - Scenario 1.1
05-13-94
15:47:05
*** SCREEN2 MODEL RUN ***
*** VERSION DATED 92245 ***
Particulate Stack Release
SIMPLE TERRAIN INPUTS:
SOURCE TYPE = POINT
EMISSION RATE (G/S) = .930000E-03
STACK HEIGHT (M) = 16.0000
STK INSIDE DIAM (M) = .1500
STK EXIT VELOCITY (M/S)= 17.8000
STK GAS EXIT TEMP (K) = 298.0000
AMBIENT AIR TEMP (K) = 298.0000
RECEPTOR HEIGHT (M) = .0000
URBAN/RURAL OPTION = RURAL
, <«->, <-">, Alt, Alt, , , ,
Graph Print Save to File Exit
Figure 13. Complete Model Output
05/13/94
15:47:05
*** SCREEN2 MODEL RUN ***
*** VERSION DATED 92245 ***
Particulate Stack Release
SIMPLE TERRAIN INPUTS:
SOURCE TYPE = POINT
EMISSION RATE (G/S) = .930000E-03
STACK HEIGHT (M) = 16.0000
STK INSIDE DIAM (M) = .1500
STK EXIT VELOCITY (M/S)= 17.8000
STK GAS EXIT TEMP (K) = 298.0000
AMBIENT AIR TEMP (K) = 293.0000
RECEPTOR HEIGHT (M) = .0000
URBAN/RURAL OPTION = RURAL
BUILDING HEIGHT (M) = 19.0000
MIN HORIZ BLDG DIM (M) = 19.0000
MAX HORIZ BLDG DIM (M) = 19.0000
SUMMARY OF SCREEN MODEL RESULTS ***
12
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CALCULATION
PROCEDURE
SIMPLE TERRAIN
BUILDING CAVITY-1
BUILDING CAVITY-2
MAX CONC
(UG/M**3)
1.241
1.717
1.717
DIST TO
MAX (M)
100.
28.
28.
TERRAIN
HT (M)
0.
(DIST = CAVITY LENGTH)
(DIST = CAVITY LENGTH)
** REMEMBER TO INCLUDE BACKGROUND CONCENTRATIONS **
***************************************************
BUOY. FLUX = .016 M**4/S**3; MOM. FLUX =
*** FULL METEOROLOGY ***
**********************************
*** SCREEN AUTOMATED DISTANCES ***
**********************************
1.752 M**4/S**2.
*** TERRAIN HEIGHT OF
0. M ABOVE STACK BASE USED FOR FOLLOWING DISTANCES
DIST
(M)
100.
200.
300.
400.
500.
600.
700.
800.
900.
1000.
1100.
1200.
1300.
1400.
1500.
1600.
1700.
1800.
1900.
2000.
2100.
2200.
2300.
2400.
2500.
2600.
2700.
2800.
2900.
3000.
3500.
4000.
CONC
(UG/M**3
1.241
.6341
.4117
.3084
.2712
.2417
.2177
.1977
.1809
.1665
.1540
.1432
.1336
.1273
.1197
.1130
.1069
.1014
.9636E-
.9177E-
.8756E-
.8368E-
.8011E-
.7679E-
.7371E-
.7085E-
.6818E-
.6568E-
.6334E-
.6115E-
.5194E-
.4493E-
)
01
01
01
01
01
01
01
01
01
01
01
01
01
01
STAB
4
4
4
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
U10M
(M/S)
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
USTK
(M/S)
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1
1
1
1
1
1
1
1
1
1
1
1
1
1
.1
.1
.1
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
MIX HT
(M)
320.
320.
320.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
13
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
PLUME
HT (M)
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
,18
,18
,18
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
,09
SIGMA
Y (M)
8
15
22
25
28
32
35
38
41
44
47
50
53
56
59
61
64
67
70
73
76
79
81
84
87
90
93
95
98
101
114
128
.20
.56
.61
.71
.87
.00
.10
.17
.21
.23
.22
.20
.15
.09
.01
.92
.81
.69
.55
.40
.23
.06
.87
.67
.46
.24
.01
.77
.52
.26
.85
.24
SIGMA
Z (M)
14
20
23
22
22
23
23
24
24
25
25
26
26
26
27
27
27
28
28
29
29
29
30
30
30
31
31
32
32
32
34
35
.30
.44
.28
.13
.70
.26
.81
.35
.88
.40
.91
.41
.91
.68
.15
.56
.96
.36
.75
.14
.52
.89
.26
.62
.98
.34
.69
.03
.37
.71
.34
.88
DWASH
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
-------
4500.
5000.
5500.
6000.
6500.
7000.
7500.
8000.
8500.
9000.
9500.
10000.
15000.
20000.
25000.
30000.
40000.
50000.
.3943E-01
.3502E-01
.3188E-01
.2885E-01
.2633E-01
.2418E-01
.2232E-01
.2070E-01
.1928E-01
.1803E-01
.1691E-01
.1591E-01
.9954E-02
.7132E-02
.5500E-02
.4464E-02
.3230E-02
.2513E-02
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
10000.
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
,0
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
16.
,09
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,09
,09
,09
,09
,09
,09
,09
,09
141
154
167
180
192
205
218
230
242
254
267
279
396
508
617
722
927
1124
.46
.52
.45
.25
.94
.52
.00
.38
.67
.89
.02
.08
.20
.44
.02
.68
.03
.00
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
55.
60.
65.
68.
74.
79.
,35
,76
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,64
,78
,87
,93
,95
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,91
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,75
,58
,87
,35
,96
,59
,28
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
MAXIMUM 1-HR CONCENTRATION AT OR BEYOND
100. 1.241 4 1.0 1.1
100. M:
320.0 16.18
S.20 14.30
SS
DIST = DISTANCE FROM THE SOURCE
CONC = MAXIMUM GROUND LEVEL CONCENTRATION
STAB = ATMOSPHERIC STABILITY CLASS (1=A, 2=
U10M = WIND SPEED AT THE 10-M LEVEL
USTK = WIND SPEED AT STACK HEIGHT
MIX HT = MIXING HEIGHT
PLUME HT= PLUME CENTERLINE HEIGHT
SIGMA Y = LATERAL DISPERSION PARAMETER
SIGMA Z = VERTICAL DISPERSION PARAMETER
DWASH = BUILDING DOWNWASH:
DWASH= MEANS NO CALC MADE (CONC = 0.0)
DWASH=NO MEANS NO BUILDING DOWNWASH USED
DWASH=HS MEANS HUBER-SNYDER DOWNWASH USED
DWASH=SS MEANS SCHULMAN-SCI RE DOWNWASH USED
DWASH=NA MEANS DOWNWASH NOT APPLICABLE, X<3*LB
3=C, 4=D, 5=E, 6=F)
SCREEN DISCRETE DISTANCES ***
*** TERRAIN HEIGHT OF
0. M ABOVE STACK BASE USED FOR FOLLOWING DISTANCES
DIST CONC U10M USTK MIX HT PLUME SIGMA SIGMA
(M) (UG/M**3) STAB (M/S) (M/S) (M) HT (M) Y (M) Z (M) DWASH
100. 1.241
1.1 320.0 16.18
S.20 14.30
SS
DWASH= MEANS NO CALC MADE (CONC = 0.0)
DWASH=NO MEANS NO BUILDING DOWNWASH USED
DWASH=HS MEANS HUBER-SNYDER DOWNWASH USED
DWASH=SS MEANS SCHULMAN-SCI RE DOWNWASH USED
DWASH=NA MEANS DOWNWASH NOT APPLICABLE, X<3*LB
*** CAVITY CALCULATION - 1 ***
CONC (UG/M**3) = 1.717
CRIT WS §10M (M/S) = 1.00
CRIT WS § HS (M/S) = 1.10
*** CAVITY CALCULATION - 2 ***
CONC (UG/M**3) = 1.717
CRIT WS §10M (M/S) = 1.00
CRIT WS § HS (M/S) = 1.10
14
-------
DILUTION WS (M/S) = 1.00
CAVITY HT (M) = 27.28
CAVITY LENGTH (M) = 27.97
ALONGWIND DIM (M) = 19.00
DILUTION WS (M/S) = 1.00
CAVITY HT (M) = 27.28
CAVITY LENGTH (M) = 27.97
ALONGWIND DIM (M) = 19.00
END OF SCREEN MODEL OUTPUT ***
Save to File
If the 'Save to File' option is selected, the user will be
asked to enter a file name of no more than eight characters in
the data entry window shown in Figure 13. To view previously
saved model output at a later time, select 'File' from the main
menu bar. Then select 'Access Model Printer Output' and a list
of files containing previously saved model output will appear as
shown in Figure 14. The menu in Figure 14 also contains 'Access
Data from Previous Scenario' which allows the user to retrieve
data from previously run scenarios by selecting the scenario's
title from a list. The other menu item is 'Access Model Graphic
Output' which allows the user the retrieve a graph from a list of
files containing previously saved graphs.
Figure 13. Save to File
Continuous Particulate Releases from Stacks, Vents - Scenario 1.1
05-13-94
15:47:05
*** SCREEN2 MODEL RUN ***
*** VERSION DATED 92245 ***
Particulate Stack Release
SIM
Enter a unique file name for this model output ->
Exit/ No Save
.RPT
STK GAS EXIT TEMP (K) = 298.0000
AMBIENT AIR TEMP (K) = 298.0000
RECEPTOR HEIGHT (M) = .0000
URBAN/RURAL OPTION = RURAL
Graph
, Alt,
Print
, , ,
Save to File Exit
15
-------
Figure 14. Retrieve Model Output
File Initial Form of Release
File ,
Chemical Database
Quit
Access Data from Previous Scenario)
Access Model Printer Output j
Acce | Model Printed Output
FAX RPT
RVD45 RPT
S411ALL RPT
SCRNALL RPT
Select Highlighted Run Exit/No Select
Up Down Up One Screen Down One Screen
Top Bottom Delete File
Press any other key to find a file beginning with that character
Graph
If the 'Graph' option in Figure 12 is selected, a plot of
the concentrations vs distances will be drawn. The following
window will appear first as shown in Figure 15.
Figure 15. Distance for Graph
Graphics - Distance
Enter Maximum Distance for Graph -> 5 Km
Graph is for Simple terrain only.
Use 50.00 Km
In this example 5 km has been selected. If the key
had been pressed, the graph would be plotted from 100 m to 50.00
km downwind. Once a distance has been specified, the following
menu will appear as shown in Figure 16 from which you can select
an output device for the graph.
16
-------
Figure 16. Graphic Output Menu
i Graphics - Main Menu ,
Screen
EPSON FX, MX
EPSON FX, MX
EPSON LQ
EPSON LQ
NEC Pinwriter
NEC Pinwriter
OKIDATA
OKIDATA
HP LaserJet/DeskJet
HP LaserJet/DeskJet
Draft Qua!ity
High Qua!i ty
Draft Qua!ity
High Qua!ity
Draft Qua!ity
High Qua!i ty
Draft Qua!ity
High Qua!ity
Draft Qua!ity
High Qua!i ty
Hewlett-Packard plotter
Houston Instruments plotter
Change Distance for Graph
Save Graph to File
Exit Graphics
From this menu the output device is selected.
example, the user should select 'Screen'.
For this
Note that if your computer does not have the ability to
display graphics, the option 'Screen' will not be on this menu.
If a printer is selected then the output device is assumed to be
LPT1. If a plotter if selected then the output device is assumed
to be COM1. For more information on redirection of output, the
user should consult the DOS manual. Before printing the graph,
be sure that the printer is connected and on-line. After
exiting from the Graphics menu the user is returned to the model
output. Consult your printer's user's manual to determine which
of the above printers is compatible with your printer.
If 'Save Graph to File' is chosen from the bottom of the menu
shown in Figure 16, then the data entry window in Figure 17 will
appear. Enter a filename of not more than eight characters. If
you choose to save the graph's data, then the graph can be
generated at a later time. To view a previously saved graph at a
later time, select 'File' from the main menu bar. Then select
'Access Model Graphic Output' and a list of previously saved
graphs will appear as shown in Figure 18.
17
-------
Figure 17. Save Graph
Graphics - Save
Enter a unique file name for this graphic output ->
.GRF
Exit/ No Save
Figure 18. Retrieve Graph
File Initial Form of Release
File
Chemical Database
Quit
Access Data from Previous Scenario
Access Model Printer Output
Access Model Graphic Output
Model Graphic Output
SCRNP2 GRF
PUFF1 GRF
SCRNP1 GRF
SCRNP6 GRF
Select Highlighted Run Exit/No Select
Up Down Up One Screen Down One Screen
Top Bottom Delete File
Press any other key to find a file beginning with that character
If you are using a plotter, the DOS MODE command should be
used to configure your computer's communications port to
correctly match the communications settings of the plotter.
Otherwise, you will probably not get any output from the plotter.
For example, the Hewlett-Packard 7475A plotter has a set of
switches located on the back of the plotter which allows you to
set the communications parameters. A common setting for these
switches is shown in Figure 19.
18
-------
Figure 19. Switch Configuration
S2 SI Y US A3 B4 B3 B2 Bl
• • • 1
The DOS MODE command which should be used to correspond to these
settings is:
MODE COM1:96,E,7,1
This command sets serial port 1 (COM1) to 9600 baud with even
parity, seven data bits, and 1 stop bit.
Each plotter has unique methods of setting the
communications parameters. You should use the plotter's manual
for the plotter configuration in conjunction with your DOS
manual's explanation on the use of the MODE command to be certain
that your computer and plotter are configured correctly.
An example of the graph whose descriptive title was saved as
"Particulate Stack Release" in the Data Entry Screen depicted in
Figure 6 is shown in Figure 20.
19
-------
Figure 20. Graphic of Concentration vs Distance
I ou 1 ate S"tacK Re
DISTANCE (Km)
Maximum concentration 1,244E+000 ug/cubic re at 0, 100 Km (Automated Distances)
Press any key to continue
Exiting TSCREEN
After exiting the graph, the user returns to the model
output viewing window shown in Figure 13. After pressing
from this window the user will return to the main menu bar shown
in Figure 2. At this point the user can exit TSCREEN by
selecting 'Quit' from the main menu bar as shown in Figure 21.
Figure 21. Quit Menu
File Initial Form of Release
Chemical Database Quit
Quit TSCREEN ?
Yes
No
Help /Scrol 1 Vertical Menus <-<->/<-->Scrol 1 Horizontal Menu
/Letter=Select Menu Item Exit Current Menu Exit All Menus
20
-------
4.
Scenario Selection
Twenty-four of most prevalent release scenarios were
selected for TSCREEN and are grouped according to four
categories: particulate matter, gases, liquids, and releases from
Superfund sites.
To select a scenario in TSCREEN, first select 'Initial Form
of Release' from the menu bar across the top of the screen. The
'Initial Form of Release' Menu as shown in Figure 22 will then
appear.
Figure 22. Initial Form of Release Menu
File
L
Initial Form of Release Chemical Database
Initial Form of Release ,
Particulate Matter Release Type
Gaseous Release Type
Liquid Release Type
Superfund Release Type
Quit
Help /Scrol 1 Vertical Menus <-<->/<-->Scrol 1 Horizontal Menu
/Letter=Select Menu Item Exit Current Menu Exit All Menus
If the release is any solid material such as particulates,
dust, or ash, then 'Particulate Matter Release Type' should be
selected. The menu in Figure 23 will appear listing particulate
scenarios.
Figure 23. Particulate Matter Release Type Menu
File Initial Form of Release Chemical Database
Initial Form of Release ,
Particulate Matter Release Typej
Ga | Particulate Matter Release Type —
Li '
Su
Quit
Stacks,Vents
Fugitive/Windblown Dust Emissions
Ducting/Connector Failures
Workbook Scenario
- 1.1
- 1.2
- 1.3
Help /Scrol 1 Vertical Menus <-<->/<-->Scrol 1 Horizontal Menu
/Letter=Select Menu Item Exit Current Menu Exit All Menus
If the release is any matter in vapor form such as sulfur
dioxide, volatile organics, etc, then the user should select
21
-------
'Gaseous Release Type'. The menu in Figure 24 will appear
listing gaseous scenarios. Two scenario numbers for one menu
choice indicates that there is both a continuous (first number)
and instantaneous (second number) scenario.
Figure 24. Gaseous Release Type Menu
File Initial Form of Release Chemical Database
Initial Form of Release ,
Participate Matter Release Typej
Gaseous Release Type j
Li | Gaseous Release Type
Su
Flared Stack Emissions
Stacks, Vents, Conventional Point Sources
Leaks from Reservoir
Leaks from a Pipe Attached to Reservoir
Multiple Fugitive Sources
Land Treatment Facilities
Municipal Solid \Help /Scrol 1 Vertical Menus <-<->/<-->Scrol 1 Horizontal Menu
/Letter=Select Menu Item Exit Current Menu Exit All Menus
If the release is material that may immediately evaporate
(no pooling results) or may pool first and then evaporate, then
the user should select 'Liquid Release Type'. The menu in Figure
25 will appear listing liquid scenarios. Two scenario numbers
for one menu choice indicates that there is both a continuous
(first number) and instantaneous (second number) scenario.
22
-------
Figure 25. Liquid Release Type
File Initial Form of Release Chemical Database Qui
Particulate Matter Release Type
Gaseous Release Type
Liquid Release Type
Su
1 —
Release Type
t
Workbook
Surface Impoundments (Lagoons)
2-Phase Saturated Liquid from Pressurized
2-Phase Subcooled Liquid from Pressurized
High Volatility Liquid Leaks
Low Volatility Liquid Leaks
Storage -
Storage -
Help /Scrol 1 Vertical Menus <-<->/<-->Scrol 1
/Letter=Sel ect Menu Item Exit Current
I
3
3
3
3
3
Scenari o
1
2,
4,
6,
8,
3
3
3
3
3
5
7
9
Horizontal Menu
Menu Exi
t
All Menus
I
If 'Superfund Release Type' is selected then the menu in
Figure 26 will appear listing Superfund scenarios.
Figure 26. Superfund Release Type
File
Initial Form of Release Chemical Database
i Initial Form of Release ,
Particulate Matter Release Type
Gaseous Release Type
Liquid Release Type
Superfund Release Type
— i Superfund Release Type
Workbook Scenario
Quit
Air Stripper
Soil Vapor Extraction
Soil Excavation
Thermal Incineration
(SVE)
L
Help /Scrol 1 Vertical Menus <-<->/<-->Scrol 1 Horizontal Menu
/Letter=Select Menu Item Exit Current Menu Exit All Menus
5. Determining Maximum Short-Term Ground Level Concentration
Maximum short-term ground level concentrations in TSCREEN
are based on three current EPA screening models (SCREEN2, RVD,
and PUFF) that are imbedded in the TSCREEN model and an
implementation of the Britter-McQuaid model. SCREEN2 is a
Gaussian dispersion model applicable to continuous releases of
23
-------
particulate matter and non-reactive, non-dense gases that are
emitted from point, area, volume and flared sources. The SCREEN2
model implements all of the single source short-term procedures
contained in the EPA screening procedures document (EPA, 1992b).
This includes providing estimated maximum ground-level
concentrations and distances to the maximum based on a pre-
selected range of meteorological conditions. In addition,
SCREEN2 has the option of incorporating the effects of building
downwash. The RVD model (EPA, 1989) provides short-term ambient
concentration estimates for screening pollutant sources emitting
denser-than-air gases and aerosols through vertically-directed
releases. The model is based on empirical equations derived from
wind tunnel tests and estimates the maximum ground level
concentration at plume touchdown at up to 30 downwind receptor
locations. The PUFF model (Petersen, 1982) is used where the
release duration is finite but smaller than the travel time
(i.e., an instantaneous release.) This model is based on the
Gaussian instantaneous puff equation and is applicable for
neutrally buoyant non-reactive toxic air releases. The Britter-
McQuaid model is used for continuous and instantaneous denser-
than-air scenarios.
6. Enter/Edit Scenario Data
This section describes the data entry procedures and the
function of various keys.
Data Fields
Data for each scenario is entered in two sections. There is
the scenario input section which contains a unique set of inputs
for each scenario. The user enters this section first and inputs
data. Based on user data, one of the four models is selected by
TSCREEN, and the user proceeds to the model input section. The
inputs for this section are unique for each model although they
are not unique for each scenario. For certain scenarios there is
no unique scenario input section, and the user proceeds directly
to the model input section. Each input section starts with 'Page
1 of. . . '. A typical data entry window for a scenario input
section is shown in Figure 27.
24
-------
Figure 27. Typical Data Entry Window
Flared Stack Emissions - Scenario 2.1
Based on user input, SCREEN2 model has been selected.
SCREEN MODEL INPUTS - Page 1 of 7
Enter a unique title for this data's model run:
RELEASE PARAMETERS
Enter the Emission Rate (Qm), if unknown enter
the boxed variables below to calculate -> g/s
Volume Fraction of Pollutant (Vol) -> I
Material Flow Rate (V) -> cubic m/s
Molecular Weight of Material Released (Mw) -> g/g-mole
Total Heat Release Rate (Hr) -> cal/s
Release Height above Ground (Hs) -> m
Help Calculator Previous Screen Abort
I 1
Commands active while editing data fields include:
- Help on current field
- Calculator
- Return to previous screen
- Abort entry and return to the main menu bar
The keys that can be used for editing while in the highlighted
data entry fields are as follows:
or - toggle insert/overwrite mode (cursor changes
size)
or - delete character at cursor position
<•*-> (left arrow) - move cursor left one character
<->> (right arrow) - move cursor right one character
<<-> (Control key and left arrow) - move cursor left one
word
<->-> (Control key and right arrow) - move cursor right one
word
- move cursor back one character and delete character
- move cursor to beginning of data in field
- move cursor to end of data in field
Valid entry into numeric fields are numbers, minus signs(-), plus
signs(+), a decimal(.), and the letter E or e to stand for
scientific notation (6.02E026 = 6.02e026 = 6.02E+26 = 6.02e+26 =
6.02 x 1026) .
Titles
25
-------
An important data field in TSCREEN for rerunning old
scenarios is the Scenario Title field. This field should contain
a unique title for each run. Several ways to make the title
unique are to give the facility name or add example 1, example 2,
etc, or the date and time to the title. This is helpful when the
user wants to retrieve data from a previously entered scenario
run by selecting 'File' from the main menu bar then selecting
'Access Data from Previous Scenario'. The selection window will
appear allowing the user to view the titles of all previously run
scenarios. A previous scenario may be selected to either run
again or update the data for another run. This window is shown
in Figure 28. The last scenario entered appears at the bottom of
the list.
Figure 28. Previously Entered Scenarios
File
Initial Form
File
of Release
Chemical Database
Quit
Access Data
Acce
Acce
from Previous
Scenari o
— Previous
Scenari o
Johnson Widget Company RunOOl
Dust Ejection Number 2 1/20/92
Cont. Part. Stack Release-Power PI ant-1/20/92
Particulate Stack Release
Select Highlighted Run Exit/No Select
Up Down Up One Screen Down One Screen
Top Bottom Delete Run
Press any other key to find a title beginning with that character
From this window a previous scenario's data can be reloaded
by highlighting that scenario's title and pressing the
key or clicking with the mouse. The 'Initial Form of Release'
menu will appear with the highlighted bar on the form of release
of the selected scenario. By selecting the highlighted bar on
the preselected release type, a second menu will appear with the
appropriate scenario name and number highlighted. By selecting
this scenario, the data entry windows of the scenario are
displayed with the data fields filled with the loaded scenario's
data. Menu selections can be changed at any point, but changing
the selections will cause the loaded data to be lost, and the
user will have to retrieve that scenario's data again from the
menu in Figure 28.
Calculated Fields
26
-------
Some of the data entry screens have fields that can be input
directly or calculated automatically from certain other
parameters. The alternative parameters will be located inside a
box directly below the unknown parameter. In Figure 29, the user
did not know the emission rate; therefore, the data fields in the
box were entered. Once all of the boxed variables were entered,
the emission rate was calculated and displayed. If the screen is
reedited and the calculated field is changed then the other
parameter fields making up the calculated value will be blanked
out. If the emission rate is known it can be entered directly
and the program will automatically skip over the parameter fields
in the box.
Figure 29. Calculated Field Illustration
Flared Stack Emissions - Scenario 2.1
Based on user input, SCREEN2 model has been selected.
SCREEN MODEL INPUTS - Page 1 of 7
Enter a unique title for this data's model run:
Gaseous Release from Flared Source
RELEASE PARAMETERS
Enter the Emission Rate (Qm), if unknown enter
the boxed variables below to calculate
0.917675 g/s
Volume Fraction of Pollutant (Vol) -> .2
Mol ecul ar
Material Flow Rate (V) -> 6.58
Weight of Material Released (Mw) -> 78.1
%
cubic m / s
g/g mole
Total Heat Release Rate (Hr) -> 3.84E7 cal/s
Release Height above Ground (Hs) -> 32 m
Edit
Previous Screen
Next Screen
Abort
End of Screen Action
Once data entry on the screen has been completed, the
program presents the user with a chance to visually review the
data entered on the current screen as shown in Figure 29. The
only active keyboard commands are highlighted at the bottom of
the screen:
- Edit the current screen
- Return to previous screen
- Proceed to next screen
- Abort current scenario and return to main menu bar
Field Sensitive Help
The help facility (see Section 7.) can be accessed by
27
-------
pressing the key from any of the selection menus or data
entry fields. After pressing the key a window with help
text will appear to further define or clarify the current data
entry field. The user can then scroll up or down through the
help text or view help for other data fields using the buttons on
the left side of the help window. An example of a help screen is
shown in Figure 30.
Figure 30. Sample Help Screen
Evaporation from Surface Impoundments (Lagoons)
Help
Emission Rate - Scenario 3.1 II
Scenario 3.1
« Topics »
< Next >
< Previous >
< Look Up >
See Also
Emission rates from well-mixed aqueous waste in surface
impoundments are described in section 4.3.1 in the
workbook. The following is a simplified screening emission
rate estimate based on parameters described in the
workbook:
E = KCoA
where:
E = emission rate
Co = initial concentration of the chemical in the
waste (g/cubic m)
A = area of impoundment (m2)
K = equilibrium constant
Help Calculator Previous Screen Abort
Chemical Look-up Database
The chemical look-up database is a table of chemicals and
their associated parameters that are applicable to TSCREEN.
TSCREEN is initially distributed with only two chemicals. Any
desired chemical and its associated parameters may be added to
suit the specific needs of the user. The chemical database can
be accessed in two ways. First, the chemical database can be
accessed by selecting 'Chemical Database' from the main menu
bar. If this selection is made the menu shown in Figure 31 will
appear.
28
-------
Figure 31. Chemical Database Menu
File
Initial Form of Release
Chemical Database Quit
i Chemical Database ,
jSearch the Database j
JAdd a Chemical to Databasej
Help /Scrol 1 Vertical Menus <-<->/<-->Scrol 1 Horizontal Menu
/Letter=Select Menu Item Exit Current Menu Exit All Menus
To search the chemical database for a specific chemical,
select 'Search the Database' and a scrollable window appears with
a list of the available chemical names as shown in Figure 32.
Figure 32. Chemical Name List
Chemical Name
BENZENE
CHLORINE
Select Highlighted Chemical Exit/No Select
Up Down Up One Screen Down One Screen
Top Bottom
Press key to find a chemical beginning with that character
The chemical names contained in the database will be
displayed in alphabetical order. The highlighted bar can be
moved directly to the first chemical name starting with a certain
letter just by pressing that letter key. The 'Chemical Name'
window will size itself proportionally to the number of chemical
names contained in the database up to the number of chemical
names that can fit on the screen. After a chemical is selected,
the chemical parameters will be displayed.
If 'Search Chemical Database' was selected from the menu in
Figure 31, the Chemical Database parameter window in Figure 33
will appear. If is pressed, the user can edit the data in
any of the fields except the Chemical Name. If is pressed,
the user can delete the chemical that is currently in the window.
If is pressed, the user will return to the chemical list.
29
-------
Figure 33. Chemical Database Parameters
Chemical Data
Chemical Name
Boiling Point
Specific Heat
at Constant
at Constant
Specific Heat
at Constant
at Constant
BENZENE
at Ambient Pressure 351 °K
of Liquid
Pressure J/kg °K
Volume J/kg°K
of Vapor
Pressure J/kg °K
Volume J/kg°K
Molecular Weight 78.12 kg/kmol
Latent Heat of Vaporization 3.938E5 J/kg
Liquid Density 885 kg/cubic
Critical Temperature 562.09 °K
Edit
Delete
Exit View Screen
If 'Add a Chemical to Database' was selected from the menu
in Figure 31, the Chemical Data window in Figure 33 will appear.
A chemical list will not appear. A chemical name must be entered
before any of the other parameters can be entered. If is
pressed, TSCREEN will ask if the new chemical is to be saved.
Then the user will return to the menu in Figure 34.
Figure 34. Chemical Database Parameters for Adding
Chemical Data
Pressure
Volume . .
Chemical Name
Boiling Point at Ambient Pressure.
Specific Heat of Liquid
at Constant
at Constant
Specific Heat of Vapor
at Constant Pressure ....
at Constant Volume
Molecular Weight
Latent Heat of Vaporization
Liquid Den si ty
Critical Temperature
J/kg °K
J/kg °K
J/kg °K
J/kg °K
kg/kmol
J/kg
kg/cubic m
°K
Up
Down
Exit Add Screen
The second way to enter the chemical database is by
accessing help for a data entry field that is a chemical
parameter. If the user enters the chemical database from a data
entry field, a value from the database can be returned to that
field. A pointer ' *•' will appear beside the value that will be
30
-------
returned. For example, if the user were in a molecular weight
input field, the user could press , and help for that field
would appear. After pressing to exit the help window, the
chemical list shown in Figure 32 would appear. The menu shown in
Figure 31 does not appear if the chemical database is accessed
through a data entry field. After the user chooses the desired
chemical, the chemical data entry screen would appear as in
Figure 35. The , , and keys work as described
above when 'Search Chemical Database' was selected from the menu
in Figure 31. Pressing will exit the chemical database
and return the marked value to the data entry field.
Figure 35. Chemical Database Accessed from Data Entry Field
Chemical Data
Chemical Name BENZENE
Boiling Point at Ambient Pressure 351 °K
Specific Heat of Liquid
at Constant Pressure J/kg °K
at Constant Volume J/kg °K
Specific Heat of Vapor
at Constant Pressure J/kg °K
at Constant Volume J/kg °K
Molecular Weight -78.12 kg/kmol
Latent Heat of Vaporization 3.938E5 J/kg
Liquid Density 885 kg/cubic m
Critical Temperature 562.09 °K
Edit Delete Exit/Select Data Exit/No Select
Calculator
When entering data, a calculator is available on-line to
perform any needed calculations. The calculator is accessed by
pressing the key from any data entry field. The results of
a calculation can be passed directly from the calculator to the
entry field by pressing the equals <=> key. While in the
calculator a help screen on the calculator's functions can be
accessed by pressing the key. The calculator has several
built-in functions that include memory clear, memory store,
memory recall, square, square root and n. An example of the
calculator is shown below in Figure 36.
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Figure 36. Calculator
Evaporation from Surface Impoundments (Lagoons) - Scenario 3.1
SOURCE PARAMETE, [ Calculator ] ,
Enter a unique
The Johnson Wid
IMPOUNDMENT TYP
Enter
EMISSION RATE
Enter the Emiss
the box
In
Help
9/s
g / c u b i c m
Abort
Model Output
Upon completing the last screen of data entry for the
scenario, the command is 'Run Model' and not 'Next Screen'
When the key is pressed, the entered data is saved. The
dispersion model then executes. For computers without math co-
processors, the SCREEN2 model will execute for 3 to 10 minutes,
the RVD model for 1 to 5 minutes and the PUFF model for 1 to 5
minutes depending on the data and the computer setup on which
TSCREEN is running. The model output will appear on the screen
in a window as shown in Figure 37.
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Figure 37. Output Window
Continuous Particulate Releases from Stacks, Vents - Scenario 1.1
05-13-94
15:47:05
*** SCREEN2 MODEL RUN ***
*** VERSION DATED 92245 ***
Continuous Particulate Stack Release from Power Plant
SIMPLE TERRAIN INPUTS:
SOURCE TYPE = POINT
EMISSION RATE (G/S) = 1200.00
STACK HEIGHT (M) = 20.0000
STK INSIDE DIAM (M) = 1.5000
STK EXIT VELOCITY (M/S)= 5.0000
STK GAS EXIT TEMP (K) = 400.0000
AMBIENT AIR TEMP (K) = 298.0000
RECEPTOR HEIGHT (M) = .0000
URBAN/RURAL OPTION = RURAL
, <«->, <-">, Alt, Alt, , , ,
Graph Print Save to File Exit
The model output can be scrolled line by line up or down by
pressing the up or down arrow keys. The output can be put into a
continuous scroll up or down by pressing the Alt - up or down
arrow key combinations and stopped by pressing any key. The
output can be scrolled a full screen at a time by pressing the
or keys. By pressing the key the output
display will show the top of the output listing and by pressing
the key the display will show the end of the output
listing.
To get a listing of the output on a printer press the
key. To avoid some common printing problems, before selecting
printed output, make sure that a printer is connected to the
computer, that the printer's power is on, that the printer is on-
line and that there is plenty of paper loaded in the printer. To
save the output data to a file press the key and give a
filename for the output. To get a graph of the concentrations vs
distances press the key.
7. Help System
The help system included with TSCREEN is field sensitive.
As a result, when the key is pressed from a data entry field
or from a menu item, help for that field or menu item will appear
in a help window like the one shown in Figure 38.
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« Topics »
< Next >
< Previous >
< Look Up >
See Also
Figure 38. Example Help Window
Help
Liquid Release Type
A Liquid type release is a release of material that may
immediately evaporate (no pooling results) or may pool
first and then evaporate.
See Also: Release Definition, Pool Definition, Evaporation
Definition
After the entering the help system, the user can access help
for any data entry field or menu item in TSCREEN pressing the
"buttons" on the panel on the left side of the help window.
These buttons can be pressed in three ways:
• The user can click on the button with a mouse.
• The user can highlight a button and then press to
select that button. To highlight a button, press the
key to first highlight the « Topics » button.
Press again to move to each succeeding active
button on the panel. If a button is not active, its
feature will not be available, and it will be a different
color than the other buttons.
• Each button has a letter that is a different color (i.e.,
a "hot-key"). Press that key to select that button.
Each button's function is described below:
« Topics
If this button is pressed, the table of contents of the help
system will appear in the help window. A portion of the
table of contents is shown in Figure 39 as it would appear
if « Topics » where pressed from the help window in
Figure 38. From the table of contents, the user can scroll
to and select any definition in the help system. The table
of contents is organized as follows: 1) help for the menu
items 2) help for the model inputs (SCREEN2, PUFF, RVD, and
Britter-McQuaid) 3) help for the scenario inputs in the
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order they appear in the workbook and 4) a glossary of
terms.
Once the topic of interest has been highlighted, press
or select the « HELP » button by the methods listed
above.
Figure 39. Help System Table of Contents
i Help
File
Access Data From Previous Scenario
Access Model Print Output
Access Model Graphic Output
Quit
Initial Form of Release
Particulate Matter Release Type
Gaseous Release Type
Liquid Release Type
Help
Next
If this button is pressed, the next help definition as
listed in the table of contents will appear.
< Previous >
If this button is pressed, the previous help definition as
listed in the table of contents will appear.
Look Up
This button is not active when the help window first
appears. To make this button active, mark (i.e., highlight)
a portion of text in the help window. Text can be marked by
holding the mouse button and dragging the mouse or by
holding down the key and moving the arrow keys.
Once text has been marked, press this button to bring up
help if the marked text is an item in the table of contents.
If the marked text is not in the table of contents, another
window appears as shown in Figure 40 that contains a list of
the topics in the table of contents. In this example
"Retrieve" was marked and < Look Up > was pressed. Since
this was not found in the table of contents, a second window
opens and 'Richardson Number Definition' is highlighted
because it is the closest topic alphabetically to
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"Retrieve".
Figure 40. Look Up Window when Topic Is Not Found
Help
« Topics »
< Next >
< Previous >
< Look Up >
See Also
No help found for Retrieve
Available Help Topics:
Molecular Weight Definition T
Neutral Definition
Passive Release Definition
Pool Definition
Reactive Definition
Release Definition
Richardson Number Definition|
Slumping Definition *
Temperature of Release Mater|
Two-phase Release Definition!
« Select »
< Cancel >
scenario
See Also
This button is only active if there is a "See Also" list of
topics in the help window. If this button is active and is
pressed a window will appear as shown in Figure 41 that lists the
topics to cross-reference. Making a selection from this menu
will bring up the help definition for the selected item.
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Figure 41. See Also Example
Help
« Topics »
< Next >
< Previous >
< Look Up >
Liquid Release Type
A Liquid type release is a release of material that may
immediately evaporate (no pooling results) or may pool
first and then evaporate.
rr
Release Definition
Pool Definition
Evaporation Definition
lease Definition, Pool Definition, Evaporation
When a topic is selected from the See Also menu and help for
that topic appears in the help window, the first item of the new
topic's See Also menu contains a reference to the topic from
which the new topic was called. Using the See Also menu from the
new topic, the user can then return to the original topic. For
example, if "Release Definition" was selected from the menu in
Figure 41, the help definition in Figure 42 will appear. The
first item in the See Also menu for "Release" is "Liquid Release
Type" which the user can select to return to the help definition
for "Liquid Release Type".
Figure 42. Cross-Referenced Help Item
• Help
« Topics »
< Next >
< Previous >
< Look Up >
Release
Chemicals or pollutants leaving containment, stacks, or
vents.
rr
Liquid Release Type
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8. Error Handling
If an error occurs while TSCREEN is running a window like
the one shown in Figure 43 will appear. This window contains an
error message, the FoxPro™ error number, the procedure in which
the error occurred, and the line number in the code at which the
error occurred.
Figure 43. Error Message Window
WARNING:
Error Number
In Procedure
At 1ine number
The error information above are saved in: ERROR.OUT
Please save this file for use in error diagnosis.
Press any key to continue ...
If an error occurs, data entered up to the point at which
the error occurred will be saved. The data can be retrieved by
selecting 'File' from the main menu bar then selecting 'Access
Data from Previous Scenario'. The data will be the last item on
the list which appears. In addition, the error information from
the window in Figure 43 will be saved in the file "ERROR.OUT".
This file should be saved for error diagnosis. After the user
exits the window shown in Figure 43, the user will exit TSCREEN.
If an error occurs while a Model is running, the ERROR.OUT
file will contain the data that was sent to the Model and the
error message which will appear in the error window that is
displayed. After the user exits the error window that is
displayed when an error in a model occurs, the user will return
to the main menu bar.
9. Backing Up Data
The file BACKUP.COM that comes with DOS must be in the DOS
PATH as explained in 2.0 GETTING STARTED. To backup the data
enter the command:
BACKUP X:\TSCREEN\*.* A: /S
where X is the drive letter where the TSCREEN system resides.
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Note that it is important to back up every time data is edited or
added in case of a hard disk failure.
The number of backup disks needed depends upon the amount of
data entered into the system. As more data is entered, more
backup disks will be required to store the data. These disks
must be formatted prior to backing up the data files. Backup
disks should be labeled accordingly and stored in a safe place.
To ward off data corruption, rotating back up disks is
recommended. Rotating backup diskettes consists of 2 or 3 sets
of backup diskettes that are rotated when the backup procedure is
called. In using a rotating backup procedure you can minimize
the possibility of backing up bad data and having corrupt files
on the system and on the backup disks.
The BACKUP.COM program fits as much data on one disk as it
is physically capable of storing. If the program is in the
middle of backing up a file it will split the file and store the
remaining part on another disk(s). These backed up files are not
DOS compatible files, DO NOT copy them to another disk,
especially NOT to the hard disk. The only way these files can be
used is to first restore them with the DOS RESTORE.COM program
(discussed below). These diskettes are created for backup
purposes only and are to be restored only when the data files on
the hard disk have become damaged beyond repair.
The command to restore the data files is:
RESTORE A: X: /S
where X is the drive letter where the TSCREEN system resides.
Note that the RESTORE.COM file must be in the DOS PATH in order
to execute this program from any prompt. This command should be
used only when there has been damage done to the data files on
the hard disk!
10. Notes on Compiling the Source Code
The procedure described on this page is only for those who
wish to make changes in the source code and recompile it. Only
someone with experience using computers and preferably with
compilers should attempt this procedure.
TSCREEN is written in and compiled with FoxPro™ Version 2,
Microsoft™ FORTRAN Version 5.1, and Microsoft™ C Version 5.1.
One C library was used: INGRAF™ Version 2.10 by Sutrasoft. The
program source code is available from the SCRAM Bulletin Board
phone (919) 541-5742. Technical questions should be directed to
Jawad S. Touma; Office of Air Quality Planning and Standards;
Technical Support Division; Source Receptor Analysis Branch (MD-
14); Research Triangle Park, NC 27711, phone (919) 541-5381.
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FoxPro™ Version 2.0 or later, C Version 5.1 or later, and
INGRAF™ Version 2.10 or later are necessary to compile the
source code. All of the .PRG (FoxPro™) files and .C (C) files
should be on a hard disk with the following files:
C
CL.EXE
LINK.EXE
MLIBCE.LIB
SLIBCE.LIB
[STRING.H]
[STDIO.H]
[STDLIB.H]
[PROCESS.H]
[MATH.H]
[DOS.H]
[10.H]
The files in brackets are included with the Microsoft C compiler.
INGRAF
INGRAF.LIB
IGEXTERN.H
Note that you may have to change the path specifications in these
files as well as in the C files. The compilation process will
create: TSCREEN.EXE, GRAPH.EXE.
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11. References
Petersen, W., 1982: Estimating Concentrations Downwind from an
Instantaneous Puff Release, EPA 600/3-82-078. U.S.
Environmental Protection Agency, Research Triangle Park, NC.
U.S. Environmental Protection Agency, 1989: User's Guide for RVD
2.0 - A Relief Valve Discharge Screening Model, EPA-
450/4-88-024. U.S. Environmental Protection Agency,
Research Triangle Park, NC.
U.S. Environmental Protection Agency, 1992a: Workbook of
Screening Techniques for Assessing Impacts of Toxic Air
Pollutants (Revised). EPA-454/R-92-024. U.S. Environmental
Protection Agency, Research Triangle Park, NC.
U.S. Environmental Protection Agency, 1992b: Screening
Procedures for Estimating the Air Quality Impact of
Stationary Sources, Revised. EPA-450/R-92-019. U.S.
Environmental Protection Agency, Research Triangle Park, NC.
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